IFN ‐γ against the 38‐kDa antigen of Mycobacterium tuberculosis discriminates pulmonary tuberculosis from infection and infection from exposure: evidence from a study of human population in a high endemic setting

Mycobacterium tuberculosis (Mtb) 38‐kDa antigen is an immunogenic lipoprotein that induces strong T‐cell responses in experimental animals. However, there is limited information on the role of this antigen in human population. In this article, we present the dynamics of pro‐inflammatory (IFN‐γ and TNF‐α) and anti‐inflammatory cytokine (IL‐10) against the 38 kDa in cohorts of pulmonary TB (PTB) patients, household contacts (HHCs), and community controls (CCs) in a high endemic setting. Whole blood assay was used to determine the levels of cytokines in 149 patients, 149 HHCs, and 68 CCs at baseline, 6 months, and 12 months. At baseline, the level of IFN‐γ was significantly (p < 0.0001) higher in CCs and HHCs than in untreated patients. CCs had significantly (p < 0.05) higher level of IFN‐γ than HHCs. There was no significant difference between treated and untreated patients, and there was no significant change in HHCs over 12 months. At baseline, the levels of IL‐10 and TNF‐α were significantly (p < 0.0001) higher in patients than in HHCs and CCs. No significant change was observed between treated patients and untreated patients and HHCs over time. The study shows that IFN‐γ against the 38 kDa discriminates clinical TB from infection and infection from exposure, suggesting its potential for immune protection and diagnosis.
Source: APMIS - Category: Research Authors: Tags: Original Article Source Type: research