Does HLA-B27 Status Influence Ankylosing Spondylitis Phenotype?

Frequency distribution of HLA class I and II alleles in Greek population and their significance in orchestrating the National Donor Registry Program

Human leukocyte antigens (HLA) represent one of the most polymorphic systems in humans, responsible for the identification of foreign antigens and the presentation of immune responses. Therefore, HLA is considered to play a major role in human disorders, donor-recipient matching and transplantation outcomes. This study aimed to determine the HLA class I and II alleles and haplotypes in the Greek population. Moreover, a comparative analysis of HLA alleles and haplotype frequencies found in Greek and pooled European populations was also performed to acquire a better knowledge about the HLA alleles distribution. A total number of 1896 healthy individuals were typed for their HLA alleles in the National Tissue Typing Center of Greece. High-resolution HLA typing for the HLA-A, -B, -C and -DR, -DQ, -DP with the use of the next-generation sequencing analysis was performed, followed by data analysis for establishing the HLA allele and haplotype differences. The results of this study showed that the most frequent alleles for the HLA-A were the A*02:01:01 (27.1%), *24:02:01 (14.4%), *01:01:01 (9.3%), for the HLA-B were the B*51:01:01 (15.3%), *18:01:01 (9.7%), *35:01:01 (6.8%) and for the HLA-C were the C*04:01:01 (15.4%), *07:01:01 (13.1%), *12:03:01 (9.6%). For the HLA class II, the most frequent alleles for the HLA-DRB1 were the DRB1*11:04:01 (16.4%), *16:01:01 (11.3%), *11:01:01 (9.5%), for the HLA-DQB1 were the DQB1*03:01:01 (30.5%), *05:02:01 (15.1%), *05:01:01 (10.6%) and for the HLA-DPB1 were the DPB1*04:01:01 (34.8%), *02:01:01 (11.6%), *04:02:01 (7.3%). Additionally, the most frequent haplotypes were the A*02:01:01∼C*07:01:01-B*18:01:01∼DRB1*11:04:01 (2.3%), followed by the A*01:01:01∼C*07:01:01∼B*08:01:01∼DRB1*03:01:01 (2.2%), A*24:02:01∼C*04:01:01∼B*35:02:01∼DRB1*11:04:01 (1.4%) and A*02:01:01∼C*04:01:01∼B*35:01:01-DRB1*14:01:01 (1.2%). The results herein were comparable to those obtained from the pooled European populations. Moreover, these results can be used for the improvement of the donor-recipient matching procedure and to understand better the disease association in Greece.

Genetic Variant of DNAM-1 rs763361 C>T Is Associated with Ankylosing Spondylitis in a Mexican Population

DNAM-1 (CD226) is an activating receptor expressed in CD8+ T cells, NK cells, and monocytes. It has been reported that two SNPs in the DNAM-1 gene, rs763361 C>T and rs727088 G>A, have been associated with different autoimmune diseases; however, the role of DNAM-1 in ankylosing spondylitis has been less studied. For this reason, we focused on the study of these two SNPs in association with ankylosing spondylitis. For this, 34 patients and 70 controls were analyzed using endpoint PCR with allele-specific primers. Our results suggest that rs763361 C>T is involved as a possible protective factor under the CT co-dominant model (OR = 0.34, 95% CI = 0.13-0.88, p = 0.022) and the CT + TT dominant model (OR = 0.39, 95% CI = 0.17-0.90, p = 0.025), while rs727088 G>A did not show an association with the disease in any of the inheritance models. When analyzing the relationships of the haplotypes, we found that the T + A haplotype (OR = 0.31, 95% CI = 0.13-0.73, p = 0.0083) is a protective factor for developing the disease. In conclusion, the CT and CT + TT variants of rs763361 C>T and the T + A haplotype were considered as protective factors for developing ankylosing spondylitis.

Evaluation of interleukins (IL-1α, IL-1Ra, IL-12, IL-17A, IL-31, and IL-33) and chemokines (CXCL10 and CXCL16) in the serum of male patients with ankylosing spondylitis

BACKGROUND

A case-control study was performed to explore eight pro-inflammatory and anti-inflammatory cytokines, namely interleukin (IL)-1α, IL-1Ra (IL-1 receptor antagonist), IL-12, IL-17A, IL-31, IL-33, CXCL10 (C-X-C motif chemokine ligand 10), and CXCL16, with the aim to understand their role in ankylosing spondylitis (AS) pathogenesis and evaluate their utility as markers to differentiate between diseased and healthy individuals. Among these cytokines, IL-31 and CXCL16 have not been well studied in AS.

PATIENTS AND METHODS

The study included 94 male patients with AS and 91 age-matched control males. Interleukin and chemokine levels were measured using ELISA kits.

RESULTS

Serum levels of IL-17A, CXCL10, and CXCL16 were significantly elevated in patients compared to controls, while IL-31 levels were significantly decreased in patients. IL-17A, CXCL10, and CXCL16 were associated with an increased risk of AS, while IL-31 was associated with a decreased risk of disease (odds ratio = 1.22, 1.78, 1.14, and 0.89, respectively). As indicated by the area under the curve (AUC), IL-17A, IL-31, CXCL10, and CXCL16 were potential markers to differentiate between AS patients and controls (AUC = 0.877, 0.735, 0.8, and 0.7, respectively). IL-1α, IL-1Ra, IL-12, and IL-33 levels showed no significant variations between patients and controls.

