Fifty years after the discovery of the association of HLA B27 with ankylosing spondylitis

Deleterious knock-outs in the HLA class I antigen processing and presentation machinery induce distinct changes in the immunopeptidome

The human leukocyte antigen (HLA) processing and presentation machinery (APPM) is altered in various diseases and in response to drug treatments. Defects in the machinery may change presentation levels or alter the repertoire of presented peptides, globally or in an HLA allele restricted manner, with direct implications for adaptive immunity. In this study, we investigated the immunopeptidome landscape across a panel of isogenic HAP1 cell line clones each with a knock-out of a single gene encoding a key protein in the APPM, including B2M, TAP1, TAP2, TAPBP, IRF2, PDIA3, ERAP1, GANAB, SPPL3, CANX, and CALR. We applied immunopeptidomic and proteomic to assess the successful gene knock-outs on the protein level, to understand how these proteins participate in antigen presentation, and to contextualize protein expression and antigen presentation. We validated the absence of the knocked-out proteins in the respective samples and found that knocking-out an APPM component leads to the loss of peptide subsets that are normally presented on the control wild type cells. We assessed the immunopeptidomes qualitatively and quantitatively, considering factors like peptide diversity, peptide length distribution, and binding affinity to the endogenously expressed HLA alleles in HAP1 cells. We demonstrated a prominent HLA allele-specific alterations in several knock-out conditions. The absence of CALR, CANX, and TAP1 led to significant changes in HLA allele-specific presentation levels. Overall, this work represents the first systematic analysis of how the absence of individual APPM components, knocked out in a single cell line under controlled conditions, affects the peptidome. This approach could facilitate the creation of predictive tools capable of prioritizing HLA-bound peptides likely to be presented when presentation defects occur, such as in cancer and viral infections.

Distribution of human leukocyte antigen B27 (HLA-B27) in Slovak patients

BACKGROUND AND OBJECTIVES

HLA-B27 is a genetic marker associated with spondyloarthropathies, particularly ankylosing spondylitis and axial spondyloarthritis. While its prevalence varies across populations, no data exist for Slovak patients. This study aimed to determine HLA-B27 prevalence in Slovak patients with suspected spondyloarthropathies and assess differences by sex and age.

METHODS

A retrospective cohort of 1,614 patients (888 females and 726 males) was analyzed for HLA-B27 status (positive/negative) using reverse hybridisation (HLA-B27 StripAssay). Statistical analyses included Pearson's Chi-square test and non-parametric Mann-Whitney U and Kruskal-Wallis tests for sex- and age-related differences.

RESULTS

HLA-B27 positivity was 20.57%, with a higher proportion in males (23.28%) than females (18.36%, p = 0.0177). The less than 20 age group had the highest absolute number of positive cases (126 cases; 17.80%), while the 21-40 group had the highest relative positivity (119 cases; 29.38%). The lowest positivity was in the more than 61 age group (17 cases; 13.08%), though age distribution differences were not statistically significant (p = 0.7765). Positivity varies across diagnoses, peaking in musculoskeletal (M) and eye disorders (H), where it exceeds 29%.

CONCLUSION

HLA-B27 positivity is strongly associated with rheumatologic and ophthalmologic conditions and exhibits age- and sex-related variability. These findings emphasize the diagnostic significance of HLA-B27 testing in Slovak patients, especially for early detection and management of spondyloarthropathies. Further research on HLA-B27 variability and its clinical implications is needed to optimize diagnostic strategies and patient care.

Inorganic pyrophosphatase 1: a key player in immune and metabolic reprogramming in ankylosing spondylitis

The relationships among immune cells, metabolites, and AS events were analyzed via Mendelian randomization (MR), and potential immune cells and metabolites were identified as risk factors for AS. Their relationships were subjected to intermediary MR analysis to identify the final immune cells and metabolites. The vertebral bone marrow blood samples from three patients with and without AS were subjected to 10× single-cell sequencing to further elucidate the role of immune cells in AS. The key genes were screened via expression quantitative trait loci (eQTLs) and MR analyses. The metabolic differences between the two groups were compared through single-cell metabolism analysis. Two subgroups of differentiated (CD)8+ memory T cells and naive B cells were obtained from the combined results of intermediary MR analysis and AS single-cell analysis. After the verification of key genes, inorganic pyrophosphatase 1 (PPA1) was identified as the hub gene, as it is differentially expressed in CD8+ memory T cells and can affect the metabolism of T cells in AS by affecting the expression of ferulic acid (FA)4 sulfate, which participates in the cellular immunity in AS.

