CD14 Gene (−159 C>T) Polymorphism and its Surface Expression on Monocytes in Pulmonary Tuberculosis Patients

Abstract

BACKGROUND: Tuberculosis (TB) is an infectious disease that affects millions of people around the world. The innate immune response against TB starts by interaction of several receptors on monocytes with mycobacterium tuberculosis (MTB). CD14 is one of these receptors present on the monocytes which facilitate the entry of MTB into the cell. Certain polymorphisms in CD14 gene, for example, CD14 (−159 C>T) in the promotor region have suggested susceptibility of TB.
 AIM: This study was designed to determine and compare CD14 (−159 C>T) gene polymorphism and its surface expression in pulmonary TB patients (before and during anti-TB treatment) and healthy controls.
 MATERIALS AND METHODS: The study population comprised three groups (pulmonary TB patients before treatment, pulmonary TB patients during treatment, and healthy controls) whereas 53 blood samples were collected from each group. The percentage of monocytes and CD14 mean fluorescence intensity (MFI) was measured by flow cytometry whereas polymerase chain reaction-restriction fragment length polymorphism was used to determine gene polymorphism.
 RESULTS: CD14 MFI was significantly high in healthy controls than in TB patients (432 as compared to 193 and 365, p < 0.0001). There was no significant difference in CD14 single nucleotide polymorphism allele frequencies or genotypes between TB patients and healthy controls.
 CONCLUSION: CD14 gene (−159 C>T) polymorphism was not associated with pulmonary TB disease in a sample of Pakistani population and surface expression of CD14 receptor on peripheral blood monocytes decreases with active TB disease and during treatment.