CONCLUSIONS

Among the eight cytokines examined, IL-17A, CXCL10, and CXCL16 were up-regulated in the serum of AS patients, while IL-31 was down-regulated. The levels of IL-1α, IL-1Ra, IL-12, and IL-33 showed no significant differences between patients and controls. Serum levels of all cytokines were not affected by disease duration, HLA-B27 positivity, or disease activity.

Prevalence of HLA B27 in Patients Diagnosed with Ankylosing Spondylitis (AS) in Diyarbakır, Southeastern Region of Turkey

AIM

The research to be conducted on human leukocyte antigen (HLA)-B27 in patients diagnosed with ankylosing spondylitis (AS) in Diyarbakır between 2019-2021 is to contribute to the understanding of the prevalence and effect of this genetic marker in the local population. As a researcher working on HLA-B27 and AS, our focus is to research the following. HLA-B27 Prevalence: To determine the prevalence of HLA-B27 in patients diagnosed with AS during the specified period in Diyarbakır. This information can provide insight into the genetic factors associated with the disease in the local population. Disease Severity: Investigate the relationship between HLA-B27 positivity and severity of AS symptoms. To examine factors such as disease progression, pain levels, functional impairment, and quality of life in HLA-B27 positive patients compared to HLA-B27 negative patients. By Genetic Associations: To enable the discovery of potential genetic relationships between HLA-B27 and other genetic markers known to be associated with AS. To investigate whether there are any specific genetic variants associated with HLA-B27 that contribute to disease susceptibility or severity. Researchers: We recommend considering the following approaches to generate knowledge on this topic globally: Literature Review: Conducting a comprehensive review of the available scientific literature on HLA-B27 and AS. It is to describe relevant studies conducted globally and summarize their findings to provide a broader understanding of the subject. Collaboration and Data Sharing: To encourage cooperation with researchers from other regions or countries doing similar studies on HLA-B27 and ASs. By sharing our data and collaborating on analysis, we can improve the global perspective and generalizability of your findings. International Conferences and Journals: Presenting our research findings at international conferences focusing on rheumatology, genetics or related fields. To disseminate our findings globally is to submit your research articles to reputable journals specializing in AS or genetic studies. Online Platforms: Using online platforms such as Researchgate.net, academia.edu or social media networks to share our research findings, connect with other researchers in the field and participate in discussions on a global scale. By using these fields, it is possible to contribute to the global knowledge and understanding of the relationship between HLA-B27 and AS. It is also to obtain insights from studies carried out in other regions.

MATERIALS AND METHODS

198 (104 male and 94 female) patients who applied to Dicle University Faculty of Medicine Physical Therapy and Rehabilitation Clinic with AS symptoms between 2019-2021 and were referred to Dicle University Medical Biology and Genetics Department for evaluation. HLA-B27 positivity was included in our study as a case group. As the control group, 50 people (25 males, 25 females) were selected among the unrelated people who applied to our laboratory to be a bone marrow donor. In both groups, DNA isolation was performed from peripheral blood using the salt precipitation method. Rotar Gene Q device was used for real-time PCR analysis. As a statistical method in analysis; The prevalences of the variables of interest were calculated. The lower and upper limits of 95% were determined as the confidence interval. According to the presence of HLA 27 positivity, the mean of ESR, CRP, and age variables were compared. Mann-Whitney U test was used due to the small number of subjects. Also, correlations between ESR and CRP were calculated. Spearman rho correlation statistics were used as a statistical method. Analyzed.

RESULT

Radiological examinations and laboratory tests were performed on 198 patients with suspicion AS and 50 healthy control group of 248 subjects. The prevalence of those with a definite diagnosis of AS was calculated as statistical analysis recalculated 20.16 (95% CI: 0.76-0.9552). The prevalence of HLA-B27 in 50 patients diagnosed with AS as a result of radiological examinations and laboratory tests was calculated as 92%.

CONCLUSION

Our study is the first study covering the province of Diyarbakır in the Southeastern Anatolia Region, which we think will contribute to the literature in the evaluation of HLA-B27 positivity in AS patients. The prevalence of HLA-B27 in our region is higher than the prevalence in Turkey.

Association between HLA-B*27:04 and genetic susceptibility to ankylosing spondylitis in Hunan Province

OBJECTIVES

Human leukocyte antigen (HLA) B27 is a susceptibility allele of ankylosing spondylitis (AS), and HLA-B27 antigen typing is an important indicator for clinical diagnosis of AS, but current typing methods such as sequence specific primer polymerase chain reaction (PCR-SSP) still possess limitation. Therefore, this study aims to analyze the correlation between B27 subtypes and susceptibility to AS in Hunan Province by applying high-resolution polymerase chain reaction-sequence-based typing (PCR-SBT).

METHODS

Peripheral blood of 116 patients with suspected AS (suspected AS group) and 121 healthy volunteers (control group) admitted to the Second Xiangya Hospital from January 2020 to December 2020 were collected for HLA-B genotyping by PCR-SBT. Among the patients in the suspected AS group, 23 patients were finally diagnosed with AS (confirmed AS group), and the remaining 93 undiagnosed patients served as the non-confirmed AS group. PCR-SBT and PCR-SSP were used to detect HLA-B27 typing in 116 patients with suspected AS, and the results of the 2 methods were compared.