Fast, Present and Future of the Concept of Spondyloarthritis

PURPOSE OF REVIEW

Axial spondyloarthritis (axSpA) is a rather prevalent chronic inflammatory rheumatic disease that affects already relatively young patients. It has been known better since the end of the nineteenth century but quite a lot has been learned since the early 60ies when the first classification (diagnostic) criteria for ankylosing spondylitis (AS) were agreed on. I have been part of many developments in the last 30 years, and I'm happy to have been able to contribute to the scientific progress in terms of diagnosis, imaging, pathophysiology and therapy. When I was asked to write a manuscript about the SpA concept I felt honored. Thus, the purpose of this extensive review was, on the one hand, to describe the history of AS and axSpA, and on the other hand, to reason about the concept and the gestalt of axSpA, and finally to deliver some ideas what future researchers could possibly do to further study the disease.

RECENT FINDINGS

The last 3 decades were full of innovations for both, classification and treatment of axSpA which also helped us to learn about the pathophysiology. Thus, TNFa, IL-17, IL-23 and Janus kinase are established targets to reduce inflammation. IL-17 and IL-23 are very special in that regard because they both work for psoriasis but only anti-IL-17 agents which don't work in IBD are approved for axSpA, while IL 23 inhibitors are approved for both, psoriasis and IBD, but they don't work in axSpA. New imaging techniques such as low dose CT and synthetic MRI are likely to improve the detection of both active and structural lesions of axSpA. This manuscript tries to describe the most important findings about axSpA. The main aim of research remains to discover the pathophysiology and to further improve treatment options in order to reduce and abolish inflammation and prevent new bone formation to increase the quality of life of our patients. The differences between male and female disease and the role of the immune system in axSpA are now the main challenges, and the role of special T-cell receptors seem to deserve special interest.

Association of ERAP1 and ERAP2 gene polymorphisms and ERAP2 protein with the susceptibility and severity of rheumatoid arthritis in the Ukrainian population

Introduction

Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. Although RA is chiefly associated with HLA class II, nevertheless some HLA class I associations have also been observed. These molecules present antigenic peptides to CD8+ T lymphocytes and natural killer cells. HLA-I molecules bind their peptide cargo (8-10 amino acids long) in the endoplasmic reticulum. Peptides longer than 10 amino acids are trimmed by the endoplasmic reticulum aminopeptidases ERAP1 and ERAP2 to fit the peptide binding groove of the HLA-I molecule. Here, we investigated the possible association of ERAP1 and ERAP2 polymorphisms with RA, and also any possible correlation between serum levels of the ERAP2 protein with disease severity.

Methods

We used Real-Time PCR to genotype ERAP1 and ERAP2 and ELISA test to detect ERAP2 protein.

Results

We found significant associations of ERAP1 rs30187, rs27044, and rs26618, as well as ERAP2 rs2248374, with susceptibility to RA. ERAP1 rs26653 and ERAP2 rs2248374 were also associated with the Disease Activity Score (DAS28), and some polymorphisms were also associated with anti-citrullinated protein or anti-mutated citrullinated vimentin antibodies. RA patients secreted higher concentrations of ERAP2 than controls. Patients with mild disease activity (DAS28 < 3.2) released a concentration of ERAP2 four times lower than that of patients with severe disease activity (DAS28 > 5.1). We detected a higher level of ERAP2 in rheumatoid factor (RF)-positive patients than in RF-negative patients. ERAP2 concentration above 5.85 ng/mL indicated a severe phase of RA.

Conclusions

Some ERAP1 and ERAP2 polymorphisms seem to be related to susceptibility to RA or the severity of the disease. The ERAP2 protein tested in serum could be a valuable biomarker of RA severity.

Emerging biochemical, microbial and immunological evidence in the search for why HLA-B∗27 confers risk for spondyloarthritis

The strong association of the human leukocyte antigen B∗27 alleles (HLA-B∗27) with spondyloarthritis and related rheumatic conditions has long fascinated researchers, yet the precise mechanisms underlying its pathogenicity remain elusive. Here, we review how interplay between the microbiome, the immune system, and the enigmatic HLA-B∗27 could trigger spondyloarthritis, with a focus on whether HLA-B∗27 presents an arthritogenic peptide. We propose mechanisms by which the unique biochemical characteristics of the HLA-B∗27 protein structure, particularly its peptide binding groove, could dictate its propensity to induce pathological T cell responses. We further provide new insights into how TRBV9+ CD8+ T cells are implicated in the disease process, as well as how the immunometabolism of T cells modulates tissue-specific inflammatory responses in spondyloarthritis. Finally, we present testable models and suggest approaches to this problem in future studies given recent advances in computational biology, chemical biology, structural biology, and small-molecule therapeutics.

Relationships between emotional state, sleep disturbance and health-related quality of life in patients with axial spondyloarthritis

BACKGROUND

Axial spondyloarthritis (ax-SpA) is an autoinflammatory disease affecting multiple organs. While emphasizing the treatment of chronic diseases, it has been found that the prevalence of mental disorders and insomnia in patients is also increasing. We investigated mood status, sleep quality and the health-related quality of life (HRQoL) in these patients.

