[GC12, marker of cells of mesodermal origin. Value and application to cytodiagnosis of serous effusions].

Monoclonal antibody GC12 was examined for its value in cytopathologic diagnosis. Its sensitivity and specificity in staining reactive mesothelial cells in serous effusions was determined using the indirect immuno alkaline phosphatase anti-alkaline phosphatase technique. Smears prepared from 78 serous effusions (15 benign, 54 malignant, 9 atypical) were immunostained with GC12 and five other monoclonal antibodies: KL1 directed against cytokeratins, D33 against desmin, E29 against epithelial membrane antigen, Calam 27 against epithelial surface antigen and NEO 723 reactive with carcinoembryonic antigen.