[Expression of serum interleukin-13 and significance of gene polymorphism on the patients with bronchiectasis in acute exacerbation period].

Objective: To explore the expression of serum interleukin-13 (IL-13) and significance of its gene polymorphism on the patients with acute exacerbation of bronchiectasis in acute exacerbation period. Methods: Forty-three patients with bronchiectasis in acute exacerbation period admitted into the respiratory ward of Fujian Provincial Hospital from December, 2014 to March, 2016 were included as bronchiectasis group. Thirty-three healthy controls from normal people of health examination were included as control group during the corresponding period. A total of 5 ml fasting peripheral blood sample was extracted from each individual. The IL-13 levels were determined by enzyme-linked immunosorbent assay (ELISA). IL-13 gene polymorphisms in+ 1923 C/T site and+ 2044 site were genotyped in these two groups by using polymerase chain reaction (PCR) combined with gene sequencing methods. About 7 days after admission, thirty patients with improved condition among the 43 patients were included as bronchiectasis improvement group, all had the extraction of 3 ml peripheral blood for IL-13 detection determined by ELISA. The expression of serum IL-13 and gene polymorphisms between bronchiectasis group and control group were analyzed statistically. The changes of serum IL-13 between bronchiectasis group and bronchiectasis improvement group were also analyzed statistically. Results: The serum IL-13 level was lower in the bronchiectasis group in acute exacerbation period than that of the healthy controls [(31.1±26.3) vs (70.6±53.6) μg/L, P<0.05]. There was no significant difference of the genotype distribution in + 1923C/T site of IL-13 gene between the two groups (χ(2)=0.915, P>0.05). In the bronchiectasis group, the C and T allele frequencies at+ 1923 site of IL-13 gene were 79.1% and 20.9%, respectively, and its single nucleotide polymorphism (SNP) was in strong linkage disequilibrium with the SNP IL-13+ 2044G/A site (R(2)=0.835, P<0.001). There was no significant difference of the serum IL-13 between allele T_ groups and allele CC group, and also no significant difference between allele A_ groups and allele GG group (P>0.05). Conclusion: The IL-13 levels decreased specifically in the bronchiectasis group in acute exacerbation period, but IL-13+ 1923C/T and+ 2044G/A polymorphisms are not significantly related to the susceptibility of bronchiectasis.