Serum CCL-18 level is a risk factor for COPD exacerbations requiring hospitalization
Authors Dilektasli AG, Demirdogen Cetinoglu E, Uzaslan E, Budak F, Coskun F, Ursavas A, Ercan I, Ege E
Received 29 July 2016
Accepted for publication 10 October 2016
Published 5 January 2017 Volume 2017:12 Pages 199—208
Checked for plagiarism Yes
Review by Single-blind
Peer reviewers approved by Dr Amy Norman
Peer reviewer comments 3
Editor who approved publication: Dr Richard Russell
Asli Gorek Dilektasli,1 Ezgi Demirdogen Cetinoglu,1 Esra Uzaslan,1 Ferah Budak,2 Funda Coskun,1 Ahmet Ursavas,1 Ilker Ercan,3 Ercument Ege1
1Department of Pulmonary Disesaes, 2Department of Immunology, 3Department of Biostatistics, Uludag University Faculty of Medicine, Bursa, Turkey
Introduction: Chemokine (C-C motif) ligand 18 (CCL-18) has been shown to be elevated in chronic obstructive pulmonary disease (COPD) patients. This study primarily aimed to evaluate whether the serum CCL-18 level differentiates the frequent exacerbator COPD phenotype from infrequent exacerbators. The secondary aim was to investigate whether serum CCL-18 level is a risk factor for exacerbations requiring hospitalization.
Materials and methods: Clinically stable COPD patients and participants with smoking history but normal spirometry (NSp) were recruited for the study. Modified Medical Research Council Dyspnea Scale, COPD Assessment Test, spirometry, and 6-min walking test were performed. Serum CCL-18 levels were measured with a commercial ELISA Kit.
Results: Sixty COPD patients and 20 NSp patients were recruited. Serum CCL-18 levels were higher in COPD patients than those in NSp patients (169 vs 94 ng/mL, P<0.0001). CCL-18 level was significantly correlated with the number of exacerbations (r=0.30, P=0.026), although a difference in CCL-18 values between infrequent and frequent exacerbator COPD (168 vs 196 ng/mL) subgroups did not achieve statistical significance (P=0.09). Serum CCL-18 levels were significantly higher in COPD patients who had experienced at least one exacerbation during the previous 12 months. Overall, ROC analysis revealed that a serum CCL-18 level of 181.71 ng/mL could differentiate COPD patients with hospitalized exacerbations from those who were not hospitalized with a 88% sensitivity and 88.2% specificity (area under curve: 0.92). Serum CCL-18 level had a strong correlation with the frequency of exacerbations requiring hospitalization (r=0.68, P<0.0001) and was found to be an independent risk factor for hospitalized exacerbations in the multivariable analysis.
Conclusion: CCL-18 is a promising biomarker in COPD, as it is associated with frequency of exacerbations, particularly with severe COPD exacerbations requiring hospitalization, as well as with functional parameters and symptom scores.
Keywords: COPD, frequent exacerbator, hospitalized exacerbation, PARC/(CCL-18)