Genetic testing of Behçet's disease using next-generation sequencing to identify monogenic mimics and HLA-B*51

OBJECTIVE

Several monogenic autoinflammatory disorders and primary immunodeficiencies can present early in life with features that may be mistaken for Behçet's disease (BD). We aimed to develop a genetic analysis workflow to identify rare monogenic BD-like diseases and establish the contribution of HLA haplotype in a cohort of patients from the UK.

METHODS

Patients with clinically suspected BD were recruited from four BD specialist care centres in the UK. All participants underwent whole exome sequencing (WES), and genetic analysis thereafter by 1. examining genes known to cause monogenic immunodeficiency, autoinflammation or vasculitis by virtual panel application; 2. scrutiny of variants prioritised by Exomiser using Human Phenotype Ontology (HPO); 3. identification of copy number variants using ExomeDepth; and 4. HLA-typing using OptiType.

RESULTS

Thirty-one patients were recruited: median age 15 (4-52), and median disease onset age 5 (0-20). Nine/31 (29%) patients had monogenic disease mimicking BD: 5 cases of Haploinsufficiency of A20 with novel TNFAIP3 variants (p.T76I, p.M112Tfs*8, p.S548Dfs*128, p.C657Vfs*14, p.E661Nfs*36); 1 case of ISG15 deficiency with a novel nonsense variant (ISG15:p.Q16X) and 1p36.33 microdeletion; 1 case of Common variable immune deficiency (TNFRSF13B:p.A181E); and 2 cases of TNF receptor associated periodic syndrome (TNFRSF1A:p.R92Q). Of the remaining 22 patients, 8 (36%) were HLA-B*51 positive.

CONCLUSION

We describe a novel genetic workflow for BD, which can efficiently detect known and potentially novel monogenic forms of BD, whilst additionally providing HLA-typing. Our results highlight the importance of genetic testing before BD diagnosis, since this has impact on choice of therapy, prognosis, and genetic counselling.

Curation and expansion of the Human Phenotype Ontology for systemic autoinflammatory diseases improves phenotype-driven disease-matching

Introduction

Accurate and standardized phenotypic descriptions are essential in diagnosing rare diseases and discovering new diseases, and the Human Phenotype Ontology (HPO) system was developed to provide a rich collection of hierarchical phenotypic descriptions. However, although the HPO terms for inborn errors of immunity have been improved and curated, it has not been investigated whether this curation improves the diagnosis of systemic autoinflammatory disease (SAID) patients. Here, we aimed to study if improved HPO annotation for SAIDs enhanced SAID identification and to demonstrate the potential of phenotype-driven genome diagnostics using curated HPO terms for SAIDs.

Methods

We collected HPO terms from 98 genetically confirmed SAID patients across eight different European SAID expertise centers and used the LIRICAL (Likelihood Ratio Interpretation of Clinical Abnormalities) computational algorithm to estimate the effect of HPO curation on the prioritization of the correct SAID for each patient.

Results

Our results show that the percentage of correct diagnoses increased from 66% to 86% and that the number of diagnoses with the highest ranking increased from 38 to 45. In a further pilot study, curation also improved HPO-based whole-exome sequencing (WES) analysis, diagnosing 10/12 patients before and 12/12 after curation. In addition, the average number of candidate diseases that needed to be interpreted decreased from 35 to 2.

Discussion

This study demonstrates that curation of HPO terms can increase identification of the correct diagnosis, emphasizing the high potential of HPO-based genome diagnostics for SAIDs.

Systemic juvenile idiopathic arthritis: The Great Ormond Street Hospital experience (2005-2021)

Systemic juvenile idiopathic arthritis (sJIA) is a complex, systemic inflammatory disorder driven by both innate and adaptive immunity. Improved understanding of sJIA pathophysiology has led to recent therapeutic advances including a growing evidence base for the earlier use of IL-1 or IL-6 blockade as first-line treatment. We conducted a retrospective case notes review of patients diagnosed with sJIA over a 16-year period (October 2005-October 2021) at Great Ormond Street Hospital for Children. We describe the clinical presentation, therapeutic interventions, complications, and remission rates at different timepoints over the disease course. We examined our data, which spanned a period of changing therapeutic landscape, to try and identify potential therapeutic signals in patients who received biologic treatment early in the disease course compared to those who did not. A total of 76-children (female n = 40, 53%) were diagnosed with sJIA, median age 4.5 years (range 0.6-14.1); 36% (27/76) presented with suspected or confirmed macrophage activation syndrome. A biologic disease-modifying anti-rheumatic drug (bDMARD) alone was commenced as first-line treatment in 28% (n = 21/76) of the cohort; however, at last review, 84% (n = 64/76) had received treatment with a bDMARD. Clinically inactive disease (CID) was achieved by 88% (n = 67/76) of the cohort at last review; however, only 32% (24/76) achieved treatment-free CID. At 1-year follow-up, CID was achieved in a significantly greater proportion of children who received treatment with a bDMARD within 3 months of diagnosis compared to those who did not (90% vs. 53%, p = 0.002). Based on an ever-increasing evidence base for the earlier use of bDMARD in sJIA and our experience of the largest UK single-centre case series described to date, we now propose a new therapeutic pathway for children diagnosed with sJIA in the UK based on early use of bDMARDs. Reappraisal of the current National Health Service commissioning pathway for sJIA is now urgently required.

The incidence of Kawasaki disease using hospital admissions data for England 2006-2021

OBJECTIVE

To describe the incidence of Kawasaki Disease (kDa) between 2006 and 2021 in England.

METHODS

We identified all cases in hospital episode statistics with an ICD-10 diagnostic code M303 (for kDa) between 1 April 2006 and 31 March 2021. We validated 83 diagnoses using hospital medical records and found >97% accuracy. We calculated incidence rate ratios (IRRs) using Poisson regression and assessed the influence of age, sex, ethnicity and index of multiple deprivation (IMD). We used Office for National Statistics population estimates for England as the denominator.

RESULTS

We identified a total of 5908 cases of kDa in all children under the age of 16 (mean age 3.8, s.d.=3.2, 95% CI: 3.7, 3.9). Incidence in children aged <5 years was 8.9 (95% CI: 8.6, 9.2)/100 000 person-years; in children aged 5-9, 2.4 (95% CI: 2.3, 2.6)/100 000 person-years; and in children aged 10-15, 0.6 (95% CI: 0.6, 0.7). Male : female ratio was 1.5 : 1. Incidence was higher among non-White than White ethnicities [adjusted IRR 2.1 (2.0-2.2) for Asian, 3.0 (2.8-3.3) for Black and 4.5 (4.2-4.8) for other ethnicities]. The incidence increased with socioeconomic deprivation; the adjusted IRR of the least deprived IMD quintile compared with the most deprived quintile was 0.81 (0.77-0.84).

CONCLUSIONS

Incidence rates of kDa derived from hospital admission data in England were higher than in studies relying on clinician reporting. We confirm previous findings on the influence of sex and ethnicity on kDa incidence and observe that there was a higher incidence of kDa within more deprived socioeconomic groups.

Case report: marfan syndrome (MFS) mimicking cutaneous vasculitis

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by variants in the extracellular microfibril fibrillin (FBN1) gene. Here we report an FBN1 variant in a child with an unusual skin rash mimicking cutaneous vasculitis, and mild aortic root dilatation. The case was complicated by lack of typical skeletal MFS phenotype; and severe needle phobia preventing any blood testing for workup of suspected vasculitis. Therefore inflammatory markers, autoantibody profile and general hematology/biochemistry results were unknown. Diagnosis of MFS was made via genetic testing of a saliva sample alone using a next-generation sequencing (NGS) targeted gene panel designed to screen for monogenic forms of vasculitis and noninflammatory vasculopathic mimics. This revealed the patient was heterozygous for a pathogenic frameshift variant in FBN1; NM_000138, c.1211delC, p.(Pro404Hisfs*44), predicted to cause premature protein truncation leading to loss of function. The variant has not been detected in control populations and has previously been detected in individuals with MFS. This rapid diagnosis significantly impacted the patient management: avoidance of invasive investigations; avoidance of unnecessary immunosuppression; facilitating genetic counselling of the index case and family; and directly informing lifelong monitoring and ongoing treatment for aortic root involvement from MFS. This case further emphasizes the diagnostic utility of NGS early in the diagnostic workup of paediatric patients referred with suspected vasculitis, and we emphasize that MFS can present with cutaneous vasculitic-like features in the absence of the typical Marfanoid skeletal phenotype.

Constitutively active Lyn kinase causes a cutaneous small vessel vasculitis and liver fibrosis syndrome

Neutrophilic inflammation is a hallmark of many monogenic autoinflammatory diseases; pathomechanisms that regulate extravasation of damaging immune cells into surrounding tissues are poorly understood. Here we identified three unrelated boys with perinatal-onset of neutrophilic cutaneous small vessel vasculitis and systemic inflammation. Two patients developed liver fibrosis in their first year of life. Next-generation sequencing identified two de novo truncating variants in the Src-family tyrosine kinase, LYN, p.Y508*, p.Q507* and a de novo missense variant, p.Y508F, that result in constitutive activation of Lyn kinase. Functional studies revealed increased expression of ICAM-1 on induced patient-derived endothelial cells (iECs) and of β2-integrins on patient neutrophils that increase neutrophil adhesion and vascular transendothelial migration (TEM). Treatment with TNF inhibition improved systemic inflammation; and liver fibrosis resolved on treatment with the Src kinase inhibitor dasatinib. Our findings reveal a critical role for Lyn kinase in modulating inflammatory signals, regulating microvascular permeability and neutrophil recruitment, and in promoting hepatic fibrosis.

Multi-centre, randomised, open-label, blinded endpoint assessed, trial of corticosteroids plus intravenous immunoglobulin (IVIG) and aspirin, versus IVIG and aspirin for prevention of coronary artery aneurysms (CAA) in Kawasaki disease (KD): the KD CAA prevention (KD-CAAP) trial protocol

BACKGROUND

Kawasaki disease (KD) is an acute self-limiting inflammatory vasculitis affecting predominantly medium-sized arteries, particularly the coronary arteries. A number of recent studies conducted in different European countries have demonstrated alarmingly high coronary complications despite treatment with intravenous immunoglobulin (IVIG). These high complication rates now emphasize the need for an urgent reappraisal of IVIG as the sole primary therapeutic agent for KD. The Kawasaki disease CAA prevention (KD-CAAP) trial will test the hypothesis that immediate adjunctive corticosteroid treatment to standard of care IVIG and aspirin will reduce coronary artery aneurysm (CAA) rates in unselected KD patients across Europe.

METHODS

KD-CAAP is a multicentre, randomised, controlled, open-label, blinded endpoint assessed trial that will be conducted across Europe supported by the conect4children pan-European clinical trials network. Patients with KD who satisfy the eligibility criteria will be randomised (1:1) to receive either oral prednisolone 2 mg/kg/day plus standard of care therapy IVIG (2 g/kg) and aspirin (40 mg/kg/day); or IVIG and aspirin alone. Further management is dictated by temperature and C-reactive protein (CRP) responses. Co-primary outcomes are as follows: (i) any CAA within the 3 months of trial follow-up; (ii) average estimate of maximum coronary Z-score at weeks 1, 2 and 6 adjusting for rescue treatment. Additional outcomes will be assessed including cost effectiveness, quality of life, corticosteroid toxicity and other safety outcomes.

