Role of TNF −308 G/A, TNFβ +252 A/G and IL10 −592 C/A and −1082 G/A SNPs in pathogenesis of Immune Thrombocytopenia Purpura in population of Gujarat, India

TNFα-308G>A Polymorphism and Susceptibility to Immune Thrombocytopenia Purpura (ITP): Evidence From a Systematic Review and Meta-analysis

BACKGROUND

Relation between the emergence of ITP and the presence of TNFα 308G/A polymorphism in the involved individuals has been studied by previous researchers in different ethnicity, but a definite result was not gained. So, this meta-analysis was performed to find an absolute answer to the question whether TNF-α-308G/A polymorphism is a susceptibility factor for ITP or not?

METHODS

Electronic databases including PubMed, Google scholar, and Science Direct were searched and case control studies compatible to the defined inclusion criteria were selected; their references were also evaluated manually. Pooled OR with 95 % confidence intervals (CIs) as a strength of association between TNF-α-308G/A polymorphism and risk of ITP were calculated using a random-effect model. Funnel plot and Egger's linear regression test were conducted to examine the risk of publication bias.

RESULTS

Totally, 16 eligible articles were found involving 1470 ITP cases and 2324 healthy controls. The Meta-results revealed that TNFα 308G/A polymorphism is associated with increased risk of ITP under the genetic models of recessive (OR: 1.54, 95 % CI: 1.03-2.29), dominant (OR: 2.29, 95 % CI: 1.44-3.64), and the heterozygote (OR: 2.46, 95 % CI:1.49-4.6). Subgroup analysis suggested a remarkable role for this SNP as a risk factor in the Caucasian ethnicity and the chronic subtype.

CONCLUSION

TNFα 308G/A polymorphism can be an ITP susceptibility factor in the Caucasian population and the chronic subtype. Although more studies in large scale are needed for clinical decision but this finding can be used in the clinical trials to prevent the ITP consequences in the involved individuals.

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.

Relationship between the IL-10 (-1082 A/G) polymorphism and the risk of immune/idiopathic thrombocytopenic purpura: A meta-analysis

BACKGROUND

The association of the IL-10 gene polymorphism with immune thrombocytopenic purpura (ITP, also called idiopathic thrombocytopenic purpura) susceptibility has been investigated in several studies; however, the association remains controversial. The present meta-analysis aimed to determine whether the IL-10 (-1082) polymorphism is associated with an increased risk of ITP.

MATERIALS AND METHODS

Eligible articles were searched in EMBASE, PubMed, CNKI, WanFang, and HuGE Navigator, without any restriction of publication language. The odds ratios (ORs) and 95% confidence intervals (CIs) were used to identify any potential associations between the IL-10 (-1082 A/G) polymorphism and the risk of ITP.

RESULTS

This meta-analysis included six eligible studies with 384 cases and 409 controls. There was no significant association between the IL-10 (-1082) polymorphism and the risk of ITP in any of the genetic models. Three subgroups were stratified according to population ethnicity, disease subtype (acute or chronic), and age (child or adult). No statistically significant differences were observed in age and ethnicity between cases and controls. However, subtype analysis indicated significant associations for acute ITP in the allele model (OR = 1.76, 95% CI = [1.07; 2,89]), the recessive model (OR = 2.66, 95% CI = [1.17; 6.07]), and the homozygote model (OR = 2.65, 95% CI = [1.07; 6.55]).

CONCLUSIONS

There is scarce evidence to confirm an association between the IL-10 (-1082) polymorphism and the risk of ITP. However, the IL-10 (-1082) polymorphism might be associated with the risk of acute ITP. Additional large, well-designed epidemiological studies should be performed to draw definitive conclusions.