Elevated CC chemokine level in bronchoalveolar lavage fluid is predictive of a poor outcome of idiopathic pulmonary fibrosis

Background: CC chemokines play important roles in the pathogenesis of interstitial lung diseases. Elevated CC chemokine levels have been observed in bronchoalveolar lavage (BAL) fluid of patients with idiopathic pulmonary fibrosis (IPF).

Objectives: We aimed to examine whether the levels of four CC chemokines, i.e. monocyte chemoattractant protein-1 (MCP-1/CCL2), macrophage inflammatory protein-1 alpha (MIP-1 alpha/CCL3), thymus- and activation-regulated chemokine (TARC/CCL17), and macrophage-derived chemokine (MDC/CCL22), in BAL fluid are predictive of the prognosis of IPF patients.

Methods: We compared the chemokine levels of patients alive 5 years after diagnosis and those who had died. Lung function data, CT scores, and serum markers were also compared.

Results: Among 39 patients (29 males, median age, 60 years), 19 patients (48%) died within 5 years after the diagnosis. Whereas percent vital capacity was not different, percent lung diffusion capacity for carbon monoxide was significantly higher in the surviving patients than in the nonsurviving patients (p < 0.01). Median CCL2 levels of surviving and nonsurviving patients were 154.3 (interquartile range, IQR: 67.3-381.8) and 427.2 (IQR: 329.2-1184.1) pg/ml, respectively (p < 0.02). CCL3 levels in BAL fluid did not differ between the surviving and nonsurviving patients. CCL17 was detected in BAL fluid of 7 patients, 6 of whom died within 5 years. CCL22 was detectable in BAL fluid of 10 patients, only 1 of whom survived. Serum levels of KL-6 and lactate dehydrogenase did not differ between the surviving and nonsurviving patients.

Conclusion: Elevated levels of CCL2, CCL17 and CCL22 in BAL fluid might be predictive of a poor outcome in patients with IPF.