PTPN22 1858C>T gene polymorphism in patients with SLE: association with serological and clinical results

Regulation of activated T cell survival in rheumatic autoimmune diseases

Adaptive immune responses rely on the proliferation of T lymphocytes able to recognize and eliminate pathogens. The magnitude and duration of the expansion of activated T cell clones are finely regulated to minimize immunopathology and avoid autoimmunity. In patients with rheumatic autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis, activated lymphocytes survive and exert effector functions for prolonged periods, defying the mechanisms that normally curb their capacities during acute and chronic infections. Here, we review the molecular mechanisms that limit the duration of immune responses in health and discuss the factors that alter such regulation in the setting of systemic lupus erythematosus and rheumatoid arthritis. We highlight defects that could contribute to the development and progression of autoimmune disease and describe how chronic inflammation can alter the regulation of activated lymphocyte survival, promoting its perpetuation. These concepts might contribute to the understanding of the mechanisms that underlie the chronicity of inflammation in the context of autoimmunity.

Association of the single nucleotide polymorphism C1858T of the PTPN22 gene with unexplained recurrent pregnancy loss: A case-control study

Background

Lymphoid-tyrosine-phosphatase which is encoded by the protein tyrosine phosphatase non-receptor 22 (PTPN22) gene plays a pivotal role in the regulation of immune responses by dephosphorylating several signaling intermediates of immune cells.

Objective

Since a balanced immune response has been shown to be important during pregnancy, the purpose of this research was to compare the frequency of the PTPN22 C1858T polymorphism in women with unexplained recurrent pregnancy loss (URPL) vs. in a control group for the first time.

Materials and Methods

Genomic DNA from 200 individuals with URPL and 200 individuals without URPL (the control group) at the infertility center in Yazd, Iran was isolated using the salting-out method. The PTPN22 C1858T polymorphism of the two groups was analyzed using polymerase chain reaction-restriction fragment length polymorphism. Genotype frequencies in the women with URPL and the fertile control group were compared using the Chi-square test.

Results

There were significant differences in the frequency of the PTPN22 1858T polymorphism in the URPL individuals vs. the healthy controls, i.e. 32.0% and 21.5%, respectively (p = 0.01).

Conclusion

Our findings suggest that the PTPN22 1858T polymorphism could play a role in recurrent pregnancy loss. Therefore, genotyping of the mentioned polymorphism can help clinicians to predict the probable risk of URPL.

Tumor necrosis factor receptor II and PTPN22 genes polymorphisms and the risk of systemic lupus erythematosus in Egyptian children

BACKGROUND

Many genes have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Tumor necrosis factor (TNF) is a potent cytokine stimulator acting through 2 cell surface receptors (TNFR I and II). TNFRII gene which controls expression of these receptors has been linked to SLE susceptibility through promoting apoptosis. Also; Protein tyrosine phosphatase non receptor 22 (PTPN22) gene enhances intrinsic phosphatase activity of T lymphocytes leading to their dysregulation and stimulates autoimmune process of lupus and its rs2476601 has been linked to susceptibility to thyroiditis in SLE patients in few studies.

OBJECTIVES

(i) to investigate the correlation between 2 SNPs of TNFR II and PTPN22 genes and SLE susceptibility in a cohort of Egyptian children compared to controls (ii) and to investigate their possible association with different clinical presentations of the disease in children.

SUBJECTS AND METHODS

Typing of TNFR II rs1061622 and PTPN22 rs2476601 SNPs were done using polymerase chain reaction-restriction fragment length polymorphism for 74 children with SLE and 100 matched healthy controls.

RESULTS

Children with SLE had more frequent G allele and GG genotype of TNFR II rs1061622 (p < 0.001) and more T allele and TT genotype of PTPN22 rs2476601 (p = 0.012 and <0.001, respectively) compared to controls. Only 6 patients (8%) had thyroiditis (hypothyroidism) with T allele and TT genotype of PTPN22 1858 T more prevalent in those patients versus those without thyroiditis (p ≤ 0.001). Apart from, thyroiditis, no significant association was found between genotypes and alleles frequencies of the 2 studied SNPs and other clinical manifestations of the disease.

