Evidence for specific tumor cytotoxic antibodies in serum of cervical cancer patients

Abstract

Antibodies against cell surface antigens of cervical carcinoma were detected using microcytotoxicity and complement fixation tests. The cytotoxic reaction was dependent on rabbit complement. CX1B, a cervical epidermoid carcinoma strain growing in our laboratory was employed exclusively in these tests. We define specific destruction of cells when less than 40 per cent of the cells remain viable after a four hour exposure to antibody and complement; cytotoxicity under these circumstances can be related to cervical carcinoma-related antibodies. Nonspecific destruction as high as 20 per cent was routinely observed as test background. The evidence for antibodies specific to cervical carcinoma is based on: (a) the serum of cervical carcinoma patients which produced specific destruction of the malignant CX1B line did not affect a normal cervix strain; (b) none of the control sera elicited a specific reaction; (c) absorption of specific serum of cervical carcinoma patients by membrane fragments of CX1B reversed the positive result: and (d) three out of four specific cytotoxic sera could be correlated with positive complement fixaton test. Correlation with clinical data revealed higher titers of tumor related antibodies in Stage I which may be interpreted as evidence that circulating antigen-antibody complexes are not common early in this disease.