To explore the expression of thymidine kinase 1(TK1) in patients with lung cancer pleural effusion and tuberculous pleurisy.

The clinical data of 354 patients with unilateral pleural effusion caused by lung cancer and tuberculous pleurisy were retrospectively collected. There were 161 cases were diagnosed with tuberculous pleurisy and 193 cases with lung cancer pleural effusion. The expression of TK1 in serum of patients with different diseases was compared and analyzed.

The average age of patients in tuberculous pleurisy group was higher than that of the malignant pleural effusion group(61.77±12.31 vs. 44.39±19.03). The expression level of TK1 is the highest in patients younger than 30 years old and there was no significant difference in patients older(4.54±4.04)pmol/L than 30 years, furthermore, the same results were observed among different genders and ethnicities. Although the expression of TK1 in patients with different pathological types of lung cancer had no significant difference(P=0.169), the expression of TK1 in tuberculous pleurisy is higher than lung cancer pleural effusion group(3.89±3.52 vs. 2.92±3.44)pmol/L(P=0.009).

There is a definite expression of TK1 in patients with pleural effusion caused by lung disease and the expression quantity has nothing to do with gender and race, but the higher expression in young patients was observed, and the expression of TK1 in tuberculous pleurisy is higher than lung cancer pleural effusion group. Its specificity in distinguishing the etiology of benign and malignant pleural effusion needs further study.