YKL-40 Protein is a Marker of Asthma

Abstract

Background. Gaining asthma control is still a challenge in a large number of patients. It could be facilitated by using biomarkers indicating the grade of inflammation and correlating with clinical picture. Chitinases and chitinase-like proteins play a role in Th2-type inflammation. Thus, they may be useful in diagnosing and monitoring of asthma. Objectives. The aim of the study was to investigate the relevance of YKL-40 as a good biomarker of asthma, its control, and severity. Methods. Level of YKL-40 was determined by means of immunoassay in sera of 59 asthmatics (39 women, 20 men, aged 23–76 years) and 29 healthy controls (18 women, 11 men, aged 20–80 years). Asthma severity and control were assessed according to GINA guidelines. Differences between groups were compared with the use of Mann–Whitney’s U-test. Correlations between variables were assessed with Pearson’s test. Results. Symptoms of asthma were found to be controlled in 12 (20%), partly controlled in 17 (29%), and uncontrolled in 30 (51%) patients. YKL-40 levels were significantly higher, on average, in asthmatics compared to control group (median levels: 125.3 U and 84.1 U, respectively, p < .001). YKL-40 correlated with the number of blood eosinophils (r = 0.376, p = 0.05). However, no relations have been found between YKL-40 level and asthma severity, control, or total serum IgE (r = −0.05, p = .05). Conclusion. YKL-40 seems to be a good marker of asthma. However, its level may not correlate with clinical outcome.

• asthma control
• chitinases
• chitinase-like protein
• eosinophilia