RESULTS

The HLA-B27 allele frequency in the suspected AS group was significantly higher than that in the control group [11.63% vs 2.48%; P<0.001, odds ratio (OR)=5.18, 95% confidence interval (CI) 2.097 to 12.795]. B*27:04, B*27:05, B*27:06, and B*27:07 were detected in the suspected AS group and the control group. The frequency of the B*27:04 allele in the suspected AS group was significantly higher than that in the control group (9.48% vs 1.24%; P<0.001, OR=8.346, 95% CI 2.463 to 28.282). The positive rate of B27 in the suspected AS group and the confirmed AS group (B27+/+ and B27+/-) was significantly higher than that in the control group (χ2=16.579, P<0.001; χ2=94.582, P<0.001, respectively). Among the confirmed AS group, 21 were HLA-B27 carriers, and the B27 positive rate in the confirmed AS group was 91.3%. PCR-SBT could achieve high resolution typing of the HLA-B gene locus, with higher sensitivity, specificity, positive predictive value, negative predictive value, and accuracy than PCR-SSP.

CONCLUSIONS

PCR-SBT typing analysis shows a strong correlation between HLA-B * 27:04 and AS in Hunan province. The PCR-SBT method can be used as the preferred option for the auxiliary diagnosis of clinical AS.

Axonal sensory-motor polyneuropathy in ankylosing spondylitis: A case report

Key Clinical Message

In ankylosing spondylitis cases, axonal-type sensory-motor polyneuropathy is a rare manifestation and should be considered an underlying etiology in patients with unexplained neuropathy.

Abstract

This case report discusses a 45-year-old male diagnosed with ankylosing spondylitis (AS), a chronic inflammatory disorder affecting the axial skeleton and peripheral joints. The patient presented with polyneuropathy, characterized by tingling and numbness in the upper and lower limbs, which is an uncommon manifestation of AS. After undergoing various tests, including CT scans and EMG-NCV, no secondary cause for the neuropathy was identified; AS was considered the etiology of the patient's axonal-type sensory-motor polyneuropathy.

SPI1 Regulates the Progression of Ankylosing Spondylitis by Modulating TLR5 via NF-κB Signaling

Ankylosing spondylitis (AS) is an autoimmune disease which associated with inflammation of the spinal joints. Enhanced osteogenic differentiation was observed in AS; however, the underlying mechanism remains undefined. A cohort of AS (n = 15) and patients with traumatic fracture (n = 15) were recruited to this study. Fibroblasts were isolated, and characterized by H&E and immunocytochemistry (ICC) analysis. The expression and secretion of key molecules were detected by qRT-PCR, western blot, immunofluorescence (IF), and ELISA. Calcium deposition and alkaline phosphatase (ALP) activity were monitored by Alizarin Red S and ALP staining. The direct association between Spi-1 proto-oncogene (SPI1) and toll-like receptor 5 (TLR5) promoter was assessed by ChIP assay. AS fibroblasts was successfully isolated and exhibited osteogenic differentiation potentials. SPI1 was elevated in AS fibroblasts, and silencing of SPI1 inhibited osteogenic differentiation of AS fibroblasts. Mechanistic study showed that SPI1 acted as a transcriptional activator of TLR5. Knockdown of TLR5 suppressed osteogenic differentiation of AS fibroblasts via nuclear factor kappa B (NF-κB) signaling. Rescue experiments revealed that overexpression of TLR5 reversed SPI1 knockdown-suppressed osteogenic differentiation via NF-κB signaling. SPI1 regulated the progression of AS by modulating TLR5 via NF-κB signaling.

Human leucocyte antigen-B27 testing in clinical practice: a global perspective

PURPOSE OF REVIEW

The association between human leucocyte antigen (HLA)-B27 and spondyloarthritis (SpA) was described half a century ago. New insights about pathophysiologic pathways and their role in bone formation were reported in recent years and will be discussed in this review.

RECENT FINDINGS

There is a considerable variation in the association between HLA-B27 and SpA across the globe, with the strongest association reported in populations of Northern European and Asian descent and the lowest in the Middle East and Africa. Other genes are also involved in disease susceptibility, highlighting the importance of newly proposed weighted genetic scores to support the diagnosis. On the global level, the interaction between genetic background and gut dysbiosis seems critical for disease predisposition. As for the individual patient, the presence of HLA-B27 can have a significant influence on SpA diagnosis and disease phenotype. More importantly, new studies suggested a role for HLA-B27 in radiographic damage in the sacroiliac joints and the progression of bone formation in the spine.

SUMMARY

Findings in recent years have enhanced our understanding of the role of HLA-B27 in the pathophysiology and in disease-related bone formation in SpA, which may pave the way for new therapeutic targets.

How Has Molecular Biology Enhanced Our Undertaking of axSpA and Its Management

PURPOSE

This review aims at investigating pathophysiological mechanisms in spondyloarthritis (SpA). Analysis of genetic factors, immunological pathways, and abnormalities of bone metabolism lay the foundations for a better understanding of development of the axial clinical manifestations in patients, allowing physician to choose the most appropriate therapeutic strategy in a more targeted manner.

