Tumor M2-PK levels in haematological malignancies

Circulating Tumor M2-PK serum levels were measured in 118 patients with various haematological malignancies. Using 17.5 U/ml as the cut-off level, elevated Tumor M2-PK concentrations were found in 7 out of 35 patients with acute myelocytic leukaemia, 17 out of 38 patients with chronic myelocytic leukaemia, 5 out of 18 patients with chronic lymphocytic leukaemia and in 6 out of 14 patients with acute lymphocytic leukaemia. Only 9 out of 195 healthy control individuals had Tumor M2-PK plasma levels above 17.5 U/ml. Serial determinations of Tumor M2-PK were performed in 3 patients with haematological malignancies during chemotherapy. Disease regression was associated with alternating Tumor M2-PK plasma levels. Thus, Tumor M2-PK is not a useful indicator of haematological malignancies. Moreover, serial Tumor M2-PK measurement may be insignificant in monitoring response to chemotherapy in these patients.