IgA deficiency and autoimmune comorbidities in juvenile idiopathic arthritis

Objectives: (1) To describe the prevalence of IgA deficiency (IgAD), uveitis, coeliac disease (CD) and thyroid disorders in a multicentre cohort of patients with juvenile idiopathic arthritis (JIA), and (2) to assess whether patients with JIA and IgAD have additional autoimmune disorders more frequently than patients with JIA and normal serum levels of IgA. Methods: Retrospective chart review of a cohort of patients with JIA managed in the paediatric rheumatology units of 2 hospitals in Madrid, Spain. Results: This study included 193 patients, 123 (64%) female. The median age at disease onset was 5.6 years (IQR 2.5-9.7) and the median duration of followup was 5.1 years (IQR 2.2-8.1). The 3 most common categories of JIA based on the ILAR classification were oligoarticular (53%), poliartritis RF-negative (20%) and enthesitis-related arthritis (10%). Serum IgA levels were available in 172/193 (89%); 25/172 (15%) had selective (<7 mg/dl, n=8) or partial (7-69 mg/dl, n=17) IgAD. All patients underwent periodic ophthalmic examinations. Eighteen children (9%) had anterior uveitis, which was chronic in 15 and acute in 3. Serum levels of anti-transglutaminase IgA, or IgG in IgAD were obtained in 135/193 (70%). Four children (3%) were diagnosed with CD either by intestinal biopsy (n=3) or by the combination of characteristic clinical, serological and genetic features (n=1); 2 of them had IgAD (OR = 6.4; 95% CI, 0.9-47.6; p=.12). Only 1 of these 153 patients (0.7%) had hyperthyrotropinaemia with positive anti-thyroid antibodies and required replacement therapy. Conclusion: Patients with JIA frequently present autoimmune comorbidities. IgAD does not seem to increase their prevalence, with the possible exception of CD. (C) 2022 Asociacion Espanola de Pediatria. Published by Elsevier Espana, S.L.U.

Automated summary

Patients with juvenile idiopathic arthritis (JIA) frequently have autoimmune comorbidities. IgA deficiency (IgAD) does not appear to increase the prevalence of autoimmune disorders, except possibly in the case of coeliac disease (CD).