RECENT FINDINGS

In addition to the contribution of MHC system, findings emerged about the role of non-HLA genes (as ERAP1 and 2, whose inhibition could represent a new therapeutic approach) and of epigenetic mechanisms that regulate the expression of genes involved in SpA pathogenesis. Increasing evidence of bone metabolism abnormalities secondary to the activation of immunological pathways suggests the development of various bone anomalies that are present in axSpA patients. SpA are a group of inflammatory diseases with a multifactorial origin, whose pathogenesis is linked to the genetic predisposition, the action of environmental risk factors, and the activation of immune response. It is now well known how bone metabolism leads to long-term structural damage via increased bone turnover, bone loss and osteoporosis, osteitis, erosions, osteosclerosis, and osteoproliferation. These effects can exist in the same patient over time or even simultaneously. Evidence suggests a cross relationship among innate immunity, autoimmunity, and bone remodeling in SpA, making treatment approach a challenge for rheumatologists. Specifically, treatment targets are consistently increasing as new drugs are upcoming. Both biological and targeted synthetic drugs are promising in terms of their efficacy and safety profile in patients affected by SpA.

Biomolecular Mechanisms of Autoimmune Diseases and Their Relationship with the Resident Microbiota: Friend or Foe?

The use of innovative approaches to elucidate the pathophysiological mechanisms of autoimmune diseases, as well as to further study of the factors which can have either a positive or negative effect on the course of the disease, is essential. In this line, the development of new molecular techniques and the creation of the Human Genome Program have allowed access to many more solutions to the difficulties that exist in the identification and characterization of the microbiome, as well as changes due to various factors. Such innovative technologies can rekindle older hypotheses, such as molecular mimicry, allowing us to move from hypothesis to theory and from correlation to causality, particularly regarding autoimmune diseases and dysbiosis of the microbiota. For example, Prevotella copri appears to have a strong association with rheumatoid arthritis; it is expected that this will be confirmed by several scientists, which, in turn, will make it possible to identify other mechanisms that may contribute to the pathophysiology of the disease. This article seeks to identify new clues regarding similar correlations between autoimmune activity and the human microbiota, particularly in relation to qualitative and quantitative microbial variations therein.

Sacroiliitis at diagnosis as a protective predictor against disease flare after stopping medication: outcomes of a Southeast Asian enthesitis-related arthritis (ERA) longitudinal cohort

OBJECTIVES

To assess short- and long-term outcomes of ERA in a large monocentric cohort in Singapore.

METHODS

Children diagnosed with ERA according to ILAR criteria from 2002 to 2021 were recruited. Nonparametric statistics were used to describe the data. Outcomes were defined according to modified Wallace criteria, and probabilities and predictors were determined using Kaplan-Meier survival and logistic regression analyses.

RESULTS

One hundred fifty-one ERA patients (male 86%; Chinese 81%) were included. The median age at onset was 11.9 years (IQR: 9.4-13.9), and disease duration was 5.3 years (IQR: 2.9-8.4). At diagnosis, 39% of the patients had sacroiliitis. HLA-B27 was positive in 83%, and biologics were used in 72% of the patients. Clinical inactive disease (CID) was achieved in 92% of the patients, of which 27% achieved within 6 months. Sacroiliitis at diagnosis is an unfavorable predictor of early CID at 6 months. Medication was discontinued in one-third of the patients. Favorable predictor of medication withdrawal includes male gender, while unfavorable predictors include positive HLA-B27 and ANA. Two-thirds of the patients with CID had at least one disease flare. Sacroiliitis at diagnosis is a protective predictor of flare after stopping medication.

CONCLUSION

Despite a high proportion of ERA patients achieving CID, only one-third could stop medication with high rates of disease flare. Unfavorable predictors include older age at onset, HLA-B27, and ANA positivity. While sacroiliitis at diagnosis is a negative predictor of CID at 6 months, it is associated with less disease flare after discontinuing medication.

Global Proteomic Analyses Reveals Abnormal Immune Regulation in Patients With New Onset Ankylosing Spondylitis

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease with serious consequences and a high rate of morbidity and mortality, In our previous work, we reveal the key features of proteins in new-onset ankylosing spondylitis patients.

Material and Methods

Ankylosing spondylitis (AS) is a chronic inflammatory condition that affects the spine, and inflammation plays an essential role in AS pathogenesis. The inflammatory process in AS, however, is still poorly understood due to its intricacy. Systematic proteomic and phosphorylation analyses of peripheral blood mononuclear cells (PBMCs) were used to investigate potential pathways involved in AS pathogenesis.

Results

Liquid chromatography-tandem mass spectrometry (LC–MS/MS) analysis was performed and discovered 782 differentially expressed proteins (DEPs) and 122 differentially phosphorylated proteins (DPPs) between 9 new-onset AS patients and 9 healthy controls. The DEPs were further verified using parallel reaction monitoring (PRM) analysis. PRM analysis verified that 3 proteins (HSP90AB1, HSP90AA1 and HSPA8) in the antigen processing and presentation pathway, 6 proteins (including ITPR1, MYLK and STIM1) in the platelet activation pathway and 10 proteins (including MYL12A, MYL9 and ROCK2) in the leukocyte transendothelial migration pathway were highly expressed in the PBMCs of AS patients.

