Cytokines assay in peripheral blood and bronchoalveolar lavage in the diagnosis and staging of pulmonary granulomatous diseases

The pulmonary granulomatous diseases may be staged using clinical examination, pulmonary function tests, Ga-67 scans, chest X-rays, BAL and serum ACE levels; furthermore, these disorders are clearly associated to changes in lymphocyte subpopulations, CD4+/CD8+ ratio and surface receptors; in particular, T cell activation characterizes early alveolitis phase, while activated macrophages and related cytokines prevail in granulomata and fibrosis development. In this study, we dosed the serum and blood concentrations of IL-6 (a well-known pro-inflammatory cytokine), sIL-2R (marker of T-cell activation), TNF-alpha and IFN-gamma (associated with the granulomata development), in patients affected by active or inactive sarcoidosis, primary tuberculosis, idiopathic pulmonary fibrosis and healthy control subjects, using the ELISA method. Cytokines assay showed significant changes only in subjects with primary tuberculosis and active sarcoidosis; infact, primary tuberculosis was characterized by high values of IL-6 and IFN-gamma both in peripheral blood and in BAL, with high values of sIL-2R in BAL; patients with active sarcoidosis showed high levels of IFN-gamma and TNF-alpha both in BAL and in peripheral blood, associated to an increase of serum sIL-2R levels. Our data confirm that the compared assay of these cytokines in peripheral blood and BAL specimens, may be useful to diagnose and to assess the disease activity in pulmonary granulomatous diseases; in particular, the levels of sIL-2R are a marker of the alveolitis phase, while TNF-alpha and IL-6 levels discriminate patients with sarcoidosis or tuberculosis granulomata, respectively.