METHODS

A total of 94 pairs ax-SpA patients and age- and sex-matched healthy controls were included in this cross-sectional study. Demographic and clinical data were collected. We assessed the disease activity by the Ankylosing Spondylitis Disease Activity Score, including C-reactive protein (ASDAS-CRP), the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Bath Ankylosing Spondylitis Functional Index (BASFI). The Hospital Anxiety and Depression Scale (HADS), the Pittsburgh Sleep Quality Index (PSQI) and the Medical Outcomes Survey Sheet Form-36 (SF-36) were used to evaluate mood status and quality of sleep and life, respectively. We evaluated the factors related to anxiety and depression scores, sleep disturbance scores and quality of life scores, and the predictors of anxiety, depression and sleep disturbance were analyzed.

RESULTS

Forty-five active patients and forty-nine relieved patients were enrolled. We found that the median HADS anxiety (HADS-A), depression (HADS-D) subscale scores and PSQI score were significantly higher in active ax-SpA than in inactive patients, and were significantly higher than those in controls (HADS-A 9 vs. 5 vs. 3, p < 0.001; HADS-D 8 vs. 5 vs. 3, p < 0.001; PSQI 10 vs. 6 vs. 3, p < 0.001). Moreover, the HADS-A scores were positively correlated to positive HLA-B27 (p = 0.042), pain (p = 0.002) and the BASFI score (p = 0.012), HADS-D scores were positively correlate to disease course (p < 0.001) and PSQI scores were significantly positively correlated to the BASFI score (p = 0.009). Logistic regression analysis showed that BASFI was a risk factor for anxiety, age was a protective factor for depression and disease course was a risk factor for depression. The optimal cut-off value of BASFI in predicting anxiety was 1.55 with an area under the curve value of 0.8488 (p < 0.001), and the optimal cut-off value of age and the course of the disease in predicting depression was 50.5 years old with an area under the curve value of 0.62 (p = 0.0482) and 54 months with an area under the curve value of 0.7988 (p < 0.001). In addition, disease activity was negatively correlated with SF-36 dimensions, and anxiety, depression and sleep disturbance in ax-SpA patients also had significant negative effects on HRQoL (p < 0.05).

CONCLUSIONS

Patients with active ax-SpA tend to be more anxious, depressed and sleep disturbed, and have worse HRQoL than patients in remission. Patients with ax-SpA are more likely to be anxious with worse spinal function, more likely to be depressed with younger age and longer course of disease. Therefore, the assessment of mental health, sleep and HRQoL should also be included in the long-term management of patients with ax-SpA. Key Points • Active ax-SpA patients tend to have more anxiety, depression, sleep disturbances and worse HRQoL compared with patients in remission • The optimal cut-off value of BASFI in predicting anxiety was 1.55, the age and the course of the disease in predicting depression was 50.5 years old and 54 months.

Investigating the causal relationship between immune factors and ankylosing spondylitis: insights from a Mendelian Randomization study

BACKGROUND

Despite previous studies indicating a close relationship between immune system and ankylosing spondylitis (AS), the causal relationship between them remains unclear.

METHODS

Genome-wide association data were utilized to explore the causal link between 731 immune cells and AS using a bidirectional two-sample MR approach. The data included immune cell data from Orrù et al.'s study and AS data from the FinnGen consortium. Cochran's Q test and leave-one-out checked instrument variable (IV) heterogeneity. IVW was the primary method for causal analysis, with MR-Egger and MR-PRESSO addressing horizontal pleiotropy. FDR correction was applied to both analysis directions to rectify multiple testing errors.

RESULTS

In our study, 22 immune phenotypes out of 731 were casually linked to AS. After excluding 5 less robust features, 17 immune factors remained, with 4 being protective and the rest posing risks. Through FDR correction, we found a significant causal relationship between HLA DR on CD14- CD16+ monocyte and AS (OR (95%CI) = 0.70(0.60 ~ 0.83), P = 2.06*10-5). In the reverse analysis with AS as exposure, potential effects on 34 immune features were discovered. After correction, we confirmed significant causal relationships between AS and two immune features, namely CD20- B cell %lymphocyte (OR (95%CI) = 1.16(1.08-1.25), P = 1.91*10-5) and CD20- B cell %B cell (OR (95%CI) = 1.17(1.09-1.26), P = 1.50*10-5).

CONCLUSIONS

Our study identified various features associated with AS in different types of immune cells. These findings provide important clues and a theoretical basis for further understanding the pathogenesis of AS, guiding clinical treatment, and drug design.

Utility of polygenic risk scores to aid in the diagnosis of rheumatic diseases

Rheumatic diseases (RDs) are characterized by autoimmunity and autoinflammation and are recognized as complex due to the interplay of multiple genetic, environmental, and lifestyle factors in their pathogenesis. The rapid advancement of genome-wide association studies (GWASs) has enabled the identification of numerous single nucleotide polymorphisms (SNPs) associated with RD susceptibility. Based on these SNPs, polygenic risk scores (PRSs) have emerged as promising tools for quantifying genetic risk in this disease group. This chapter reviews the current status of PRSs in assessing the risk of RDs and discusses their potential to improve the accuracy of the diagnosis of these complex diseases through their ability to discriminate among different RDs. PRSs demonstrate a high discriminatory capacity for various RDs and show potential clinical utility. As GWASs continue to evolve, PRSs are expected to enable more precise risk stratification by integrating genetic, environmental, and lifestyle factors, thereby refining individual risk predictions and advancing disease management strategies.

