future investigations must address the types of antigens and antibodies present in the circulating immune complexes , the detection of specific antigen in cutaneous blood vessels , the reproduction of lesions in experimental animals , and the mechanisms responsible for the spectrum of clinicopathologic lesions produced , with special attention to the possibility that vessel damage results from circulating immune complex-induced lymphocytic rather than only leukocytoclastic vasculitis .
C0003241
antibodies
C0003313
immune