CONCLUSION

The G allele and GG genotype of TNFR II rs1061622 and T allele and TT genotype of PTPN22 rs2476601 genes polymorphism can be considered as risk factors for the development of SLE. The presence of the T allele of PTPN22 rs2476601 may increase the risk of concomitant thyroiditis in Egyptian children with SLE but further studies are required to confirm this finding as thyroiditis was reported only in few cases in this study.

Genetic Factors in Antiphospholipid Syndrome: Preliminary Experience with Whole Exome Sequencing

As in many autoimmune diseases, the pathogenesis of the antiphospholipid syndrome (APS) is the result of a complex interplay between predisposing genes and triggering environmental factors, leading to a loss of self-tolerance and immune-mediated tissue damage. While the first genetic studies in APS focused primarily on the human leukocytes antigen system (HLA) region, more recent data highlighted the role of other genes in APS susceptibility, including those involved in the immune response and in the hemostatic process. In order to join this intriguing debate, we analyzed the single-nucleotide polymorphisms (SNPs) derived from the whole exome sequencing (WES) of two siblings affected by APS and compared our findings with the available literature. We identified genes encoding proteins involved in the hemostatic process, the immune response, and the phospholipid metabolism (PLA2G6, HSPG2, BCL3, ZFAT, ATP2B2, CRTC3, and ADCY3) of potential interest when debating the pathogenesis of the syndrome. The study of the selected SNPs in a larger cohort of APS patients and the integration of WES results with the network-based approaches will help decipher the genetic risk factors involved in the diverse clinical features of APS.

Modulation of TCR Signaling by Tyrosine Phosphatases: From Autoimmunity to Immunotherapy

Early TCR signaling is dependent on rapid phosphorylation and dephosphorylation of multiple signaling and adaptor proteins, leading to T cell activation. This process is tightly regulated by an intricate web of interactions between kinases and phosphatases. A number of tyrosine phosphatases have been shown to modulate T cell responses and thus alter T cell fate by negatively regulating early TCR signaling. Mutations in some of these enzymes are associated with enhanced predisposition to autoimmunity in humans, and mouse models deficient in orthologous genes often show T cell hyper-activation. Therefore, phosphatases are emerging as potential targets in situations where it is desirable to enhance T cell responses, such as immune responses to tumors. In this review, we summarize the current knowledge about tyrosine phosphatases that regulate early TCR signaling and discuss their involvement in autoimmunity and their potential as targets for tumor immunotherapy.

Genetics of Antiphospholipid Syndrome

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is a rare heterogenous disorder associated with the presence of antiphospholipid antibodies and can present in a wide variety of clinical manifestations including thrombosis and pregnancy complications. Although the etiology of APS remains poorly understood, there is strong support for considering APS as a complex genetic disease in which multiple genetic risk factors, in conjunction with environmental factors, affect its onset, progression, and severity. Here, we provide a comprehensive review of the current knowledge of the genetic basis of APS, which remains in its infancy.

RECENT FINDINGS

Most genetic studies to date in APS were performed in small cohorts of patients. As a result, only few genetic associations reported are convincing. Several reports suggested genetic associations with HLA class II alleles in APS, and only two genetic loci outside of the HLA region (STAT4 and C1D) reached the threshold for genome-wide level of significance (P < 5 × 10^-8). In this review, we also shed light on the genetic differences among the diverse clinical subsets of APS and briefly discuss the role that DNA methylation changes might play in the pathophysiology of this disease. The genetic basis of APS remains poorly characterized. Larger collaborative multicenter studies using well-characterized patients are needed to comprehensively understand the role of genetic susceptibility in APS.

