Peptidylarginine deiminase type 4 and methyl-CpG binding domain 4 polymorphisms in Chinese patients with rheumatoid arthritis

A common missense variant rs874881 of PADI4 gene and rheumatoid arthritis: Genetic association study and in-silico analysis

The peptidylarginine-deiminase 4 (PADI4) is involved in the post-translational catalytic conversion of arginine into citrulline. The autoantibodies including anti-citrullinated protein antibodies (ACPAs) produced in response to hypercitrullinated proteins are a hallmark of rheumatoid arthritis (RA) autoimmunity. Therefore, the role of a missense variant rs874881 (Gly112Ala) of PADI4 in RA susceptibility was analyzed, along with in-silico analysis of structural and functional impacts of this substitution. We did a case-control association study and in-silico analysis. For the case-control study, confirmed RA cases and healthy controls were recruited. Genotyping for rs874881 (n = 750) was performed through polymerase chain reaction-restriction fragment length polymorphism. Multivariate logistic regression analysis was employed to determine association. The in-silico analysis was carried out through HOPE, VarMap, MutationAssessor, MutPred2, SIFT, PolyPhen, CADD, REVEL and MetaLR. In the case-control study, the rs874881 exhibited a strong association with increased RA susceptibility (G vs C odds ratio = 3.85, 95 % confidence interval = 2.81-5.27). Interaction analysis revealed significant interaction of genotype with smoking and gender (p < 0.05). Significant results (p < 0.05) were also obtained in stratified analysis by presence/absence of comorbidities and radiographic damage. According to in-silico pathogenicity prediction analysis, this Gly112Ala substitution does not exert a major effect on protein structure and function including its enzymatic activity. We report a significant association of PADI4 rs874881 with overall RA susceptibility. To our knowledge, this is the first study to do the interaction and stratified analyses on the PADI4 rs874881 in RA. Similar detailed studies should also be performed in other populations.

Role of the PADI family in inflammatory autoimmune diseases and cancers: A systematic review

The peptidyl arginine deiminase (PADI) family is a calcium ion-dependent group of isozymes with sequence similarity that catalyze the citrullination of proteins. Histones can serve as the target substrate of PADI family isozymes, and therefore, the PADI family is involved in NETosis and the secretion of inflammatory cytokines. Thus, the PADI family is associated with the development of inflammatory autoimmune diseases and cancer, reproductive development, and other related diseases. In this review, we systematically discuss the role of the PADI family in the pathogenesis of various diseases based on studies from the past decade to provide a reference for future research.

Polymorphism of protein tyrosine phosphatase non-receptor type 22 and protein arginine deiminase 4 gene among Ghanaian rheumatoid arthritis patients: A case-control study

AIM

Rheumatoid arthritis (RA) is an autoimmune disease which affects millions of lives globally characterized by chronic inflammation in the joints of the body. There is no known cause for RA; however, genetic predisposition has been associated with its occurrence. The association between genetic predisposition and RA has been reported largely among Caucasians and Asians. However, few studies with limited data have reported genome-wide association studies of RA in Africa, especially in Ghana. In addition, there is genetic heterogeneity that exists geographically among different populations. This study therefore investigated the association of protein arginine deiminase type 4 (PAD4) and protein tyrosine phosphatase non-receptor type 22 (PTPN22) single nucleotide polymorphisms with susceptibility of RA among Ghanaians.

METHODS

This case-control study included 75 RA patients and 75 healthy controls from the Komfo Anokye Teaching Hospital in Ghana. Validated questionnaires were used to obtain demographic data, and blood samples were collected and processed for DNA and polymerase chain reaction analysis. Statistical analysis was done using SPSS version 25.0.

RESULTS

PTPN22 demonstrated a 100% minor allele frequency (GG) in both cases and healthy controls; however, an association could not be made for PTPN22 polymorphism with susceptibility of RA when comparing cases to controls. The homozygous minor allele (GG) of PAD4 was absent in the population.

CONCLUSION

PAD4 polymorphism was absent, while PTPN22 was present in the Ghanaian population. The association between PTPN22 (rs2476601) and PAD4 (rs2240340) with RA susceptibility could not be established, thus may not contribute as risk factors for RA in the Ghanaian population.

Novel functional polymorphism on PADI-4 gene and its association with arthritis onset

Background

Citrullinated proteins formed by peptidyl arginine deiminases (PADIs) deimination of arginine residues in proteins are of particular interest in arthritis pathogenesis. Polymorphisms on the PADI-4 gene lead to the malfunctioning of PADIs leading to the onset of arthritis.

