CLINICAL-SIGNIFICANCE OF SERUM THYMIDINE KINASE IN ADULT T-CELL LEUKEMIA AND ACUTE MYELOID-LEUKEMIA

To clarify the clinical and biological significance of serum thymidine kinase (TK) in adult T-cell leukaemia (ATL) associated with human lym photropic virus type-I (HTLV-I) and in acute myeloid leukaemia (AML), TK was measured in 52 patients with ATL (acute ATL, 35 patients; lymph oma ATL, two patients; chronic ATL, 12 patients; smouldering ATL, thre e patients), and in 27 patients with AML (one FAB MO, one M1, 10 M2, s even M3, five M4, one M5, one M6, one MU). In ATL patients, statistica l analysis disclosed a close correlation between TK level and the leuc ocyte count (P < 0.01), and absolute number of abnormal lymphocytes (P < 0.01). However, no correlation was observed between serum lactic de hydrogenase (LDH) level and these items. Concerning the therapeutic re sponse, a statistical difference was present in TK between complete re mission and no response (P < 0.05), but not in LDH. We also investigat ed a significant inverse correlation between TK level as well as LDH l evel and the length of survival after the initial diagnosis (P < 0.01) , In AML patients a close correlation of TK level with the count of le ucocytes (P < 0.01), percentage of blasts in the blood (P < 0.05), the rapeutic response (P < 0.01) and the length of survival after the init ial diagnosis (P < 0.05) was present. Therefore the TK level may indic ate the aggressiveness of leukaemic cells and predict the response to the chemotherapy and the length of survival in ATL and AML.