Obstetric and neonatal outcomes in women with Ankylosing spondylitis - an evaluation of a population database

BACKGROUND

Ankylosing Spondylitis (AS) is a systemic chronic rheumatic disease characterized by involvement of the axial skeletal and sacroiliac joints. Although this disease is not rare amongst women of reproductive age, data regarding pregnancy outcomes have demonstrated conflicting results. We therefore aimed to compare pregnancy and perinatal outcomes between women who suffered from AS to those who did not.

METHODS

A retrospective cohort study using the Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (HCUP-NIS). Included in the study were all pregnant women who delivered or had a maternal death in the US between 2004 and 2014. Women with an ICD-9 diagnosis of AS before or during pregnancy were compared to those without. Pregnancy, delivery, and neonatal outcomes were compared between the two groups using multivariate logistic regression models adjusting for potential confounders.

RESULTS

A total of 9,096,788 women were inclusion in the analysis. Amongst them, 383 women (3.8/100,000) had a diagnosis of AS and the rest were controls. Women with AS, compared to those without, were more likely to be older; Caucasian; from higher income quartiles; suffer from thyroid disorders, and have multiple pregnancies (p < 0.001, all). After adjusting for confounders, patients in the AS group, compared to those without, had a higher rate of cesarean delivery (CD) (aOR 1.47, 95% CI 1.14-1.91, p = 0.003); gestational diabetes (aOR 1.55, 95% CI 1.02-2.33, p = 0.038); and placenta previa (aOR 3.6, 95% CI 1.6-8.12, p = 0.002). Regarding neonatal outcomes, patients with AS, compared to those without, had a higher rate of small-for-gestational-age (SGA) neonates (aOR 2.19, 95% CI 1.22-3.93, p = 0.009); and intrauterine fetal death (IUFD) (aOR 3.46, 95% CI 1.11-10.83, p = 0.033).

CONCLUSION

Women diagnosed with AS have an increased risk of obstetric complications, including CD, as well as an increased risk of SGA and IUFD.

Illuminating the impact of γδ T cells in man and mice in spondylarthritides

Spondylarthritides (SpA) are a group of autoinflammatory diseases affecting the spine, peripheral joints, and entheses, including axial spondyloarthritis (axSpA) and psoriatic arthritis. AxSpA has a multifactorial etiology that involves genetic predispositions, such as HLA-B27 and IL-23R. Although HLA-B27 is strongly associated with axSpA, its role remains unclear. GWAS studies have demonstrated that genetic polymorphisms related to the IL-23 pathway occur throughout the spectrum of SpA, including but not limited to axSpA and PsA. IL-23 promotes the production of IL-17, which drives inflammation and tissue damage. This pathway contributes not only to peripheral enthesitis but also to spinal inflammation. γδ T cells in axSpA express IL-23R and RORγt, crucial for their activation, although specific pathogenic cells and factors remain elusive. Despite drug efficacy in PsA, IL-23R inhibition is ineffective in axSpA. Murine models provide valuable insights into the intricate cellular and molecular interactions that contribute to the development and progression of SpA. Those models are useful tools to elucidate the dynamics of γδ T cell involvement, offering insights into disease mechanisms and potential therapeutic targets. This review aims to illuminate the complex interplay between IL-23 and γδ T cells in SpA pathogenesis, emphasizing their roles in chronic inflammation, tissue damage, and disease heterogeneity.

Looking back on 51 years of the Carol Nachman Prize in Rheumatology-significance for the field of spondyloarthritis research

The city and casino of Wiesbaden, capital of the German state Hessen, have endowed the Carol Nachman Prize to promote research work in the field of rheumatology since 1972. The prize, endowed with 37,500 €, is the second highest medical award in Germany and serves to promote clinical, therapeutic, and experimental research work in the field of rheumatology. In June 2022, the 50-year anniversary was celebrated. In the symposium preceding the award ceremony, an overview was given on the significance of spondyloarthritis for the work of the awardees in the past 30 years. This overview has now been put together to inform the interested community of the work performed, including the opinion of the awardees regarding what they consider to be their most important contribution.