Conclusion

The key proteins involved in antigen processing and presentation, platelet activation and leukocyte transendothelial migration revealed abnormal immune regulation in patients with new-onset AS. These proteins might be used as candidate markers for AS diagnosis and new therapeutic targets, as well as elucidating the pathophysiology of AS.

Characteristics of Patients With Axial Spondyloarthritis by Geographic Regions: PROOF Multicountry Observational Study Baseline Results

Objectives

To compare demographic and clinical characteristics of patients with axial SpA (axSpA) across geographic regions.

Methods

Patients With Axial Spondyloarthritis: Multicountry Registry of Clinical Characteristics (PROOF) is an observational study that enrolled recently diagnosed (≤1 year) axSpA patients fulfilling the Assessment of SpondyloArthritis international Society classification criteria from rheumatology clinical practices in 29 countries across six geographic regions. Demographics and disease-related parameters were collected. Here we present baseline data for patients who were classified as radiographic axSpA (r-axSpA) or non-radiographic axSpA (nr-axSpA) confirmed by central reading.

Results

Of the 2170 patients enrolled, 1553 were classified based on central evaluation of sacroiliac radiographs [r-axSpA: 1023 (66%); nr-axSpA: 530 (34%)]. Patients with nr-axSpA had a significantly higher occurrence of enthesitis (40% vs 33%), psoriasis (10% vs 5%) and IBD (4% vs 2%) vs r-axSpA patients. Significant differences in axSpA characteristics were observed between geographic regions. The highest occurrence of peripheral arthritis (60%), enthesitis (52%) and dactylitis (12%) was in Latin America, and the lowest was in Canada (9%, 9% and 2%, respectively). The occurrence of uveitis and psoriasis was highest in Canada (18% and 14%, respectively) and lowest in China (6% and <1%, respectively). IBD was highest in Arabia (21%), and no cases were observed in China. In multivariable analysis adjusted for factors potentially affecting peripheral and extramusculoskeletal manifestations, geographic regions still exhibited significant differences in frequencies of uveitis (P < 0.01), psoriasis (P < 0.0001) and peripheral arthritis (P < 0.0001).

Conclusion

The multinational PROOF study of axSpA patients showed significant regional differences in peripheral and extramusculoskeletal manifestations of SpA, which could be considered in management guidelines and clinical trials.

A review of JAK-STAT signalling in the pathogenesis of spondyloarthritis and the role of JAK inhibition

Spondyloarthritis (SpA) comprises a group of chronic inflammatory diseases with overlapping clinical, genetic and pathophysiological features including back pain, peripheral arthritis, psoriasis, enthesitis and dactylitis. Several cytokines are involved in the pathogenesis of SpA, variously contributing to each clinical manifestation. Many SpA-associated cytokines, including IL-23, IL-17, IL-6, type I/II interferon and tumour necrosis factor signal directly or indirectly via the Janus kinase (JAK)–signal transducer and activator of transcription pathway. JAK signalling also regulates development and maturation of cells of the innate and adaptive immune systems. Accordingly, disruption of this signalling pathway by small molecule oral JAK inhibitors can inhibit signalling implicated in SpA pathogenesis. Herein we discuss the role of JAK signalling in the pathogenesis of SpA and summarize the safety and efficacy of JAK inhibition by reference to relevant SpA clinical trials.

Genetics, Epigenetics, and Gender Impact in Axial-Spondyloarthritis Susceptibility: An Update on Genetic Polymorphisms and Their Sex Related Associations

Spondyloarthritis (SpA) is a group of chronic inflammatory rheumatic disease that can be divided into predominantly axial or predominantly peripheral involvement, with or without associated psoriasis, inflammatory bowel disease or previous infection. Axial SpA (axSpA) encompasses ankylosing spondylitis (AS) with radiological sacroiliitis, and a type without radiographic sacroiliitis, called “non-radiographic axial SpA” (nr-axSpA). Males and females show large differences in their susceptibility to SpA, such as distinctions in clinical patterns, phenotypes and in therapeutical response, particularly to TNF inhibitors (TNFi). Several studies indicate that AS women have doubled risk to failure TNFi compared with males. This diversity in drugs’ efficacy among women and men may be caused by differences in the balance of sex hormones and in gene-specific expression likely triggered by X-chromosome instability and gene-specific epigenetic modifications. Evidence reported that polymorphisms in microRNAs on X- and other chromosomes, such as miR-146a, miR-155, miR-125a-5p, miR-151a-3p and miR-22-3p, miR-199a-5p could be involved in the different clinical presentation of SpA, as well as disease activity. In addition, association with non−response to TNFi treatment and presence of IRAK3 and CHUCK genes in SpA patients was recently detected. Finally, polymorphisms in genes involved in IL-23/IL-17 pathway, such as in drug pharmacodynamics and pharmacokinetics may have a role in response to TNFi, IL17i, and IL23i. A major understanding of genomic variability could help in the development of new therapeutic targets or in taking advantages of different mechanisms of action of biological drugs. Moving from the multifactorial etiology of disease, the present review aims at evaluating genetic and epigenetic factors and their relationship with sex and bDMARDs response, helping to investigate the different expression among males and females of genes on X- and other chromosomes, as well as mi-RNA, to highlight relationships between sex and occurrence of specific phenotypes and symptoms of the disease. Moreover, the role of the epigenetic modification in relation to immune-regulatory mechanisms will be evaluated.

