Serum YKL-40 as predictor of outcome in hypersensitivity pneumonitis

• Published in: The European respiratory journal Vol. 49; no. 2; p. 1501924
• Main Authors: Long, Xiaoping, He, Xuan, Ohshimo, Shinichiro, Griese, Matthias, Sarria, Rafael, Guzman, Josune, Costabel, Ulrich, Bonella, Francesco
• Format: Journal Article
• Language: English
• Published: England European Respiratory Society Journals Ltd 01.02.2017
• Subjects: Alveoli; Alveolitis; Alveolitis, Extrinsic Allergic - blood; Alveolitis, Extrinsic Allergic - diagnosis; Alveolitis, Extrinsic Allergic - mortality; Biomarkers - blood; Bronchoalveolar Lavage Fluid - chemistry; Bronchus; Carbon monoxide; Case-Control Studies; Chitinase; Chitinase-3-Like Protein 1 - blood; Disease Progression; Enzyme-linked immunosorbent assay; Epithelial cells; Female; Germany; Humans; Hypersensitivity; Kaplan-Meier Estimate; Leukocytes (neutrophilic); Lung diseases; Lung Diseases, Interstitial - blood; Lung Diseases, Interstitial - diagnosis; Macrophages; Macrophages - metabolism; Male; Middle Aged; Multivariate Analysis; Neutrophils - metabolism; Pneumonitis; Retrospective Studies; ROC Curve; Sarcoidosis; Tomography, X-Ray Computed
• ISSN: 0903-1936; 1399-3003
• DOI: 10.1183/13993003.01924-2015

YKL-40, a chitinase-like protein mainly secreted by macrophages, neutrophils and epithelial cells, is increased in patients with idiopathic interstitial pneumonia and sarcoidosis. We aimed to investigate the role of YKL-40 as a biomarker in hypersensitivity pneumonitis (HP).72 HP patients, 100 interstitial lung disease (ILD) controls and 60 healthy controls were studied. YKL-40 was measured by ELISA in serum and bronchoalveolar lavage fluid (BALF) at baseline and follow-up. The relationship between YKL-40 levels, clinical variables and disease outcome was evaluated.Baseline serum YKL-40 levels were significantly higher in HP patients than in healthy controls (p<0.001), but lower than in patients with other ILDs. Baseline BALF YKL-40 levels in HP patients were the highest among ILD patients. In HP patients, serum YKL-40 correlated with the diffusing capacity of the lung for carbon monoxide at baseline (p<0.01) and over time (p<0.001). HP patients whose disease progressed or who died had higher baseline YKL-40 levels than those who remained stable and survived (p<0.001). At a cut-off of 119 ng·mL , the baseline serum YKL-40 level predicted disease progression (hazard ratio 6.567; p<0.001), and at a cut-off of 150 ng·mL was associated with mortality (hazard ratio 9.989; p<0.001).Serum YKL-40 may be a useful prognostic biomarker in HP patients.