Practical Approach to Diagnosis and Management of IL-1-Mediated Autoinflammatory Diseases (CAPS, TRAPS, MKD, and DIRA)

Systemic autoinflammatory diseases (SAIDs) are a group of rare genetic and nongenetic immune dysregulatory disorders associated with high morbidity and mortality if left untreated. Therefore, early diagnosis and initiation of targeted treatment is vital in SAID patients to control the disease activity and prevent long-term immune-mediated damage. A specific group of genetically defined SAIDs is associated with increased inflammasome-mediated production of active interleukin (IL)-1. Even though progress in immunobiology and genetics has brought forth diagnostic tools and novel treatments that have been described in the literature extensively, many challenges remain in the clinical setting. Some challenges that health care providers may face on a day-to-day basis include the requirement of a multidisciplinary approach due to the complexity of these diseases, limited evidence-based treatment options, and barriers to access available therapies. Primarily, IL-1 inhibitors anakinra, canakinumab, and rilonacept are used to control the inflammation in these patients, with the goal of achieving sustainable remission. Recently published provisional points to consider from the European Alliance of Associations for Rheumatology (EULAR) and American College of Rheumatology (ACR) provide diagnosis, management, and monitoring recommendations for four IL-1-mediated autoinflammatory diseases: cryopyrin-associated periodic syndromes (CAPS), tumour necrosis factor receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), and deficiency of the IL-1 receptor antagonist (DIRA). The goal of this paper is to aid health care professionals by providing a practical approach to diagnosis and management of these four IL-1 mediated SAIDs on the basis of the recent EULAR/ACR recommendations.

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.

Paediatric Behçet’s Disease: A Comprehensive Review with an Emphasis on Monogenic Mimics

Behçet’s disease (BD) is a polygenic condition with a complex immunopathogenetic background and challenging diagnostic and therapeutic concepts. Advances in genomic medicine have provided intriguing insights into disease pathogenesis over the last decade, especially into monogenic mimics of BD. Although a rare condition, paediatric BD should be considered an important differential diagnosis, especially in cases with similar phenotypes. Emerging reports of monogenic mimics have indicated the importance of genetic testing, particularly for those with early-onset, atypical features and familial aggregation. Treatment options ought to be evaluated in a multidisciplinary setting, given the complexity and diverse organ involvement. Owing to the rarity of the condition, there is a paucity of paediatric trials; thus, international collaboration is warranted to provide consensus recommendations for the management of children and young people. Herein, we summarise the current knowledge of the clinical presentation, immunopathogenetic associations and disease mechanisms in patients with paediatric BD and BD-related phenotypes, with particular emphasis on recently identified monogenic mimics.

Hereditary Systemic Autoinflammatory Diseases: Therapeutic Stratification

Hereditary systemic autoinflammatory diseases (SAIDs) are rare, often severe conditions characterised by mutations in the key regulators of innate immune responses. Dramatic advances in the molecular genetics and next-generation sequencing in the past decade enabled identification of novel mutations that play a pivotal role in the mechanistic pathways of inflammation. Although genetic testing may not always provide straightforward guidance in diagnosis and clinical decision making, through translational research, it sheds light into molecular immunopathogenesis, particularly in IL-1 inflammasome and cytokine signalling pathways. These remarkable insights provided a better understanding of autoinflammatory conditions and their association with the innate and adaptive immune systems, as well as leading to development of cytokine-targetted biologic treatments. Use of targetted therapeutics not only helps control disease flares, reduce acute-phase responses and prevent devastating complications such as amyloidosis, but also improves health-related quality of lives and support patients to pursue almost a normal life. Herein, we discuss the commonest monogenic SAIDs, describe their immunopathology, and summarise the approaches in the management and targetted treatment of these conditions, including presentation of novel data based on a cohort of children with these rare diseases from a single quaternary referral centre in London.

Treatment of Calcinosis in Juvenile Dermatomyositis

PURPOSE OF REVIEW

Juvenile dermatomyositis (JDM) is a rare autoimmune disease characterised by muscle and skin involvement. Calcinosis is a debilitating complication of JDM which is difficult to treat and may cause long-term morbidity. The purpose of this review is to provide an update for the treatment of JDM-associated calcinosis based on previously published studies.

RECENT FINDINGS

Evidence-based studies are lacking for the management of calcinosis, and current treatment modalities have been largely based on case reports, case series, cohort studies, limited controlled studies and anecdotal clinical experience. The use of early aggressive therapy for resistant cases is strongly suggested to halt persistent disease activity which may help in reducing steroid use and their associated complications. Recent insights into disease pathogenesis, myositis-specific antibodies and genetic associations have led to identification of novel therapeutic targets such as Janus kinase (JAK) 1/2. Different treatment regimens with variable outcomes are in use for the treatment of refractory calcinosis; nevertheless, the level of evidence is not sufficient to propose specific guidelines. Recently, JAK 1/2 inhibitors have shown to be effective as an emerging therapeutic option highlighting that translational and clinical research is crucial to develop targeted treatment for JDM-associated calcinosis.

P43 Immunoglobulin G4-related disease in a 10 year-old girl with multisystem involvement

Background

IgG4-related disease (IgG4RD) is an immune-mediated fibroinflammatory condition characterized by the infiltration of IgG4-carrying plasma cells and storiform fibrosis in most of the tissues. The condition is reported to cause multisystem involvement, however salivary gland is the most commonly affected organ with IgG4-related sialadenitis. Raised IgG4 concentrations in the serum and prominent infiltration by plasmacytes expressing IgG4 in the lacrimal and salivary glands have been confirmed.