DISCUSSION

Several recent studies have indicated that coronary complications associated with KD across Europe are much higher than early trials of IVIG had initially suggested. KD-CAAP directly addresses this issue by exploring the therapeutic benefit of adjunctive corticosteroids in unselected KD cases. If we find that corticosteroids prevent CAA and are safe, this is a cheap and widely available intervention that could be implemented immediately for the benefit of children.

TRIAL REGISTRATION

ISRCTN71987471- March 31, 2020; Eudract 2019-004433-17.

Risk-proportionate approach to paediatric clinical trials: The legal requirements, challenges, and the way forward under the European Union Clinical Trials Regulation

BACKGROUND

It is now widely accepted that there is a need for safety and efficacy data on medicines used in children. In the European Union, legislation has provided the necessary framework obligating and incentivizing pharmaceutical companies to carry out appropriate paediatric research to support the development of new medicines. This change in research culture, that medicines used in children should be appropriately researched in children, has also led to the recognition of the importance of investigator-initiated clinical trials in furthering medical knowledge on the off-label use of authorized medicines for which paediatric data are often limited. However, medicines regulatory authorities of European Union countries have largely adopted a uniform approach to the regulation of both industry-sponsored and investigator-initiated trials and, in doing so, have added disproportionate burden to the conduct of paediatric clinical trials investigating authorized medicines.

CASE STUDIES

Two European multinational paediatric clinical trials funded by the conect4children consortium are presented to provide a comparative insight into past challenges and to illustrate how the new framework provided by the European Clinical Trials Regulation (No. 536/2014) addresses these barriers in practice.

CONCLUSION

The European Clinical Trials Regulation gives a strong impetus to a risk-proportionate approach and offers a path for more efficient delivery of investigator-initiated paediatric clinical trials.

OA28 A rare case of cardiac tumour in infancy mimicking sarcoidosis

Introduction/Background

Sarcoidosis is a rare multisystemic inflammatory disorder with 2 distinct presentations in childhood. A monogenic form associated with mono-allelic mutation in NOD2 presents with the triad of uveitis, rash and arthritis in children less than 4-years (early-onset sarcoidosis). The other presentation affects older children with similar presentation to adults, with greater pulmonary and lymph node involvement. Histopathological evidence of non-caseating granulomas is essential for the diagnosis but does not exclude alternative diagnoses. We report a 17-month-old infant, who presented with atypical features suggestive of sarcoidosis, but was subsequently found to have a rare cardiac angiosarcoma driving an exaggerated granulomatous reaction.

Description/Method

A previously healthy 17-month-old girl born to non-consanguineous Caucasian parents presented with recurrent fever for 3-months, associated with lethargy, weight loss and worsening anemia. Examination revealed an irritable febrile child, weight on 5th centile, with muffled heart sounds; there were no skin lesions, no lymphadenopathy, and no arthritis. Investigations showed severe anemia (Hb 46g/L), leukocytosis (WBC 24/L), thrombocytosis (662/L), high inflammatory markers (CRP &gt;300mg/L, ESR 160mm/hr), high ferritin (600ug/L). CT thorax with cardiac angiogram revealed a large intra-atrial septal mass, extensive pulmonary nodules, bilateral hilar and mediastinal lymphadenopathy and pericardial effusion. She was managed with broad-spectrum antibiotics, blood transfusions and pericardiocentesis with endomyocardial biopsy. Extensive infectious workup, including TB from pericardial exudate, was negative. Serum angiotensin-converting enzyme was normal, with no blasts in blood film; eye examination was unremarkable. The endomyocardial biopsy was inconclusive, so underwent lung and lymph node biopsies, which were initially reported as revealing florid multiple non-necrotising granulomas, but no evidence of malignant cells. Whole-exome sequencing was performed, result pending at that stage. Differential diagnosis included malignancy, infection, immunodeficiency or autoimmune disorder including sarcoidosis, in light of histopathology. With malignancy and infection felt to be excluded, she was managed empirically for atypical sarcoidosis and treated with IV methylprednisolone 30mg/kg followed by tapering steroid and anti-TNF; IL-1 was added later. However, there was no clinical response with ongoing fever, irritability and static inflammatory markers (CRP∼300mg/L). Immunomodulating medications were subsequently stopped. Repeat chest imaging revealed progression of pulmonary findings and increasing cardiac mass. Open-heart bypass surgery with debulking of cardiac mass and further biopsies. Histopathology revealed an extremely rare primary cardiac malignant vascular tumour, angiosarcoma, with loss of SMARCB1 protein staining. Retrospective review and specific staining with SMARCB1 of initial lung biopsy subsequently confirmed that the granulomatous reaction was in response to micro-metastases of tumour throughout the lungs.

Discussion/Results

The differential diagnosis of granulomatous disease in paediatric patients is very broad. Ultimately, the diagnosis of cancer driving and exaggerated immunological response was provided by a combination of very invasive surgical biopsy of the heart; combined with whole exome sequencing. Whole exome sequencing revealed 2 distinct genetic diagnoses which fully explained the phenotype: heterozygosity for a stop mutation in SMARCB1 (p.R158X) consistent with Rhabdoid Tumour Predisposition Syndrome Type 1; and homozygosity for the hypomorphic PRF1 p.A91V mutation explaining low (but not absent) intracellular perforin levels and exaggerated granulomatous immunological response to tumour. The rare angiosarcoma detected is scarcely reported in the literature, but entirely compatible with the type of cancer associated with RTPS1. Hypomorphic perforin mutation probably explains the exaggerated but frustrated granulomatous immunological response to tumour in this case.

Key learning points/Conclusion

This case serves to remind us that granulomas can occur in response to malignancy in children. Lack of response to immunosuppression with ongoing severe systemic inflammation in this case provided an important clue to the need for more invasive diagnostic biopsies. Particular challenges relates to the time it takes to obtain genetic test results; but in this case whole-exome sequencing resolved the phenotype fully. Patients with rare and unusual presentations may have more than one genetic diagnosis, with a blending of phenotypes thereafter. Screening of other family members for the mutation associated with RTPS1 is ongoing.

P47 The conundrums of Macrophage activation syndrome (MAS) - when to consider a Haematopoietic Stem Cell Transplant (HSCT)

Introduction/Background

MAS is a severe, potentially fatal complication of systemic JIA (sJIA). It is characterised by uncontrolled activation and proliferation of T cells and macrophages, leading to a “cytokine storm” which manifests as hyperinflammation. Its consequences include fever, rash, cytopenias, transaminitis, coagulopathy and hyperferritinaemia.

Prompt careful assessment is required to identify MAS and exclude other conditions like sepsis. This is often done in parallel, performing a septic screen and commencing antibiotics whilst considering immunosuppressive therapy and its timing. MAS can be refractory to familiar first line agents, presenting a challenge for Paediatric Rheumatologists as no consensus guidelines exist to inform management.

Description/Method

We present a case of a 15-month-old girl with sJIA and refractory MAS. Our patient became unwell at 8-months of age with fever and rash. She was initially treated with antibiotics. She then developed peeling of the fingers and toes. Management of Kawasaki Disease was initiated - IVIG (2 doses), IV methylprednisolone (IVMP) for 5 days, followed by oral prednisolone for ten days, and aspirin. Her fever persisted. The prednisolone and aspirin doses were increased which resulted in clinical improvement.

After a few weeks, the fever recurred three times daily and associated with an erythematous rash. She was admitted to hospital and treated with antibiotics for a presumed UTI. The diagnosis of sJIA was made after exclusion of other infectious and haematological causes. Despite IVMP followed by oral prednisolone and anakinra, the fever persisted.

She was transferred to our hospital for further management. Initial bloods showed Hb 103g/L, platelets 257x109/L, WBC 13.07x109/L, Neutrophils 4.18x109/L, ESR 32mm/hr, CRP 30mg/L, ferritin 2201ng/mL, ALT 89U/L, AST 218U/L, LDH 1859IU/L, triglycerides 4.2mmol/L, fibrinogen 2.8mg/dL, d-dimers 4641ng/mL. She was pulsed with IVMP for 3 days. The anakinra dose increased. Remission was not achieved biochemically. A further pulse with IVMP (3 days) was given with no improvement. IV ciclosporin was added. Tocilizumab 12mg/kg/day once daily was commenced. She remained on oral prednisolone 2mg/kg/day. She then developed sepsis. She had a positive blood culture from her PICC line. Despite IV antibiotics, her clinical picture didn’t improve. She eventually developed septic shock requiring a fluid bolus and worsening MAS. The PICC line was removed. She also required amlodipine for hypertension.

There was no sign of MAS remission (table 1), and the decision was made to commence etoposide (initial 150mg/M2 for 6 doses; current dose 50mg/M2) whilst working our patient up for a HSCT eight months after first presentation.

Discussion/Results

MAS is a severe complication of sJIA. MAS can progress very rapidly and if left untreated, it is associated with high morbidity and mortality. Abnormal investigations include cytopenia, coagulopathy and hyperferritinaemia. These distinctive features usually occur in the later stages of MAS. This can lead to a delay in the diagnosis of the condition, resulting in a worse outcome. Early recognition of MAS is key to improving morbidity and mortality.

The mainstay of treatment for MAS is glucocorticoids. However, as this patient highlights glucocorticoids alone are not often satisfactory in controlling the disease. Other treatments can be used, but there is a paucity of data from clinical trials as to what treatment should be used and in what order.

HSCT is a potentially curative option for patients with refractory sJIA. Some of these patients can achieve drug free remission, although not all. In some, disease remission is only transient. HSCT is associated with significant risks, in particular Graft versus Host Disease. The data on success of HSCT in sJIA is sparce – making it challenging for clinicians to counsel parents.

Currently this patient’s condition is being controlled with Etoposide whilst HSCT is awaited. Etoposide is a well-established therapy for Primary Hemophagocytic Lymphhistiocytosis (HLH). As clinicians we are continuing to learn more about its use in controlling sJIA. A recent article by Horne et al suggests that a moderate dose of etoposide may be beneficial in severe/refractory HLH. We are currently trialling this approach in our patient with the hope of decreasing the overall Etoposide dose, aiming to minimise toxicity whilst adequately controlling her disease.

Finally, it is vital to screen for primary HLH in those whose first rheumatological presentation is with MAS. An important differential is a genetic cause which may or may not be identifiable.

Key learning points/Conclusion

Learning points:

Improved awareness of MAS is paramount to aid timely diagnosis and ensure prompt treatment in order to try and improve MAS associated morbidity and mortality.

Careful evaluation of serum ferritin in conjunction with other blood parameters is important and helpful in monitoring response to therapy.

It is vital to screen for Primary HLH in patients whose first rheumatological presentation is MAS.

There is a lack of evidence for treatment pathways in refractory sJIA and MAS.

