Visualization of a protein involved in seric immune complexes of patients with epithelial tumors having elevated levels of anti-'benzo[a]pyrene-like' IgA.

Many authors have previously described that several types of human cancer were associated with elevated levels of IgA and IgA-containing immune complexes. We have recently identified and characterized IgA directed against a "benzo[a]pyrene-like' antigen in sera of patients with mammary tumors. Circulating immune complexes from these sera were precipitated and analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A 18-20-kDa protein was found closely associated with high levels of anti-'benzo[a]pyrene-like' IgA in sera of patients having a proliferative pathology.