AB0965\u2005PAEDIATRIC SARCOIDOSIS: A PROFESSIONAL IMITATOR

Abstract

Background Sterile granulomatous inflammation is a hallmark of disorders covered by the term “paediatric sarcoidosis”, a rare disease classified among autoinflammatory conditions. While the classical triad of arthritis, uveitis and dermatitis associated with the NOD2 gene mutation is typical for Early-onset sarcoidosis (EOS), mutation-negative disease has extremely variable phenotype in children and can mimic various other conditions. Objectives To illustrate variability of clinical presentation of sarcoidosis in a cohort of children from 2 collaborating paediatric rheumatology units Methods Retrospective case analysis. Results Seven Caucasian patients (2 boys) followed for a median of 1 (0.2-12) year were identified (Table). Patients 1 and 3 presented with typical rash (with biopsy-proven granuloma), polyarthritis and severe, treatment-resistant uveitis which has never been fully controlled. Patient 2 presented with recurrent self-limited febrile episodes and was investigated for periodic fever syndrome. Within 3 months she developed erythema nodosum-like rash, granulomatous uveitis and arthritis. In 4 patients with disease onset after 10 years of age two major organ systems were affected: renal and gastrointestinal (GIT). In patients 4 and 5 renal biopsy performed for insufficiency showed tubulointerstitial nephritis with granulomas. Patients 6 and 7 had been initially treated for “atypical inflammatory bowel disease” with granulomas on biopsy. In both of them finding of granulomatous uveitis eventually lead to the diagnosis of sarcoidosis. Additional symptoms are listed in the Table. Presence of granulomatous inflammation was confirmed in all patients. Chronic uveitis was present in 6/7 patients and was an important diagnostic clue in EOS as well as adult-type of sarcoidosis while respiratory tract was affected subclinically in 2 older patients only. Apart from combinations of clinical symptoms elevation of chitotriosidase significantly aided diagnostic process and when available, it also reflected disease activity. (1) Pt – patient, F – female, M – male, Dx – diagnosis, CS – corticosteroids, MTX – Methotrexate, ADA – Adalimumab, MMF – Mycophenolate mophetil Pt Sex Age (yrs) at Onset/Dx NOD2 gene mutation Manifestations ChitotriosidaseN 4.4-89 nmol/ml/h Therapy 1 F 0,25/4 R334Q Rash, fever, uveitis, arthritis, meningitis 299 MTX, MMF, ADA, 2 F 0,6/1 Negative Rash, fever, uveitis, arthritis, panniculitis 433 MTX, ADA, CS 3 F 1/3 Variants S178S, V955I, N289S Rash, fever, panuveitis, arthritis, liver granuloma N/A CS,MTX,ADA,Infliximab 4 M 4/15 Pending Fever,arthralgia, lymphadenopathy, granulomatous nephritis N/A CS, MMF 5 F 13/13 Negative Uveitis, granulomatous nephritis, hearing loss 604 CS, MTX, ADA 6 M 6/15 Negative Uveitis, granulomatous colitis, pneumonitis, splenomegaly 512 MTX 7 F 10/10 Pending Uveitis, granulomatous gastroenterocolitis and bronchitis N/A CS, ADA Conclusion Manifestations of sarcoidosis vary significantly across the paediatric age spectrum. While EOS is a known juvenile idiopathic arthritis mimic, nephritis and GIT inflammation may lead to a non-rheumatologic misdiagnosis. Apart from specific infections other childhood diseases may also present with granuloma formation: Crohn’s disease, chronic granulomatous disease (and other primary immunodeficiencies), granulomatosis with polyangiitis. Our small series reflects disease heterogeneity and diagnostic difficulties that prolonged the diagnosis by years in 4/7 patients. References [1] Popevic S. et al. Verifying Sarcoidosis Activity: Chitotriosidase versus ACE in Sarcoidosis – A Case-control Study. J Med Biochem. 2016 Nov 2;35(4):390-400 Disclosure of Interests None declared