Soluble TNF-alpha receptor and IL-1 receptor antagonist elevation in BAL in active pulmonary TB

Accumulating evidence suggests that patients with active pulmonary tuberculosis (TB) have an alveolar inflammation resulting in the release of tumour necrosis factor (TNF)‐α and interleukin (IL)‐1β in bronchoalveolar epithelial fluid. It was proposed that the levels of these cytokines would correlate with clinical status parameters (extent of pulmonary involvement, fever, and body weight loss) and that their naturally occurring inhibitors would be concomitantly released in the local inflammatory sites. To test this hypothesis lung epithelial lining fluid (ELF) obtained by bronchoalveolar lavage and serum were collected from 29 patients with active pulmonary TB and 15 healthy subjects to determine the levels of these variables using a sandwich enzyme‐linked immunosorbent assay (ELISA). ELF levels of TNF‐α, soluble (s)TNF receptor I (RI), sTNF‐receptor II (RII) and interleukin‐1 receptor antagonist (IL‐1RA) but not IL‐1β, and their serum levels except for sTNF‐RII and IL‐1β were significantly higher in TB patients. Nevertheless, only ELF levels of TNF‐α and IL‐1β were significantly correlated with disease status. No correlation was found between TNF‐α levels and those of sTNF‐RI and sTNF‐RII, nor between IL‐1β and IL‐1RA in ELF and serum of TB patients, although there was a significant correlation between sTNF‐RI and sTNF‐RII levels both in ELF and serum. These findings suggest local release of tumour necrosis factor‐α and interleukin‐1β and a correlation with disease status. Soluble tumour necrosis factor‐α receptors and interleukin‐1β receptor antagonist, although increased in lung epithelial lining fluid and serum in tuberculosis patients, were not correlated with tumour necrosis factor‐a and interleukin‐1β or with disease status. Eur Respir J 1999; 14: 490–495.