Objective

The present study was conducted to determine the polymorphisms on the PADI-4 gene and their association with rheumatoid arthritis (RA) as well as Osteoarthritis (OA).

Methodology

To achieve the above-mentioned objective a case-control study was conducted. Blood samples were collected from RA, OA, and control subjects. DNA was extracted from each blood sample by modified organic method and was quantified as well as qualified by DNA gel electrophoresis and Nanodrop. Patients were tested for rs874881, rs11203366, rs11203367, rs2240336, rs2240337, rs2240339, rs1748033 and rs2240340 polymorphic sites by amplifying targeted regions through PCR with site-specific primers. Genotyping was performed by Restriction Fragment Length Polymorphism and direct sequencing method. Mutations were identified by analyzing sequences on BioEdit software. Allelic, genetic, and multiple site analysis were performed by SHEsis and PLINK software. Change in the amino acid sequence was identified by MEGA 6.0 software.

Results

Polymorphisms were identified on all targeted polymorphic sites except rs2240337 in both RA and OA individuals. In addition, two novel mutations were also identified in exon 4 identified i-e SCV000804840: c.218T > C and SCV000807675: c.241G > T. All the SNPs except rs11203366 were found to be significantly associated with RA at an allelic level whereas all SNP’s have been significant risk factors in the onset of OA. At genotypic level rs874881, rs11203366, rs2240339, SCV000804840 and SCV000807675 were significantly associated to RA development whereas rs874881, rs11203366, rs11203367, rs2240339, SCV000804840 and SCV000807675 were genetic risk factors in OA onset. Haplotype analysis indicated that GACCACGCC and GACCACGCT were highly significant in disease development. Polymorphisms identified altered the functioning of PADIs by altering their amino acid sequence.

Conclusion

In conclusion, it was found that PADI-4 gene polymorphism was not only involved in the onset of RA but was also found to be a significant risk factor in OA onset.

IL18 rs360719 A>G, IL18R1 rs13015714 G>T, IL18RAP rs917997 C>T and IL28B rs8099917 T>G polymorphisms and risk of gastric cardiac adenocarcinoma

The present study was conducted to investigate the association between gastric cardiac adenocarcinoma (GCA) and four functional single-nucleotide polymorphisms (SNPs), including interleukin 18 (IL18) rs360719 A>G, IL18 receptor 1 (IL18R1) rs13015714 G>T, IL18 receptor accessory protein (IL18RAP) rs917997 C>T and interleukin 28B (IL28B) rs8099917 T>G variants. A hospital-based case-control study was performed to evaluate the genetic effects of these SNPs. A total of 243 GCA cases and 476 controls were enrolled in this study. A custom-by-design 48-Plex SNPscan™ kit was used to determine the genotypes. When the IL18 rs360719 AA homozygote genotype was used as the reference group, the AG genotype was not associated with the risk for GCA; the GG genotype was also not associated with the risk for GCA. In the dominant model, the IL18 rs360719 AG/GG variants were not associated with the risk for GCA, compared with the IL18 rs360719 AA genotype. In the recessive model, when the IL18R1 rs13015714 AA/AG genotypes were used as the reference group, the GG homozygote genotype was not associated with risk for GCA. No association was observed between IL18R1 rs13015714 G>T, IL18RAP rs917997 C>T and IL28B rs8099917 T>G polymorphisms and the risk for GCA. These results demonstrated that the functional polymorphisms IL18 rs360719 A>G, IL18R1 rs13015714 G>T, IL18RAP rs917997 C>T and IL28B rs8099917 T>G do not contribute to GCA susceptibility. However, as the statistical power of our study was limited, large well-designed studies and further functional investigations are required to confirm our findings.

