Study On The Correlation Between Single Nucleotide Polymorphism Of CTLA-4, CD84 And Chronic Bronchitis Genetic Infection Susceptiblilty

ObjectiveTo investigate the correlation between single nucleotide polymorphisms (SNP) of +2379G/C (rs17281995) and +1057G/A (rs1129055) in Cluster of differentiation 86(CD86) and -318C/T (rs5742909) and +49A/G (rs231775) in Cytotoxic T lymphocyto-associated Antigen 4(CTLA-4) genes and chronic bronchitis(CB) genetic infection susceptiblilty in the HAN population of Nanchong, Sichuan province.Materials and MethodsThe investigation was conducted by means of case control study, including 298 patients of CB, 300 health controls. CTLA-4 and CD86 gene polymorphisms were identified by Polymerase Chain Reaction–Restriction Fragment Length Polymorphism(PCR-RFLP). Then the genotype frequencies and alleles frequencies and haplotype frequencies were cauculated according to the PCR-RFLP, the differences of genotype frequencies between groups were analyzed by apposite statistical methods.ResultsBoth patients and controls, there are three genotypes(CC,CT,TT) in -318C/T SNP of CTLA-4 gene, three genotypes(AA,AG,GG) in +49A/G SNP of CTLA-4 gene, two genotypes(GG,GC) in +2379G/C SNP of CD86 gene, three genotypes(GG,GA,AA) in +1057G/A SNP of CD86 gene. Comparison of genotype frequencies showed that -318CT and +1057GA genotype were overrepresented in the Experimental group, respectively (-318CT: 47.3% vs 27.2%, p<0.0001; ₁057GA: 56.4% vs 50.7%, p= 0.022). The frequencies of C and T alleles in -318C/T SNP of CTLA-4 gene were 75.3% and 24.7% in the patients, and 86.2% and 13.8% in the healthy controls, respectively. The frequencies of A and G alleles in +49A/G SNP of CTLA-4 gene were 33.1% and 66.9% in the patients, and 28.2% and 71.8% in the healthy controls, respectively.The frequencies of G and C alleles in +2379G/C SNP of CD86 gene were 93.3% and 6.7% in the patients, and 92.7% and 7.3% in the healthy controls, respectively.The frequencies of G and C alleles in +1057G/A SNP of CD86 gene were 58.7% and 41.3% in the patients, and 54.8% and 45.2% in the healthy controls, respectively.The frequency of the T allele of the -318C/T in CTLA-4 showed significant association with CB when compared with controls (T allele: p<0.0001). There were 9 haplotypes det ected in patients and controls, among +2379G/C ,+1057G/A ,-318C/T,+49A/G. The haplotype AGGC was associated with 25 percent reduction in CB risk. The haplotype AGGT and GGAT were associated with 304.2 percent and 93.8 percent increase in CB risk. However, we failed to find any association between the four SNP of CB when cases were classified by smoking status or clinical stages (p>0.05). The genotype frequency and allele frequency distribution of rs231775 and rs1129055 in the HAN population of Nanchong Sichuan province were polymorphic, and can be valuable genetic marks for forensic personal identification and paternity testing.ConclusionThe results indicate that the polymorphisms of CTLA-4 (-318C/T) and CD86 (+1057G/A) may be important correlation with chronic bronchitis genetic infection susceptiblilty in the HAN population of Nanchong Sichuan province.