TISSUE POLYPEPTIDE SPECIFIC ANTIGEN FOR THE DETECTION OF LYMPHOPROLIFERATIVE DISEASES INDUCED BY CYCLOSPORINE

Aim-To evaluate the efficacy of tissue polypeptide specific (TPS) anti gen for the early detection of cyclosporin A (CyA) induced post-transp lant lymphoproliferative diseases. Methods-Serum concentrations of TPS antigen were analysed using a monoclonal enzyme immunoassay and whole blood CyA concentrations were measured using high pressure liquid chr omatography. Infection with Epstein-Barr virus and cytomegalovirus was detected by determining levels of IgM and IgG antibodies directed aga inst viral capsid antigen (VCA). Immunohistochemistry and analysis of clonality were carried out on formalin fixed, paraffin wax embedded ti ssue. Results-The mean serum concentration of TPS antigen in the eight transplant recipients investigated was 60 U/1 during periods without complication (control), 101 U/1 during infection, 166 U/1 when the dia gnosis of a lymphoma was confirmed, and 172 Un when lymphoma and infec tion coincided. Increased TPS antigen concentrations were detected in six patients one month before detection of malignancy. After reduction of immunosuppression and the start of tumour regression, TPS antigen concentrations decreased. TPS antigen concentrations increased in the one patient who experienced a recurrence. Conclusions-Continuous monit oring of TPS antigen concentrations leads to the early discovery of Cy A induced lymphoprolilferative disease.