Tissue polypeptide antigen (TPA), some cytokeratins and epithelial membrane antigen (EMA) in normal, inflamed and malignant urothelium.

The distribution of tissue polypeptide antigen (TPA), epithelial membrane antigen (EMA) and various cytokeratins was studied with immunohistochemical techniques in malignant, normal and inflamed urothelium. TPA and cytokeratins 8, 18 and 19 were similarly distributed and there was no difference between benign and malignant conditions. All keratins were most abundant in the outer cell layers of the urothelium. EMA was present primarily in the so called umbrella cells. Increased levels of TPA in urine and serum are found in patients with urothelial carcinoma. TPA is reported to be related to the cytoskeletal keratins and its presence definitely does not imply malignant transformation as we have demonstrated it in both benign and malignant urothelium. The increased levels of TPA in urine and serum are probably due to a more rapid turnover and autolysis of cells and may parallel a more aggressive tumor behaviour.