1019 AUTOIMMUNITY TO ARTICULAR ANTIGENS IN JUVENILE ARTHRITIS

Abstract

We studied 103 JA children, 46 controls and 25 patients with osteoarticular syndromes (OAS) to determine if differences in immune reactivity characterized different onsets or outcomes. We measured cell-mediated immunity (CMI) to human collagen, proteoglycan monomer (PM) and link protein (LP). Production of leukocyte inhibitory factor by mononuclear leukocytes was assayed and correlated with HLA type. Antibodies to native type II collagen were measured in an enzyme-linked immunosorbent assay. Results were analyzed using Fisher's Exact Test. JA patients were less reactive to ConA than controls, yet were more reactive to collagen I, II and PM. JA patients did not differ from OAS patients, CMI did not correlate with onset, course, out come, ANA, RF or HLA type. Collagen antibodies were found in 23/86 JA, 1/20 OAS, and 0/31 controls (p<0.01). These antibodies, confirmed by absorption studies, distinguished erosive disease from other JA (p<0.001). CMI to articular antigens may be of pathogenetic importance in JA, but in vitro reactivity does not predict risks or complications. The presence of antibodies to native type II collagen may be of greater importance in signaling poor outcome in JA.