Blood group antigens in the normal and neoplastic bladder epithelium.

The indirect immunofluorescence technique was used to study the expression of the blood group A and H antigens in fresh-frozen and formalin-fixed paraffin-embedded sections of the bladder mucosa of 21 patients with non-neoplastic diseases of the bladder. Reliable assessment of these antigens could only be made using cryostat sections of fresh-frozen tissues. Also included in this study were tumour tissues of 5 patients with bladder cancer. The blood group A antigen was totally deleted in cryostat sections of the tumour of one patient with aggressive carcinoma and the appropriate antigens were diminished or focally deleted in the four patients with tumours that were non-invasive during one to three years of follow-up. It is concluded that sections of fresh-frozen tissues or sections processed in the absence of glycolipid-extracting solvents should be used for visualising the expression of blood group antigens in bladder tissues and assessing their value as prognosticators of the malignant potential of bladder tumours.