Dysregulated Non-Coding RNA Expression in T Cells from Patients with Ankylosing Spondylitis Contributes to Its Immunopathogenesis

Ankylosing spondylitis (AS) is a chronic inflammatory disorder characterized by inflammatory back pain and bony fusion of vertebral joints. Genetic associations and environmental factors have been proposed to explain the immunopathogenesis of AS. In the past few years, there have been major advances in understanding T cell dysfunction in AS. Clinically, targeting interleukin-17A, a major cytokine secreted by T helper 17 cells, has been approved for treating patients with active AS. Non-coding RNAs (ncRNAs) are RNA transcripts that do not translate into proteins. The ncRNAs regulate both innate and adaptive immunity and participate in the pathogenesis of autoimmune diseases, including AS. The main purpose of this article is to review the up-to-date studies investigating the aberrant expression of ncRNAs in T cells from patients with AS and to summarize their roles in its pathogenesis. After searching PubMed for studies published between January 2013 and June 2024, nine studies investigating the expression of ncRNAs in AS T cells were included. We found that aberrantly expressed ncRNAs in AS T cells could cause abnormal cytokine release, cell signaling abnormalities, and dysregulated cell proliferation and death, which contribute to the immunopathogenesis of AS. We discussed some limitations of these studies and suggested several research fields for further investigation.

Regional Differences in Diagnosis Journey and Healthcare Utilization: Results from the International Map of Axial Spondyloarthritis (IMAS)

INTRODUCTION

To assess differences in the diagnosis journey and access to care in a large sample of patients with axial spondyloarthritis (axSpA) from around the world, included in the International Map of Axial Spondyloarthritis (IMAS).

METHODS

IMAS was a cross-sectional online survey (2017-2022) of 5557 unselected patients with axSpA from 27 countries. Across five worldwide geographic regions, the patient journey until diagnosis and healthcare utilization in the last 12 months prior to survey were evaluated. Univariable and multivariable linear regression was used to analyze factors associated with higher healthcare utilization.

RESULTS

Of 5557 participants in IMAS, the diagnosis took an average of 7.4 years, requiring more than two visits to HCPs (77.7% general practitioner and 51.3% rheumatologist), and more than two diagnostic tests [67.5% performed human leukocyte antigen B27 (HLA-B27), 64.2% x-ray, and 59.1% magnetic resonance imaging (MRI) scans]. North America and Europe were the regions with the highest number of healthcare professional (HCP) visits for diagnosis, while the lowest number of visits was in the Asian region. In the previous 12 months, 94.9% (n = 5272) used at least one healthcare resource, with an average of 29 uses per year. The regions with the highest healthcare utilization were Latin America, Europe, and North America. In the multiple linear regression, factors associated with higher number of healthcare utilization were younger age (b =  - 0.311), female gender (b = 7.736), higher disease activity (b = 1.461), poorer mental health (b = 0.624), greater functional limitation (b = 0.300), greater spinal stiffness (b = 1.527), and longer diagnostic delay (b = 0.104).

CONCLUSION

The diagnosis of axSpA usually takes more than two visits to HCPs and at least 7 years. After diagnosis, axSpA is associated with frequent healthcare resource use. Younger age, female gender, higher disease activity, poorer mental health, greater functional limitation, greater spinal stiffness, and longer diagnostic delay are associated with higher healthcare utilization. Europe and North America use more HCP visits and diagnostic tests before and after diagnosis than the other regions.

[Advances in the Application of Nanozymes in Joint Disease Therapy]

Nanozymes are nanoscale materials with enzyme-mimicking catalytic properties. Nanozymes can mimic the mechanism of natural enzyme molecules. By means of advanced chemical synthesis technology, the size, shape, and surface characteristics of nanozymes can be accurately regulated, and their catalytic properties can be customized according to the specific need. Nanozymes can mimic the function of natural enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), to scavenge reactive oxygen species (ROS). Reported findings have shown that nanozymes have the advantages of excellent stability, low cost, and adjustable catalytic activity, thereby showing great potential and broad prospects in the application of disease treatment. Herein, we reviewed the advances in the application of nanozymes in the treatment of joint diseases. The common clinical manifestations of joint diseases include joint pain, swelling, stiffness, and limited mobility. In severe cases, joint diseases may lead to joint destruction, deformity, and functional damage, entailing crippling socioeconomic burdens. ROS is a product of oxidative stress. Increased ROS in the joints can induce macrophage M1 type polarization, which in turn induces and aggravates arthritis. Therefore, the key to the treatment of joint diseases lies in ROS scavenging and increasing oxygen (O2) content. Nanozymes have demonstrated promising application potential in the treatment of joint diseases, including rheumatoid arthritis, osteoarthritis, and gouty arthritis. However, how to ensure their biosafety, reduce the toxicity, and increase enzyme activity remains the main challenge in current research. Precise control of the chemical composition, size, shape, and surface modification of nanomaterials is the main development direction for the future.

Four-year real-world experience of secukinumab in a large Italian cohort of axial spondyloarthritis

Objectives

This study aims to evaluate in a real-life Italian multicenter cohort of axial spondyloarthritis (axSpA) (1) the 4-year effectiveness and safety of secukinumab, (2) the drug retention rate (DRR), and (3) the impact of the line of bDMARDs treatment, subtype of axSpA, and sex on achieving low disease activity (LDA) and very low disease activity (VLDA).

