Frequency distribution of interleukin-10 haplotypes (-1082 A>G, -819 C>T, and -592 C>A) in a Mexican population

Polymorphism of the IL-10 gene in Azeri population of Iran

Background

Interleukin (IL)-10 is one of the key interleukins in the immune system. It plays an anti-inflammatory role in body by inhibition of the synthesis of pro-inflammatory cytokines and reducing the expression of major histocompatibility complex II molecules. The single-nucleotide polymorphism in the gene of this interleukin affects its expression level. Thus, this study was conducted to investigate the IL-10 gene polymorphism at position -1082A/G in Azeri population of Iran.

Methods

Blood samples were taken from 254 healthy and non-relevant Iranian Azeri individuals. After DNA extraction, the frequency of IL-10 genotypes and alleles at -1082A/G position was determined by allele specific-PCR method. Then, q-square test was used to compare allele frequencies and IL-10 genotypes with other populations, and p value of < 0.05 was considered significant.

Results

In Iranian Azeri population, the frequency percentage of AA, AG and GG genotypes in IL-10 gene at the -1082A/G location was 37.4, 43.3 and 19.3%, respectively. The frequency percentage of A and G alleles also were 59.1 and 40.9%, respectively. Based on statistical analysis, frequency of IL-10 genotypes in the current study was very similar to the population of Saudi Arabia, but it had a significant difference with East Asia and Ireland populations.

Conclusion

Results of the present study indicate similar polymorphism of IL-10 genotype with neighbor ethnicities in Middle East country. Based on patients backgrounds mentioned in their questioners, this polymorphism was associated with the susceptibility to asthma and Alzheimer in this population which are common in the region.

Interleukin-10 Gene Promoter Polymorphisms and Susceptibility to Asthma: Systematic Review and Meta-analysis

Several studies have previously assessed the association between interleukin (IL)-10 gene polymorphisms and the risk of asthma, leading to conflicting results. To resolve the incongruent outcomes yielded from different single studies, we conducted the most up-to-date meta-analysis of the IL-10 gene rs1800896, rs1800871, and rs1800872 single-nucleotide polymorphisms (SNPs) and susceptibility to asthma. A systematic literature search performed until April 2020, and the pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were calculated to determine the association strength. Thirty articles comprising 5678 asthmatic patients and 6079 controls met the inclusion criteria. No significant association was found between rs1800872 SNP and susceptibility to asthma across all genetic models in the overall and subgroup analyses. The rs1800871 SNP had only significant association with a decreased risk of asthma in Europeans (OR 0.66, CI 0.53-0.82, P < 0.001). However, rs1800896 SNP was significantly associated with a decreased risk of asthma by dominant (OR 0.67, CI 0.50-0.90, P < 0.001) and heterozygote (OR 0.66, CI 0.49-0.88, P < 0.001) models in the overall analysis. Subgroup analyses indicated significant association of rs1800896 SNP by dominant (OR 0.45, CI 0.28-0.72, P < 0.001) and heterozygote (OR 0.43, CI 0.26-0.70, P < 0.001) models in the African population. The IL-10 rs1800896 SNP confers protection against the risk of asthma, especially in Africans. Additionally, rs1800871 SNP has a protective role against asthma in Europeans.

IL10 haplotypes are associated with diabetic nephropathy susceptibility in patients from western Mexico

INTRODUCTION

Diabetic Nephropathy (DN) is the main cause of chronic kidney disease (CKD) in diabetic patients. An IL-10 imbalance could be related to renal hypertrophy and trigger to nephropathy. Three promoter polymorphisms (-1082G>A, -819C>T, and -592C>A) at IL10 gene have been associated with changes in the IL-10 expression and DN susceptibility. Therefore, the aim of this study was to analyze this association in Mexican patients with DN.

METHODS

We conducted a case-control study on 128 patients with DN and 150 control subjects (CS) from western Mexico. All patients were tested for IL10 polymorphisms by PCR-RFLP. Allele frequencies, genotypes, and haplotypes were compared between groups. The significant haplotypes were correlated with patient clinical features.

RESULTS

IL10 gene ATC haplotype (-1082A/-819T/-592C) was found significantly more frequent in DN patients than in CS (P < 0.001; OR = 3.6, 95% CI: 1.7-7.4). Similarly GTA (-1082G/-819T/-592A) haplotype was more frequent in DN patients than CS with significant differences (P < 0.05; OR = 4.02, 95% CI: 1.10-14.78). There were no correlations between IL10 haplotypes and clinical parameters in patients with DN. However, that there is a trend of higher serum urea levels and lower eGFR in ATC haplotype carriers compared to carriers of the other haplotypes (P < 0.05).

CONCLUSIONS

These results indicate that IL10 promoter haplotypes ATC and GTA carriers have a higher risk factor to develop DN in the western Mexican population.