[Evaluation of interleukin-13 in the serum and bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis].

Objective: To study the significance of interleukin-13 (IL-13) in peripheral blood and bronchoalveolar lavage fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF).

Methods: The level of IL-13 was determined with ELISA in the serum and BALF of 17 patients with IPF and 8 subjects with non-interstitial lung diseases (non-smokers).

Results: The level of IL-13 in the BALF of the patients with IPF was significantly higher than that in non-interstitial lung disease group [(301 +/- 86) ng/L vs. (103 +/- 24) ng/L (P < 0.01)] and was higher than that in serum [(178 +/- 36) ng/L vs. (55 +/- 15) ng/L, P < 0.01]. The level of IL-13 in the BALF of the patients with IPF was positively correlated with the percentage of neutrophils (r = 0.786, P < 0.01). The analysis of Spearman correlation showed that the level of IL-13 in the BALF was correlated with lung function, PaO(2), and D(LCO) (Spearman correlation coefficient r = -0.898, -0.878, -0.874, -0.890, respectively, P < 0.01).

Conclusion: IL-13 may play an important role in the pathogenesis of IPF and be a potential marker of IPF activity.