Meta-analysis of the association between PADI4 -92C/G polymorphism and rheumatoid arthritis in the Chinese population

Many studies have evaluated the correlation between peptidylarginine deiminase 4 (PADI4) -92C/G polymorphism and rheumatoid arthritis (RA), but the results remain inconclusive. Therefore, we performed a meta-analysis in the Chinese population to provide comprehensive data on the association between PADI4 -92C/G polymorphism and RA. Eligible studies published before May 2016 were identified in PubMed and Chinese databases. The strengths of these associations were assessed by pooled odds ratios (OR) and 95% confidence interval (CI). Eight studies documenting a total of 1351 RA cases and 1585 controls were included in this meta-analysis. In the overall analysis, a significant association between the PADI4 -92C/G polymorphism and RA was found in the Chinese population (G vs C: OR=1.32, 95%CI=1.02-1.71; GG+CG vs CC: OR=1.75, 95%CI=1.20-2.53). The subgroup analyses stratified by geographic area(s) and source of controls revealed significant results in South China, in hospital-based studies and population-based studies. In summary, this meta-analysis suggested that PADI4 -92C/G polymorphism may be associated with the RA incidence in the Chinese population, especially for South China. Further studies conducted on other ethnic groups are required for definite conclusions.

PADI4 and the HLA-DRB1 shared epitope in juvenile idiopathic arthritis

OBJECTIVE

Both genetic and environmental factors are associated with susceptibility to juvenile idiopathic arthritis (JIA). Many studies have reported that both a 'shared epitope' (SE) encoded by several HLA-DRB1 alleles and the peptidyl arginine deiminase type 4 (PADI4) gene polymorphisms are associated with susceptibility to rheumatoid arthritis (RA). However, it is uncertain whether JIA and RA share the latter genetic risk factor. Therefore, here we investigated relationships between HLA-SE and PADI4 polymorphisms with clinical subtypes of JIA.

METHODS

JIA patients (39 oligoarthritis, 48 RF-positive polyarthritis, 19 RF-negative polyarthritis and 82 systemic) and 188 healthy controls were genotyped for HLA-DRB1 by PCR-sequence-specific oligonucleotide probe methodology. Three PADI4 gene single nucleotide polymorphisms (SNPs), rs2240340, rs2240337 and rs1748033, were genotyped using TaqMan SNP Genotyping Assays.

RESULTS

Frequencies of the HLA-SE were higher in RF-positive polyarticular JIA than in healthy controls. RF-positive polyarticular JIA was associated with HLA-SE (OR = 5.3, 95% CI = 2.5-11.9, pc < 0.001). No associations were found between clinical subtypes of JIA and PADI4 allele frequency. Nonetheless, rs2240337 in the PADI4 gene was significantly associated with anti-cyclic citrullinated peptide antibody (ACPA)-positivity in JIA. The A allele at rs2240337 was a significant risk factor for ACPA positivity in JIA (OR = 5.6, 95% CI = 1.71-23.7 pc = 0.03).

CONCLUSION

PADI4 gene polymorphism is associated with ACPA-positivity in JIA. The association of HLA-SE with RF-positive polyarticular JIA as well as RA is confirmed in Japanese. Thus, HLA-SE and PADI4 status both influence JIA clinical manifestations.

Associations of the VEGF level, VEGF rs2010963 G/C gene polymorphism and ankylosing spondylitis risk in a Chinese Han population

To investigate the roles of the plasma vascular endothelial growth factor (VEGF) level and VEGF gene polymorphisms in ankylosing spondylitis (AS) susceptibility. The plasma VEGF level was measured using an enzyme-linked immunosorbent assay. The VEGF rs2010963 G/C gene polymorphism was analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Our data indicated that the average plasma VEGF concentration in the AS patients was markedly higher than in the controls. Stratification analysis indicated a significant correlation between an elevated plasma VEGF level in AS patients and sex, but not age, HLA-B27, C-reactive protein (CRP), or grade of the sacroiliac joint. We also found that VEGF rs2010963 G/C was associated with a decreased risk of AS. Significant differences were found between the VEGF rs2010963 G/C genotypes and elevated plasma level in AS patients when compared with the controls. However, we did not find a significant association between the plasma VEGF level and different rs2010963 G/C genotypes in the AS patients or controls. To sum up, serum VEGF levels are significantly associated with the inflammatory process of AS. This study suggests that VEGF is involved in the immunological or inflammatory process of AS.

Associations Between PADI4 Gene Polymorphisms and Rheumatoid Arthritis: An Updated Meta-analysis

BACKGROUND AND AIMS

Studies investigating the association between the peptidylarginine deiminase 4 (PADI4) gene polymorphisms and rheumatoid arthritis (RA) reported conflicting results. The aim of this meta-analysis was to assess the association between PADI4 gene polymorphisms and RA.

METHODS

A systematic literature search was conducted to identify relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of the association.

