Evaluation of carcinoembryonic antigen, tissue polypeptide antigen, placental alkaline phosphatase, and modified nucleosides as biological markers in malignant lymphomas.

We have evaluated CEA, TPA, PLAP in sera from patients with three different kinds of malignant lymphomas. Six modified nucleosides, psi, m1A, m1G, m1I, m2G, and m2(2)G were analyzed in the urine from the same group of patients. The histological diagnoses were histiocytic lymphoma (21 patients), lymphocytic lymphoma (19 patients) and Hodgkin's disease (23 patients). The patients were classified into four different clinical stages. Consecutive samples were analyzed before and during ongoing radiotherapy and chemotherapy and during the post-treatment period. Our results showed that TPA and PLAP had limited value as biological markers for patients with malignant lymphomas. For CEA a possible correlation with clinical stage was observed only in patients with Hodgkin's disease. The modified nucleosides, especially psi, showed a correlation with clinical stage for patients with all three diagnoses. Elevated levels of psi in urine were in healthy adults 4%, in patients in clinical stage 1 14%, and in patients with advanced disease 62%. Six cases showed a good correlation between the change in clinical stage upon treatment and the parallel change in the level of psi in the urine. Our results suggest that modified nucleosides, especially psi, are valuable as biological markers for patients with malignant lymphomas.