IMMUNOCYTOLOGICAL ANALYSIS OF THE TN ASSOCIATED ANTIGEN 83D(4) IN SEROUS EFFUSIONS FROM PATIENTS WITH CANCER - COMPARISON WITH TN SOLUBLE GLYCOPROTEIN

Aims-To determine whether the monoclonal antibody (MoAb) 83D(4), previ ously shown to be highly specific for carcinoma cells, can be used as an immunocytological marker to discriminate between benign and maligna nt cells in serous effusions; and to test for a correlation between ex pression of the antigen reacting with MoAb 83D(4) on effusion cells an d the amount of soluble 83D(4) antigen in effusion fluids. Methods-Thi rty three pleural and 23 peritoneal effusions from 56 cancer patients with metastatic disease were tested for the presence of Tn associated 83D(4) antigen by immunocytochemical staining, and for the presence of soluble antigen in supernatants. The patients had undergone various c hemotherapy and radiation therapy protocols. Results-As a result of th e various types of treatment, the cytological characteristics of the c ells were often modified and the antigenic epitopes may have been alte red. Positive staining for 83D(4) MoAb was obtained in 36 (97%) of the 37 malignant effusions, eight (73%) of 11 suspect effusions, and thre e (38%) of the eight apparently benign effusions (free of malignant ce lls). In these latter cases, cytological reassessment showed a few sus pect cells in two cases. 83D(4) soluble antigen was detected in 30 of 37 malignant effusions (81%), five of 11 suspect infusions (46%), and five of eight apparently benign effusions (63%). Conclusions-Immunocyt ochemical staining with anti-83D(4) antibody is useful for differentia ting reactive or atypical mesothelial cells from epithelial cells, esp ecially in breast cancer effusions.