Methods

Consecutive axSpA patients receiving secukinumab between 2016 and 2023 were prospectively evaluated. Data on disease characteristics, previous/ongoing treatments, comorbidities, and follow-up duration were collected. Treatment response was evaluated at 6 and 12 months after initiation and yearly up to 48 months (T48). DRR and effectiveness outcomes were evaluated according to bDMARDs treatment, axSpA subtype, and sex. Infections and adverse events (AEs) were recorded.

Results

We enrolled 272 patients (48.2% male; median age, 51; 39.7% HLA-B27+; 40.4% nr-axSpA), of whom 30.9% were naïve to secukinumab. Overall, secukinumab yielded improvement in effectiveness outcomes; the naïve patients maintained lower disease activity vs. the non-naïve ones. At T48, the LDA and VLDA rates were higher in naïve patients and in male individuals. Treatment was discontinued in 104 patients due to primary/secondary loss of effectiveness and in 34 patients due to AEs. The DRR at T48 was 67.4% in the whole population, regardless of treatment line, axSpA subtype, and sex.

Conclusions

Secukinumab was safe and effective in all axSpA patients irrespective of treatment line, disease subtype, and sex. The patients achieved sustained 4-year remission and DRR.

CARD9 in the pathogenesis of axial spondyloarthritis

Axial spondyloarthritis (axSpA) has been long classified as an autoimmune disease caused by a breakdown in the ability of the immune system to delineate self from foreign, resulting in self-reactive T cells. The strong genetic association of HLA-B27 supports this role for T cells. More recently, genetic and clinical studies indicate a prominent role of the environment in triggering axSpA, including an important role for microbes and the innate immune response. As an example, mutations in genes associated with innate immunity, including the anti-fungal signaling molecule Caspase recruitment domain-containing protein 9 (CARD9), have been linked to axSpA susceptibility. Thus, current thought classifies axSpA as a "mixed pattern condition" caused by both autoimmune and autoinflammatory mechanisms. The goal of this review is to convey.

Diagnostic accuracy in axial spondyloarthritis: a systematic evaluation of the role of clinical information in the interpretation of sacroiliac joint imaging

OBJECTIVES

Radiography and MRI of the sacroiliac joints (SIJ) are relevant for the diagnosis and classification of patients with axial spondyloarthritis (axSpA). This study aimed to evaluate the impact of clinical information (CI) on the accuracy of imaging interpretation.

METHODS

Out of 109 patients referred because of suspicion of axSpA with complete imaging sets (radiographs and MRI of SIJ), 61 were diagnosed with axSpA (56%). Images were independently evaluated by three radiologists in four consecutive reading campaigns: radiographs and radiographs+MRI without and with CI including demographic data, SpA features, physical activity and pregnancy. Radiographs were scored according to the modified New York criteria, and MRIs for inflammatory and structural changes compatible with axSpA (yes/no). The clinical diagnosis was taken as reference standard. The compatibility of imaging findings with a diagnosis of axSpA (precision) before and after the provision of CI and radiologists' confidence with their findings (0-10) were evaluated.

RESULTS

The precision of radiographs evaluation without versus with CI increased from 70% to 78% (p=0.008), and for radiographs+MRI from 81% to 82% (p=1.0), respectively. For CR alone, the sensitivity and specificity of radiologic findings were 51% and 94% without and 60% and 100% with CI, while, for radiographs+MRI, they were 74% and 90% vs 71% and 98%, respectively. The diagnostic confidence of radiologists increased from 5.2±1.9 to 6.0±1.7 with CI for radiographs, and from 6.7±1.6 to 7.2±1.6 for radiographs+MRI, respectively.

CONCLUSION

The precision, specificity and diagnostic confidence of radiologic evaluation increased when CI was provided.

[Diagnosis and classification of axial spondyloarthritis (axSpA) - the current status]

Axial spondyloarthritis (axSpA) is an inflammatory rheumatic disease typically characterized by inflammatory back pain (IBP). The term axSpA has largely replaced the long-used term ankylosing spondylitis (AS). IBP is caused by inflammation in the axial skeleton, with the sacroiliac joints (SIJ) being particularly frequently affected initially. The spine is usually added in later stages, which is then increasingly characterized structurally by the formation of new bone. The overall concept of spondyloarthritis includes other disease manifestations such as uveitis, psoriasis and colitis and comorbidities such as cardiovascular disease and osteoporosis.The ASAS classification criteria for axSpA, in place since 2009, have replaced the 1984 modified New York criteria. In the former, in addition to conventional X-rays, changes in the SIJ detected by magnetic resonance imaging (MRI) and also the detection of HLA B27 have, for the first time, played a role. It is important to note that these are not diagnostic criteria, as they do not exist. This paper outlines 10 points that should be considered when making a diagnosis.

[The role of HLA-B27 in the pathogenesis and diagnosis of axial spondyloarthritis : 50 years after discovery of the strong genetic association]

BACKGROUND

The association of the human lymphocyte antigen B27 (HLA-B27) with ankylosing spondylitis (AS), also now called axial spondylarthritis (axSpA), was first described 50 years ago.

