[Antigenic determinants within immune complexes: similar and heterogeneous distribution in cutaneous vasculitis...

Twenty-one patients with various cutaneous vasculitis (8 with leukocytoclastic lesions, 5 with lymphocytic infiltration, 4 with anaphylactoid purpura, 2 with essential mixed cryoglobulinemia and 2 other cases) were studied for the presence and the characterization of circulating immune comlexes. Thirteen patients had circulating immune complexes evidenced by 2 p. 100 polyethylene glycol precipitation. A solid phase cross reaction applied to isolated complexes showed common antigenic determinants and/or antibody specificity in patients with different histopathological and clinical features. On the other hand, patients suffering from identical vasculitis possessed different determinants in their immune complexes. These findings are interpreted to indicate that the distribution of the complexed antigens does not square with a clinical classification.