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.

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

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

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

Inflammatory Cytokines, Endothelial Function, and Chronic Allograft Vasculopathy in Children: An Investigation of the Donor and Recipient Vasculature After Heart Transplantation

Chronic allograft vasculopathy (CAV) limits the lifespan of pediatric heart transplant recipients. We investigated blood markers of inflammation, endothelial dysfunction, and damage to both the native and transplanted vasculature in children after heart transplantation. Serum samples were taken from pediatric heart transplant recipients for markers of inflammation and endothelial activation. The systemic vasculature was investigated using brachial artery flow-mediated dilatation and carotid artery intima-medial hyperplasia. CAV was investigated using intravascular ultrasound. Mean intima-media thickness (mIMT) > 0.5 mm was used to define significant CAV. Forty-eight children (25 male) aged 8-18 years were enrolled in the study. Patients were a median (interquartile range) 4.1 (2.2-8.7) years after transplant. Patients had increased levels of circulating IL6 (3.86 [2.84-4.95] vs. 1.66 [1.22-2.63] p < 0.0001), vascular cell adhesion molecule 1 (539 [451-621] vs. 402 [342-487] p < 0.001), intracellular adhesion molecule 1 305 (247-346) vs. 256 (224-294) p = 0.002 and thrombomodulin (7.1 [5.5-8.1] vs. 3.57 [3.03-4.71] p < 0.0001) and decreased levels of tumor necrosis factor-α, E selectin, and P selectin, compared with controls. The systemic vasculature was unaffected. Patients with severe CAV had raised serum von Willebrand factor and decreased serum thrombomodulin. Posttransplant thrombomodulin levels are elevated after transplant but significantly lower in those with mIMT > 0.5 mm. This suggests that subclinical inflammation is present and that natural anticoagulant/thrombomodulin activity is important after transplant.

Contribution of inflammation to the pathology of idiopathic pulmonary arterial hypertension in children

Idiopathic pulmonary arterial hypertension (IPAH) is an incurable disease of multifactorial origin. Inflammation is frequently observed in IPAH, but its role in the pathobiology is unclear. In this study the distribution, nature and number of inflammatory cells in periarterial infiltrates in lungs of children with IPAH, pulmonary arterial hypertension associated with congenital heart disease (APAH) and in normal lung tissue were characterised and compared using immunohistochemistry The influence of treatment with combined prostacyclin and endothelin receptor blockers was also studied. In children with IPAH, both treated and untreated, but not in children with APAH or normal children, extensive periarterial infiltrates were present comprising macrophages and T lymphocytes with S100A4- and bone morphogenetic protein receptor type-2 (BMPR2)-positive cells. Although rarely co-expressing macrophage-specific antigens, BMPR2-positive cells were frequently closely associated with macrophages and lymphocytes. They were more abundant around peripheral arteries of children with IPAH than in APAH or normal lungs (15.1 (3.5), 2.3 (0.9) and 2.3 (0.9) cells/mm external elastic lamina, respectively; p<0.01 for IPAH vs APAH or normal lungs). Prostacyclin with endothelin receptor blockade resulted in a significant reduction in endothelial cell activation as indicated by human leucocyte antigen (HLA)-DR expression (treated 17% vs untreated 100%, p<0.002). This study shows that pulmonary inflammation is present in the lungs of children with IPAH. This may indicate a role for inflammation in the pathobiology of IPAH and provide the rationale for novel therapeutic intervention.

Occult T3 toxicosis in McCune-Albright syndrome

We report a girl with McCune-Albright syndrome who presented with Cushing syndrome from adrenal hypersecretion and gonadotrophin-independent precocious puberty in the first year of life. At age 5, she failed to gain weight and was found to have hyperthyroidism, which was occult in that she had T3 toxicosis without a goitre or thyroid ultrasound abnormality. The latter has not been previously reported in McCune-Albright syndrome.