Serum Thymidine Kinase Level in Chinese Chronic Lymphocytic Leukemia and Its Correlation with Other Prognostic Factors

Objective To investigate serum thymidine kinase (TK) level in Chineses patients with chronic lymphocytic leukemia (CLL) and its correlation with other prognostic factors, including Binet stages, absolute lymphocyte count (ALC), lactate dehydrogenase (LDH), immunoglobulin heavy-chain variable region (IgVH) gene mutation status, ZAP-70 protein and CD38 expression level, and cytogenetic aberrations.

Methods Serum TK1 level in 39 CLL patients was detected by TK monoclonal antibody (Anti-TK mAb) and enhanced chemiluminecence (ECL). IgVH mutation status was detected by multiplex PCR and sequencing of purified PCR amplification products. A panel of monoclonal antibodies and multiparametic flow cytometry were employed to immunophenotype and determine the expression of ZAP-70 protein and CD38. A panel of probes and interphase fluorescence in stu hybridization (FISH) were used to detect cytogenetic aberrations including 6q-, 11q-, +12, 13q-,17p- and IgH translocation.

Results The level of TK1 was higher in CLL patients that in normal control (P<0.05). TK1 level was not signifigantly correlated with sex, age, Binet stages, CD38, and cytogenetic aberrations. Patients with higher level of ALC, LDH, ZAP-70 and unmutated IgVH genes had higher levels of TK1 than those with lower level of ALC, LDH, ZAP-70 and mutated IgVH genes (P=0.018, P=0.018, P=0.038 and P=0.030, respectively).

Conclusions Serum TK1 level significantly correlates with ALC, LDH, ZAP-70 and IgVH mutational status, and could be a predictive marker of IgVH mutation status. Serum TK1 might be applied for the assessment of prognosis in Chinese patients with CLL.