[Different cytokine profiles in usual interstitial pneumonia and nonspecific interstitial pneumonia].

OBJECTIVE: To study the distribution, the expression and the significance of TGF-beta(1), b-FGF, IL-8, IL-13 and IFN-gamma in different lung tissue compartments in usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF) and nonspecific interstitial pneumonia (NSIP).

METHODS: Specimens were obtained by open or video-assisted thoracoscopic lung biopsy from patients with UIP (n = 5) and NSIP (n = 8). Control specimens were obtained by surgical lobectomy from patients with primary lung cancer (n = 5). The distribution of these cytokines in lung tissues was observed by semi-quantitative method using immunohistochemical staining.

RESULTS: TGF-beta(1), IL-8 and b-FGF were localized in alveolar epithelial cells, alveolar macrophages, and the bronchial epithelium. Overall intensity of TGF-beta(1), IL-8 and b-FGF expression in UIP was stronger in comparison with NSIP. IL-13 was distributed in alveolar epithelial cells, alveolar macrophages and interstitial mononuclear cells. Its expression in UIP was similar to that in NSIP. IFN-gamma was expressed mainly in interstitial mononuclear cells. Its expression in NSIP was stronger than that in UIP. The ratio of IL-13 to IFN-gamma in UIP (2.18 +/- 0.76) was significantly higher than that in NSIP (0.95 +/- 0.28) or that in the control (0.91 +/- 0.16) (P < 0.05, UIP versus NSIP or control), whereas the ratio of IL-13 to IFN-gamma in NSIP was similar to that in the control. In normal lungs, only alveolar macrophages expressed these cytokines.

CONCLUSION: The different expression of TGF-beta(1), IL-8 and b-FGF in UIP and NSIP and the balance of IL-13/IFN-gamma may be involved in the different pathogenesis in these two diseases.