Methods

We conducted a retrospective case review of a 10 year-old girl who was diagnosed with IgG4-RD at Great Ormond Street Hospital for Children in 2017. Patient’s clinical, laboratory and imaging data was extracted from our database and literature search was done to find out different manifestations of the IgG4-RD in Children.

Results

10 year-old-girl with lacrimal and salivary gland swelling, sicca symptoms and fatigue. Ultrasound scan neck revealed multiple small lymph nodes and enlargement of both submandibular glands (Picture1) Salivary glands also appeared bulky and heterogenous with multiple small hypoechoic focci. Appearances likely to represent sialoadenitis and there was no evidence of malignancy or lymphoma. USS abdomen normal.

Full blood count, routine biochemistry and urine microscopy normal. Autoantibodies came back negative (ANA: Negative, ANCA: Negative, Anti-Ro and Anti-La: Negative, RF:Negative, Thyroid autoantibodies:Negative) IgG level elevated (in repeated samples). IgA, IgM and IgE levels normal. IgG subgroups revealed significantly elevated IgG4 levels (21.49 Normal range: 0-1.1) IgG1, IgG2 and Ig G3 levels elevated as well. Lymphocyte subsets were normal.

The biopsy of salivary gland: Chronic inflammation with IgG4 staining, suggestive of IgG4 related disorder.

Lung function test showed decreased DLCO at 76 %, FEV1 at 82% and FVC at 89% suggestive of interstitial lung involvement. CT Thorax: Multiple abnormalities including moderate lymphadenopathy, renal parenchymal lesions and interstitial lung abnormality. MRI Abdomen: T2 hypointense renal foci, suggestive of infiltration as part of the IgG4 related disease.

Diagnosed with IgG4 related disease. Treatment started with intravenous methylprednisolone followed by Anti-CD20 (Rituximab) therapy and a weaning plan for steroids. Mycophenolate mofetil commenced for the maintenance therapy. Patient has shown good response with clinical and lung function improvement.

Conclusion

IgG4-RD is a rare condition which can cause multisystem involvement with the infiltration of IgG4-bearing plasma cells in the tissues. We wanted to emphasize that this condition could also be seen in the paediatric population. We also wanted to highlight that after further investigations multisystem involvement can be discovered.

Steroids are mainstay of the treatment with Anti-CD20 medication (Rituximab) and steroid sparing agents such as mycophenolate mofetil could be the choice for maintenance therapy. However, further studies need to be done in paediatric age group.

Conflicts of Interest

The authors declare no conflicts of interest.

P24 Can high ANA titre combined with clinical features predict developing autoimmune conditions in children?

Poster presentation Tuesday 8 October

Background

Antinuclear antibodies (ANA) are autoantibodies that recognise cellular antigens found predominantly in the cell nucleus. They are associated with numerous autoimmune diseases such as systemic lupus erythematosus, but may also be found in infectious diseases, malignancies and healthy individuals.

ANA is requested as part of an initial work-up for autoimmune conditions. In healthy children (5-18%), positive ANA titres of 1/80 to 1/320 have been reported. A prospective study of healthy children with positive ANA found that children who developed autoimmune disease had clinical features at presentation that were suspicious for such an outcome. Therefore, the usefulness of a positive ANA result for diagnosing autoimmune conditions is limited without clinical correlation. The aim of our study was to assess whether high ANA titre and clinical features at presentation could predict final diagnosis.

Methods

Single centre retrospective study at Great Ormond Street Hospital for Children (GOSH). The immunology laboratory provided a list of positive ANA results (using indirect immunofluorescence technique) from January 2013 to July 2018. A retrospective chart review was performed to ascertain presence of clinical features at presentation under the five following titles: arthritis, skin involvement, eyes, CNS involvement and Raynaud’s phenomenon. We then reviewed the last clinical contact to document confirmed diagnosis.

Results

We performed a retrospective chart review on 1,354 children (67% female; median age 7.5 years (0.1-17.5); median follow-up 4.8 years (0-18)) with positive ANA results (titres 1/160, 1/320, 1/640, 1/1280, 1/2560 and >1/2560). Table 1 reports ANA titres at first presentation in relation to final diagnosis. A titre of 1/640 or above was most commonly seen (>50%) in children with an autoimmune rheumatology condition. In fact, children with the highest titre (>1:2560) were significantly more likely to be diagnosed with one of these conditions. Finally, we looked at the number of presenting features and correlated with final diagnosis. Those diagnosed with a CTD were most likely to present with 2-5 clinical features (p < 0.0001).

P24 Table 1: Percentage of patients grouped according to their diagnosis and ANA titres Final Diagnoses ANA Titres >1: 2560 1: 2560 1: 1280 1: 640 1: 320 1: 160 Connective Tissue Diseases 24% 9% 13% 16% 16% 22% JIA and Uveitis 8% 11% 15% 22% 22% 22% JIA 6% 8% 13% 24% 24% 25% Autoimmune (other) 4% 5% 11% 19% 32% 29% Unidentified autoimmune/ autoinflammatory 8% 12% - 24% 12% 44% Vasculitis - - 5% 26% 16% 53% Sarcoidosis - 20% - 20% - 60% Autoinflammatory 7% - - 43% - 50% Malignancy - - - 25% - 75% Other 3% 2% 3% 17% 28% 47% Non-inflammatory MSK 3% - 9% 18% 27% 43%

Conclusion

This study suggests that, patients presenting with higher ANA titres and a combination of clinical features should be assessed systemically and followed-up as they may have increased risk of developing an autoimmune rheumatological conditions.

Conflicts of Interest

The authors declare no conflicts of interest.