Some children develop refractory MAS and HSCT needs to be seriously considered, but when should clinicians consider HSCT?

Many unanswered questions exist. It can be challenging as clinicians to know when to refer patients for HSCT and how best to manage these patients whilst awaiting HSCT. It would be useful to develop consensus guidelines to help answer some of the following questions:

When should a child be referred for HSCT?

How many drugs should be trialled prior to referral?

What is the definition of treatment failure?

Who should decide that the child should be referred for HSCT?

What treatment should be used to bridge to HSCT and at what dose?

Microvasculopathy in SMA is driven by a reversible autonomous endothelial cell defect

Spinal muscular atrophy (SMA) is a neuromuscular disorder due to degeneration of spinal cord motor neurons caused by deficiency of the ubiquitously expressed SMN protein. Here, we present a retinal vascular defect in patients, recapitulated in SMA transgenic mice, driven by failure of angiogenesis and maturation of blood vessels. Importantly, the retinal vascular phenotype was rescued by early, systemic SMN restoration therapy in SMA mice. We also demonstrate in patients an unfavorable imbalance between endothelial injury and repair, as indicated by increased circulating endothelial cell counts and decreased endothelial progenitor cell counts in blood circulation. The cellular markers of endothelial injury were associated with disease severity and improved following SMN restoration treatment in cultured endothelial cells from patients. Finally, we demonstrated autonomous defects in angiogenesis and blood vessel formation, secondary to SMN deficiency in cultured human and mouse endothelial cells, as the underlying cellular mechanism of microvascular pathology. Our cellular and vascular biomarker findings indicate microvasculopathy as a fundamental feature of SMA. Our findings provide mechanistic insights into previously described SMA microvascular complications, and highlight the functional role of SMN in the periphery, including the vascular system, where deficiency of SMN can be addressed by systemic SMN-restoring treatment.

The pediatric glucocorticoid toxicity index

OBJECTIVES

To develop a Pediatric glucocorticoid toxicity index (pGTI), a standardized, weighted clinical outcome assessment that measures change in glucocorticoid (GC) toxicity over time.

METHODS

Fourteen physician experts from 7 subspecialties participated. The physician experts represented multiple subspecialties in which GCs play a major role in the treatment of inflammatory disease: nephrology, rheumatology, oncology, endocrinology, genetics, psychiatry, and maternal-fetal medicine. Nine investigators were from Canada, Europe, or New Zealand, and 5 were from the United States. Group consensus methods and multi-criteria decision analysis were used. The pGTI is an aggregate assessment of GC toxicities that are common, important, and dynamic. These toxicities are organized into health domains graded as minor, moderate, or major and are weighted according to severity. The relative weights were derived by group consensus and multi-criteria decision analysis using the 1000Minds^TM software platform. Two quantitative scores comprise the overall toxicity profile derived from pGTI data: (1) the Cumulative Worsening Score; and (2) the Aggregate Improvement Score. The pGTI also includes a qualitative, unweighted record of GC side-effects known as the Damage Checklist, which documents less common toxicities that, although potentially severe, are unlikely to change with varying GC dosing.

RESULTS

One hundred and seven (107) toxicity items were included in the pGTI and thirty-two (32) in the Damage Checklist. To assess the degree to which the pGTI corresponds to expert clinical judgement, the investigators ranked 15 cases by clinical judgement from highest to lowest GC toxicity. Expert rankings were then compared to case ranking by the pGTI, yielding excellent agreement (weighted kappa 0.86). The pGTI was migrated to a digital environment following its development and initial validation. The digital platform is designed to ensure ease-of-use in the clinic, rigor in application, and accuracy of scoring. Clinic staff enter vital signs, laboratory results, and medication changes relevant to pGTI scoring. Clinicians record findings for GC myopathy, skin toxicity, mood dysfunction, and infection. The pGTI algorithms then apply the weights to these raw data and calculate scores. Embedded logic accounts for the impact of age- and sex-related reference ranges on several health domains: blood pressure, lipid metabolism, and bone mineral density. Other algorithms account for anticipated changes in the height Z-scores used in the growth domain, thereby addressing a concern unique to GC toxicity in children. The Damage Checklist ensures comprehensive measurement of GC toxicity but does not contribute to pGTI scoring, because the scored domains emphasize manifestations of GC toxicity that are likely to change over the course of a trial.

CONCLUSIONS

We describe the development and initial evaluation of a weighted, composite toxicity index for the assessment of morbidity related to GC use in children and adolescents. Developing the pGTI digital platform was essential for performing the nuanced calculations necessary to ensure rigor, accuracy, and ease-of-use in both clinic and research settings.

OP0193 EFFICACY AND SAFETY OF EMAPALUMAB, AN ANTI-INTERFERON GAMMA MONOCLONAL ANTIBODY, IN PATIENTS WITH MACROPHAGE ACTIVATION SYNDROME (MAS) IN SYSTEMIC JUVENILE IDIOPATHIC ARTHRITIS (sJIA) WHO HAD FAILED HIGH-DOSE GLUCOCORTICOIDS

Background

MAS is a severe, life-threatening complication of rheumatic diseases that occurs most frequently in patients with sJIA. The mainstay of treatment for MAS is high dose glucocorticoids (GCs); however, GCs do not provide adequate control in all patients. Additional treatments are used without a standardized approach; however, morbidity and mortality remain high. Data from animal models of MAS and from observational studies in patients suggest that overproduction of IFNγ is a driver of the hyperinflammation observed in MAS; neutralization of IFNγ has been shown to revert the signs and symptoms of MAS in murine models, and high IFNγ levels are strongly correlated with laboratory parameters of disease severity in patients.

Objectives

To assess the efficacy and safety of intravenous (IV) infusions of emapalumab, a fully human, anti-IFNγ monoclonal antibody, in patients with MAS in sJIA.

Methods

Open-label, single-arm, phase 2 study (NCT03311854) that included patients with MAS (2016 ACR/EULAR criteria) in sJIA who had failed high-dose IV GCs and other treatments. Emapalumab was initiated at a dose of 6 mg/kg on Day 0 and continued at 3 mg/kg every 3 days until Day 15, and then twice weekly until Day 28 to ensure rapid and complete IFNγ neutralization after initiating treatment. As per protocol, 10 infusions were planned over the 4 weeks; however, treatment could be shortened if MAS remission was achieved earlier, or extended if required to achieve remission. Complete response (CR) was defined as resolution of clinical signs and symptoms of MAS according to the investigator, and normalization of laboratory parameters relevant to MAS. All patients were followed up for 4 weeks after the last infusion of emapalumab and offered to enter a 1-year, follow-up study (NCT02069899).

Results

Fourteen patients (10 females) were enrolled (11 in Europe, 3 in the USA). Several patients had previously received cyclosporine A and/or anakinra, in addition to high-dose GCs. Six patients received emapalumab until Day 28. Seven patients discontinued emapalumab early due to MAS remission (as per investigator’s assessment); one patient received treatment up to Day 38. Emapalumab treatment rapidly neutralized IFNγ, as documented by CXCL9 levels. A CR was achieved by 13/14 patients during the study. One patient stopped emapalumab after 3 doses because of achievement of MAS remission as per investigator’s assessment, but lactate dehydrogenase levels remained >1.5× upper limit of normal. At Week 8, 11/14 patients had a CR; 2 achieved a CR during the study, but not at Week 8, because of a single laboratory parameter abnormality in each patient. Overall, all measured laboratory parameters related to MAS activity rapidly improved with emapalumab treatment. GCs were tapered in all patients by Week 8 (≥50% reduction, n=12; GC dose ≤1 mg/kg/day, n=8). Administration of anakinra for the treatment of underlying sJIA was maintained/introduced during the study, as required. No patients discontinued treatment for safety reasons. One treatment-related serious adverse event was reported (cytomegalovirus reactivation that resolved with antiviral treatment). All patients entered the long-term, follow-up study and were alive at last visit.

Conclusion

Emapalumab administration led to rapid IFNγ neutralization, was efficacious in controlling MAS in all patients, and was well tolerated with a favorable safety profile. These results support the pathogenic role of IFNγ in MAS in sJIA and the therapeutic value of IFNγ neutralization in MAS patients who have failed high-dose GCs.

Disclosure of Interests

Fabrizio De Benedetti Consultant of: Sobi, AbbVie, Pfizer, Roche, Sanofi, Novartis, Novimmune, Grant/research support from: Sobi, AbbVie, Pfizer, Roche, Sanofi, Novartis, Novimmune, Alexei Grom Consultant of: Novartis, AB2 Bio, Paul Brogan Consultant of: Sobi, Novartis, Roche, UCB, Claudia Bracaglia: None declared, Manuela Pardeo: None declared, Giulia Marucci: None declared, Despina Eleftheriou Speakers bureau: Sobi, Charalampia Papadopoulou Speakers bureau: Sobi, Pierre Quartier Speakers bureau: Sobi, AbbVie, Chugai-Roche, Lilly, Novartis, Pfizer, Consultant of: Sobi, AbbVie, Chugai-Roche, Lilly, Novartis, Pfizer, Jordi Anton Consultant of: Sobi, Novartis, Roche, Pfizer, AbbVie, GSK, Rikke Frederiksen Employee of: Sobi, Veronica Asnaghi Employee of: Sobi, Cristina de Min Consultant of: Sobi

The impact of the Eurofever criteria and the new InFevers MEFV classification in real life: Results from a large international FMF cohort

INTRODUCTION

New Eurofever/PRINTO classification criteria (EPCC) for Familial Mediterranean Fever (FMF) and other recurrent fevers have been recently developed, together with the classification of the pathogenicity of MEFV variants.

OBJECTIVES

To evaluate the impact in real life of both the EPCC and INSAID pathogenicity classification of MEFV variants in the large international Eurofever FMF cohort.

METHODS

Baseline demographic, genetic and clinical data of FMF patients included in the Eurofever registry were evaluated. The EPCC and the 2018 INSAID classification for MEFV variants were applied in all eligible FMF patients.

RESULTS

Since November 2009, clinical information was available for 1012 FMF (532 males/480 females, 827 children/185 adults) from 119 centres. Complete data were available for 887 patients in whom 623 (70.2%) satisfied EPCC (EPCC+), while 264 (29.8%) did not (EPCC-). The majority of the EPCC- patients (172, 65.1%) displayed negative or non-informative genetics (monoallelic or biallelic benign variants, monoallelic variant of unknown significance). At baseline, colchicine was used in most of EPCC+ patients (88%) and in a lower percentage of EPCC- patients (69%, p < 0.0001), who were treated in a higher proportion with steroid or NSAID on demand (p = 0.003 and 0.008, respectively). Four percent of patients received Anti-IL-1 treatment.

CONCLUSIONS

The combination of EPCC and the 2018 INSAID classification of MEFV variants is able to identify two distinct groups of patients, which differ in clinical characteristics, therapeutic approach and response to treatment. EPCC+ patients displayed the typical features of FMF, while EPCC- patients had a more variable phenotype with a lower percentage of response to colchicine.