RESULTS

A total of 34 studies from 28 articles involving 19859 patients with RA and 25771 healthy controls were included. Significant association of PADI4-94G/A polymorphism and RA was observed (OR = 0.891, 95% CI = 0.833-0.954, p = 0.001) in the overall study population and in the Asian populations (OR = 0.824, 95% CI = 0.759-0.894, p = 0.000) respectively. For the -92C/G polymorphism, a significant association was observed (OR = 1.481, 95% CI = 1.166-1.882, p = 0.001) in Africans. For the -90C/T polymorphism, a significant association was observed (OR = 0.576, 95% CI = 0.381-0.872, p = 0.009) in the Latin American population. The pooled estimates for the other polymorphisms were not statistically significantly associated with RA (PADI4-104C/T, -89A/G, -96T/C).

CONCLUSIONS

This meta-analysis demonstrates that PADI4-94G/A polymorphism is associated with susceptibility to RA in the overall population and in the Asian population. The PADI4 -92C/G polymorphism confers susceptibility to RA in Africans and the PADI4-90C/T polymorphism was associated with RA in the Latin American population.

Variant TP53BP1 rs560191 G>C is associated with risk of gastric cardia adenocarcinoma in a Chinese Han population

OBJECTIVE

To investigate the association between gastric cardia adenocarcinoma (GCA) and ten functional single nucleotide polymorphisms (SNPs), including TP53BP1 rs560191 G>C, CASP8 rs1035142 G>T, CASP7 rs3127075 G>C, CASP7 rs7907519 C>A, and six C1orf10/CRNN variants. We performed a hospital-based case-control study to evaluate the genetic effects of these SNPs.

METHODS

Two hundred and forty-three GCA cases and 476 controls were enrolled in this study. A custom-by-design 48-Plex SNPscan(TM) Kit was used to determine their genotypes.

RESULTS

When the TP53BP1 rs560191 GG homozygote genotype was used as the reference group, the GC genotype was associated with a significantly increased risk of GCA. The CC genotype was not associated with the risk of GCA compared with the GG genotype. None of the CASP8 rs1035142 G>T, CASP7 rs3127075 G>C, CASP7 rs7907519 C>A or the six C1orf10/CRNN polymorphisms showed a significant difference in genotype distributions between the cases and the controls.

CONCLUSIONS

The results demonstrated that the functional polymorphism TP53BP1 rs560191 G>C might contribute to GCA susceptibility. However, the statistical power of our study was limited. Large, well-designed studies and further functional investigations are needed to confirm our findings.

Interleukin 12B rs3212227 T > G polymorphism was associated with an increased risk of gastric cardiac adenocarcinoma in a Chinese population

Gastric cardiac adenocarcinoma (GCA) is one of common malignant tumors in the world. Multiple genes that play critical roles in inflammatory pathways probably are associated with GCA risk. We conducted a hospital-based case-control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs): interleukin 9 (IL9) rs31563 C > T, IL9 rs31564 G > T, IL10 rs1800872 T > G, IL12A rs2243115 T > G, IL12B rs3212227 T > G, and IL13 rs1800925 C > T on the development of GCA. Two hundred and forty-three GCA cases and 476 controls were recruited. Their genotypes were determined using a custom-by-design 48-Plex SNPscan kit. IL12B rs3212227 T > G polymorphism was associated with the increased risk of GCA. However, there was no significant association between the other five SNPs and GCA risk. Stratified analyses indicated that the risk of GCA associated with the IL12B rs3212227 T > G polymorphism was evident among female patients and patients who never smoked or consumed alcoholic drinks. These findings indicated that functional polymorphism IL12B rs3212227 T > G might correlate with GCA risk. However, our results were obtained with a limited sample size; the power of our analysis was low. Larger studies are required to confirm the current findings.

Interleukin 17A rs3819024 A>G polymorphism is associated with an increased risk of gastric cardia adenocarcinoma in a Chinese population

Gastric cardia adenocarcinoma (GCA) is one of the most common malignant tumors. In addition to environmental risk factors, genetic factors might play an important role in GCA carcinogenesis. To evaluate the association between polymorphisms in the interleukin 17A (IL17A) gene on the development of GCA, we conducted a hospital-based case-control study. A total of 243 GCA cases and 476 controls were recruited and their genotypes were determined using a custom-by-design 48-Plex SNPscan™ Kit. IL17A rs3819024 A > G polymorphism was found to be associated with the increased risk of GCA. When the IL17A rs3819024 AA homozygote genotype was used as the reference group, the AG genotype was associated with a significantly increased risk of GCA (AG versus AA: adjusted OR = 1.53, 95% CI = 1.05-2.23, p = 0.026). However, there was no significant association between five other SNPs and GCA. Stratified analyses indicated that a significantly increased risk of GCA associated with the IL17A rs3819024 A > G polymorphism was evident among male patients, patients who drank alcohol or those who never smoked. These findings indicated that functional polymorphism IL17A rs3819024 A > G might contribute to GCA susceptibility. Future larger studies with more rigorous study designs are required to confirm the current findings.