OBJECTIVE

This article gives an overview of the available knowledge on the topic.

MATERIAL AND METHODS

This is a narrative review based on the experience of the authors.

RESULTS

The HLA-B27 is a member of the HLA class I family of genes of the major histocompatibility complex (MHC). The prevalence of HLA-B27 in the central European population is approximately 8 %, i.e., the vast majority of carriers of HLA-B27+ remain healthy. The frequency of HLA-B27 shows a decline from north to south. The HLA-B27 explains only 30 % of the genetic burden of axSpA. The prevalence of the disease correlates with the frequency of HLA-B27 in the population, i.e., there are geographic differences. Approximately 60-90 % of patients with axSpA worldwide are HLA-B27+. Some 200 subtypes of HLA-B27 can be differentiated using the polymerase chain reaction (PCR). In Thailand and Sardinia two subtypes were found that are not associated with axSpA. The physiological function of HLA class I molecules is the defence of the organism against microbes. Microbial peptides are presented to the immune system, which can be specifically attacked by CD8+ T‑cells. Genetic polymorphisms of the enzyme endoplasmic reticulum aminopeptidase 1 (ERAP1), which breaks down peptides in the endoplasmic reticulum, are associated only with HLA-B27+ diseases.

DISCUSSION

The pathogenesis of axSpA is unclear but a major hypothesis is that of the arthritogenic peptides. In this it is assumed that potentially pathogenic foreign or autologous peptides can be presented by HLA-B27. If nothing else, HLA-B27 plays an important role in the diagnosis, classification and determination of the severity of axSpA.

Serum biomarkers and their relationship to axial spondyloarthritis associated with inflammatory bowel diseases

Spondyloarthritis (SpA) constitute a group of chronic inflammatory immune-mediated rheumatic diseases characterized by genetic, clinical, and radiological features. Recent efforts have concentrated on identifying biomarkers linked to axial SpA associated with inflammatory bowel disease (IBD), offering predictive insights into disease onset, activity, and progression. Genetically, the significance of the HLA-B27 antigen is notably diminished in ankylosing spondylitis (AS) associated with IBD, but is heightened in concurrent sacroiliitis. Similarly, certain polymorphisms of endoplasmic reticulum aminopeptidase (ERAP-1) appear to be involved. Carriage of variant NOD2/CARD15 polymorphisms has been demonstrated to correlate with the risk of subclinical intestinal inflammation in AS. Biomarkers indicative of pro-inflammatory activity, including C-reactive protein (CRP) along with erythrocyte sedimentation rate (ESR), are among the consistent predictive biomarkers of disease progression. Nevertheless, these markers are not without limitations and exhibit relatively low sensitivity. Other promising markers encompass IL-6, serum calprotectin (s-CLP), serum amyloid (SAA), as well as biomarkers regulating bone formation such as metalloproteinase-3 (MMP-3) and Dickkopf-related protein 1 (DKK-1). Additional candidate indicators of structural changes in SpA patients include matrix metalloproteinase-3 (MMP-3), vascular endothelial growth factor (VEGF), tenascin C (TNC), and CD74 IgG. Fecal caprotein (f-CLP) levels over long-term follow-up of AS patients have demonstrated predictive value in anticipating the development of IBD. Serologic antibodies characteristic of IBD (ASCA, ANCA) have also been compared; however, results exhibit variability. In this review, we will focus on biomarkers associated with both axial SpA and idiopathic intestinal inflammation, notably enteropathic spondyloarthritis.

Global trends and research status in ankylosing spondylitis clinical trials: a bibliometric analysis of the last 20 years

BACKGROUND

Ankylosing spondylitis (AS) is a rheumatic and autoimmune disease associated with a chronic inflammatory response, mainly characterized by pain, stiffness, or limited mobility of the spine and sacroiliac joints. Severe symptoms can lead to joint deformity, destruction, and even lifelong disability, causing a serious burden on families and society as a whole. A large number of clinical studies have been published on AS over the past 20 years. This study aimed to summarize the current research status and global trends relating to AS clinical trials through a bibliometric analysis.

METHODS

The Web of Science Core Collection database was searched for publications related to AS clinical trials published between January 2003 and June 2023. Bibliometric analysis and web visualization were performed using CiteSpace, VOSviewer, and a bibliometric online analysis platform (https://bibliometric.com), which included the number of publications, citations, countries, institutions, journals, authors, references, and keywords.

RESULTS

1,212 articles published in 201 journals from 65 countries were included in this study. The number of publications related to AS clinical trials is increasing annually. The United States and the Free University of Berlin, the countries and institutions, respectively, that have published the most articles on AS, have made outstanding contributions to this field. The author with the most published papers and co-citations over the period covered by the study was Desiree Van Der Heijde. The journal with the most published and cited articles was Annals of the Rheumatic Diseases. The keywords: "double-blind," "rheumatoid arthritis," "efficacy," "placebo-controlled trial," "infliximab," "etanercept," "psoriatic arthritis" and "therapy" represent the current research hotspots regarding AS.