Curation and expansion of Human Phenotype Ontology for defined groups of inborn errors of immunity

BACKGROUND

Accurate, detailed, and standardized phenotypic descriptions are essential to support diagnostic interpretation of genetic variants and to discover new diseases. The Human Phenotype Ontology (HPO), extensively used in rare disease research, provides a rich collection of vocabulary with standardized phenotypic descriptions in a hierarchical structure. However, to date, the use of HPO has not yet been widely implemented in the field of inborn errors of immunity (IEIs), mainly due to a lack of comprehensive IEI-related terms.

OBJECTIVES

We sought to systematically review available terms in HPO for the depiction of IEIs, to expand HPO, yielding more comprehensive sets of terms, and to reannotate IEIs with HPO terms to provide accurate, standardized phenotypic descriptions.

METHODS

We initiated a collaboration involving expert clinicians, geneticists, researchers working on IEIs, and bioinformaticians. Multiple branches of the HPO tree were restructured and extended on the basis of expert review. Our ontology-guided machine learning coupled with a 2-tier expert review was applied to reannotate defined subgroups of IEIs.

RESULTS

We revised and expanded 4 main branches of the HPO tree. Here, we reannotated 73 diseases from 4 International Union of Immunological Societies-defined IEI disease subgroups with HPO terms. We achieved a 4.7-fold increase in the number of phenotypic terms per disease. Given the new HPO annotations, we demonstrated improved ability to computationally match selected IEI cases to their known diagnosis, and improved phenotype-driven disease classification.

CONCLUSIONS

Our targeted expansion and reannotation presents enhanced precision of disease annotation, will enable superior HPO-based IEI characterization, and hence benefit both IEI diagnostic and research activities.

A rapid turnaround gene panel for severe autoinflammation: Genetic results within 48 hours

There is an important unmet clinical need for fast turnaround next generation sequencing (NGS) to aid genetic diagnosis of patients with acute and sometimes catastrophic inflammatory presentations. This is imperative for patients who require precise and targeted treatment to prevent irreparable organ damage or even death. Acute and severe hyper- inflammation may be caused by primary immunodeficiency (PID) with immune dysregulation, or more typical autoinflammatory diseases in the absence of obvious immunodeficiency. Infectious triggers may be present in either immunodeficiency or autoinflammation. We compiled a list of 25 genes causing monogenetic immunological diseases that are notorious for their acute first presentation with fulminant inflammation and which may be amenable to specific treatment, including hemophagocytic lymphohistiocytosis (HLH); and autoinflammatory diseases that can present with early-onset stroke or other irreversible neurological inflammatory complications. We designed and validated a pipeline that enabled return of clinically actionable results in hours rather than weeks: the Rapid Autoinflammation Panel (RAP). We demonstrated accuracy of this new pipeline, with 100% sensitivity and 100% specificity. Return of results to clinicians was achieved within 48-hours from receiving the patient's blood or saliva sample. This approach demonstrates the potential significant diagnostic impact of NGS in acute medicine to facilitate precision medicine and save "life or limb" in these critical situations.

Phase IIa Global Study Evaluating Rituximab for the Treatment of Pediatric Patients With Granulomatosis With Polyangiitis or Microscopic Polyangiitis

Objective

To assess the safety, tolerability, pharmacokinetics, and efficacy of rituximab (RTX) in pediatric patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA).

Methods

The Pediatric Polyangiitis Rituximab Study was a phase IIa, international, open‐label, single‐arm study. During the initial 6‐month remission‐induction phase, patients received intravenous infusions of RTX (375 mg/m² body surface area) and glucocorticoids once per week for 4 weeks. During the follow‐up period, patients could receive further treatment, including RTX, for GPA or MPA. The safety, pharmacokinetics, pharmacodynamics, and exploratory efficacy outcomes with RTX were evaluated.

Results

Twenty‐five pediatric patients with new‐onset or relapsing disease were enrolled at 11 centers (19 with GPA [76%] and 6 with MPA [24%]). The median age was 14 years (range 6–17 years). All patients completed the remission‐induction phase. During the overall study period (≤4.5 years), patients received between 4 and 28 infusions of RTX. All patients experienced ≥1 adverse event (AE), mostly grade 1 or grade 2 primarily infusion‐related reactions. Seven patients experienced 10 serious AEs, and 17 patients experienced 31 infection‐related AEs. No deaths were reported. RTX clearance correlated with body surface area. The body surface area–adjusted RTX dosing regimen resulted in similar exposure in both pediatric and adult patients with GPA or MPA. Remission, according to the Pediatric Vasculitis Activity Score, was achieved in 56%, 92%, and 100% of patients by months 6, 12, and 18, respectively.

Conclusion

In pediatric patients with GPA or MPA, RTX is well tolerated and effective, with an overall safety profile comparable to that observed in adult patients with GPA or MPA who receive treatment with RTX. RTX is associated with a positive risk/benefit profile in pediatric patients with active GPA or MPA.

POS1330 SAFETY OF ANAKINRA IN PATIENTS WITH CRYOPYRIN ASSOCIATED PERIODIC SYNDROMES (CAPS) USING A GRADUATED PRE-FILLED SYRINGE

Background:

Cryopyrin associated periodic syndromes (CAPS) are a group of ultra-rare autoinflammatory diseases caused by mutations in the NLRP3 gene, leading to overproduction of IL-1β. CAPS includes the following subdiagnoses: familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and chronic infantile neurological cutaneous articular syndrome/neonatal-onset multisystem inflammatory disease (CINCA/NOMID), where FCAS is the mildest form of CAPS and CINCA/NOMID the most severe. A graduated pre-filled syringe of the IL-1 receptor antagonist anakinra was introduced to meet the need of smaller and varying doses when treating children with CAPS.

Objectives:

To evaluate the safety of anakinra in CAPS patients using the novel pre-filled syringe.

Methods:

Investigators managing patients with CAPS treated with anakinra were identified via the Eurofever registry. Follow-up data of at least 3 years for each patient were prospectively collected and analyzed (EUPAS6366). The primary study endpoints were the occurrence of adverse events (AEs) with focus on serious infections, malignancies, injection site reactions, allergic reactions and medication errors, including re-use of the syringe. Secondary endpoints included dose at specific time points, discontinuations, and switch to other IL-1 blocking treatment.

Results:

12 patients with CAPS were included in the study, 8 with MWS, 2 with FCAS and 2 with CINCA/NOMID. The majority were male (75%) and white (83.3%). At baseline, all but one patient were already using the graduated prefilled syringe with anakinra. 5 patients required a median dose of 2 to 3 mg/kg/day and 6 patients below 2 mg/kg/day. During a total of 26.1 patient years of treatment, there were 7 AEs with rate of 26.8 (95% CI 4.2-169.6) per 100 patient years. All AEs were infections from 1 patient with CINCA/NOMID and were considered unrelated to anakinra by the investigator. Two of the AEs were considered serious as hospitalization was required (1 tonsillitis and 1 urinary tract infection). No AEs were severe, 6 of the AEs were of moderate severity and 1 was of mild severity. In total, 6 patients discontinued anakinra permanently, 2 during the first year of treatment, 3 during the second year and 1 after the third year of follow-up. The reasons for discontinuation included switch to canakinumab (4 patients), switch to canakinumab and inefficacy (1 patient) and non-compliance (1 patient). The remaining 5 patients continued anakira until the end of the study. 1 patient discontinued anakinra temporarily during the second year of treatment due to non-compliance. No deaths, malignancies, injection site reactions, allergic reactions or medication errors, including re-use of the pre-filled syringe, were observed.

Table 1.

Study results

Patients12 (100)Gender, M:F9:3 (75:25)Ethnicity, white:black10:2 (83.3:16.7)Age at baseline, median (range), years25.3 (1.4-54.9)Age at disease onset, median (range), years2.5 (0-29.5)Age at diagnosis, median (range), years24.4 (0.6-54.6)Disease duration, median (range), years15.5 (1.4-51.3)Patients already using anakinra at baseline11 (91.7)Patients with history of other IL-1 blocking treatments at baseline3 (25)Anakinra dose at baseline, median (range), mg/kg/day1.7 (1.1-2.5)Anakinra dose during follow-up years 1:2:3:>3, median (range), mg/kg/day1.6:1.6:2.6:1.4 (1.1-3.9:1-4.4:1.7-3.7:1-3.2)Patients with AEs1 (8.3)Patients with permanent discontinuation of anakinra6 (50)Patients with continuation of anakinra until the end of the study5 (41.7)Patients with temporary discontinuation of anakinra1 (8.3)Total duration of anakinra exposure, median (range), years1.3 (0.5-7)Any AE7 (100)Urinary tract infection1 (14.3)Upper respiratory tract infection1 (14.3)Tonsillitis5 (71.4)

Results are shown as number (%) unless stated otherwise.

Conclusion:

The results of the present study confirm the safety profile of anakinra treatment in CAPS patients using the graduated pre-filled syringe. No new safety findings were identified.

Disclosure of Interests:

Riccardo Papa: None declared, Gabriella Giancane: None declared, Helen J. Lachmann: None declared, Paul Brogan: None declared, Elizabeth Legger: None declared, Daniel Lindqvist Shareholder of: Sobi employee and holder of Sobi shares, Speakers bureau: Sobi employee and holder of Sobi shares, Paid instructor for: Sobi employee and holder of Sobi shares, Consultant of: Sobi employee and holder of Sobi shares, Grant/research support from: Sobi employee and holder of Sobi shares, Employee of: Sobi employee and holder of Sobi shares, Susanna Cederholm Shareholder of: Sobi employee and holder of Sobi shares, Speakers bureau: Sobi employee and holder of Sobi shares, Paid instructor for: Sobi employee and holder of Sobi shares, Consultant of: Sobi employee and holder of Sobi shares, Grant/research support from: Sobi employee and holder of Sobi shares, Employee of: Sobi employee and holder of Sobi shares, Francesca Bagnasco: None declared, Nicolino Ruperto: None declared, Marco Gattorno: None declared

Management of severe hyperinflammation in the COVID-19 era: the role of the rheumatologist

Objectives

The objectives of this study were (i) to describe the clinical presentation, treatment and outcome of paediatric inflammatory multisystem syndrome temporally related to Sars-CoV-2 (PIMS-TS) in children; (ii) to propose a framework to guide multidisciplinary team (MDT) management; and (iii) to highlight the role of the paediatric rheumatologist in this context.

Methods

This study involved a retrospective case notes review of patients referred to a single specialist paediatric centre with suspected PIMS-TS, with a focus on clinical presentation, laboratory parameters, treatment, and outcome in the context of an MDT framework.

Results

Nineteen children of median age 9.1 years fulfilled the definition of PIMS-TS and were managed within an MDT framework: 5/19 were female; 14/19 were of Black, Asian or minority ethnicity; 9/19 also fulfilled diagnostic criteria for complete or incomplete Kawasaki disease (KD). Severe systemic inflammation, shock, and abdominal pain were ubiquitous. Treatment was stratified within an MDT framework and included CSs in all; i.v. immunoglobulin in all; anakinra in 4/19; infliximab in 1/19; and antiviral (aciclovir) in 4/19.

