Anomalous tumour marker concentrations in renal transplant patients

Serial serum determinations of the tumour associated antigens carcinoembryonic antigen, tissue polypeptide antigen, CA 19-9, CA 15-3 and CA 125 were performed on 70 patients who were undergoing, or had undergone renal transplantation. The period of observation ranged from 4 days pre-operative to 708 days post-operative, although daily monitoring was usually carried out during the first 14-35 days post-operatively. With the exception of tissue polypeptide antigen, which was analysed with an immunoluminometric assay, all analytes were measured with the Enzymun-Test System ES-300 using immunoenzymometric assays with colorimetric determination. The interassay coefficients of variation were less than 5% for the immunoenzymometric assays and 8.7% for tissue polypeptide antigen, all values being derived from 20 consecutive assays. Only 8/70 patients with no complications showed normal concentrations for all five analytes. 6/79 patients showed parallel changes of at least three markers. 7/70 patients had transient elevations of at least one marker, whereas 25/70 patients had a continual elevation of CA 125, 9/70 CA 19-9 and 1/70 CA 15-3, although no patient showed evidence of disease. Two patients, each with 2 rejection episodes, showed daily fluctuations up to 100% for all markers, with the exception of carcinoembryonic antigen. There was no correlation between elevated tumour markers and cytomegalovirus infection.