Loss of isoantigens A, B and H in prostate.

Formalin-fixed tissues from 65 prostates were grouped and investigated by the technic of mixed cell agglutination reaction (MCAR) for studying isoantigens A, B and H. The results of this study indicated that the MCAR was strongly positive at the epithelium of the acini in the majority of patients with benign prostatic hyperplasia. On the other hand, patients with primary carcinomas and metastatic carcinomas of prostates were found to be uniformly negative for any agglutination reaction. Prostates from a group of younger individuals only showed a patchy distribution of the MCAR at the epithelium of the acini. In view of these findings, it seemed that the traces of isoantigens in normal prostates show a considerable increase when the disease process of BPH becomes manifest in this organ, while in cases of primary and metastatic carcinomas the isoantigens are totally lost. In the light of previous studies on similar lines, the various possible mechanisms for this sudden transition are discussed.