Association between the CD14 gene C-159T polymorphism and serum soluble CD14 with pulmonary tuberculosis

BACKGROUND: Functional C-159T polymorphism in the promoter region of the CD14 lipopolysaccharide receptor has been reported to be associated with the development of tuberculosis (TB). OBJECTIVE: To assess the association of CD14 C-159T polymorphism and serum soluble CD14 (sCD14) levels with pulmonary tuberculosis (TB) in an Iranian population living in a TB-endemic area. DESIGN: A case-control study was performed prospectively on 120 newly diagnosed pulmonary TB patients and 131 healthy subjects. C-159T polymorphism was performed using amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Concentrations of sCD14 were measured in scrum samples using enzyme-linked immunosorbent assay. RESULTS: The genotype frequencies of C-159T polymorphism differed significantly between TB patients and controls (P = 0.006). The risk of TB was 2.3-fold greater in individuals with the T-allele (CT + TT) in comparison to those without (OR 2.3, 95%CI 1.2-4.3, P = 0.006). Mean total sCD14 was significantly increased in the serum of patients with newly diagnosed pulmonary TB (mean +/- SD = 3177 +/- 751 ng/ml) compared to healthy controls (mean +/- SD = 2955 +/- 424 ng/ml, P < 0.004). CONCLUSION: These data indicate that the C-159T polymorphism of the CD14 gene is associated with TB; serum sCD14 levels were higher in TB patients in a sample of the Iranian population.