Endoplasmic reticulum aminopeptidase 2 gene single nucleotide polymorphisms in association with susceptibility to ankylosing spondylitis in an Iranian population

The association between endoplasmic reticulum aminopeptidase 2 gene single nucleotide polymorphisms and the risk of psoriasis and psoriatic arthritis in Egyptians

BACKGROUND

Psoriasis (Ps) is a disorder attributed to the immune system that involves inflammation of the skin and joints. Psoriasis is a multifactorial disorder in which genetic factors represent about 70% of the disease risk. This study aims to establish the correlation between the ERAP2 gene's single nucleotide polymorphisms (SNPs) rs2910686 and rs2248374 with the susceptibility to Ps and/or psoriatic arthritis (PsA) among the Egyptian population.

METHODS AND RESULTS

Genotyping of ERAP2 gene SNPs (rs2910686 and rs2248374) in 120 psoriatic patients with and without arthritis and 100 controls was done using real-time PCR. The genotype frequency and distribution of the ERAP2 SNP (rs2910686 and rs2248374) were in Hardy-Weinberg equilibrium (HWE). For rs2910686, the TC and CC genotypes and C allele frequency were significant risk factors for PsA compared to the controls (OR = 5.708, OR = 10.165, and OR = 4.282, respectively). They also were significant risk factors for Ps compared to the controls (OR = 5.165, OR = 5.040, and OR = 3.258, respectively). For rs2248374, the AG genotype significantly increased the risk of PsA (OR = 2.605) and Ps (OR = 3.768) compared to controls. The AG genotype was significantly related to the risk of Ps (OR = 3.369) G allele with PsA (OR = 1.608) and Ps (OR = 1.965) compared to controls.

CONCLUSION

In Egyptian individuals, the ERAP2 gene polymorphisms (rs2248374 and rs2910686) may contribute genetically to the pathophysiology of psoriasis and PsA.

A study of the association between single nucleotide polymorphisms of the endoplasmic reticulum aminopeptidase 2 (ERAP2) gene and the risk of ankylosing spondylitis in Egyptians

BACKGROUND

Ankylosing spondylitis (AS) is often regarded as the prototypical manifestation of spondylo-arthropathies that prevalently involves the axial skeleton with the potential attribution of ERAP2 polymorphisms to AS predisposition. The purpose of this study was to determine the genetic association between ERAP2 gene rs2910686, and rs2248374 single nucleotide polymorphisms (SNPs) and the risk of ankylosing spondylitis in the Egyptian population.

METHODS AND RESULTS

A cross-sectional work involved 200 individuals: 100 AS individuals diagnosed based on modified New York criteria in 1984 with 100 healthy controls matched in age and gender. The study included a comprehensive evaluation of historical data, clinical examinations, and evaluation of the activity of the disease using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). A comprehensive laboratory and radiological evaluation were conducted, accompanied by an assessment and genotyping of the ERAP2 gene variants rs2248374 and rs2910686. This genotyping was performed utilizing a real-time allelic discrimination methodology.Highly statistically substantial variations existed among the AS patients and the healthy control group regarding rs2910686 and rs2248374 alleles. There was a statistically significant difference between rs2910686 and rs2248374 regarding BASDAI, BASFI, mSASSS, ASQoL, V.A.S, E.S.R, and BASMI in the active AS group.

CONCLUSIONS

ERAP2 gene SNPs have been identified as valuable diagnostic biomarkers for AS patients in the Egyptian population being a sensitive and non-invasive approach for AS diagnosis especially rs2910686. Highly statistically significant variations existed among the AS patients and the healthy control group regarding rs2910686 alleles and genotypes.Further research is recommended to explore the potential therapeutic implications of these SNPs.

