Increased IL-6 and IL-8 in bronchoalveolar lavage fluids (BALF) from patients with sarcoidosis: correlation with the clinical parameters.

A variety of cytokines have been implicated in the pathogenesis of pulmonary sarcoidosis, but the exact roles of IL-6 and IL-8 are not yet clear. We studied these cytokine levels in BALF from patients with pulmonary sarcoidosis, idiopathic pulmonary fibrosis (IPF), systemic screlosis (SSc) with interstitial lung disease and control subjects. IL-6 and IL-8 levels were significantly elevated in sarcoidosis, IPF and SSc with interstitial lung disease compared with control subjects. Subjects with sarcoidosis had significantly increased levels of both cytokines compared with controls when the cytokine values were corrected by the total albumin content and the two cytokine levels correlated with each other (r = 0.876). BALF IL-6 levels correlated with percent lymphocytes and percent CD3+ cells. Moreover, when sarcoidosis patients were divided into three groups, those who needed steroid therapy or had progressive disease showed increased cytokine levels in BALF over stable or improved patients. These observations suggest that locally derived IL-6 and IL-8 were increased in sarcoidosis and correlated with activity of this granulomatous lung disease.