Synthesis of ABH blood group substances in bladder tumours.

A specific red cell adherence test which can detect the cell surface ABH blood group antigens was performed on formalin-fixed frozen sections of 38 bladder tumours. In 27 tumours decreased glycosyltransferase activity was suggested, but the site and the degree of the blockade did not seem to be identical in every tumour. Blood group A and B tumours could be grouped into 4 types according to the presence of these 3 isoantigens. One group which showed A or B but no H activity (Type I) consisted only of grade 1, superficial tumours. All of the invasive tumours belonged to other types. For blood group O tumours no clear-cut correlation could be found between malignancy of the tumour and the presence of H activity. Eight of 22 grade 2 or 3 tumours and 9 of 21 invasive tumours retained the isoantigen, which seemed to invalidate the use of this test as a predictive indicator. Only where blood group A or B patients were concerned, and the presence of H activity was regarded as abnormal as well as the absence of A and B, could all grade 2 or 3 tumours and all invasive tumours be detected by this test.