Atopy in children with systemic onset juvenile idiopathic arthritis (SoJIA) is associated with a worse outcome.

CONTEXT

Atopy and systemic onset juvenile idiopathic arthritis (SoJIA) are two potential outcomes of a dysregulated immune system. Although rare, SoJIA causes 60% of the morbidity of JIA patients which exhibit a wide heterogeneity of prognosis and treatment. Co-morbidities can complicate the responses to therapy.

OBJECTIVE

To study the influence of co-existing atopy on the prognosis of SoJIA.

MATERIALS AND METHODS

Patients diagnosed with SoJIA between Jan 2006 and Sep 2010 were screened, enrolled in this prospective cohort study, and followed for 2 years. Management of SoJIA patients was assessed by ACR Pedi30/50/70 criteria, laboratory variables, and systemic feature score.

RESULTS

At disease onset, 61 SoJIA patients (34 male and 27 female) were enrolled and were divided into SoJIA patients with atopy (n = 27) or those without atopy (n = 34). Atopic group at disease onset had significantly higher numbers of affected joints, ferritin levels and IgE serum levels than the non-atopic group. At 3 and 6 months, fewer SoJIA patients with atopy reached the ACR Pedi50 criteria (p < 0.02). During the 2 years of follow-up time, the number of infections and the number of flares were significantly higher in the SoJIA with atopy group (p < 0.01).

CONCLUSION

Atopy may exert an adverse influence on SoJIA, as patients with atopy had a more active disease at diagnosis and poorer outcome. This prospective study showed that the TH1/TH2 hypothesis was too simplistic to explain the interaction between atopy and SoJIA.