Significance of circulatory immune complexes in thromboangiitis obliterans (Buerger's disease).

Circulatory immune complexes were estimated in the sera of 25 patients and 20 age and sex matched controls by precipitation with 8% polyethylene glycol (PEG). Characterization of the immune complexes, thus obtained, was performed by the double immuno-diffusion method. The mean protein content of the PEG precipitates was significantly higher in the patients of thromboangiitis obliterans than in the controls. The immunoglobulins in the immune complexes were predominantly of mixed type in contrast to mainly single class immunoglobulins in the controls. C3 complement distribution in immune complexes of patients and control sera was 64% and 45% respectively. The immune complexes in patients were found to be biologically active. The mechanism of formation of circulatory immune complexes and their role in the pathogenesis of arteritis in relation to smoking of tobacco has been postulated.