Increased expression of serum periostin and YKL40 in children with severe asthma and asthma exacerbation.

Children with severe asthma or acute asthma exacerbation may encounter difficulties in performing pulmonary function tests. In this situation, serum biomarkers can play a great role in evaluation of such patients. The aim of this study was to estimate the serum levels of human chitinase-3-like protein 1 (YKL40) and periostin in a group of Egyptian children with asthma during acute asthma exacerbation and in stable asthmatics compared with healthy control, and to correlate these findings with the severity of asthma. This cross-sectional study enrolled 120 childrenwith asthma with different degrees of asthma severity, according to the Global Initiative for Asthma guidelines, along with 60 age-matched and sex-matched healthy control. A complete blood count and an estimation of serum periostin and YKL40 levels were performed for all cases and control. Individual and mean values of periostin and YKL40 were significantly higher during acute asthma exacerbations, p<0.001. A highly significant relation between serum levels of periostin and YKL40 and asthma severity, p value for each was <0.001. Absolute eosinophil count was significantly correlated with the serum periostin levels in stable asthmatic group (p=0.01) only. There was significantly positive correlation (P<0.001) between both markers in stable asthmatic group. Spearman's correlation coefficient shows a statistically significant positive correlation between both markers and patient's age and duration of asthma, p value for each was 0.001. These findings highlight the importance of periostin and YKL40 as serum biomarkers for assessment of asthma severity and acute asthma exacerbations in children with asthma.