Higher Abundance of Vitronectin (S-protein) in Serum-derived Exosomes of Pulmonary and Extra-Pulmonary Tuberculosis Patients as Compared to HIV-Tuberculosis Dual-infected Patients and Healthy Humans

Background Despite the crucial involvement of vitronectin in affecting the perseverance of certain respiratory pathogens and the progression of several lung diseases, the association of vitronectin with tuberculosis (TB) has been poorly studied. The present study aimed to determine whether vitronectin levels are altered in TB patients compared to healthy humans. Methods Twenty-four laboratory-confirmed tuberculosis patients (pulmonary TB -8, extra-pulmonary-8 and HIV-TB dual infected -8) and eight healthy individuals were included in this study. The quantitative detection of vitronectin in serum-derived exosomes of study participants was performed using a sandwich enzyme-linked immunosorbent assay. Measured concentrations of vitronectin were compared with the demographic variables of the study participants and between the study groups. The Mann-Whitney U unpaired test was used in statistical analysis, and the p-value < 0.05 was considered statistically significant. Results Vitronectin was detected in serum-derived exosomes of all study participants. The demographic characteristics (gender, age, smoking and alcohol consumption habit, history of cough, and weight loss) were not significantly correlated with the vitronectin concentrations of the study participants (p-value> 0.05). The level of vitronectin was higher in patients with pulmonary TB (778.54 ng/l) and extra-pulmonary-TB patients (773.04 ng/l) while lower in HIV-pulmonary TB dual-infected patients (354.86 ng/l) as compared to healthy humans (456.20ng/l). There was a significant difference between vitronectin concentrations of patients with pulmonary TB (p-value: 0.0002) and extra-pulmonary TB (p-value: 0.003) compared to healthy controls. Conclusion The present study reported an increased concentration of vitronectin in serum-derived exosomes of pulmonary and extra-pulmonary TB patients compared to HIV-TB dual-infected patients and healthy humans. Further studies are needed to fully elucidate the diagnostic potential and functionalities of higher concentrations of vitronectin in the pathogenic processes of human TB.