Association of HLA-DP/DQ and STAT4 polymorphisms with ankylosing spondylitis in Southwest China

Spectrum of Spondyloarthritis Among Chinese Populations

Purpose of Review

This review aims to emphasize interesting and important new findings with a focus on the spectrum of spondyloarthritis (SpA) in China.

Recent Findings

Over the past decade, significant advances have been made in the investigation of SpA epidemiology, the exploration of genetic and environmental risk factors, the identification of clinical features, and the updating of treatment protocols in the Chinese population. The prevalence of ankylosing spondylitis (AS) in China is 0.20–0.42%, and the prevalence of HLA-B27 in AS patients is 88.8–89.4%. HLA-B*2704 is the most common subtype in Chinese AS patients, followed by HLA-B*2705. HLA-A*01, more precisely HLA-A*01:01, may be associated with psoriatic arthritis (PsA). Tumor necrosis factor inhibitors and IL-17A inhibitors have been shown to be effective and safe for AS patients in China. Juvenile-onset AS is relatively rare, accounting for only 9.1% of the AS population. The prevalence of arthritis related to inflammatory bowel disease is 6.9 to 7.2%. A Chinese study showed that the most frequently prescribed medication was methotrexate (66.4%). Biological agents were prescribed in only16.4% of patients with PsA.

Summary

This review summarizes the latest research in the epidemiology, pathogenesis, clinical manifestations, and management of SpA among Chinese populations. Multiple HLA associations with SpA have also been described, and it is hoped that discoveries of such ethnic-specific risk factor(s) and understanding of their pathological mechanisms may potentially lead to newer targeted therapies for the Chinese populations worldwide.

HLA-DPB1 rs9277535 polymorphism is associated with rheumatoid arthritis risk in a Chinese Han population

We used a custom-by-design 48-Plex single nucleotide polymorphism scan™ kit to investigate the relationship between susceptibility to rheumatoid arthritis (RA) and HLA-DPB1 rs9277535 polymorphism in 805 RA patients and 1095 healthy controls from the Chinese Han population. Blood plasma levels of HLA-DPB1 were also examined using enzyme-linked immunosorbent assays in 170 RA patients and 170 matched control individuals. Quantitative reverse transcription PCR (qRT-PCR) was used to evaluate relative HLA-DPB1 mRNA levels in these blood samples as well. The results indicated that some HLA-DPB1 rs9277535 polymorphisms decreased RA susceptibility. Stratified analysis indicated that risk of RA decreased specifically in women and those who were at least 55 years old. In addition, the AG and GG+AG genotypes were associated with CRP status, ACPA status, and ESR in RA patients when the AA genotype was used as the reference group. Furthermore, average HLA-DPB1 plasma levels were increased in RA patients, and HLA-DPB1 plasma levels and mRNA expression were lower in those with the GG genotype than in those with the AA genotype. These results indicate that HLA-DPB1 rs9277535 polymorphism is associated with a decreased risk of RA in the Chinese population.

Genetic polymorphism of rs9277535 in HLA-DP associated with rheumatoid arthritis and anti-CCP production in a Chinese population

HLA-II molecules are critical in triggering human immune response, especially in activating CD4+ T cells. HLA-DP, belonging to HLA-II molecules, draws increasing attention for its role in presentation of viral antigen and autoantigen to T cells. Researches reported single nucleotide polymorphism (SNP) of HLA-DP associated with HBV infection and autoimmune diseases such as SLE. However, little is known about the relationship between HLA-DP and rheumatoid arthritis (RA). Rs9277535 is located in 3' UTR region of HLA-DPB1, a subunit of HLA-DP, and was reported to affect HLA-DP mRNA expression. In the present study, we explored the relationship between gene polymorphism of rs9277535 in HLA-DPB1 and RA susceptibility and progression. Samples from 254 patients with RA and 391 age- and sex-matched healthy controls were collected and genotyped by a polymerase chain reaction-high-resolution melting (PCR-HRM) assay. Serological tests (anti-CCP, rheumatoid factor, C-reactive protein, anti-keratin antibody) were detected by laboratory assays. Strong association was observed between SNP rs9277535 in HLA-DP and RA susceptibility (allele frequency distribution: OR = 1.409, 95%CI = 1.121-1.773, P = 0.004). Further validation was provided by disease model analysis (recessive model: OR = 1.889, 95%CI = 1.194-2.990, P = 0.008; dominant model: OR = 1.464, 95%CI = 1.050-2.041, P = 0.025; additive model: OR = 2.208, 95%CI = 1.335-3.652, P = 0.003). Allele A was correlated to increased risk of RA. Serological test results demonstrated patients carrying allele A of rs9277535 had elevated serum anti-CCP antibody level. The present study provided evidence that HLA-DP gene polymorphism associated with RA susceptibility. Allele A of rs9277535 in HLA-DP correlated to increased risk of RA and elevated serum anti-CCP level.

The relationship between human leukocyte antigen-DP/DQ gene polymorphisms and the outcomes of HCV infection in a Chinese population

Background

Recently, human leukocyte antigen (HLA) class-II gene polymorphisms have been reported to be related to Hepatitis C virus (HCV) infection and chronicity. The objective of this study was to explore the relationship of HLA-DP rs9277535 and HLA-DQ rs7453920 with the outcomes of HCV infection.

Methods

The rs9277535 and rs7453920 were genotyped in 370 subjects with chronic HCV infection, 194 subjects with spontaneous HCV clearance, and 973 subjects with non-HCV infection from the Chinese population using the ABI TaqMan allelic discrimination assay.

Results

Logistic regression analyses showed that the minor allele A of rs7453920 significantly increased the susceptibility of HCV infection in dominant model (adjusted OR = 1.33, 95% CI: 1.04–1.71, P = 0.026) and additive models (adjusted OR = 1.30, 95% CI: 1.06–1.60, P = 0.012). Rs9277535 A allele significantly increased the risk of chronic HCV infection in dominant model (adjusted OR = 1.52, 95% CI: 1.01–2.28, P = 0.046). Haplotype AA showed a higher risk of HCV infection than the most frequent haplotype GG (adjusted OR = 1.37, 95% CI: 1.05–1.78, P = 0.018).

Conclusion

The HLA-DQ rs7453920 and -DP rs9277535 mutations were significantly associated with HCV infection susceptibility and chronicity, respectively.

Electronic supplementary material

The online version of this article (10.1186/s12985-017-0901-7) contains supplementary material, which is available to authorized users.