Study On The Relationship Between Genetic Polymorphism Of Transforming Growth Factor-betal And Chronic Obstructive Pulmonary Disease

Objective:Explore the relationship between genetic polymorphism of transforming growth factor-betal (TGF-β1 and the susceptibility of Han nationality with chronic obstructive pulmonary disease (COPD) in Jiangxi province of China. And analyze the relativity between genetic polymorphisms of TGF-β1 and severity of airflow limitation in COPD patients of this population.Methods:It was a case-control study.117 patients with COPD and 82 healthy controls were recruited if they satisfied the inclusion criteria. DNA was extracted from whole blood of all subjects. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine four single nucleotide polymorphisms (SNPs) of TGF-β1 gene. There were two SNPs (-800G/A and -509C/T) in promoter region and two SNPs (+869T/Cå'Œ+915G/C) in exon 1 region. Analyze the frequency distributions of these genotypes and alleles in different SNPs between the two groups.COPD patients were categorized into severity groups by level of FEV1% predicted in lung function:mild, moderate, severe and very severe groups. Then, analyze the relationship between genetic polymorphisms of TGF-β1 and severity of airflow limitation in COPD patients.Results:1. Significant difference was observed in the frequencies of C allele and T allele of +869T/C locus (χ2=5.300,P<0.05). The genotype frequencies of +869T/C locus (CC, CT and TT) were respectively 21.4%,52.1% and 26.5% in the COPD group and respectively 30.5%,57.3%å'Œ12.2% in the control group. There was a significant difference in the distribution of genotypes between the two groups (χ2=6.620,P<0.05). Logistic regression was used to analyze the correlation between the polymorphism of +869T/C locus and COPD. The TT genotype of +869T/C locus was found to be a greater risk factor in COPD patients than in controls. The odds ratio (OR) and 95% confidence interval (CI) of TT genotype were respectively 3.100 and (1.257～7.648). After adjustment for age, gender and smoking index, OR and 95%CI were respectively 3.321 and (1.307-8.439). When compared with CC genotype, all P<0.05.2. The genotype or allele frequencies of -509C/T locus showed no significant difference between the two groups (P>0.05).3. There was only GG genotype showed in -800G/A locus and +915G/C locus between the two groups. So no significant differences were found in the genotypes or alleles frequencies of the two SNPs between the two groups.4. The genotype and allele frequencies of -509C/T locus and +869T/C locus showed no significant differencies between different severity groups of airflow limitation in COPD patients (P>0.05).Conclusions:1. The genetic polymorphism of +869T/C locus in TGF-β1 may be a susceptibility factor for COPD in Han nationality of Jiangxi province of China. And the TT genotype of this locus may be a predisposing genotype in COPD.2. The genetic polymorphisms of -509C/T locus,-800G/A locus and +915G/C locus in TGF-β1 may not associated with the susceptibility of Han nationality with COPD in Jiangxi province of China.3. The genetic polymorphisms of -509C/T locus and +869T/C locus in TGF-β1 may not associated with the severity of airflow limitation in COPD patients.