Interleukin 15 receptor alpha rs2228059 A > C polymorphism decreased risk of gastric cardiac adenocarcinoma in a Chinese population

Gastric cardiac adenocarcinoma (GCA) is one of the common malignant tumors in the world and has a high incidence in China. Both environmental risk factors and genetic factors might play an essential role in the GCA carcinogenesis. We performed a hospital-based case-control study to evaluate the genetic effects of interleukin 15 (IL15) and IL15 receptor alpha (IL15RA) functional single nucleotide polymorphisms (SNPs) on the pathogenesis of GCA. A total of 243 GCA cases and 476 controls were enrolled in this study. The genotypes were determined using a custom-by-design 48-Plex SNPscan(TM) Kit. When the IL15RA rs2228059 AA homozygote genotype was used as the reference group, the CC genotype was correlated with a significantly decreased risk for GCA (CC vs. AA: adjusted OR = 0.61, 95 % CI = 0.37-0.98, p = 0.042). Our results revealed that functional variant IL15RA rs2228059 A > C might attenuate individual's risk of GCA. However, there was no significant association between the other five IL15 SNPs and GCA susceptibility. This present study demonstrated that IL15RA rs2228059 A > C polymorphism might modify GCA susceptibility. The results were based on a limited sample size; future larger studies with more rigorous designs are warranted to validate our findings.

B-cell Lymphoma 2 rs17757541 C>G polymorphism was associated with an increased risk of gastric cardiac adenocarcinoma in a Chinese population

AIM

Apoptosis has been considered as a fundamental component in cancer pathogenesis, and related genetic factors might play an important role in gastric cardiac adenocarcinoma (GCA) genesis.

METHODS

We conducted a hospital based case-control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs): BCL2 rs17757541 C>G, BCL2 rs12454712 T>C, FAS rs2234767 G>A, FASL/FASLG rs763110 C>T, ERBB2 rs1136201 A>G and VEGFR2/KDR rs11941492 C>T on the development of GCA. A total of 243 GCA cases and 476 controls were recruited for the study and genotypes were determined using a custom-by-design 48-Plex SNPscanTM Kit.

RESULTS

The BCL2 rs17757541 C>G polymorphism was associated with increased risk of GCA. However, there was no significant associations with the other five SNPs. Stratified analyses indicated a significantly increased risk of GCA associated with the BCL2 rs17757541 C>G polymorphism among males, older patients and those with a history of smoking or drinking.

CONCLUSION

These findings indicated that the functional polymorphism BCL2 rs17757541 C>G might contribute to GCA susceptibility. However, our results were limited by small sample size. Future larger studies are required to confirm our current findings.

Human leukocyte antigen (HLA)-C polymorphisms are associated with a decreased risk of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune rheumatological disease thought to have substantial genetic contributions. Several genetic factors involved in the susceptibility to psoriasis and psoriatic arthritis (PsA) have been identified with genome-wide association studies, including human leukocyte antigen (HLA)-C, junction adhesion molecule 2 (JAM2) and REL. Psoriasis and PsA may share many features in common with RA. We hypothesized that this polymorphism may contribute to RA susceptibility in a Chinese population. We studied HLA-C rs10484554 C/T, HLA-C rs12212594 T/C, HLA-C rs12191877 C/T, JAM2 rs2829866 A/T and REL rs702873 G/A polymorphisms in 520 patients with RA and 520 controls in a Chinese population. HLA-C rs12191877 C/T polymorphism was in complete linkage disequilibrium (LD) (D' = 1.0, r (2) = 1.0) with HLA-C rs10484554 C/T polymorphism. When the HLA-C rs10484554 CC homozygote genotype was used as the reference group, the TT/CT genotypes were associated with a significantly decreased risk for RA (adjusted OR = 0.72, 95% CI = 0.52-0.99, p = 0.044). We found that the HLA-C rs12191877 C/T polymorphism was also associated with a decreased risk of RA. HLA-C rs12212594 T/C, JAM2 rs2829866 A/T and REL rs702873 G/A polymorphisms were not associated with the risk of RA. These results provide evidence that HLA-C polymorphisms are associated with a decreased risk of RA.

