[Detection of an antigen containing 3-hydroxyanthranilic acid in the sera of patients with tumors of different localizations].

An unusual antigen containing a carcinogenic tryptophane metabolite -- 3-hydroxyanthranylic acid as a hapten (3-HAA-antigen) was found to be present in the blood serum in the overwhelming majority of patients with malignant tumours of various stages and localizations. The 3-HAA-antigen was rarely determined in the patients with nonmalignant diseases was not revealed in the blood serum of healthy donors and patients with benign tumours. The significance of the data obtained for the diagnosis of the tumour process, irrespective of its localization, is discussed.