Conclusions

We observed significant diagnostic equipoise using a current definition of PIMS-TS, overlapping with KD. Outside of clinical trials, an MDT approach is vital. The role of the paediatric rheumatologist is to consider differential diagnoses of hyperinflammation in the young, to advise on empiric immunomodulatory therapy, to set realistic therapeutic targets, to gauge therapeutic success, to oversee timely step-down of immunomodulation, and to contribute to the longer-term MDT follow-up of any late inflammatory sequelae.

British kindred with dominant FMF associated with high incidence of AA amyloidosis caused by novel MEFV variant, and a review of the literature

OBJECTIVES

Hereditary systemic autoinflammatory diseases are rare genetic disorders, which if untreated, can be complicated by AA amyloidosis leading to renal failure and premature death. Our objective was to find a genetic cause in a British family with a dominantly inherited autoinflammatory disease complicated by AA amyloidosis.

METHODS

The index patient and his sister underwent comprehensive clinical and laboratory assessment including the next-generation sequencing panel targeting autoinflammatory genes. Subsequently, other relatives underwent clinical evaluation and genetic testing. Screening of the SAA1 gene was performed in all symptomatic cases.

RESULTS

The index case and his sister presented with proteinuria due to AA amyloidosis. They have been suffering from episodes of fever accompanied by severe abdominal and chest pain, arthritis and erythema since childhood. Their father died aged 52 years from complications following a cadaveric renal transplantation. The post-mortem examination demonstrated AA amyloidosis. The index case's grandmother, two paternal cousins and two of their children described similar symptoms. All symptomatic individuals had excellent responses to colchicine. Next-generation sequencing analysis identified a single MEFV p.P373L variant in the index case, his sister and subsequently, in symptomatic family members. Sequencing of the SAA1 gene revealed all cases were heterozygous for the SAA1.1 allele.

CONCLUSION

Typically FMF is an autosomal recessive disorder; nonetheless rare cases of dominantly inherited disease have previously been described. Here we report a novel MEFV variant p.P373L, causing dominant FMF complicated by AA amyloidosis in four generations of a British family.

OP0290 EMAPALUMAB (ANTI-INTERFERON-GAMMA MONOCLONAL ANTIBODY) IN PATIENTS WITH MACROPHAGE ACTIVATION SYNDROME (MAS) COMPLICATING SYSTEMIC JUVENILE IDIOPATHIC ARTHRITIS (SJIA)

Background:

MAS is a severe complication of rheumatic diseases and occurs most frequently in patients with sJIA. Data from animal models and from observational studies in patients suggest that interferon gamma (IFNy) is a driver of the hyperinflammation and hypercytokinemia observed in MAS.

Objectives:

To assess the pharmacokinetics, efficacy, and safety of intravenous (IV) infusions of emapalumab, a fully human anti-IFNγ monoclonal antibody, in patients with MAS in the context of sJIA.

Methods:

This ongoing, pilot, open-label, single-arm study (NCT03311854) includes patients with MAS (2016 ACR/EULAR criteria) on a background of confirmed, or high presumption of, sJIA, and with inadequate response to high-dose IV glucocorticoids. Emapalumab is initiated at 6 mg/kg (1 dose) and continued at 3 mg/kg twice weekly for a total of 4 weeks, or less upon achievement of complete response (CR). CR is defined as an absence of MAS clinical signs plus white blood cell and platelet counts above the lower limit of normal, LDH, AST and ALT <1.5 x upper limit of normal, fibrinogen >100 mg/dL, and ferritin decreased by ≥80% or to <2,000 ng/mL.

Results:

We report preliminary data from the first 9 patients (median age [range] 11.6 [2.1-25.3] years) enrolled (7 in Europe and 2 in the USA). All patients had failed high-dose methylprednisolone, of which there were prior treatment failures from cyclosporin A (n=4) and from anakinra (n=4). Treatment with emapalumab resulted in rapid IFNγ neutralization, as demonstrated by the decrease in CXCL9 levels (Figure 1), and subsequent deactivation of T cells, as indicated by the decrease in sIL-2R levels. CR was achieved in all patients after a median of 23 (12-56) days. A progressive improvement in all clinical and laboratory parameters of MAS was observed (Table 1 and Figure 2). Glucocorticoids were tapered in all patients (median % tapering -92%; range -45% to -98% at Week 8). Emapalumab infusions were well tolerated by all patients, with no discontinuation. CMV reactivation was reported in 1 patient as a serious event possibly related to emapalumab and resolved with antiviral treatment.

Table 1.

Time to response for key clinical and laboratory parameters.

ParametersMedian baseline value (range)Median days of treatment (range)D-dimers to <1000 mg/L12,480 (550-89,552)15 (1-49)sIL-2R to <2000 ng/L4596 (1664-20,954)21 (6-37)Ferritin <500 mg/L29,240 (716-192,584)21 (9-42)Physician visual analog scale of MAS activity ≤19.0 (2-10)19 (9-56)All MAS laboratory parameters within range of CRNA21 (15-55)All MAS parameters within range of CRNA23 (12-56)Glucocorticoid tapering at ≤1 mg/kg prednisolone equivalent*NA42 (16-50)

*Data incomplete for 1 patient

Figure 1.

Rapid neutralization of IFNy. Each line represents an individual patient (n=9).

Figure 2.

Ferritin levels and platelet counts over time.

Conclusion:

Emapalumab administration led to rapid neutralization of IFNy and was efficacious in controlling MAS with a favorable safety profile. These results support the pathogenic role of IFNγ in MAS/sJIA and the therapeutic value of IFNγ neutralization in MAS patients who have failed standard of care.

Disclosure of Interests:

Fabrizio De Benedetti Grant/research support from: AbbVie, Pfizer, Novartis, Novimmune, Sobi, Sanofi, Roche, Speakers bureau: AbbVie, Novartis, Roche, Sobi, Paul Brogan Grant/research support from: Sobi, Novartis, Roche, Chemocentryx, Consultant of: Roche, Sobi, Speakers bureau: Sobi, Roche, Novartis, UCB, Claudia Bracaglia: None declared, Manuela Pardeo: None declared, Giulia Marucci: None declared, Emanuela Sacco: None declared, Despina Eleftheriou Speakers bureau: Sobi, Charalampia Papadopoulou: None declared, Alexei Grom Grant/research support from: Novartis, AB2Bio, Consultant of: Novartis, Pierre Quartier Consultant of: AbbVie, Chugai-Roche, Lilly, Novartis, Sanofi, Sobi, Speakers bureau: AbbVie, BMS, Chugai-Roche, Novartis, Pfizer, Sobi, Rayfel Schneider Grant/research support from: Roche, Novartis, Sobi, Pfizer, Consultant of: Sobi, Novartis, Novimmune, Philippe Jacqmin Consultant of: Sobi, Rikke Frederiksen Employee of: Sobi, Maria Ballabio Employee of: Sobi, Cristina De Min Employee of: Sobi

SAT0503 SERIOUS INFECTION RISK IN PEDIATRIC PATIENTS WITH LOW IMMUNOGLOBULIN LEVELS FOLLOWING RITUXIMAB TREATMENT FOR GRANULOMATOSIS WITH POLYANGIITIS (GPA) OR MICROSCOPIC POLYANGIITIS (MPA)

Background:

Low immunoglobulin (Ig) levels can occur after rituximab treatment, but the clinical significance is not completely understood. Not all patients (pts) who develop low Ig levels after rituximab are at an increased risk of serious infection (SI), but factors such as pre-existing low Ig levels, prior biologic therapies, history of SI and other disease and age-related factors may increase the risk.

Objectives:

To assess the risk of SI in pediatric pts with prolonged low IgG or IgM serum concentrations following rituximab treatment for GPA or MPA in a global clinical trial.

Methods:

In the Phase 2a PePRS study (WA25615), pts aged ≥ 2 to ≤ 18 yrs with GPA or MPA received 4 weekly intravenous rituximab infusions of 375 mg/m2body surface area and concomitant oral glucocorticoid taper. After 6 months, pts could receive further rituximab and/or other immunosuppressants at the investigator’s discretion during a minimum 12-month follow-up phase. Pts with IgG/IgM levels below age-specific reference ranges at baseline were excluded. Ig levels were measured every 4-12 wks. SI occurrence was assessed during/after low IgG or IgM. Prolonged low Ig was defined as IgG or IgM levels < lower limit of normal (LLN) reference range for age for a ≥ 4-month period.

Results:

All 25 pts completed 4 weekly rituximab infusions and the 6-month Remission Induction Phase; 24/25 pts completed ≥ 18 months of follow-up. 17 pts received additional rituximab treatment on or after Month 6. 11 pts received concomitant immunosuppressants (cyclophosphamide, azathioprine, mycophenolate mofetil) during the study. All pts had a decrease in IgG and IgM mostly after the first rituximab infusion. There was no consistent trend in IgG or IgM levels over time and no clear relationship between low IgG or IgM levels and the number of follow-up rituximab treatments. 18 pts (72%) had prolonged low IgG ≥ 4 months, of whom 5 had IgG levels < LLN at screening and/or baseline; in 7 pts, IgG levels returned to within normal range by study end. During or after prolonged low IgG, 6/18 pts experienced a total of 7 SIs. Three pts received treatment with intravenous Ig. 19 pts (76%) had prolonged low IgM, of whom 5 had IgM levels < LLN at screening and/or baseline. During or after prolonged low IgM levels, 6/19 pts experienced a total of 8 SIs. There were no deaths or study discontinuation due to SI. All pts with prolonged low IgG or IgM had past and/or concomitant treatment with steroids and/or immunosuppressants as potential contributory factors. Analysis of SI onset in relation to timing of low Ig was limited due to protocol-defined time points for Ig assessments.

Conclusion:

In pediatric pts with GPA/MPA treated with rituximab, there was no consistent pattern in IgG or IgM levels over time. The majority of pts with prolonged low IgG or IgM did not experience any SIs; no increase in the number of SIs was observed over time or with multiple rituximab treatments. While no firm conclusions can be made on a possible relationship between prolonged low IgG or IgM and risk of SI following rituximab due to study limitations (low pt numbers, lack of placebo comparator), these observations are consistent with the known rituximab safety profile in adult pts with GPA/MPA.

Disclosure of Interests:

Simone Melega Shareholder of: F. Hoffmann-La Roche, Employee of: F. Hoffmann-La Roche, Paul Brogan Grant/research support from: Roche, Novartis, SOBI, Chemocentryx, Novimmune, Consultant of: Roche, SOBI, UCB, Novartis, Speakers bureau: Roche, SOBI, UCB, Novartis, Gavin Cleary Speakers bureau: AbbVie, Aimee Hersh: None declared, Ozgur Kasapcopur: None declared, Satyapal Rangaraj: None declared, Rae Yeung Consultant of: AbbVie, Novartis, Speakers bureau: AbbVie, Novartis, Andrew Zeft: None declared, Jennifer Cooper Employee of: Genentech, Inc., Pooneh Pordeli Shareholder of: Roche, Employee of: Roche, Petra Kirchner Shareholder of: Roche, Employee of: Roche, Patricia Lehane Shareholder of: Roche, Employee of: Roche

FRI0457 LONG-TERM OUTCOMES AND TREATMENT EFFICACY IN PATIENTS WITH TNF RECEPTOR-ASSOCIATED AUTOINFLAMMATORY SYNDROME (TRAPS) FROM THE EUROFEVER INTERNATIONAL REGISTRY

Background:

Tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is one of the best-known monogenic auto-inflammatory disorders resulting from an autosomal dominant variation in the TNF super family receptor 1A (TNFRSF1A) gene (1).

