TNF-α promoter single nucleotide polymorphisms and haplotypes associate with susceptibility of immune thrombocytopenia in Chinese adults

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.

Identification of ORM1, vWF, SPARC, and PPBP as immune-related proteins involved in immune thrombocytopenia by quantitative LC-MS/MS

BACKGROUND

Immune thrombocytopenia (ITP) is a common autoimmune disease characterized by loss of immune tolerance to platelet autoantigens leading to excessive destruction and insufficient production of platelets.

METHOD

Quantitative liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed to detect the differentially expressed proteins in bone marrow samples from active ITP patients and normal controls.

RESULT

Our bioinformatic analysis identified two upregulated proteins (ORM1 and vWF) and two downregulated proteins (PPBP and SPARC) related to immune function. The four proteins were all found to be related to the tumor necrosis factor (TNF) -α signalling pathway and involved in the pathogenesis of ITP in KEGG pathway analysis.

CONCLUSION

Bioinformatics analysis identified differentially expressed proteins in bone marrow that are involved in the TNF-α signalling pathway and are related to the activation of immune function in ITP patients. These findings could provide new ideas for research on the loss of immune tolerance in ITP patients.

Single Nucleotide Polymorphisms of the HIF1A Gene are Associated With Sensitivity of Glucocorticoid Treatment in Pediatric ITP Patients

BACKGROUND

Hypoxia-inducible factor-1α (HIF-1α) plays a crucial role in both innate and adaptive immunity. Emerging evidence indicates that HIF-1α is associated with the inflammation and pathologic activities of autoimmune diseases, suggesting that HIF1α may be involved in immune dysregulation in patients with immune thrombocytopenia (ITP). The purpose of this study was to evaluate whether single nucleotide polymorphisms (SNPs) of the HIF1A gene are associated with susceptibility to ITP and its clinical prognosis including incidence of chronic ITP and glucocorticoid sensitivity.

MATERIALS AND METHODS

This study involved 197 Chinese ITP pediatric patients (discovery cohort) and 220 healthy controls. The Sequenom MassArray system (Sequenom, San Diego, CA) was used to detect 3 SNPs genotypes in the HIF1A gene: rs11549465, rs1957757, and rs2057482. We also used another ITP cohort (N=127) to validate the significant results of SNPs found in the discovery cohort.

RESULTS

The frequencies of the three SNPs did not show any significant differences between the ITP and healthy control groups. The CT genotype at rs11549465 was significantly higher in ITP patients sensitive to glucocorticoid treatment than in those insensitive to glucocorticoid treatment (P=0.025). These results were validated using another ITP cohort (N=127, P=0.033). Moreover, the CC genotype was a risk factor for insensitive to GT the odds ratio (95% confidence interval) was 5.96 (5.23-6.69) in standard prednisone (P=0.0069) and 6.35 (5.33-7.37) in high-dose dexamethasone (P=0.04).

CONCLUSIONS

Although HIF1A gene polymorphisms were not associated with susceptibility to ITP, the CT genotype at rs11549465 was associated with the sensitivity to glucocorticoid treatment of ITP patients, suggesting that the rs11549465 SNP may contribute to the sensitivity of glucocorticoid treatment in pediatric ITP patients.

Indirubin regulates MPL and TNF expression in peripheral blood mononuclear cells from patients with primary immune thrombocytopenia

Indirubin, a traditional Chinese medicine, is currently used to treat certain autoimmune diseases such as primary immune thrombocytopenia (ITP) in clinics. However, the effects of indirubin on expression of related genes in peripheral blood mononuclear cells (PBMCs) from ITP patients have not been investigated. In the present study, PBMCs were isolated from 19 adult patients with well-characterized active ITP and 20 healthy controls (HCs) and then treated with increasing concentrations of indirubin. The mRNA expression levels of thrombopoietin receptor (MPL), GATA binding protein 3 (GATA3), DNA methyltransferase 3B (DNMT3B), interleukin-6 (IL6), tumor necrosis factor (TNF), and interferon gamma (IFN-γ) were determined by quantitative real-time polymerase chain reaction (PCR). We found that indirubin had no cytotoxic effect on PBMC viability. Significantly lower MPL (p < 0.05) and GATA3 (p < 0.05) expression together with markedly higher IL6 (p < 0.05), TNF (p < 0.0001), and IFN-γ (p < 0.001) mRNA levels were observed in ITP patients compared with HCs. Notably, indirubin significantly enhanced MPL expression and inhibited TNF expression in PBMCs from ITP patients (p < 0.05). In summary, indirubin may play a direct role in thrombopoiesis by activating cellular MPL and normalizing TNF expression to suppress inflammation in ITP. This study may thus improve our understanding of indirubin and provide important information for optimizing therapeutic strategies for ITP patients.

Association between gene polymorphisms and clinical features in idiopathic thrombocytopenic purpura patients

: Immune thrombocytopenic purpura (ITP) is an autoimmune disease in which increased platelet destruction and thrombocytopenia are diagnostic features. In fact, the exact pathogenesis of this disease is still unknown, but genetic changes can be a potential factor in the development of ITP. In this study, the relationship between polymorphisms with platelet destruction has been studied, which leads to decreased platelet count. Relevant literature was identified by a PubMed search (2000-2016) of English language papers using the terms 'ITP', 'polymorphism,' and 'immune system'. The majority of genetic changes (polymorphisms) occur in immune system genes, including interferon (IFN)-γ gene. These changes lead to the dysfunction of immune system and production of pathogenic antibodies against platelet surface glycoproteins such as glycoprotein IIb/IIIa, which eventually result in the destruction of platelets and increasing disease severity. In addition, IFN-γ as well as factors and cytokines involved in megakaryopoiesis, including stem cell factor and interleukin-3 (IL-3), leads to the differentiation of megakaryocytes and platelet release. Considering the fact that IFN-γ is a factor of inflammation and thrombocytopenia, coexistence of this cytokine with thrombopoietin, stem cell factor, and IL-3 results in megakaryocytes differentiation and platelet production, which can be effective to reduce disease severity and increase the platelet counts.

TNF-α -308 A allele is associated with an increased risk of distant metastasis in rectal cancer patients from Southwestern China

Tumor necrosis factor-α (TNF-α), an important factor in systematic inflammation, is reportedly involved in several cancer types. The TNF-α -308 G>A (rs1800629) polymorphism in the promoter region influences TNF-α production. The association between TNF-α -308 G>A polymorphism and colorectal cancer (CRC) is not fully understood, especially the connections between TNF-α -308 G>A polymorphism and clinical features of CRC. In this study, TNF-α -308 G>A polymorphism was genotyped in 1140 individuals with or without CRC from Southwestern China. In case-control studies, we found no association between TNF-α -308 G>A polymorphism and CRC risk. Analysis of the correlations between TNF-α -308 G>A polymorphism and clinical features of CRC revealed that TNF-α -308 A allele was associated with higher body mass index (BMI) larger tumor size, and distant tumor metastasis in all CRC patients. Notably, rectal cancer (a subtype of CRC) patients with TNF-α -308 A allele had a very high risk of distant tumor metastasis [odds ratio (OR) = 4.481; 95% confidence interval (CI): 2.072–9.693; P = 0.00025]. The association between TNF-α -308 A allele and distant tumor metastasis remained even significant after adjusting all clinical characteristics (OR = 7.099; 95% CI: 2.482–20.301; P = 0.000256) in rectal cancer patients. Our results suggested that TNF-α -308 A allele was significantly associated with distant tumor metastasis in rectal cancer patients.