The Molecular Pathophysiology of Psoriatic Arthritis-The Complex Interplay Between Genetic Predisposition, Epigenetics Factors, and the Microbiome

Psoriasis is a symmetric autoimmune/inflammatory disease that primarily affects the skin. In a significant proportion of cases, it is accompanied by arthritis that can affect any joint, the spine, and/or include enthesitis. Psoriasis and psoriatic arthritis are multifactor disorders characterized by aberrant immune responses in genetically susceptible individuals in the presence of additional (environmental) factors, including changes in microbiota and/or epigenetic marks. Epigenetic changes can be heritable or acquired (e.g., through changes in diet/microbiota or as a response to therapeutics) and, together with genetic factors, contribute to disease expression. In psoriasis, epigenetic alterations are mainly related to cell proliferation, cytokine signaling and microbial tolerance. Understanding the complex interplay between heritable and acquired pathomechanistic factors contributing to the development and maintenance of psoriasis is crucial for the identification and validation of diagnostic and predictive biomarkers, and the introduction of individualized effective and tolerable new treatments. This review summarizes the current understanding of immune activation, genetic, and environmental factors that contribute to the pathogenesis of psoriatic arthritis. Particular focus is on the interactions between these factors to propose a multifactorial disease model.

Prevalence of HLA-B*27 subtypes in the Tamil population of India with Ankylosing spondylitis and its correlation with clinical features

INTRODUCTION

HLA-B*27 is strongly associated with Ankylosing spondylitis (AS). Its subtypes show considerable geographic and ethnic difference. The main aim of this study was to assess the frequency of subtypes of HLA-B*27 in the Indian Tamil AS patients.

METHODS AND MATERIALS

Adult AS patients positive for HLA-B*27 were considered for the study. The high-resolution typing to define HLA-B*27 subtypes were done using Invitrogen B kits from One Lambda (SeCore® Sequencing Kits, Thermo Fisher, United States).

RESULTS AND CONCLUSION

Prevalence of subtypes identified were HLA-B*27:04 (52.2%), HLA-B*27:05 (41.6%), HLA-B*27:07 (3.5%) and HLA-B*27:02 (2.7%). All subtypes showed disease predisposition for males. The most common extra articular manifestation seen was enthesitis in HLA-B*27:04 and HLA-B*27:05. Uveitis was mainly associated with HLA-B*27:05 and dactylitis with HLA-B*27:04. A significant peripheral joints involvement for female and axial joint involvement for males was seen in HLA-B*27:04. Our study establishes the prevalence of HLA-B*27 subtypes and the associated clinical phenotypes among the Indian Tamil population. Considering the variability of presentation, organ involvement, and disease course in different subtypes and across ethnicities it is critical to define these associations in the ethnic populations we treat for their appropriate care considering the significant negative health and socioeconomic effects of AS.

Microbial-derived antigens and metabolites in spondyloarthritis

Spondyloarthritis (SpA) is a group of chronic, immune-mediated, inflammatory diseases affecting the bone, synovium, and enthesis. Microbiome, the community of microorganisms that has co-evolved with human hosts, plays a pivotal role in human health and disease. This invisible "essential organ" supplies the host with a myriad of chemicals and molecules. In turn, microbial metabolites can serve as messengers for microbes to communicate with each other and in the cross-talk with host cells. Gut dysbiosis in SpA is associated with altered microbial metabolites, and an accumulated body of research has contributed to the understanding that changes in intestinal microbiota can modulate disease pathogenesis. We review the novel findings from human and animal studies to provide an overview of the contribution of individual microbial metabolites and antigens to SpA.

Spondyloarthritis in North Africa: an update

Spondyloarthritis (SpA) has been less well studied than rheumatoid arthritis in North Africa, due to a belief that it is rare and benign in certain populations. The main genetic trait of SpA is its association with human leukocyte antigen (HLA)-B27. The distribution of this allele largely explains the prevalence and severity of SpA. The prevalence of HLA-B27 in the general population of North Africa is estimated at about 4%, and rises to about 60% among people affected with SpA. Coxitis is one of the main features of North African SpA, but the response to treatment is comparable to the literature from the West. The major challenge in North Africa remains accessibility to specialized care and means of early diagnosis. Prevalent infections in North Africa do not seem to be a major obstacle to optimal treatment strategies.

