COMPLEMENT ACTIVATION AND IMMUNE-COMPLEXES IN CHILDREN WITH POLYARTICULAR JUVENILE RHEUMATOID-ARTHRITIS - A LONGITUDINAL-STUDY

Objective. To determine whether levels of either circulating immune co mplexes (IC) or complement activation fragments change as disease acti vity changes in children with polyarticular juvenile rheumatoid arthri tis (JRA). Methods. Twenty-six children with polyarticular JRA were ex amined over a time course of 4-21 months. Plasma complement activation fragments and IC were measured by commercially available enzyme linke d immunoabsorbant assays. Results. Both complement activation fragment s and IC levels were lower in individual children when their articular disease was inactive. Children with persistently active disease had n o change in any of these measures. Conclusion. Elevated levels of plas ma IC and complement activation fragments are features of active polya rticular JRA. We believe our data support a role for the complement sy stem in the pathophysiology of polyarticular JRA.