Immunohistochemical reactivity of monoclonal antibodies to human milk fat globule with breast carcinoma and with other normal and neoplastic tissues.

The immunohistochemical reactivity of three monoclonal antibodies, generated against human milk fat globule membranes (HMFG), were studied using peroxidase conjugated secondary antibody or avidin-biotin-peroxidase complex method. Two of the antibodies, III E 8 and III H 2 showed rather broad reactivity, staining all mammary, ovarian, endometrial, cervical and bronchial adenocarcinomas. They also stained all pancreatic adenocarcinomas but only 30% of the carcinomas of the colon. Reaction with prostatic and renal adenocarcinomas varied. No reaction was seen with squamous or transitional cell carcinomas. Antibody III D 5, which previously has been shown to recognize an estrogen receptor activation associated antigen in mammary carcinomas, stained 60% of mammary or gynecological adenocarcinomas. This antibody had a more limited reactivity with other tissues as well, as all intestinal carcinomas were negative. It stained all bronchial adenocarcinomas, however, and 50% of the prostatic carcinomas. The three monoclonal antibodies, although not specific, show a more restricted reactivity than the so far described HMFG antibodies and they may therefore be of value in histopathological diagnosis.