The Expression Levels of MicroRNAs Associated with T and B Cell Differentiation/stimulation in Ankylosing Spondylitis

Spondyloarthropathies (SpAs), are a group of chronic inflammatory diseases with a number of genetic, physiopathological, clinical and radiological features. Ankylosing spondylitis (AS) is the most common type of spondylo-arthropathies, and >90.0% of patients with ankylosing spondylitis are human leukocyte antigen-B27 (HLA-B2 7)-positive. In recent years, non-HLA genetic factors have been reported to have an effect on ankylosing spondylitis. MicroRNAs (miRNAs), are endogenous non coding RNA molecules containing 18-23 nucleotides that play a role in the post-transcriptional regulation of gene expression. In this study, we aimed to determine the expression levels of miRNAs associated with T- and B-cell differentiation/stimulation in peripheral blood mononuclear cells and their relationship with the etiology of the AS in patients and healthy controls. In a molecular study, peripheral blood mononuclear cell isolation, and total RNA isolation were performed first. In the second step, cDNA synthesis and quantitative real-time PCR (qPCR) expression analysis were completed. Ultimately, in the patient and control group, the expression levels of miR-142-5p and miR-143 were found to be significantly different (p <0.05). According to current knowledge, miR-142-5p andmiR-143 expressions were found to be important for those diseases that share similar etiology with AS. We suggest that miR-142-5p and miR-143 may play a role in the pathogenesis, especially miR- 142-5p may be a potential biomarker and a target molecule for the treatment.

Insulin resistance in non-diabetes patients with spondyloarthritis

Objectives: Insulin resistance (IR) constitutes a major underlying abnormality driving cardiovascular disease in the general population and has been linked to inflammatory diseases. In this study, we aimed to determine the prevalence of IR in patients with spondyloarthritis (SpA) and whether IR can be explained by disease-related features in such cases. Method: The study included 577 subjects: 306 patients diagnosed with SpA according to Assessment of SpondyloArthritis international Society criteria and 271 controls. Insulin and C-peptide serum levels, IR and β-cell function (%B) indices by homoeostatic model assessment (HOMA2), and lipid profiles were assessed in patients and controls. A multivariable regression analysis was performed to evaluate the differences in IR indices between patients and controls and to determine how IR is associated with disease-related characteristics in SpA patients. Results: HOMA2-%B and HOMA2-IR scores, both calculated with insulin or C-peptide, had significantly higher values in SpA patients compared to controls in multivariable analysis adjusted for age, gender, traditional IR-related factors, and glucocorticoid intake. Disease activity, functional status, and metrological SpA indices were positively related to IR, but only in univariable analysis. Disease duration and positivity for human leucocyte antigen-B27 were independently associated with a higher HOMA2-%B after multivariable analysis. Conclusion: Patients with SpA have an increased IR compared to controls. SpA disease-related data are independently associated with β-cell dysfunction.

What Does Human Leukocyte Antigen B27 Have to Do with Spondyloarthritis?

Human leukocyte antigen (HLA) B27 is the key laboratory parameter for axial spondyloarthritis (axSpA). Its prevalence is variable across different geographic zones and ethnicities, and often mirrors the prevalence of axSpA. HLA-B27 plays a role in axSpA physiopathology. It is correlated with spondyloarthritis phenotype with a consistent positive association with family history, early disease onset, shorter diagnostic delay, hip involvement, and acute anterior uveitis. HLA-B27 has a pivotal role in many referral strategies. However, these strategies were developed in European populations and need to be evaluated in populations with lower HLA-B27 background prevalence, and where additional parameters might be needed.

Clinical Findings of Ankylosing Spondylitis With and Without Human Leukocyte Antigen (HLA)-B27 and HLA-B51

Introduction: Ankylosing spondylitis (AS) and Behçet’s disease are known to be associated with the human leukocyte antigen (HLA)-B27 and HLA-B51 genes, respectively. However, many of their clinical findings―including articular and extra-articular symptoms―are similar, making diagnosis a challenge in the early stage of the disease. The aim of this study was to investigate the differences in clinical findings of AS patients with and without the HLA-B27 gene. Materials and Methods: We performed a retrospective chart review of 151 AS patients. The following clinical findings were evaluated: oral ulcer, genital ulcer, skin manifestation, uveitis, peripheral arthritis; and gastrointestinal, cardiac and pulmonary involvement. Patients were divided into 4 groups based on absence or presence of the HLA-B27 and HLA-B51 genes. The number of patients with each clinical finding was subsequently examined in each group. Results: The incidence of uveitis was significantly higher in the HLA-B27-positive group (P = 0.004); however, other clinical findings did not differ significantly according to the absence or presence of the HLA-B27 gene. There were no significant differences in the clinical findings of patients with positive and negative HLA-B51. Conclusion: HLA-B27 was associated with the development of uveitis but not with other clinical findings or disease activity in AS patients. HLA-B51 was not associated with the clinical findings or disease activity of AS. Key words: Axial spondyloarthritis, Behçet’s disease, Uveitis

Enthesitis-related arthritis is the most common category of juvenile idiopathic arthritis in Taiwan and presents persistent active disease

BACKGROUND

Juvenile idiopathic arthritis (JIA) has been categorized into seven different categories according to the International League of Associations for Rheumatology (ILAR) criteria. Enthesitis-related arthritis (ERA) was found to represent the largest category in a Taiwanese cohort study. The aim in this study was to compare the clinical characteristics, treatments, and outcomes of ERA in a single tertiary center in Taiwan, as compared to those of other categories of JIA. Furthermore, we determined patients' characteristics and risk factors that can help assess the outcomes in ERA.

METHODS

A retrospective chart review of all patients with JIA referred to a pediatric rheumatology clinic in the National Taiwan University Hospital between 1993 and 2018 were identified according to ILAR criteria. Outcomes were assessed based on the Wallace criteria to categorize patients into active and non-active, including inactive, remission on medication, and remission off medication, groups. A subset of samples was further tested by DNA sequencing to identify HLA-B27 subtypes.

