Serum Thymidine Kinase in Vitamin B₁₂Deficiency

Abstract

In DNA synthesis deoxythymidine kinase (TK) catalyses the conversion of deoxythymidine to deoxythymidine monophosphate (dTMP) via the ‘salvage pathway’. Serum deoxythymidine kinase (S‐TK) was measured in this study in 75 patients with vitamin B12 deficiency by a new, very sensitive method, using 125I‐deoxyuridine as substrate. Elevated S‐TK levels were found in those patients who had developed haemolysis and anaemia and the more advanced the disease the higher the S‐TK value. Thus there was a highly significant correlation between S‐TK, haemoglobin level and lactic dehydrogenase activity. These findings are consistent with the theory that elevated levels of S‐TK are due to release from unstable proliferating tissue.

Serum Thymidine Kinase 1, Canine‐C‐Reactive Protein, Haptoglobin, and Vitamin D Concentrations in Dogs with Immune‐Mediated Hemolytic Anemia, Thrombocytopenia, and Polyarthropathy

“…Thymidine kinase 1 is increased in highly proliferative cells. Although most commonly associated with neoplastic disease, human studies have identified increased in serum TK1 in with patients with hemolytic disease . In a similar fashion, TK1 activity was increased in dogs with IMHA and concentrations of TK1 declined with control of disease as indicated by resolution of hemolysis.…”

“…TK1 is commonly associated with neoplastic disease . However, increased TK1 activity is documented in humans with hemolysis and erythro‐megakaryocytopoiesis . TK1 may have utility as a marker of disease control in conditions characterized by cellular proliferation, such as immune‐mediated cytopenias.…”

Serum Thymidine Kinase Activity: Analytical Performance, Age-Related Reference Ranges and Validation in Chronic Lymphocytic Leukemia

“…Hagberg et al showed that severe vitamin B12 deficiency caused elevated serum TK1 levels, as the proliferating tissues became unstable in the absence of the vitamin [41]. Chen et al also showed that serum TK1 concentration was useful in health screening as their patients with elevated TK1 concentration had a significantly increased risk of developing malignancies [42].…”

Markers for internal neoplasia in the horse

“…The serum activity of TK1 is high in the human fetus and remains elevated in maternal blood up to the 39th week of gestation (Bieniarz et al., 1988 ). Increased TK1 activity is also described in patients with vitamin B12 deficiency and kidney failure due to the impaired excretion of the enzyme with urine (Hagberg et al., 1984 ). The effects of age, pregnancy, vitamin B12 deficiency and kidney failure have not been studied in horses so far.…”