[Serum thymidine kinase activity of various cancer and HBV positive liver diseases]

Clinical utility of determination of serum deoxythymidine kinase (TK) activity is described. It is well known that elevated TK level is observed in leukemia and other malignant diseases, or some viral infectious diseases. The TK activity was assayed on normal subjects, hepatitis B virus (HBV) positive liver diseases and various cancer by a newly developed high sensitive method, radio enzyme assay (REA) utilizing 125I-iododeoxyuridine as the substrate. Measurement of TK activity by the REA is revealed to be useful for "the marker of DNA metabolism anomaly" in leukemia, etc.