The Contribution of PTPN22 to Rheumatic Disease

One of the unresolved questions in modern medicine is why certain individuals develop a disorder such as rheumatoid arthritis (RA) or lupus, while others do not. Contemporary science indicates that genetics is partly responsible for disease development, while environmental and stochastic factors also play a role. Among the many genes that increase the risk of autoimmune conditions, the risk allele encoding the W620 variant of protein tyrosine phosphatase N22 (PTPN22) is shared between multiple rheumatic diseases, suggesting that it plays a fundamental role in the development of immune dysfunction. Herein, we discuss how the presence of the PTPN22 risk allele may shape the signs and symptoms of these diseases. Besides the emerging clarity regarding how PTPN22 tunes T and B cell antigen receptor signaling, we discuss recent discoveries of important functions of PTPN22 in myeloid cell lineages. Taken together, these new insights reveal important clues to the molecular mechanisms of prevalent diseases like RA and lupus and may open new avenues for the development of personalized therapies that spare the normal function of the immune system.

TP53 single nucleotide polymorphism (rs1042522) in Iranian patients with coronary artery disease

Chronic diseases including coronary artery disease (CAD) impose a high burden in terms of mortality and disability particularly in developing countries. Both genetic and environmental risk factors confer susceptibility to CAD. Meanwhile, a functional polymorphism in the tumor protein p53 (TP53) gene (codon 72, exon 4) has been reported to be associated with a wide range of cancers and inflammatory disorders. There are controversies regarding CAD and involvement of the TP53 codon 72 single nucleotide polymorphism; therefore, the present case-control study was conducted to evaluate the potential association between this TP53 polymorphism and CAD in an Iranian population. A total of 153 subjects (including 70 patients diagnosed with CAD and 83 subjects with normal coronary parameters, determined by angiography) were genotyped for the TP53 (rs1042522) polymorphism by the polymerase chain reaction-restriction fragment length polymorphism technique. Clinical and laboratory findings were also evaluated. The χ² test and unpaired Student's t-test were applied to compare genotype and allele distributions and clinical characteristics between the two groups. Significant associations of the Pro72 allele [odds ratio (OR)=1.66, P=0.027] and Pro/Pro genotype (OR=2.91, P=0.022) with CAD were identified. No associations between patients' clinical findings and genotypes were apparent. Therefore, according to present findings, the TP53 Pro72 allele may be involved in the development of CAD along with conventional risk factors in patients from Northern Iran.

PTPN22 1858C > T polymorphism and susceptibility to systemic lupus erythematosus: a meta-analysis update

Studies performed in the past years showed PTNP22 1858 C > T (rs2476601) polymorphism as associated with systemic lupus erythematosus susceptibility, although conflicting findings are still found. In this context, a powerful statistical study, such as meta-analysis, is necessary to establish a consensus. The aim of this study was to evaluate association studies between the PTPN22 1858 C > T polymorphism and SLE by a meta-analysis update, including three recently published studies in the last three years. A total of 3868 SLE patients and 7458 healthy individuals were considered herein, enclosing 19 studies from Asian, American, European and Latin ethnic groups. Odds ratio (OR) was performed for allelic, dominant and recessive genetic models. Statistically significant association was found between the PTPN22 1858 C > T polymorphism and susceptibility to SLE in all inheritance models. Allelic genetic model data (OR = 1.54, 95% confidence interval (CI) = 1.38-1.72, p value=.000) shows that T allele confers increased SLE susceptibility. As well as recessive genetic model (OR = 2.04, 95% CI = 1.09-3.82, p value = .030) for T/T genotype. Instead, dominant genetic model shows that C/C genotype confers lower susceptibility for SLE development (OR = 0.62, 95% CI = 0.54-0.72, p value = .000). In addition, we provided an ethnicity-derived meta-analysis. The results showed association in Caucasian (OR = 1.47, p value = .000) and Latin (OR = 2.41, p value = .000) ethnic groups. However, rs2476601 polymorphism is not associated nor in Asian (OR= 1.31; p value = .54) and African (OR = 2.04; p value=.22) populations. In conclusion, present meta-analysis update confirms that T allele and T/T genotype in PTPN22 1858 C > T polymorphism confers SLE susceptibility, particular in Caucasian and Latin groups, suggesting PTPN22 1858 C > T as a potential genetic marker in SLE susceptibility.

