Circulating antibodies in human connective tissue malignancy.

In a comparative study, sera from patients with connective tissue tumours, various carcinomata and from individuals without malignancy were evaluated by indirect immunofluorescence (IF) for antibodies reactive with apparently specific antigens shared by sarcoma derived tissue culture cell lines; for antibodies by IF to 2 tissue autoantigens (nuclear antigen and smooth muscle antigen) on rat liver substrate; and for HL-A antibodies by microcytotoxicity against a panel of 22 lymphocytes. Antibodies reactive with 11/16 cell lines originating from sarcomata were detected in 36% of all sarcoma sera tested, 12% carcinoma sera and 9% sera from controls. The incidence of antisarcoma antibody (ASA) was higher in the sera of sarcoma patients whose disease was in the primary phase (53%) compared with those in whom disease was advanced. A lower incidence (8%) of antibodies to nuclear antigen was detected in the sera of sarcoma patients compared with carcinoma patients (22%) and controls (23%), but the incidence of smooth muscle antibodies (SMA) was higher (45%) compared with carcinomata and controls (36% and 35% respectively). HL-A antibodies were present in 13% sarcoma sera, 36% carcinoma sera and 33% control sera. Evidence is presented to show that the various antibodies are distinct and that those reacting with sarcoma derived cell lines may be tumour associated antibodies possibly related to a virus specified antigen.