Associations of IL-33 and IL-18R1 gene polymorphisms in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic respiratory disease common in premature babies, and is associated with increased mortality and significant long-term cardiorespiratory and neurodevelopmental sequelae. The gestational age (GA) is less than 34 weeks with the infants who are BPD, and their birth weight (BW) is less than 1500 grams. Single Nucleotide Polymorphisms (SNPs), are small genetic changes of DNA, which occur in only one base, these polymorphisms happen when a single nucleotide (A, T, C, or G) in a specific position in the genome sequence changes. IL-33 is the 11th member of the interleukin 1 (IL-1) cytokine family, and it was first characterized as a protein expressed by the endothelial cells associated with the lymph node. It has been shown that IL-33 is expressed at higher levels in asthmatic patients than healthy patients, and in mouse models of asthma than wild-type mice. IL-18R1 is the ligand binding chain of IL-18 receptor complex, and in various study groups has been found to be associated with asthma and BPD. The purpose of this study was to investigate possible associations between gene polymorphisms in IL-33 and IL-18R1 and developing BPD in the Turkish population. DNA was isolated from a hundred and twenty two blood samples was done using the PureLinkTM Genomic DNA Mini Kit and then the concentration of the DNA samples was measured by nanophotometer Implen P 300. IL-33 (rs10975519) and IL-18R1 (rs1974675) optimized primer (TaqMan SNP Assays) were used for the SNP analysis, and CFX96 thermocycler was used to perform the Real Time Polymerase Chain Reaction (QRT-PCR). By using SPSS Software 21 and performing the Chi-square χ2 test, the odds ratio (OR) and confidence intervals (CI) were calculated to compare allelic and genotype frequencies. The results showed that the C allele (p=0.0043*; OR 1.727, 95% CI 1.014-2.940) of the IL-18R1 gene was more protective against the development of BPD.