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The role of Interleukin-8 in interstitial pneumonia


Yoshiaki Fujimori, Department of Internal Medicine II, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama City, Okayama 700-8558, Japan. Email:


Objective:  A variety of inflammatory cells accumulate in the lungs of patients with interstitial lung disease. The potential for IL-8 to be released from these cells into the lungs of patients with idiopathic interstitial pneumonia (IIP), interstitial pneumonia with collagen vascular disease (IP-CVD), sarcoidosis (SAR) and hypersensitivity pneumonitis (HP) was investigated.

Methodology:  IL-8 levels were assessed by enzyme-linked immunosorbent assay in BAL fluid and serum, and the expression of IL-8 in the lungs of these patients was evaluated by immunohistochemistry.

Results:  Serum IL-8 levels were significantly elevated in patients with IIP (P < 0.05) and SAR (P < 0.01). In BAL fluid, the IL-8 level was significantly higher in patients with IIP (P < 0.05), IP-CVD (P < 0.01), SAR (P < 0.01) and HP (P < 0.01). In several cases, IL-8 level correlated with neutrophil density. The IL-8 immunopositive cells were type II pulmonary epithelial cells and alveolar and interstitial macrophages in patients with IIP and IP-CVD.

Conclusions:  IL-8 is likely to be a key factor in the pathogenesis of fibrosis of the lung and in lung injury.