Objectives:

To define best treatment approach in patients with TRAPS and effect on long-term outcomes.

Methods:

We reviewed all data on patients with TRAPS enrolled in the Eurofever international registry according the INSAID gene variant classification and the new Eurofever/PRINTO classification criteria (EPCC).

Results:

Data on 226 patients were available. Patients not fulfilling the EPCC carrying likely benign/benign variants (21 patients, 9%) or VOUS/not classified variants (40 patients, 18%) displayed a milder disease than the patients fulfilling the EPCC with VOUS/not classified variants (38 patients, 17%) or pathogenic/likely pathogenic variants (127 patients, 56%). In particular, in patients not fulfilling the EPCC, less frequent abdominal pain and skin rashes, higher efficacy rate of colchicine and no development of AA amyloidosis have been reported. Almost 90% of patients fulfilling the EPCC required maintenance therapy and anti-interleukin (IL)-1 drugs were the most frequently used, with the highest efficacy rate (>85% complete response), while Etanercept was less effectively used and discontinued in 65% of patients.

Conclusion:

Anti-IL-1 drugs are the best maintenance treatment in TRAPS with potential to reverse the most serious disease complications of AA amyloidosis and infertility. The diagnosis of TRAPS should be considered very carefully in patients carrying VOUS/not classified variants not fulfilling the EPCC.

References:

[1]Lachmann HJ, Papa R, Gerhold K, Obici L, Touitou I, Cantarini L, et al. The phenotype of TNF receptor-associated autoinflammatory syndrome (TRAPS) at presentation: a series of 158 cases from the Eurofever/EUROTRAPS international registry. Annals of the rheumatic diseases 2014;73:2160-7.

Acknowledgments:

RP would like to thank the European Federation of Immunology (EFIS) for the short-term bursary and HL for her continuous support and guidance during the fellowship at the National Amyloidosis Centre in London.

Disclosure of Interests:

Riccardo Papa: None declared, Thirusha Lane: None declared, Francesca Bovis: None declared, Kirsten Minden Consultant of: GlaxoSmithKline, Sanofi, Speakers bureau: Roche, Isabelle Touitou: None declared, Luca Cantarini: None declared, Marco Cattalini: None declared, Laura Obici: None declared, Annette Jansson: None declared, Alexander Belot: None declared, Beata Woska-Kuśnierz: None declared, Rainer Berendes: None declared, Agustin Remesal: None declared, Marija Jelusic: None declared, Graciela Espada: None declared, Irina Nikishina: None declared, Esther Hoppenreijs: None declared, Maria Cristina Maggio: None declared, Taryn Youngstein: None declared, Tamer Rezk: None declared, Charalampia Papadopoulou: None declared, Paul Brogan Grant/research support from: Roche, Novartis, SOBI, Chemocentryx, Novimmune, Consultant of: Roche, SOBI, UCB, Novartis, Speakers bureau: Roche, SOBI, UCB, Novartis, Philip N Hawkins: None declared, Patricia Woo: None declared, Nicolino Ruperto Grant/research support from: Bristol-Myers Squibb, Eli Lily, F Hoffmann-La Roche, GlaxoSmithKline, Janssen, Novartis, Pfizer, Sobi (paid to institution), Consultant of: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lily, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi, Takeda, Speakers bureau: Ablynx, AbbVie, AstraZeneca-Medimmune, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lily, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sanofi, Servier, Sinergie, Sobi, Takeda, Marco Gattorno Consultant of: Sobi, Novartis, Speakers bureau: Sobi, Novartis, Helen J. Lachmann: None declared

European consensus-based recommendations for the diagnosis and treatment of Kawasaki disease - the SHARE initiative

OBJECTIVES

The European Single Hub and Access point for paediatric Rheumatology in Europe initiative aimed to optimize care for children with rheumatic diseases. Kawasaki disease (KD) is the most common cause of acquired heart disease in children and an important cause of long-term cardiac disease into adulthood. Prompt diagnosis and treatment of KD is difficult due to the heterogeneity of the disease but is crucial for improving outcome. To date, there are no European internationally agreed, evidence-based guidelines concerning the diagnosis and treatment of KD in children. Accordingly, treatment regimens differ widely. The aim of this study is to provide consensus-based, European-wide evidence-informed recommendations for diagnosis and treatment of children with KD.

METHODS

Recommendations were developed using the EULAR's standard operating procedures. An extensive systematic literature search was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of international experts via online surveys and subsequently discussed in three consensus meetings, using nominal group technique. Recommendations were accepted when ⩾80% agreed.

RESULTS

In total, 17 recommendations for diagnosis and 14 for treatment of KD in children were accepted. Diagnostic recommendations included laboratory and imaging workup for complete as well as incomplete KD. Treatment recommendations included the importance of early treatment in both complete and incomplete KD, use of intravenous immunoglobulin, aspirin, corticosteroids for high-risk cases, and other treatment options for those with resistant disease.

CONCLUSION

The Single Hub and Access point for paediatric Rheumatology in Europe initiative provides international evidence-based recommendations for diagnosing and treating KD in children, facilitating improvement and uniformity of care.

European consensus-based recommendations for the diagnosis and treatment of rare paediatric vasculitides - the SHARE initiative

OBJECTIVES

The European initiative Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) aimed to optimize care for children with rheumatic diseases. Systemic vasculitides are very rare in children. Consequently, despite recent advances, paediatric-specific information is sparse. The lack of evidence-based recommendations is an important, unmet need. This study aimed to provide recommendations for diagnosing and treating children with rare forms of childhood systemic vasculitis.

METHODS

Recommendations were developed by a consensus process in accordance with the European League Against Rheumatism standard operating procedures. A systematic literature review informed the recommendations, which were devised and evaluated by a panel of experts via an online survey, and two consensus meetings using nominal group technique. Recommendations were accepted when ⩾ 80% of experts agreed.

RESULTS

Ninety-three relevant articles were found, and 78 recommendations were accepted in the two consensus meetings. General, cross-cutting recommendations and disease-specific statements regarding the diagnosis and treatment of childhood-onset PAN, granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, and Takayasu arteritis are provided.

CONCLUSION

These Single Hub and Access point for paediatric Rheumatology in Europe recommendations were formulated through an evidence-based consensus process to support uniform, high-quality standard of care for children with rare forms of paediatric systemic vasculitis.

Genotype and functional correlates of disease phenotype in deficiency of adenosine deaminase 2 (DADA2)

BACKGROUND

Deficiency of adenosine deaminase 2 (DADA2) is a syndrome with pleiotropic manifestations including vasculitis and hematologic compromise. A systematic definition of the relationship between adenosine deaminase 2 (ADA2) mutations and clinical phenotype remains unavailable.

OBJECTIVE

We sought to test whether the impact of ADA2 mutations on enzyme function correlates with clinical presentation.

METHODS

Patients with DADA2 with severe hematologic manifestations were compared with vasculitis-predominant patients. Enzymatic activity was assessed using expression constructs reflecting all 53 missense, nonsense, insertion, and deletion genotypes from 152 patients across the DADA2 spectrum.

RESULTS

We identified patients with DADA2 presenting with pure red cell aplasia (n = 5) or bone marrow failure (BMF, n = 10) syndrome. Most patients did not exhibit features of vasculitis. Recurrent infection, hepatosplenomegaly, and gingivitis were common in patients with BMF, of whom half died from infection. Unlike patients with DADA2 with vasculitis, patients with pure red cell aplasia and BMF proved largely refractory to TNF inhibitors. ADA2 variants associated with vasculitis predominantly reflected missense mutations with at least 3% residual enzymatic activity. In contrast, pure red cell aplasia and BMF were associated with missense mutations with minimal residual enzyme activity, nonsense variants, and insertions/deletions resulting in complete loss of function.

CONCLUSIONS

Functional interrogation of ADA2 mutations reveals an association of subtotal function loss with vasculitis, typically responsive to TNF blockade, whereas more extensive loss is observed in hematologic disease, which may be refractory to treatment. These findings establish a genotype-phenotype spectrum in DADA2.

Microparticle-mediated VZV propagation and endothelial activation: Mechanism of VZV vasculopathy

Objective

Varicella zoster virus (VZV) can spread anterogradely and infect cerebral arteries causing VZV vasculopathy and arterial ischemic stroke. In this study, we tested the hypothesis that virus-infected cerebrovascular fibroblasts undergo phenotypic changes that promote vascular remodeling and facilitate virus transmission in an in vitro model of VZV vasculopathy. The aims of this project were therefore to examine the changes that virus-infected human brain adventitial vascular fibroblasts (HBVAFs) undergo in an in vitro model of VZV vasculopathy and to identify disease biomarkers relating to VZV-related vasculopathy.

Methods

HBVAFs were infected with VZV, and their ability to migrate, proliferate, transdifferentiate, and interact with endothelial cells was studied with flow cytometry. Microparticles (MPs) released from these cells were isolated and imaged with transmission electron microscopy, and their protein content was analyzed with mass spectrometry. Circulating MP profiles were also studied in children with VZV and non-VZV vasculopathy and compared with controls.

Results

VZV-infected HBVAFs transdifferentiated into myofibroblasts with enhanced proliferative and migratory capacity. Interaction of VZV-infected HBVAFs with endothelial cells resulted in endothelial dysfunction. These effects were, in part, mediated by the release of MPs from VZV-infected HBVAFs. These MPs contained VZV virions that could transmit VZV to neighboring cells, highlighting a novel model of VZV cell-to-cell viral dissemination. MPs positive for VZV were significantly higher in children with VZV-related vasculopathy compared to children with non-VZV vasculopathy (p = 0.01) and controls (p = 0.007).

Conclusions

VZV-infected HBVAFs promote vascular remodeling and facilitate virus transmission. These effects were mediated by the release of apoptotic MPs that could transmit VZV infection to neighboring cells through a Trojan horse means of productive viral infection. VZV+ MPs may represent a disease biomarker worthy of further study.

Lifetime cardiovascular management of patients with previous Kawasaki disease

Kawasaki disease (KD) is an inflammatory disorder of young children, associated with vasculitis of the coronary arteries with subsequent aneurysm formation in up to one-third of untreated patients. Those who develop aneurysms are at life-long risk of coronary thrombosis or the development of stenotic lesions, which may lead to myocardial ischaemia, infarction or death. The incidence of KD is increasing worldwide, and in more economically developed countries, KD is now the most common cause of acquired heart disease in children. However, many clinicians in the UK are unaware of the disorder and its long-term cardiac complications, potentially leading to late diagnosis, delayed treatment and poorer outcomes. Increasing numbers of patients who suffered KD in childhood are transitioning to the care of adult services where there is significantly less awareness and experience of the condition than in paediatric services. The aim of this document is to provide guidance on the long-term management of patients who have vascular complications of KD and guidance on the emergency management of acute coronary complications. Guidance on the management of acute KD is published elsewhere.