RNASET2, GPR174, and PTPN22 gene polymorphisms are related to the risk of liver damage associated with the hyperthyroidism in patients with Graves' disease

OBJECTIVES

This study was designed to unveil the association of GPR174 rs3827440, PTPN22 rs3789604, and RNASET2 rs9355610 with the onset of liver damage (LD) among the Graves' disease (GD) patients.

METHODS

A total of 120 GD patients were divided into the none-LD and LD groups. Several indicators were detected for assessing liver functions, and genotypes of single nucleotide polymorphisms (SNPs) were identified. Logistic regression was introduced for investigating the relationship between risk SNPs and LD-associated hyperthyroidism in GD patients.

RESULTS

Significant differences were identified between LD and none-LD groups regarding genotype distributions of rs3827440, rs3789604, and rs9355610. Results from logistic regression indicted that among the GD patients, C carriers of PTPN22 rs3789604 were associated with a higher risk of LD-associated hyperthyroidism, while C carriers of rs3827440 (GPR174) and G carriers of rs9355610 (RNASET2) were associated with a reduced risk of LD-associated hyperthyroidism.

CONCLUSIONS

The C allele of rs3789604 (PTPN22) was a significant risk factor for LD-associated hyperthyroidism in GD patients, whereas C allele of GPR174 rs3827440 and G allele of RNASET2 rs9355610 appeared to be a protective factor for this disease.

Associations between PTPN22 and TLR9 polymorphisms and systemic lupus erythematosus: a comprehensive meta-analysis

Previous studies have explored the relationship of PTPN22 and TLR9 polymorphisms with systemic lupus erythematosus (SLE). In consideration of the population stratification, conflicting results and updating data, we conducted a comprehensive meta-analysis, which consists of a total of 17 research articles (9120 cases and 11,724 controls) for PTPN22 and 20 articles (including up to 2808 cases and 3386 controls) for TLR9. Significant association was verified between PTPN22 rs2476601 and SLE in the overall population (OR = 1.511 per T allele, 95% CI 1.338-1.706, P = 2.931 × 10^-11) and under dominant model of T allele (TT+CT vs. CC: OR = 1.531, 95% CI 1.346-1.742, P = 9.17 × 10^-11). Analysis after stratification by ethnicity indicated that PTPN22 rs2476601 was related to SLE in Americans (OR = 2.566, 95% CI 1.796-3.665, P = 2.219 × 10^-7), Europeans (OR = 1.399, 95% CI 1.261-1.552, P = 2.153 × 10^-10), and Africans (OR = 4.14, 95% CI 1.753-9.775, P = 1.0 × 10^-3). We did not observe any association between TLR9 polymorphisms (rs187084, rs352140, rs5743836 and rs352139) and SLE under any model, after excluding the data that were inconsistent with Hardy-Weinberg equilibrium (HWE). In summary, PTPN22 rs2476601 was significantly interrelated with SLE and contributed to susceptibility and development of SLE in Americans, Europeans and Africans in this analysis, while their relationship needs to be validated in Africans by future research.

A polymorphism upstream MIR1279 gene is associated with pericarditis development in Systemic Lupus Erythematosus and contributes to definition of a genetic risk profile for this complication

Recently, a study has shown that a polymorphism in the region of MIR1279 modulates the expression of the TRAF3IP2 gene. Since polymorphisms in the TRAF3IP2 gene have been described in association with systemic lupus erithematosus (SLE) susceptibility and with the development of pericarditis, our aim is to verify if the MIR1279 gene variability could also be involved. The rs1463335 SNP, located upstream MIR1279 gene, was analyzed by allelic discrimination assay in 315 Italian SLE patients and 201 healthy controls. Moreover, the MIR1279 gene was full sequenced in 50 patients. A case/control association study and a genotype/phenotype correlation analysis were performed. We also constructed a pericarditis genetic risk profile for patients with SLE. The full sequencing of the MIR1279 gene in patients with SLE did not reveal any novel or known variation. The variant allele of the rs1463335 SNP was significantly associated with susceptibility to pericarditis ( P = 0.017 and OR = 1.67). A risk profile model for pericarditis considering the risk alleles of MIR1279 and three other genes (STAT4, PTPN2 and TRAF3IP2) showed that patients with 4 or 5 risk alleles have a higher risk of developing pericarditis ( OR = 4.09 with P = 0.001 and OR = 6.04 with P = 0.04 respectively). In conclusion, we describe for the first time the contribution of a MIR1279 SNP in pericarditis development in patients with SLE and a genetic risk profile model that could be useful to identify patients more susceptible to developing pericarditis in SLE. This approach could help to improve the prediction and the management of this complication.

