INTERLEUKIN-8 AND NEUTROPHILS IN SYSTEMIC-SCLEROSIS WITH LUNG INVOLVEMENT

We investigated the mechanisms and consequences of neutrophil accumula tion in the airspace in 11 patients with systemic sclerosis (SSc) and interstitial lung disease. Seven normal subjects served as controls. W e measured total neutrophil elastase burden, elastase activity, and al pha-1-antitrypsin (alpha1AT) in bronchoalveolar lavage (BAL) fluid an d we evaluated the in vitro interleukin-8 (IL-8, a potent chemoattract ant for neutrophils) secretion by alveolar macrophages (AM). A mild ne utrophil alveolitis was observed in patients when compared with contro l subjects. Total BAL elastase burden was higher in patients than in c ontrol subjects and correlated positively with the percentage of neutr ophils in BAL. BAL elastase activity was undetectable in control subje cts, but it was detected in all patients but one (mean:257 +/- 87 mU/L ). Spontaneous IL-8 secretion by AM was higher in patients with SSc th an in control subjects (518 +/- 115 versus 228 +/- 65 ng/ml, p = 0.04) and positively correlated with the percentage of neutrophils in BAL ( r = 0.505). We conclude that (1) the neutrophil could participate in t he pathogenesis of SSc lung disease through the release of elastase; ( 2) the AM could contribute to the influx of neutrophils in the alveolu s through the release of IL-8.