Secondary C1q Deficiency in Activated PI3Kδ Syndrome Type 2

Monogenic forms of vasculitis are rare but increasingly recognized. Furthermore, genetic immunodeficiency is increasingly associated with inflammatory immune dysregulatory features, including vasculitis. This case report describes a child of non-consanguineous parents who presented with chronic digital vasculitis early in life, is of short stature, has facial dysmorphia, immunodeficiency (low serum IgA, high serum IgM), recurrent bacterial infections, lymphoproliferation, absence of detectable serum C1q, and low classical complement pathway activity. We identified a previously reported de novo heterozygous pathogenic splice mutation in PIK3R1 (c.1425 + 1G > A), resulting in the skipping of exon 11 of the p85α subunit of phosphatidylinositol 3-kinase and causing activated PI3Kδ syndrome type II (APDS2). This explained the phenotype, with the exception of digital vasculitis and C1q deficiency, which have never been described in association with APDS2. No mutations were identified in C1QA, B, or C, their promoter regions, or in any other complement component. Functional studies indicated normal monocytic C1q production and release, suggesting that the observed C1q deficiency was caused by peripheral consumption of C1q. Since C1q deficiency has never been associated with APDS2, we assessed C1q levels in two unrelated patients with genetically confirmed APDS2 and confirmed C1q deficiency in those two cases as well. This observation suggests C1q deficiency to be an inherent but previously unrecognized feature of APDS2. We speculate that the consumption of C1q is driven by increased apoptotic bodies derived from immune cellular senescence, combined with elevated IgM production (both inherent features of APDS2). Secondary C1q deficiency in APDS2 may further contribute to immunodeficiency and could also be associated with inflammatory immune dysregulatory phenotypes, such as the digital vasculitis observed in our case.

Comparing the clinical profile of adults and children with Behçet's syndrome in the UK

OBJECTIVES

Behçet's syndrome (BS) is a rare multi-system inflammatory disorder. Clinical phenotypic variance across geographical regions is recognised but UK BS patients' variance by age groups and gender has not been studied. This study compares the clinical features of adult and juvenile onset Behçet's Syndrome (JBS) in a UK population.

METHODS

Two clinical databases of BS patients were compared. The JBS database was collected at the Great Ormond Street Hospital for Children, London (n=46). The adult database was collected at the Hammersmith Hospital, London (n=560).

RESULTS

Oro-genital aphthosis had high prevalence in both the JBS and the adult cohort (oral: 97.8% vs. 96.6%, genital: 73.9% vs. 75.7%). The JBS cohort was more likely to have gastrointestinal involvement (21.7% vs. 4.5%, p<0.001) and arthritis (21.7% vs. 9.6%, p=0.021) compared to adults. The JBS cohort was less likely to have eye involvement (4.3% vs. 37%, p<0.001), skin (21.7% vs. 55.4%, p<0.001) and vascular involvement (6.5% vs. 17.5% p=0.063). JBS females had a higher rate of genital aphthosis than JBS males (87.5% vs. 59.1%, p=0.044). Adult females had higher rates of genital (85.2% vs. 64.5%, p<0.001) and oral (99.0% vs. 93.8%, p=0.001) aphthosis than adult males. Adult males were more likely to have ophthalmological (44.9% vs. 30.3%, p<0.001) and vascular (23.0% vs. 12.8%, p=0.002) manifestations than adult females.

CONCLUSIONS

UK JBS patients displayed less ocular and skin manifestations compared to the adult BS patients. This information will aid clinicians in diagnosing BS in UK adult and paediatric populations.

Development and Validation of a Targeted Next-Generation Sequencing Gene Panel for Children With Neuroinflammation

IMPORTANCE

Neuroinflammatory disorders are a range of severe neurological disorders causing brain and spinal inflammation and are now increasingly recognized in the pediatric population. They are often characterized by marked genotypic and phenotypic heterogeneity, complicating diagnostic work in clinical practice and molecular diagnosis.

OBJECTIVE

To develop and evaluate a next-generation sequencing panel targeting genes causing neuroinflammation or mimicking neuroinflammation.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study in which a total of 257 genes associated with monogenic neuroinflammation and/or cerebral vasculopathy, including monogenic noninflammatory diseases mimicking these entities, were selected. A customized enrichment capture array, the neuroinflammation gene panel (NIP), was created. Targeted high-coverage sequencing was applied to DNA samples taken from eligible patients referred to Great Ormond Street Hospital in London, United Kingdom, between January 1, 2017, and January 30, 2019, because of onset of disease early in life, family history, and/or complex neuroinflammatory phenotypes.

MAIN OUTCOMES AND MEASURES

The main outcome was the percentage of individuals with definitive molecular diagnoses, variant classification, and clinical phenotyping of patients with pathogenic variants identified using the NIP panel. The NIP panel was initially validated in 16 patients with known genetic diagnoses.

RESULTS

The NIP was both sensitive (95%) and specific (100%) for detection of known mutations, including gene deletions, copy number variants, small insertions and deletions, and somatic mosaicism with allele fraction as low as 3%. Prospective testing of 60 patients (30 [50%] male; median [range] age, 9.8 [0.8-20] years) presenting with heterogeneous neuroinflammatory phenotypes revealed at least 1 class 5 (clearly pathogenic) variant in 9 of 60 patients (15%); 18 of 60 patients (30%) had at least 1 class 4 (likely pathogenic) variant. Overall, a definitive molecular diagnosis was established in 12 of 60 patients (20%).

CONCLUSIONS AND RELEVANCE

The NIP was associated with molecular diagnosis in this cohort and complemented routine laboratory and radiological workup of patients with neuroinflammation. Unexpected genotype-phenotype associations in patients with pathogenic variants deviating from the classic phenotype were identified. Obtaining an accurate molecular diagnosis in a timely fashion informed patient management, including successful targeted treatment in some instances and early institution of hematopoietic stem cell transplantation in others.

Retrospective case series describing the efficacy, safety and cost-effectiveness of a vial-sharing programme for canakinumab treatment for paediatric patients with cryopyrin-associated periodic syndrome

BACKGROUND

Cryopyrin-associated periodic syndrome (CAPS) is a rare autoinflammatory disease, caused by gain of function mutation in NLRP3 resulting in excess production of interleukin-1 (IL-1). Canakinumab is a human monoclonal antibody against Interleukin-1 beta (IL-1β), licensed for the treatment of CAPS. The objective of the study was to describe the feasibility and cost-effectiveness of a canakinumab vial-sharing programme for paediatric patients with CAPS.

METHOD

Retrospective case series and clinical service description of a national specially commissioned CAPS clinic at Great Ormond Street Hospital (GOSH). Effectiveness was assessed using a CAPS disease activity score (DAS) and serum amyloid A protein (SAA). Adverse events were collected to determine safety. The number of canakinumab vials saved was considered when investigating the cost-effectiveness of vial-sharing.

RESULTS

Nineteen/20 (95%) of our paediatric patients achieved minimally active clinical disease activity with canakinumab monotherapy; and 75% achieved both minimally active clinical disease and serological remission using a pre-specified definition based on the CAPS DAS and SAA level. Canakinumab was well tolerated, with only one child developing an infection requiring hospitalisation during the study. Canakinumab vial sharing resulted in 117 vials of canakinumab saved over a 24-month period, equating to a direct drug-related cost saving of £1,385,821, and a conservative estimated 5-year cost-saving of £3,464,552.50.

CONCLUSION

We provide further evidence for the effectiveness and safety of canakinumab in children with CAPS, and highlight the cost-effectiveness of a vial-sharing programme for this high cost medicine. We suggest that this could have important implications for the delivery of other high cost medicines used in paediatric practice.

Inflammatory Arthritis as a Possible Feature of Coffin-Siris Syndrome

Coffin-Siris syndrome (CSS) and Nicolaides-Baraitser syndrome (NBS) are 2 overlapping syndromes caused by mutations in genes of the barrier-to-autointegration factor chromatin-remodeling complex, presenting with multiple malformations and intellectual disability. Musculoskeletal changes such as noninflammatory prominence of interphalangeal joints in hands, feet, and, to a lesser extent, knee joints are common in NBS (up to 85%) and also reported in CSS. We present the case of a 7-year-old boy with polyarthritis of several years' duration (without uveitis), developmental delay, microcephaly, and dysmorphic features reminiscent of NBS. Sanger sequencing of the SMARCA2 gene revealed no mutations. Laboratory test results were normal. With synovial biopsy, we confirmed a chronic inflammatory synovitis. Brain MRI revealed dysgenesis of the corpus callosum. Treatment with methotrexate and, subsequently, etanercept led to significant clinical improvement. Whole-exome sequencing revealed a de novo heterozygous nonsense mutation in the ARID1B gene, resulting in a premature stop codon (c.C5404T; p.R1802×), a genotype consistent with CSS. The absence of significantly raised inflammatory markers and a clinical diagnosis of a genetic syndrome associated with noninflammatory joint changes may have contributed to this patient's polyarthritis being missed for several years. We propose that some patients with CSS may have inflammatory arthritis (with or without coexisting skeletal dysplasia), which may be helped by treatment as described herein. Early recognition and treatment of inflammatory arthritis in CSS would have a significant impact on reducing disease burden and improving quality of life for patients with this rare genetic syndrome.

European consensus-based recommendations for diagnosis and treatment of immunoglobulin A vasculitis—the SHARE initiative

Objectives

IgA vasculitis (IgAV, formerly known as Henoch–Schönlein purpura) is the most common cause of systemic vasculitis in childhood. To date, there are no internationally agreed, evidence-based guidelines concerning the appropriate diagnosis and treatment of IgAV in children. Accordingly, treatment regimens differ widely. The European initiative SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) aims to optimize care for children with rheumatic diseases. The aim therefore was to provide internationally agreed consensus recommendations for diagnosis and treatment for children with IgAV.

Methods

Recommendations were developed by a consensus process in accordance with the EULAR standard operating procedures. An extensive systematic literature review was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of 16 international experts via online surveys and subsequent consensus meeting, using nominal group technique. Recommendations were accepted when ⩾80% of experts agreed.

Results

In total, 7 recommendations for diagnosis and 19 for treatment of paediatric IgAV were accepted. Diagnostic recommendations included: appropriate use of skin and renal biopsy, renal work-up and imaging. Treatment recommendations included: the importance of appropriate analgesia and angiotensin-converting enzyme inhibitor use and non-renal indications for CS use, as well as a structured approach to treating IgAV nephritis, including appropriate use of CS and second-line agents in mild, moderate and severe disease along with use of angiotensin-converting enzyme inhibitors and maintenance therapy.

Conclusion

The SHARE initiative provides international, evidence-based recommendations for the diagnosis and treatment of IgAV that will facilitate improvement and uniformity of care.

