The role of CD14 gene promoter polymorphism in tuberculosis susceptibility

Abstract

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 aim of the present study was to investigate the association between the CD14-159C/T polymorphism and tuberculosis in a Turkish population. For this purpose, 88 consecutive patients with tuberculosis (63 pulmonary, 25 extrapulmonary) and 116 control subjects were enrolled into a prospective study. We determined CD14-159 genotypes by polymerase chain reaction - restriction fragment length polymorphism analysis and also measured serum concentrations of soluble CD14 (sCD14) by using a quantitative sandwich enzyme immunoassay technique. There was no significant difference in terms of genotype distribution between patients with tuberculosis (CC 18.2%, CT 48.9%, TT 33.0%) and controls (CC 12.9%, CT 50.9%, TT 36.2%) or between patients with pulmonary and extrapulmonary tuberculosis. Serum levels of sCD14 were significantly increased in patients with active tuberculosis compared to those with inactive tuberculosis and healthy controls (p<0.001). However, levels of sCD14 were not associated with any genotypes of CD14-159. The genotyping findings of the present study do not support a role for the CD14-159C/T polymorphism in the development of tuberculosis, at least in the geographical region of central Anatolia. Significantly elevated serum sCD14 levels in patients with active disease reflect the importance of the mononuclear phagocytic system activation in tuberculosis.