• Open Access

Serum Thymidine Kinase Activity: An Alternative to Histologic Markers of Cellular Proliferation in Canine Lymphoma



Thymidine kinase (TK) is a cellular enzyme which is involved in a salvage pathway of DNA synthesis. It is activated in the G1/S phase of the cell cycle, and its activity has been shown to correlate with the proliferative activity of tumor cells⃜Clin-ical studies have reported high serum TK concentrations in a variety of neoplasias. The majority of these studies concerned hematological malignancies. TK seems to be a useful marker in non-Hodgkins lymphoma, where it correlates with clinical stag-ing and provides marked prognostic information on (progres-sion-free) survival.