The -159C/T polymorphism in the CD14 gene and pulmonary tuberculosis

Background: CD14 is expressed principally by cells of monocyte/macrophage lineage and plays a pivotal role in the innate immunity to intracellular infections. Recent research findings have revealed an association between the CD14 gene promoter polymorphism and several major infectious diseases. The purpose of the present study is to confirm the association between CD14-159C/T polymorphism (rs2569190) and pulmonary tuberculosis. Furthermore, association of various serum based biomarkers would be helpful in understanding better susceptibility to the disease state. Methods: This study included a tertiary hospital based age and sex matched 12 patients with pulmonary tuberculosis and 15 subjects with normal lung functioning. These cases were recruited from January 2014 to April 2014. Subjects were included in the pulmonary tuberculosis group on the basis of smear positive for acid fast bacilli. DNA extraction was done by isopropanol precipitation method and amplification of CD14 gene was done by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP). Results: It was found that CT heterozygotes were more susceptible to pulmonary tuberculosis (OR=5.6, 95% CI=1.01 - 30.91, p = 0.05) whereas TT homozygotes were found to be less susceptible to pulmonary tuberculosis in Central Indian Cohort. Elevated level of IgE (182.5ng/ml) were found in CT genotype. Slight elevated N-GAL level were found in cases with CT genotype 5.31 ng/ml when compared with control’s level. It was found that CT genotype had high bacterial load of 10.4x103 copies/μl) whereas TT has bacterial load of 48.39x102 copies/ μl and CC has very less bacterial load. Serum sCD14 estimation displayed somewhat high values (741 pg/ml) in cases with TT genotype. The results of our study on sCD14 level in TB Conclusion: An association between the C-159-T polymorphism of the CD14 gene and presence of tuberculosis in the Central Indian population was evident as the risk of TB was greater in participants with heterozygous CT genotype than in those with homozygous CC genotype. It was also seen that heterozygous CT genotype was found to be more susceptible for pulmonary tuberculosis whereas TT genotype was found to be less susceptible for TB and homozygous CC genotype was found as protective role against TB, which was evident from elevated cytokines in CT heterozygotes.