CIRCULATING IMMUNE-COMPLEXES IN ACTIVE BEHCETS DISEASE

Abstract

Levels of immune complexes (IC) were determined by the Raji [human Burkitt''s lymphoma] cell and C1q[fragment of complement component 1]-binding radioimmunoassays in the sera of 18 patients with Behcet''s disease. Eight patients (44%) had significantly elevated levels of IC (range 56-1600 .mu.g equivalent aliquots of heat aggregated Ig[immunoglobulin]G [AHG]/ml) by the former test and 9 by the latter (7-500 .mu.g equivalent AHG/ml). The presence of IC showed a significant correlation with disease activity score (P = 0.003, Mann-Whitney Rank Sum Test). Abnormal values of IC tended to remain abnormal when sera were retested after 1 yr. There was no correlation between IC and duration of disease or any specific organ involvement. The IC were found predominantly in fractions of about 19S and greater when fractionated by sucrose density gradient or Sephadex column techniques. IC may contribute to the pathophysiology of Behcet''s disease.