Ber-EP4, an anti-EpCAM antibody, detects epithelial glycoproteins of 34 and 39 kDa on the cell membrane surface and in the cytoplasm of epithelial cells. Ber-EP4 labels epithelial tissues but does not label mesothelial cells (1). Ber-EP4 can assist in differentiating epithelial pleural mesotheliomas from adenocarcinomas (1,2). One study observed 100% reactivity for lung adenocarcinomas with Ber-EP4 (2). In another study, Ber-EP4 appears to stain all adenocarcinomas except breast and kidney (1).
BG8 (Blood Group Lewis Y) [F3] detects the Lewis Y antigen. One study showed that BG8 was negative for almost all epithelial malignant mesotheliomas (91% sensitivity) (3). When trying to distinguish epithelioid mesothelioma from adenocarcinoma, BG8 appears to be very sensitive for breast carcinoma (96%) (4). A panel of Ber-EP4, BG8 and MOC-31 stained 100% of lung carcinomas (4). Studies have shown that specificity of BG8 and Ber-EP4 for adenocarcinoma was 98% and 95%, respectively (4).
A cocktail of Ber-EP4 and BG8 may be a useful tool to distinguish adenocarcinoma from mesothelioma.