PTPN22-1123G > C polymorphism is associated with susceptibility to primary immune thrombocytopenia in Chinese population

Association of PTPN22 SNP1858 (rs2476601) and Gene SNP1123 (rs2488457) Polymorphism With Primary Immune Thrombocytopenia Susceptibility: A Meta-Analysis of Case-Control Studies and Trial Sequential Analysis

Objective: Systematic review of the association of protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene 1858 and 1123 sites single nucleotide polymorphism (SNP) with the susceptibility of primary immune thrombocytopenia (ITP).

Method: Database searched includes PubMed, Embase, Web of Science, CNKI, CBM, VIP and WanFang Data. The retrieval period is from the establishment of the database to 30 June 2021. After screening articles according to inclusion and exclusion criteria, the data were extracted and methodological quality of the included studies was evaluated. Meta-analysis was performed using RevMan 5.4 and Stata 16.0 software. The combined OR value and its 95%CI were calculated. Sensitivity analysis and publication bias assessment were performed. Trial sequential analysis (TSA) was performed using TSA 0.9.5.10 Beta software.

Results: A total of 10 studies with 10 articles were included, with a total of 932 cases and 2,112 controls. The results of meta-analysis showed that for SNP1858, the susceptibility of TT genotype to ITP was 5.01 times higher than CC genotype [95%CI (1.81, 13.86), p = 0.002]. For SNP1123, G allele carriers were more susceptible to ITP than C allele carriers [OR = 1.23, 95%CI (1.05, 1.45), p = 0.01], and GG genotype carriers were 1.51 times more susceptible to ITP than CC genotype carriers [95%CI (1.11, 2.06), p = 0.009]. Although the results are statistically significant, the results of sensitivity analysis showed certain limitations of stability, and the TSA analysis still indicated the possibility of false positive. No significant publication bias was observed.

Conclusion: PTPN22 gene SNP1858 (rs2476601) and SNP1123 (rs2488457) polymorphisms are associated with susceptibility to primary immune thrombocytopenia. Due to the limitation of the number and quality of the included studies, the above conclusions need to be verified by more high-quality studies.

PTPN22 gene polymorphism as a genetic risk factor for primary immune thrombocytopenia in Egyptian children

OBJECTIVES

Several genetic and non-genetic risk factors are implicated in the etiology and pathogenesis of primary immune thrombocytopenia (ITP). Protein tyrosine phosphatase non-receptor 22 gene (PTPN22) plays an important role in regulation of signal transduction through the T-cell receptors. PTPN22 1858 C > T single nucleotide polymorphism was reported to be associated with increased risk of autoimmune diseases. There are very few studies investigating the role of PTPN22(SNP) 1858 C > T in childhood ITP.

METHODS

This case-control study was designed for assessing the contribution of PTPN22 1858 C > T polymorphism to the risk of ITP in Egyptian children. Eighty children with newly diagnosed ITP were recruited from pediatric hematology out-patient clinic. Also, eighty age and sex-matched healthy children were enrolled as a control group. PTPN22 1858 C/T SNP gene polymorphism was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Frequency of PTPN22 1858 C/T genotypes CT, CC, and TT were 32.5,55, and 12.5% in patients versus 10, 90, and 0% in controls (p < 0.05).TT genotype was significantly associated with higher risk of ITP (OR = 17.8(0.94-333.35), 95% CI, and P = 0.02).

CONCLUSION

PTPN22 gene polymorphism may play a pivotal role in genetic predisposition to ITP and disease progress in Egyptian children.

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.

A functional variant of PTPN22 confers risk for Vogt-Koyanagi-Harada syndrome but not for ankylosing spondylitis

BACKGROUND

Protein tyrosine phosphatase non-receptor 22 (PTPN22) is a key negative regulator of T lymphocytes and has emerged as an important candidate susceptibility factor for a number of immune-related diseases. This study aimed to examine the predisposition of PTPN22 SNPs to Vogt-Koyanagi-Harada (VKH) syndrome and acute anterior uveitis (AAU) associated with ankylosing spondylitis (AS).

METHODS

A total of 1005 VKH syndrome, 302 AAU+AS+ patients and 2010 normal controls among the Chinese Han population were enrolled in the study. Genotyping, PTPN22 expression, cell proliferation, cytokine production and cell activation were examined by PCR-RFLP, Real-time PCR, CCK8, ELISA and Flow cytometry.

RESULTS

The results showed significantly increased frequencies of the rs2488457 CC genotype and C allele but a decreased frequency of the GG genotype in VKH syndrome patients (PBonferroni correction (Pc) = 3.47×10(-7), OR = 1.54; Pc = 3.83×10(-8), OR = 1.40; Pc = 6.35×10(-4), OR = 0.62; respectively). No significant association of the tested SNPs with AAU+AS+ patients was observed. Functional studies showed a decreased PTPN22 expression, impaired cell proliferation and lower production of IL-10 in rs2488457 CC cases compared to GG cases (Pc = 0.009, Pc = 0.015 and Pc = 0.048 respectively). No significant association was observed concerning T cell activation and rs2488457 genotype.

CONCLUSIONS

The study showed that a functional variant of PTPN22 confers risk for VKH syndrome but not for AAU+AS+ in a Chinese Han population, which may be due to a modulation of the PTPN22 expression, PBMC proliferation and IL-10 production.