Background & objectives: Tuberculous pleuritis is used as a model to understand the protective immune
response in tuberculosis. It is predominated by Th1 response at the site of infection, where a possible role
for the leptin, a known enhancer of Th1 response, could be speculated. Hence, we investigated leptin levels
in pleural effusions in patients with both tuberculous (TP) and non-tuberculous (NTP) pleural effusion.
Methods: Leptin and cytokine levels were assessed in serum and pleural fluid of TP and NTP patients
(N = 20 each) by ELISA. Multivariate regression analysis were performed to find the possible
determinants of leptin taking leptin as the dependent and body mass index (BMI), gender, source of
leptin [i.e., serum or pleural fluid (PF)], age and disease status as independent variables.
Results: PF leptin levels were significantly higher than serum leptin levels in both the groups however
the PF leptin levels were significantly lower in TP subjects compared to NTP. The results showed that the
leptin was found to be dependent on BMI but not on the other parameters. However, regression analysis
based on the source of leptin showed males to be a better predictor of leptin. No correlation was observed
between leptin and measured immune parameters.
Interpretation & conclusions: Our findings demonstrated that the decreased leptin levels were associated
with reduction in BMI but not with the disease status in tuberculous pleuritis