Fc receptor function and circulating immune complexes in gluten sensitive enteropathy - Possible significance of serum IgA

Abstract

The capacity to clear IgG containing immune complexes from the circulation was studied in patients with coeliac disease (n=13), dermatitis herpetiformis (n=8), and coeliac disease with concomitant serum IgA deficiency (n=4). A smali group of patients with active ulcerative colitis (n=4) was included as a bowel disease control group. Clearance was estimated by measuring the disappearance rate of a bolus dose of intravenously injected IgG coated autologous erythrocytes. The mean T1/2 of clearance was prolonged in both celiac disease (86 (24) minutes) and dermatitis herpetiformis (111 (35) minutes), compared with healthy subjects (20 (5) minutes) and coeliac patients with concomitant segum IgA deficiency (Tl/2=17 (6) minutes). Patients with ulcerative colitis had a prolonged clearance, with a T]u2 of 195 (63) minutes. Values of circulating immune complexes were measured by four assays; Clq binding and C3, IgG, and IgA containing immune complexes. Clq binding immune complexes were detected only in IgA deficient gluten sensitive enteropathy. Patients with coeliac disease and dermatitis herpetiformis had higher values of C3, IgG, and IgA containing immune complexes than control subjects and serum IgA deficient patients with coeliac disease. The clearance rate was inversely correlated to the amount of immune complexes for the subgroups of gluten sensitive enteropathy.