OBJECTIVETo investigate the association between CHI3L1 single nucleotide polymorphisms (SNPs) and the susceptibility to childhood asthma.

METHODSA total of 316 children diagnosed with asthma between January 2011 and October 2013 and 297 healthy children were selected as asthma group and control group respectively. Peripheral blood samples were collected from all subjects. Chemiluminescence and flow cytometry were applied to measure total IgE level and the percentage of eosinophils. ELISA was used to measure YKL-40 level. Genomic DNA was extracted from peripheral blood hemocytes, and the genotype and allele frequencies at CHI3L1 SNPs rs4950928, rs10399805, and rs883125 were determined by MALDI-TOP mass spectrometry.

RESULTSThe total IgE and YKL-40 levels were significantly higher in the asthma group than in the control group (P<0.05), while the percentage of eosinophils showed no significant difference between the two groups (P>0.05). The frequency of GG genotype at rs883125 in the asthma group was significantly higher than that in the control group (P<0.05). For rs4950928, the asthma group had a significantly lower frequency of CC genotype (P<0.05) but a significantly higher frequency of CG genotype (P<0.05) compared with the control group. In the asthma group, the patients with GG and CG genotypes at rs4950928 had significantly increased total IgE and YKL-40 levels compared with those with CC genotype at this locus (P<0.05).

CONCLUSIONSYKL-40 is a potential molecular biomarker for the primary diagnosis of childhood asthma. CHI3L1 SNPs rs4950928 and rs883125 may be associated with childhood asthma. G allele at rs4950928 may increase the risk of childhood asthma.