PTPN22 Variant R620W Is Associated With Reduced Toll-like Receptor 7-Induced Type I Interferon in Systemic Lupus Erythematosus

OBJECTIVE

Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) is associated with an increased risk of systemic lupus erythematosus (SLE). PTPN22 encodes Lyp, and a disease-associated coding variant bears an R620W substitution (LypW). LypW carriage is associated with impaired production of type I interferon (IFN) by myeloid cells following Toll-like receptor (TLR) engagement. The aim of this study was to investigate the effects of LypW carriage on TLR signaling in patients with SLE.

METHODS

Plasma IFNα concentrations and whole-blood IFN gene scores were compared in SLE patients who were LypW carriers and those who were noncarriers. TLR-7 agonist R848-stimulated IFNα and tumor necrosis factor levels, IFN-dependent gene expression, and STAT-1 activation were determined in peripheral blood mononuclear cells (PBMCs) and/or plasmacytoid dendritic cells (PDCs) obtained from these patients. The effect of LypW expression on the systemic type I IFN response to R848 stimulation in vivo was assessed in transgenic mice.

RESULTS

Plasma IFNα levels and whole-blood IFN gene signatures were comparable in SLE patients who were LypW carriers and those who were noncarriers. However, PBMCs from LypW carriers produced less IFNα and showed reduced IFN-dependent gene up-regulation and STAT-1 activation after R848 stimulation. The frequency of PDCs producing IFNα2 and the per-cell IFNα2 levels were significantly reduced in LypW carriers. LypW-transgenic mice displayed reduced TLR-7-induced circulating type I IFN responses.

CONCLUSION

PDCs from SLE patients carrying the disease-associated PTPN22 variant LypW showed a reduced capacity for TLR-7 agonist-induced type I IFN production, even though LypW carriers displayed systemic type I IFN activation comparable with that observed in noncarriers. LypW carriage identifies SLE patients who may harbor defects in TLR- and PDC-dependent host defense or antiinflammatory functions.

The Association between PTPN22 Genetic Polymorphism and Juvenile Idiopathic Arthritis (JIA) Susceptibility: An Updated Meta-Analysis

BACKGROUND

Limited studies have focused on the association between the protein tyrosine phosphates non-receptor type 22 (PTPN22) genetic polymorphisms and Juvenile idiopathic arthritis (JIA) susceptibility in different populations, but the results were inconclusive. Therefore, this meta-analysis of PTPN22 polymorphism (1858 C>T) was performed to get a precise systematic estimation. The "rs" number of the PTPN22 polymorphism (1858 C>T) is 4.

METHODS

A systematic literature search strategy was carried out using English databases (PubMed, Embase.) for the eligible studies. We ultimately identified 11 records from 10 articles involving the relationship between PTPN22 genetic polymorphisms and JIA risk from PubMed and Embase databases. Overall, 4552 cases and 10161 controls were investigated in this study to evaluate the association between PTPN22 (C allele vs. T allele) genotype and JIA susceptibility.

RESULTS

Analysis using random effects model showed an increased risk of JIA with T allele of rs2476601 vs. A allele (P<0.001). Subgroup analysis suggested that the PTPN22 polymorphism (1858C>T) was significantly associated with JIA risk in America population (OR=1.52, 95% CI:1.30-1.78). Additionally, the subgroup analysis also showed that the associations were still significant in case number more than 500 (OR=1.38, 95% CI: 1.04-1.83), while in the case number less than 500 was OR=1.55, 95% CI: 1.39-1.72.

CONCLUSIONS

SNPs of PTPN22 (1858C>T) showed an increased risk of developing JIA.