TLR4 gene expression in patients with chronic suppurative otitis media

Abstract

Chronic suppurative otitis media (CSOM) is an infectious disease of the middle ear that involves inflammation and accumulation of fluid behind the eardrum. The pathogenesis of CSOM involves reduced bacterial clearance due to impairment of Toll-Like Receptor (TLR) 4 pathway. TLR4 receptor serves as the molecular sensor for bacterial endotoxin (lipopolysaccharide) and activates inflammatory cell signaling for clearing the bacteria. Previous studies have shown that the expression of TLR4 gene is reduced in middle ear epithelia of CSOM patients. Whether the expression of TLR4 gene is reduced in leukocytes is not known. In our present study we aim to compare the expression of the TLR4 gene in the blood samples of CSOM patients and healthy controls. A case-control study was carried out by involving 16 participants in each group. The levels of the TLR4 gene expression were measured by using the qRT-PCR method. The median (interquartile range) ΔCt values of the TLR4 gene expression was 4.85 (2.61- 8.55) in the patient group and 2.29 (-1.63-4.85) in healthy controls. Expression of the TLR4 gene in the leukocytes of CSOM patient group was reduced by ~5.9 fold compared to the control group and the difference was found to be significant (P = 0.01).

Keywords

• chronic suppurative otitis media
• gene expression
• toll-like receptor 4 (tlr4)