Vascular endothelial growth factor A (VEGFA) polymorphisms in Chinese patients with rheumatoid arthritis

OBJECTIVES

Vascular endothelial growth factor A (VEGFA) is the most potent proangiogenic molecule promoting the angiogenic phenotype of rheumatoid arthritis (RA). We hypothesized that VEGFA polymorphisms may contribute to RA susceptibility.

METHOD

We studied VEGFA rs699947 C/A, rs2010963 G/C, and rs3025039 C/T gene polymorphisms in 329 patients with RA and 697 controls in a Chinese population. Genotyping was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

RESULTS

VEGFA rs699947 C/A, rs2010963 G/C, and rs3025039 C/T polymorphisms were not associated with the risk of RA. However, in the dominant genetic model, a significantly decreased risk for RA associated with the VEGFA rs699947 CA/AA genotypes was evident among older patients and anti-cyclic citrullinated peptide antibody (ACPA)-negative patients compared with the VEGFA rs699947 CC genotype. A significantly decreased risk for RA associated with the VEGFA rs699947 CA genotype was evident among older patients.

CONCLUSIONS

These findings suggest that the functional single nucleotide polymorphism (SNP) VEGFA rs699947 C/A allele may decrease the risk of RA in older patients and ACPA-negative patients. However, our results were obtained from a moderate-sized sample and therefore this is a preliminary conclusion. Validation by a larger study from a more diverse ethnic population is needed to confirm these findings.

Peptidylarginine deiminases in citrullination, gene regulation, health and pathogenesis

Peptidylarginine deiminases are a family of enzymes that mediate post-translational modifications of protein arginine residues by deimination or demethylimination to produce citrulline. In vitro, the activity of PADs is dependent on calcium and reductive reagents carrying a free sulfhydryl group. The discovery that PAD4 can target both arginine and methyl-arginine for citrullination about 10years ago renewed our interest in studying this family of enzymes in gene regulation and their physiological functions. The deregulation of PADs is involved in the etiology of multiple human diseases, including cancers and autoimmune disorders. There is a growing effort to develop isoform specific PAD inhibitors for disease treatment. However, the regulation of the activity of PADs in vivo remains largely elusive, and we expect that much will be learned about the role of these enzymes in a normal life cycle and under pathology conditions.

Replication study of STAT4 rs7574865 G/T polymorphism and risk of rheumatoid arthritis in a Chinese population

AIM

Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are common systemic autoimmune diseases with genetic and environmental predisposing factors. Signal transducer and activator of transcription 4 (STAT4) transmits signals induced by interleukin-12, interleukin-23 and interferon-γ, which are key cytokines and play important roles in the development of autoimmune diseases. Previous studies confirmed the STAT4 rs7574865 G/T locus to be associated with RA. Thus we conducted a replication study to investigate STAT4 rs7574865 G/T polymorphism and RA/AS susceptibility in a Chinese population.

METHODS

We studied STAT4 rs7574865 G/T gene polymorphism in 520 patients with RA, 100 AS patients and 520 controls in a Chinese population. Genotyping was done using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

RESULTS

When the STAT4 rs7574865 GG homozygote genotype was used as the reference group, the GT or GT/TT genotypes were associated with the risk for RA. After stratification analyses, a significantly increased risk for RA associated with the STAT4 rs7574865 GT genotype was evident among the rheumatoid factor (RF)-positive patients, patients with higher erythrocyte sedimentation rate (ESR) level and patients with higher RA disease activity score (DAS28) compared with the STAT4 rs7574865 GG genotype. A significantly increased risk for RA associated with the STAT4 rs7574865 TT genotype was evident among older patients and RF-negative patients compared with the STAT4 rs7574865 GG genotype. STAT4 rs7574865 G/T was not associated with susceptibility to AS.

CONCLUSION

This replication study confirmed that STAT4 rs7574865 G/T polymorphism was associated with the risk of RA.

CONDENSED ABSTRACT

STAT4 polymorphisms are associated with rheumatoid arthritis risk.