Serum YKL-40 in children with asthma

Asthma is one of the most common chronic diseases in children. To date the diagnosis of asthma is mainly clinical, based on the clinical history, a careful physical examination and lung function tests. However, symptoms are often not specific and lung function tests are not very sensitive. In order to find a solution to this problem new biomarkers of airway inflammation are being developed. YKL-40 is a chitinase-like protein that has a role in the inflammation and tissue remodeling in several human diseases. The aim of this study is to evaluate serum levels of YKL40 in children with intermittent or persistent asthma. We performed a cross-sectional analysis of serum samples from a cohort of patients with asthma and healthy controls. Patients with asthma were stratified according to four levels of asthma severity (mild intermittent, mild persistent, moderate persistent, and severe persistent). The analysis of serum samples was performed with the use of a commercially available enzyme-linked immune-adsorbent assay (ELISA) kit (Quidel). The minimum detection limit of the assay for YKL-40 is 15.6 ng per milliliter (ng/ml). Our data showed that circulating YKL-40 levels are significantly higher in patients with asthma than healthy subjects (36±18.6 vs 14:41±2.88, p= 0.001). Furthermore, we found significantly higher values of YKL-40 in both groups of children with intermittent asthma (p<0.001) and persistent asthma (p<0.001) than healthy controls. However, no correlation was found with duration and severity of asthmatic disease (r = 0:18, p= 0:33, r = 0.28 P = 0:13, respectively). Our data allow us to suggest that YKL-40 represents a useful biomarker of asthma in children with intermittent or persistent asthma