<b>Results:</b> A SNP (rs4950928) in the <i>CHI3L1</i> promoter was associated with elevated plasma YKL-40 levels (<i>p</i> = .02), asthma (<i>p</i> = .042) and lung function (<i>p</i> = .029 to .002) in this Chinese population.
Plasma YKL-40 levels were examined in relation to CHI3L1 rs4950928 genotype and clinical characteristics including Asthma Predictive Index, medication use, time spent with respiratory symptoms, atopic status, and blood leukocytes.
Serum chitotriosidase (CHIT1) activity and YKL-40 (CHI3L1) levels, as well as the CHIT1 rs3831317 and CHI3L1 rs4950928 genotypes, were examined in subsets of patients with mild to moderate asthma (n = 76), severe asthma (n = 93), and COPD (n = 64) taking part in the European multicenter BIOAIR (Longitudinal Assessment of Clinical Course and Biomarkers in Severe Chronic Airway Disease) study.
In contrast to the promoter SNP rs4950928, the intronic SNP rs12141494 in CHI3L1 is associated with asthma severity, lung function, and YKL-40 expression in the blood and airway.
Our study shows that rs4950928 is significantly associated with hospital admissions in children and young adults; screening for rs4950928 may predict asthma-related hospital admissions, and through individually defined treatment management plans, potentially reduce health care costs.
Interestingly, it has been reported that rs10399931 (-329 G/A) of CHI3LI contributes to the inter-individual plasma YKL-40 levels in patients with sarcoidosis, and that rs4950928 (-131 C/G) is a susceptibility polymorphism for asthma and a decline in lung function.
The rs10399931 CT/TT genotype increased the risk of asthma under the dominant model (<i>P</i> = 0.031, OR = 1.428, 95% CI, 1.033-1.974), while the CT genotype showed the same tendency under the heterozygous model (<i>P</i> = 0.003, OR = 1.680, 95% CI, 1.186-2.380).
Our findings suggest that the CHI3L1 polymorphisms rs1538372 and rs10399931 can be used as genetic markers for predicting asthma risk in the Taiwanese population.
Interestingly, it has been reported that rs10399931 (-329 G/A) of CHI3LI contributes to the inter-individual plasma YKL-40 levels in patients with sarcoidosis, and that rs4950928 (-131 C/G) is a susceptibility polymorphism for asthma and a decline in lung function.
In contrast to the promoter SNP rs4950928, the intronic SNP rs12141494 in CHI3L1 is associated with asthma severity, lung function, and YKL-40 expression in the blood and airway.
Our findings suggest that the CHI3L1 polymorphisms rs1538372 and rs10399931 can be used as genetic markers for predicting asthma risk in the Taiwanese population.