Detection of blood group antigens in frozen sections of prostatic epithelium

The detection of blood group antigens (BGA) in non-malignant prostates by previous workers has been at best inconsistent. BGA have not before been detected in prostatic carcinomas. In this preliminary study, a variety of anti-BGA reagents, with known specificities that involve the carbohydrate backbone in addition to the BGA specific terminal monosaccharides, were used to study the expression of the A and H (O) BGA in cryostat sections of 16 patients with benign prostatic disease and nine with prostatic cancer. Positive staining, appropriate to the patients' blood group, was seen in all of the benign tissues when anti-BGA reagents that included specificity against type 2 backbone structures were used. Staining was absent, however, if the reagent had only type 1 specificity. The anti-A and anti-H (O) reagents which gave the best staining patterns in benign tissues were used in malignant tissues. No cancer was found to express A antigen but eight of the nine prostatic cancers were positive for the H (O) antigen irrespective of blood group. Using fresh frozen material and appropriate reagents, BGA may be reproducibly detected in the epithelium of all non-malignant prostates, suggesting that a significant component of BGA is probably lipid-based on type 2 carbohydrate backbone chains. Further studies of changes in BGA expression in prostatic cancer are warranted.