RESULTS

One-hundred and eighty-three patients were included in the study, with a mean of 8 years' follow-up. ERA was the single largest category of JIA (39.9%); psoriasis and undifferentiated JIA were both the least common type (0.5%). ERA was male predominant (86%), had a late age of onset (11.0 ± 3.2 years), and the majority of ERA patients was HLA-B27-positive (97%). Of 25 HLA-B27-positive ERA patients checked by HLA-B27 sequencing, 23 were B*27:04 and 2 were B*27:05. ERA patients were significantly less likely to achieve non-active status compared to patients with persistent oligoarthritis (P = 0.036). In terms of treatment response to TNF-α inhibitors in methotrexate-refractory ERA, 26 patients remained active and only 11 patients (30%) achieved a non-active status. Sacroiliitis was a risk factor contributing to poorer treatment response in ERA (P = 0.006).

CONCLUSION

ERA represented the most common category of JIA in Taiwan. Those ERA patients with sacroiliitis were likely to have persistent active disease and may require a more aggressive treatment strategy to improve their outcomes.

Comparison of HLA-B*27 subtypes between Chinese patients with ankylosing spondylitis and non-ankylosing spondylitis carriers

Objective

To investigate the distribution of subtypes between HLA-B*27 (+) patients with ankylosing spondylitis (AS) and carriers.

Methods

This case–control study recruited Chinese Han patients with HLA-B*27 (+) AS from six hospitals in Zhejiang Province, China between 2013 and 2018. Patients who were examined for HLA-B*27 because of back pain or arthralgia but who did not have AS or arthritis were recruited as controls. HLA-B*27 target DNA was amplified by amplification refractory mutation systems and HLA-B*27 subtypes were determined by sequencing.

Results

The positive rate of HLA-B*27 was significantly higher in the AS group than in the control group. In AS patients, HLA-B*2704 was predominant at 86.4%, followed by HLA-B*2705 at 12.6%; HLA-B*2704 and HLA-B*2705 were found in 70.0% and 10.0% of controls, respectively. HLA-B*2702 and HLA-B*2706 were detected at low frequencies in the control group, while the rare subtype HLA-B*2715 was only observed in two (1.0%) patients with AS. HLA-B*2707 was not detected in AS or control groups.

Conclusion

HLA-B*2704 is the predominant subtype among patients with AS and carriers in southeast China.

Association of HLA-B27 and Behcet's disease: a systematic review and meta-analysis

Background

To calculate the genetic impact of the “HLA-B27” allele on the risk of Behcet’s disease (BD) progression using a systematic review and meta-analysis on case control papers.

Methods

A systematic review search was conducted on the MeSH keywords of Behcet’s disease, HLAB27 and B27 in PubMed, Scopus, ProQuest, EMBASE, SID, Magiran, IranDoc and IranMedex databases from 1975 to Aug 2017. Data underwent meta-analysis (random effect model) in CMA2 software. Pooled odds ratios with 95% confidence intervals were calculated for each study. The heterogeneity of the articles was measured using the I² index.

Results

Twenty two articles met the inclusion criteria for 3939 cases and 6077 controls. The pooled OR of “HLA-B27” in BD patients compared with controls was [1.55 (CI 95% 1.01–2.38), P = 0.04]. The OR differ among different countries or geographical areas, focus on domination the European countries. Quality of studies was moderate and heterogeneity was relatively high (I² = 66.9%).

Conclusions

There is a significant correlation between HLA-B27 and Behcet’s Disease, but it was weak. Environmental and genetic factors might determine which the “HLA-B27” alleles manifest Behcet’s disease progression. Future researches is required to perform about what factors can do to positively and separately influence Behcet’s disease.

Genetic polymorphisms of G protein-coupled receptor 65 gene are associated with ankylosing spondylitis in a Chinese Han population: A case-control study

OBJECTIVE

This study aimed to assess the association between two tag single nucleotide polymorphisms (SNPs) (rs68177277 and rs11624293) of G protein-coupled receptor 65 (GPR65) gene and ankylosing spondylitis (AS) susceptibility in a Chinese Han population.

METHODS

673 patients with AS diagnosed according to the modified New York criteria and 679 age- and gender-matched healthy controls were recruited. SNP genotyping for rs68177277 and rs11624293 polymorphisms were performed using the SNPscan technique. Disease activity was assessed by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI).

RESULTS

Genotype and allele distribution of rs11624293 but not rs68177277 were significantly different between AS and controls (p = 0.004 and p = 0.002). Compared to the wild-type T/T genotype and T allele at rs11624293, the frequencies of C/T genotype and C allele were significantly higher in AS than controls after adjusting for age and gender (OR = 1.527, 95%CIs: 1.190-1.958; OR = 1.515, 95%CIs: 1.183-1.942, respectively). Dominant and co-dominant model of rs11624293 were predictive of AS susceptibility. In AS patients, the genotype of rs11624293 was significantly associated with BASFI scores in those with low disease activity (BASDAI < 4, p = 0.007).

CONCLUSIONS

The results of our study suggest that rs11624293 polymorphism of GPR65 gene is associated with the susceptibility and severity of AS in Chinese Han population.