Human Beta Defensin 1 (hBD1) levels in sputum and lysate of mononuclear blood cells of drug-sensitive and drug-resistant pulmonary tuberculosis patients attending a tertiary hospital in Ibadan, Nigeria

Abstract

Background: Mycobacterium tuberculosis (M. tb) that causes pulmonary tuberculosis (PTB) occupies the lungs, while human β-defensin-1 (hBD1) is expressed in all human epithelial tissues as one of the products of phagocytic leucocytes, especially at the site of microbial colonisation such as the lungs. The involvement of hBD1 in mycobacterial infection has not been extensively studied, thus there is the need to measure the levels of the hBD1 in mononuclear cell lysates and sputum of PTB patients at diagnosis.

Materials and Methods: Ninety participants aged between 15 and 64 years were recruited as follows: 30 newly diagnosed multi-drug-resistant TB (MDR-TB) patients and 30 newly diagnosed drug-sensitive TB patients (DS-TB) from MDR-TB Treatment centre and the Medicine Outpatient Clinic at University College Hospital (UCH) Ibadan, Nigeria. Thirty (30) non-TB apparently healthy individuals served as controls. The analytical method employed for the measurement of hBD1 in the sputum and lysate was the Enzyme-linked immunosorbent assay (ELISA). The data were expressed as mean and standard deviation, and the differences between the means were established using Student (t) test. P-value ≤ 0.05 indicated statistical significance.

Results: The mean levels of lysate and sputum hBD1 were not significantly different in newly diagnosed DS–TB patients (D₀)compared with control (p > 0.05). Whereas, the mean levels of lysate and sputum hBD1 were significantly higher in newly diagnosed MDR–TB patients (M₀) compared with newly diagnosed DS–TB patients (D₀)or control (p < 0.05).

Conclusion: Due to the higher levels of hBD1 in the sputum and lysate of M₀ than in D₀, one might conclude that there is a relationship between chronicity of PTB and hBD1 level.

Keywords: defensins, tuberculosis, lysate