Identification of antigenic components recognized by "membrane-bound" antibodies from ovarian cancer patients.

Immunoglobulins, eluted from ascites fluid-derived membrane fragments, were used to identify antigens with which they react from ovarian cancer patients. These immunoglobulin preparations were demonstrated to bind antigens from ovarian tumors, but not from normal ovaries. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to identify the components responsible for the reactivity. The different patients' immunoglobulin preparations were reactive with a similar group of antigens; however, the level of response to each individual component varies. In previous studies, the acid-eluted immunoglobulin was shown to be reactive with tissues other than ovarian tumors. Relating this cross-reactivity with the antigens found in ovarian tumors, we found that some components were found only in ovarian tumors, and others appear to be shared by gynecologic tumors, in general. Of these antigens, most are apparently placental antigens. Two proteins were found in normal ovaries.