DISCUSSION

This is the first study to perform a bibliometric analysis and visualization of AS clinical trial publications, providing a reliable research focus and direction for clinicians. Future studies in the field of AS clinical trials should focus on placebo-controlled trials of targeted therapeutic drugs.

Global trends and research status in ankylosing spondylitis clinical trials: a bibliometric analysis of the last 20 years

Background

Ankylosing spondylitis (AS) is a rheumatic and autoimmune disease associated with a chronic inflammatory response, mainly characterized by pain, stiffness, or limited mobility of the spine and sacroiliac joints. Severe symptoms can lead to joint deformity, destruction, and even lifelong disability, causing a serious burden on families and society as a whole. A large number of clinical studies have been published on AS over the past 20 years. This study aimed to summarize the current research status and global trends relating to AS clinical trials through a bibliometric analysis.

Methods

The Web of Science Core Collection database was searched for publications related to AS clinical trials published between January 2003 and June 2023. Bibliometric analysis and web visualization were performed using CiteSpace, VOSviewer, and a bibliometric online analysis platform (https://bibliometric.com), which included the number of publications, citations, countries, institutions, journals, authors, references, and keywords.

Results

1,212 articles published in 201 journals from 65 countries were included in this study. The number of publications related to AS clinical trials is increasing annually. The United States and the Free University of Berlin, the countries and institutions, respectively, that have published the most articles on AS, have made outstanding contributions to this field. The author with the most published papers and co-citations over the period covered by the study was Desiree Van Der Heijde. The journal with the most published and cited articles was Annals of the Rheumatic Diseases. The keywords: "double-blind," "rheumatoid arthritis," "efficacy," "placebo-controlled trial," "infliximab," "etanercept," "psoriatic arthritis" and "therapy" represent the current research hotspots regarding AS.

Discussion

This is the first study to perform a bibliometric analysis and visualization of AS clinical trial publications, providing a reliable research focus and direction for clinicians. Future studies in the field of AS clinical trials should focus on placebo-controlled trials of targeted therapeutic drugs.

HLA-B*27 and Ankylosing Spondylitis: 50 Years of Insights and Discoveries

PURPOSE OF REVIEW

To commemorate the 50th anniversary of the groundbreaking discovery of a remarkably strong association between HLA-B*27 and ankylosing spondylitis (AS).

RECENT FINDINGS

In addition to HLA-B*27, more than 116 other recognized genetic risk variants have been identified, while epigenetic factors largely remain unexplored in this context. Among patients with AS who carry the HLA-B*27 gene, clonally expanded CD8 + T cells can be found in their bloodstream and within inflamed tissues. Moreover, the α and β chain motifs of these T-cell receptors demonstrate a distinct affinity for certain self- and microbial-derived peptides, leading to an autoimmune response that ultimately results in the onset of the disease. These distinctive peptide-binding and presentation characteristics are a hallmark of the disease-associated HLA-B*27:05 subtype but are absent in HLA-B*27:09, a subtype not associated with the disease, differing by only a single amino acid. This discovery represents a significant advancement in unraveling the 50-year-old puzzle of how HLA-B*27 contributes to the development of AS. These findings will significantly accelerate the process of identifying peptides, both self- and microbial-derived, that instigate autoimmunity. This, in return, will pave the way for the development of more accurate and effective targeted treatments. Moreover, the discovery of improved biomarkers, in conjunction with the emerging technology of electric field molecular fingerprinting, has the potential to greatly bolster early diagnosis capabilities. A very recently published groundbreak paper underscores the remarkable effectiveness of targeting and eliminating disease-causing T cells in a HLA-B*27 patients with AS. This pivotal advancement not only signifies a paradigm shift but also bolsters the potential for preventing the disease in individuals carrying high-risk genetic variants.

Revisiting articular syndrome in the peri-pandemic COVID-19 era

Articular syndrome is often the presentation of a person's various rheumatic or related diseases. It includes both arthralgia and arthritis, with objective signs of joint inflammation defining the latter. This syndromic approach to joint pain enables a scientific method for early diagnosis of common rheumatic conditions without compromising the recognition of uncommon conditions. This review explores common rheumatic conditions associated with articular syndrome, including osteoarthritis, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE). It supports the early differentiation of uncommon but emerging entities such as reactive arthritis (ReA). The aim of the review is to comprehensively overview various forms of articular syndrome to update rheumatologists' and allied health specialists' knowledge. Epidemiology, clinical presentations, diagnostic approaches, and therapeutic strategies are discussed in the context of articular syndrome. The challenges emerging in the peri-pandemic COVID-19 era are highlighted. The improved understanding of the spectrum of clinical conditions and disease states presenting with articular syndrome may facilitate early diagnosis, optimal management, and enhanced patient outcomes within the realm of rheumatology.