Efficacy and safety of anakinra for undifferentiated autoinflammatory diseases in children: a retrospective case review

Objective

The aim was to carry out a retrospective review of the efficacy and safety of anakinra in paediatric patients with undifferentiated autoinflammatory disease (uAID).

Methods

We carried out a retrospective study of children with uAID at a single quaternary centre. The clinical efficacy of anakinra was evaluated using physician global assessment (PGA) and serological response assessed by levels of serum amyloid A and CRP. Safety was assessed by exploring adverse events, including infection and drug reactions.

Results

This study included 22 patients, 64% females and 36% males of median age 7.1 years (range 0.13–14.11 years), with uAID. The median starting dose of anakinra was 2 mg/kg (range 2–6 mg/kg) and the median duration of treatment 19.6 months (range 0.8–100 months). Before anakinra treatment, the median PGA, on a three-point Likert scale, was 2 (range 1–2), which fell to 1 (range 0–2) within 3 months of treatment. Eight of 22 (36%) patients achieved complete clinical and serological remission; 8/22 (36%) achieved a partial response; and 6/22 (28%) had no response to anakinra. Adverse events included death (3/22, 14%) and allogeneic haematopoietic stem cell transplantation (1/22, 5%). There were no new safety signals, and anakinra was well tolerated overall.

Conclusion

Retrospectively, 72% of children with uAID responded well to anakinra, with 36% achieving full clinical and serological remission within 3 months. This suggests that empirical trials of IL-1 blockade might be warranted in children with uAID. Clear stopping criteria based on predefined parameters should be considered, because non-responders required alternative therapies, facilitated by a definitive molecular diagnosis where possible.

Mycophenolate mofetil versus cyclophosphamide for remission induction in ANCA-associated vasculitis: a randomised, non-inferiority trial

OBJECTIVES

Cyclophosphamide induction regimens are effective for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), but are associated with infections, malignancies and infertility. Mycophenolate mofetil (MMF) has shown high remission rates in small studies of AAV.

METHODS

We conducted a randomised controlled trial to investigate whether MMF was non-inferior to cyclophosphamide for remission induction in AAV. 140 newly diagnosed patients were randomly assigned to MMF or pulsed cyclophosphamide. All patients received the same oral glucocorticoid regimen and were switched to azathioprine following remission. The primary endpoint was remission by 6 months requiring compliance with the tapering glucocorticoid regimen. Patients with an eGFR <15 mL/min were excluded from the study.

RESULTS

At baseline, ANCA subtype, disease activity and organ involvement were similar between groups. Non-inferiority was demonstrated for the primary remission endpoint, which occurred in 47 patients (67%) in the MMF group and 43 patients (61%) in the cyclophosphamide group (risk difference 5.7%, 90% CI -7.5% to 19%). Following remission, more relapses occurred in the MMF group (23 patients, 33%) compared with the cyclophosphamide group (13 patients, 19%) (incidence rate ratio 1.97, 95% CI 0.96 to 4.23, p=0.049). In MPO-ANCA patients, relapses occurred in 12% of the cyclophosphamide group and 15% of the MMF group. In PR3-ANCA patients, relapses occurred in 24% of the cyclophosphamide group and 48% of the MMF group. Serious infections were similar between groups (26% MMF group, 17% cyclophosphamide group) (OR 1.67, 95% CI 0.68 to 4.19, p=0.3).

CONCLUSION

MMF was non-inferior to cyclophosphamide for remission induction in AAV, but resulted in higher relapse rate.

TRIAL REGISTRATION NUMBER

NCT00414128.

Successful use of ofatumumab in two cases of early-onset juvenile SLE with thrombocytopenia caused by a mutation in protein kinase C δ

BACKGROUND

We previously described an endogamous Pakistani kindred in whom we identified a novel homozygous missense mutation in the PRKCD gene encoding for protein kinase C δ (PKCδ) as a cause of monogenic systemic lupus erythematosus (SLE). PKCδ has a role in the negative regulation of B cells. Given the nature of the disease, a logical targeted therapeutic approach in these patients is B cell depletion. Indeed, the 3 siblings all had a marked clinical response and resolution of symptoms with rituximab, although 2 of the siblings had severe reactions to rituximab thus precluding further treatment with this. We therefore describe the first successful use of ofatumumab for this rare form of monogenic SLE.

CASE PRESENTATION

All three affected siblings presented with SLE before the age of 3-years with lethargy, intermittent fever, thrombocytopenia, cutaneous involvement, alopecia, and hepatosplenomegaly. Tubulointerstitial nephritis was also present in 1 of the siblings. Homozygosity mapping followed by whole exome sequencing identified a homozygous missense mutation in PRKCD (p.Gly432Trp), subsequently confirmed by Sanger sequencing to be present in all 3 siblings. All 3 patients were initially treated with rituximab, however 2 of the siblings developed severe infusion-related reactions. For subsequent disease flare in these individuals we therefore used an alternative B cell depleting agent, ofatumumab (300 mg/1.73m² on day 1; 700 mg/1.73m² on day 15). This resulted in marked clinical improvement in both patients. To the best of our knowledge, this is the first report describing the successful use of ofatumumab for PKCδ deficiency.

CONCLUSIONS

PKCδ deficiency causes a monogenic form of SLE which responds well to B cell depletion. Ofatumumab is also likely to have a therapeutic role for sporadic juvenile SLE (jSLE) patients intolerant of rituximab.

Canakinumab for the Treatment of Autoinflammatory Recurrent Fever Syndromes

BACKGROUND

Familial Mediterranean fever, mevalonate kinase deficiency (also known as the hyperimmunoglobulinemia D syndrome), and the tumor necrosis factor receptor-associated periodic syndrome (TRAPS) are monogenic autoinflammatory diseases characterized by recurrent fever flares.

METHODS

We randomly assigned patients with genetically confirmed colchicine-resistant familial Mediterranean fever, mevalonate kinase deficiency, or TRAPS at the time of a flare to receive 150 mg of canakinumab subcutaneously or placebo every 4 weeks. Patients who did not have a resolution of their flare received an add-on injection of 150 mg of canakinumab. The primary outcome was complete response (resolution of flare and no flare until week 16). In the subsequent phase up to week 40, patients who had a complete response underwent a second randomization to receive canakinumab or placebo every 8 weeks. Patients who underwent a second randomization and had a subsequent flare and all other patients received open-label canakinumab.

RESULTS

At week 16, significantly more patients receiving canakinumab had a complete response than those receiving placebo: 61% vs. 6% of patients with colchicine-resistant familial Mediterranean fever (P<0.001), 35% versus 6% of those with mevalonate kinase deficiency (P=0.003), and 45% versus 8% of those with TRAPS (P=0.006). The inclusion of patients whose dose was increased to 300 mg every 4 weeks yielded a complete response in 71% of those with colchicine-resistant familial Mediterranean fever, 57% of those with mevalonate kinase deficiency, and 73% of those with TRAPS. After week 16, an extended dosing regimen (every 8 weeks) maintained disease control in 46% of patients with colchicine-resistant familial Mediterranean fever, 23% of those with mevalonate kinase deficiency, and 53% of those with TRAPS. Among patients who received canakinumab, the most frequently reported adverse events were infections (173.3, 313.5, and 148.0 per 100 patient-years among patients with colchicine-resistant familial Mediterranean fever, those with mevalonate kinase deficiency, and those with TRAPS, respectively), with a few being serious infections (6.6, 13.7, and 0.0 per 100 patient-years).

CONCLUSIONS

In this trial, canakinumab was effective in controlling and preventing flares in patients with colchicine-resistant familial Mediterranean fever, mevalonate kinase deficiency, and TRAPS. (Funded by Novartis; CLUSTER ClinicalTrials.gov number, NCT02059291 .).

Tumour compartment transcriptomics demonstrates the activation of inflammatory and odontogenic programmes in human adamantinomatous craniopharyngioma and identifies the MAPK/ERK pathway as a novel therapeutic target

Adamantinomatous craniopharyngiomas (ACPs) are clinically challenging tumours, the majority of which have activating mutations in CTNNB1. They are histologically complex, showing cystic and solid components, the latter comprised of different morphological cell types (e.g. β-catenin-accumulating cluster cells and palisading epithelium), surrounded by a florid glial reaction with immune cells. Here, we have carried out RNA sequencing on 18 ACP samples and integrated these data with an existing ACP transcriptomic dataset. No studies so far have examined the patterns of gene expression within the different cellular compartments of the tumour. To achieve this goal, we have combined laser capture microdissection with computational analyses to reveal groups of genes that are associated with either epithelial tumour cells (clusters and palisading epithelium), glial tissue or immune infiltrate. We use these human ACP molecular signatures and RNA-Seq data from two ACP mouse models to reveal that cell clusters are molecularly analogous to the enamel knot, a critical signalling centre controlling normal tooth morphogenesis. Supporting this finding, we show that human cluster cells express high levels of several members of the FGF, TGFB and BMP families of secreted factors, which signal to neighbouring cells as evidenced by immunostaining against the phosphorylated proteins pERK1/2, pSMAD3 and pSMAD1/5/9 in both human and mouse ACP. We reveal that inhibiting the MAPK/ERK pathway with trametinib, a clinically approved MEK inhibitor, results in reduced proliferation and increased apoptosis in explant cultures of human and mouse ACP. Finally, we analyse a prominent molecular signature in the glial reactive tissue to characterise the inflammatory microenvironment and uncover the activation of inflammasomes in human ACP. We validate these results by immunostaining against immune cell markers, cytokine ELISA and proteome analysis in both solid tumour and cystic fluid from ACP patients. Our data support a new molecular paradigm for understanding ACP tumorigenesis as an aberrant mimic of natural tooth development and opens new therapeutic opportunities by revealing the activation of the MAPK/ERK and inflammasome pathways in human ACP.

An international delphi survey for the definition of the variables for the development of new classification criteria for periodic fever aphtous stomatitis pharingitis cervical adenitis (PFAPA)

BACKGROUND

Diagnosis of Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) is currently based on a set of criteria proposed in 1999 modified from Marshall's criteria. Nevertheless no validated evidence based set of classification criteria for PFAPA has been established so far. The aim of this study was to identify candidate classification criteria PFAPA syndrome using international consensus formation through a Delphi questionnaire survey.

METHODS

A first open-ended questionnaire was sent to adult and pediatric clinicians/researchers, asking to identify the variables thought most likely to be helpful and relevant for the diagnosis of PFAPA. In a second survey, respondents were asked to select, from the list of variables coming from the first survey, the 10 features that they felt were most important, and to rank them in descending order from most important to least important.

RESULTS

The response rate to the first and second Delphi was respectively 109/124 (88%) and 141/162 (87%). The number of participants that completed the first and second Delphi was 69/124 (56%) and 110/162 (68%). From the first Delphi we obtained a list of 92 variables, of which 62 were selected in the second Delphi. Variables reaching the top five position of the rank were regular periodicity, aphthous stomatitis, response to corticosteroids, cervical adenitis, and well-being between flares.

CONCLUSION

Our process led to identification of features that were felt to be the most important as candidate classification criteria for PFAPA by a large sample of international rheumatologists. The performance of these items will be tested further in the next phase of the study, through analysis of real patient data.