Objective To evaluate the possible association between the expression level of chitinase-3-like protein( YKL40/CHI3L) in serum of asthma patients and asthma severity. Methods 106 asthmatic patients( n =106) were divided into the moderate group( n = 61) and the severe group( n = 45) according to GINA classification,and another 100 healthy adults were taken as the control group. Their serum level of YKL40 were detected and analyzed to eventually determine whether YKL40 was associated with asthma severity. Res...