A case of juvenile idiopathic polyarticular arthritis complicated by IgA deficiency in 22q11 deletion syndrome.

Chronic arthritis may occur in association with antibody deficiency and chromosomal aberrations. This report presents the case of a 6-year-old girl with chromosome 22q11 deletion syndrome and chronic arthritis. The onset of arthritis occurred at 4 years of age. The chronic arthritis course has been the polyarticular type. Neither antinuclear antibody nor rheumatoid factor was detected. Serum IgA was extremely low. She was diagnosed with juvenile idiopathic polyarticular arthritis (JIA) complicated by IgA deficiency in the 22q11 deletion syndrome. There is an increased prevalence of chronic arthritis in association with 22q11 deletion syndrome with IgA deficiency, but the reasons for this association are unknown. This study evaluated the possible correlation between cytokines and the susceptibility to chronic arthritis in the 22q11 deletion syndrome with IgA deficiency. The expression of pro-inflammatory cytokines such as IL-8, IL-6, MIP-1β, and MCP-1 suggests that T and B cells, macrophages and neutrophils modulate joint inflammation by an immune response. And the presence of IL-10 and IL-5 might suggest that the synovitis is associated with JIA and IgA deficiency.