Searching for New Genetic Biomarkers of Axial Spondyloarthritis

Background: Axial spondyloarthritis (axSpA) is a chronic inflammatory condition of the spine. In addition to musculoskeletal symptoms, there are also extra-articular manifestations. The aim of this study was to search for new biomarkers associated with the clinical presentation and treatment response in axSpA patients. Methods: In this study, 106 axSpA patients and 110 healthy controls were enrolled. Six single-nucleotide polymorphisms (SNPs) were selected for genotyping: ERAP1 rs2287987, ERAP2 rs2549782, TNF rs1800629, TNFRSF1A rs767455, TNFRSF1B rs1061622, and FCGR2A rs1801274. Participants were examined at baseline and after 12 and 24 weeks of anti-TNF therapy. Results: SNPs associated with high axSpA initial activity were TNFRSF1A rs767455 and TNFRSF1B rs1061622 (p < 0.008). The ERAP1 rs2287987 AA genotype was more frequently observed in patients with enthesitis (AA vs. G+, p = 0.049), while the TNFRSF1B rs1061622 GG genotype was more common in participants with uveitis (GG vs. TT, p = 0.042). Potential in predicting anti-TNF treatment response was demonstrated by ERAP1 rs2287987, ERAP2 rs2549782, TNFRSF1B rs1061622, and FCGR2A rs1801274. Conclusions: SNPs can be used to identify patients at risk of severe disease to initiate treatment earlier. Genetic testing will allow clinicians to choose the right drug for the patient.

Association of the genetic variants in the endoplasmic reticulum aminopeptidase 2 gene with ankylosing spondylitis susceptibility

BACKGROUND

Genetic polymorphisms in the endoplasmic reticulum aminopeptidase gene ERAP2 has been attributed with the etiopathogenesis of ankylosing spondylitis (AS). Here we assessed the association of ERAP2 gene single nucleotide polymorphisms (SNPs) with AS predisposition in Iranian patients and determined their effect on the inflammatory state of the patients.

METHODS

For genotyping of rs2548538, rs2287988, and rs17408150 SNPs using a real-time allelic discrimination approach, DNA was extracted from the whole blood of 250 AS patients and 250 healthy individuals. RNA of the peripheral blood mononuclear cells was separated, cDNA was synthesized, and transcriptional levels of cytokines, including interleukin (IL)-17A, IL-23, IL-10, and transforming growth factor-β, were measured. Enzyme-linked immunosorbent assay was used to measure the serum concentration on the cytokines.

RESULTS

Three ERAP2 gene SNPs were not associated significantly with AS risk. Nonetheless, rs2287988 and rs17408150 SNPs showed statistically significant association with susceptibility to the disease in those AS patients who were positive for human leukocyte antigen (HLA)-B27. Transcriptional level and serum concentration of IL-17A and IL-23 were higher, but those of IL-10 were lower in both AS patients and the HLA-B27-positive patient group relative to the control group. Nevertheless, ERAP2 gene SNPs in the HLA-B27-positive AS patients did not affect the transcription level and serum concentration of cytokines.

CONCLUSIONS

ERAP2 gene rs2287988 and rs17408150 SNPs are associated with susceptibility to AS, but they are probably not determining the levels of IL-17A, IL-23, and IL-10 in this disease.

Lack of Associations between Endoplasmic Reticulum Aminopeptidase 2 Gene Polymorphisms and Ankylosing Spondylitis: A Meta-analysis with Trial Sequential Analysis

Background: Endoplasmic reticulum aminopeptidase 2 (ERAP2) gene is reported to be associated with inflammation-related diseases. Several studies have investigated the associations of ERAP2 gene polymorphisms and susceptibility to ankylosing spondylitis (AS). However, the findings of those studies were inconsistent. The aim of this study was to elucidate the associations by a meta-analysis with trial sequential analysis (TSA).Methods: Online databases of PubMed, Web of Science, EMBASE, Cochrane Library, Wanfang, and CNKI were searched to identify eligible studies on the associations of ERAP2 gene polymorphisms and AS. Study quality was judged based on the Newcastle-Ottawa scale (NOS). Strengths of associations were presented by P-value, odds ratios (ORs), and 95% confidence intervals (95%CIs). TSA was employed to evaluate the information size and statistical power.Results: A total of six studies encompassing 2774 AS patients and 4119 disease-free controls were eligible for this meta-analysis. Five studies reported rs2248374 polymorphism and three studies reported rs2549782 polymorphism. The pooled data suggested that the two polymorphisms were not significantly associated with AS susceptibility: rs2248374, A vs. G, OR = 0.94, 95%CI 0.86-1.02, P = .14; rs2549782, T vs. G, OR = 1.03, 95%CI 0.95-1.12, P = .45. TSA indicated that the sample sizes appeared to be inadequate to obtain a positive outcome.Conclusion: The present findings of this study do not support any evidence on the associations of rs2248374 and rs2549782 polymorphisms in the ERAP2 gene and susceptibility to AS. Additional well-designed and large-sample studies in diverse ethnicities are encouraged to validate the current findings.