Serum and ascitic fluid protein electrophoresis and immunoglobulin levels in gynecologic cancer

Clinical evaluation of radioimmunoimaging with 131I-C0C183B2 monoclonal antibody against ovarian carcinoma by intraperitoneal injection

Forty-eight cases subjected to radioimmunoimaging (RII) by intraperitoneal injection with 131I-C0C183B2 monoclonal antibody (MAb) prepared in our laboratory were studied. Thirteen of 14 cases of proved primary ovarian carcinoma were positive. In 11 follow-up cases of ovarian carcinoma after initial surgery and chemotherapy, 5 recurrences were positive and 6 cases without recurrence were negative; all were confirmed histopathologically after a second operation. One false negative was ovarian mucinous adenocarcinoma, which also negatively stained with C0C183B2 by the peroxidase anti-peroxidase method. Twenty of 23 cases of nonepithelial or metastatic carcinoma of the ovary, benign tumors, and benign diseases were negative. The sensitivity and specificity were 94.7 and 89.7%, respectively. If patients had complications with ascites, the MAb which positively stained with the cancer cells in the ascites was chosen for RII. For follow-up cases PAP staining with the tumor tissue from the initial surgery and the MAb should be done before RII. These are the principal factors that increase the positive rate and accuracy of RII. The intraperitoneal route seems to be a valuable method for clinical staging and tumor localization as well as for follow-up use.

The study of antibodies and antigens dissociated from the immune complexes extracted from ovarian carcinoma ascitic fluid

In previous studies in our laboratory, heteroantisera were produced in rabbits by immunization with extracts of ascitic fluids from ovarian epithelial carcinomas. Reverse passive hemagglutination (RPHA) assay of these sera was used for the immunodiagnosis of ovarian cancer. Antibodies attached to lysed sheep red blood cells were able to detect tumor antigens in 63% of ovarian carcinoma sera. In the present study we have shown that the antigens detected in these assays are in fact contained in circulating immune complexes and are recoverable by disassociation with 8 M urea and separation of antibody and antigen by ion exchange chromatography. The antibodies thus obtained from immune complexes (IC) were assayed by indirect immunofluorescence against a variety of paraffin-embedded tissue sections. Poorly differentiated ovarian epithelial carcinomas and papillary serous adenocarcinomas, as well as the tumors grown by implantation of the latter in nude mice, were all positively stained, while the Krukenberg tumor metastatic to the ovary, the benign ovarian cyst, the normal ovary, and the normal fallopian tube were all negative. Complete blocking of immunofluorescence staining by prior absorption of antibody with the dissociated antigen was achieved. The present study demonstrates that the antibodies and antigens dissociated from the immune complexes isolated from the ascitic fluids provide useful reagents for immunodiagnosis.