Updates on ankylosing spondylitis: pathogenesis and therapeutic agents

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.

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.

Effectiveness of exercise intervention in relieving symptoms of ankylosing spondylitis: A network meta-analysis

BACKGROUND

Ankylosing spondylitis(AS) is a chronic inflammatory rheumatic disease that leads to a reduced quality of life. Exercise appears to be one of the promising modes of intervention. The aim of this study was to review the available evidence and compare the effectiveness of different exercises in relieving symptoms of AS.

METHODS

We searched the Pubmed, WOS, EMbase, CNKI, Cochrane Library, and Scopus databases. The search has spanned from the creation of the database until September 15, 2023. We extracted the first author, year of article publication, sample information, intervention, duration of intervention, and outcome indicators from the literature that met the inclusion criteria. The Cochrane Risk Assessment Tool was used to assess the risk of bias for included studies. I² was used to judge the consistency of the included studies. Egger's test and Begg's test were used to judge whether there was significant publication bias. Forest plots were used to compare intervention effects and SUCRA was provided to rank the effects of the interventions. This study has been registered in PROSPERO(No. CRD42024518522).

RESULTS

After screening, 10 papers matched the inclusion criteria for this study, and the total sample size of the 10 papers was 623. Upon analysis, the papers included in this study did not have significant publication bias (Begg's Test P = 0.210) and had good consistency (P>0.05). The direct comparisons showed that Running, Pilates, Stretching, Yoga, and Tai Chi were more effective interventions than traditional therapies. The effect sizes, confidence intervals, and number of studies for each intervention are shown below: Running [MD -1.90 (95% CI -3.14,-0.66) n = 1], Pilates [MD -1.70 (95% CI -2.90,-0.51) n = 1], Stretching [MD -1.54 (95% CI -2.21,-0.88) n = 4], Yoga [MD -1.24 (95% CI -2.18,-0.30) n = 1], Tai Chi [MD -0.78 (95% CI -1.44,-0.12) n = 2], Exergame[MD -0.80 (95% CI -1.99,0.39) n = 1], Swiss balls[MD -1.07 (95% CI -2.58,0.44) n = 1]. The indirect comparisons showed that the range of effect sizes for each sport intervention intersected the null line. Based on cumulative probability, the order of effectiveness of different exercises in relieving AS symptoms is Running, Pilates, Stretching, Yoga, Tai Chi, Exergame, and Swiss ball.

CONCLUSION

Running, Pilates, Stretching, Yoga, and Tai Chi provided significant relief from AS symptoms. Exergame and Swiss ball were not statistically significant in relieving AS symptoms. There were no significant differences in the effectiveness of different exercise interventions in relieving AS symptoms. Running may have the most beneficial effect on alleviating AS symptoms.

Exploring the molecular mechanism of Epimedium for the treatment of ankylosing spondylitis based on network pharmacology, molecular docking, and molecular dynamics simulations

Ankylosing spondylitis (AS) is a rheumatic disease that causes inflammation and bone formation in the spine. Despite significant advances in treatment, adverse side effects have triggered research into natural compounds. Epimedium (EP) is a traditional Chinese herb with a variety of pharmacological activities, including antirheumatic, anti-inflammatory, and immunomodulatory activities; however, its direct effects on AS treatment and the underlying molecular mechanisms have not been systematically studied. Thus, here, we used network pharmacology, molecular docking, and molecular dynamics simulations to explore the targets of EP for treating AS. We constructed an interaction network to elucidate the complex relationship between EP and AS. Sixteen active ingredients in EP were screened; 80 potential targets were identified. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone, anhydroicaritin, and luteolin were the core components and TNF, IL-6, IL-1β, MMP9, and PTGS2 were the core targets. The GO and KEGG analyses indicated that EP may modulate multiple biological processes and pathways, including the AGE-RAGE, TNF, NF-κB/MAPK, and TLR signaling pathways, for AS treatment. Molecular docking and molecular dynamics simulations showed good affinity between the active components and core targets of EP, with stable binding within 100 nanoseconds. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone possessed the highest free energy of binding to PTGS2 and TNF (-115.575 and - 87.676 kcal/mol, respectively). Thus, EP may affect AS through multiple pathways, including the alleviation of inflammation, oxidative stress, and immune responses. In summary, we identified the active components and potential targets of EP, highlighting new strategies for the further experimental validation and exploration of lead compounds for treating AS.

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.

Role of endoplasmic reticulum aminopeptidase-1 gene polymorphism (rs13167972) in occurrence susceptibility of ankylosing spondylitis in a sample of Iraqi male patients

BACKGROUND

Ankylosing spondylitis (AS) is a chronic and systemic seronegative inflammatory spondyloarthropathy, an autoimmune disease that has been associated with impaired Endoplasmic Reticulum Aminopeptidase (ERAP)-1 activity, which is involved in priming antigenic peptides. The purpose of this study is to investigate the association of 3-UTR of ERAP1 gene polymorphism (rs13167972) with the AS occurrence susceptibility in a sample of Iraqi male patients.

METHODS

The AS patients were diagnosed clinically and by magnetic resonance imaging (MRI) and other clinical and laboratory criteria like symptoms, increased C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The blood grouping and Body Mass Index (BMI) were also investigated to be associated with AS occurrence. The genotyping of the 3-UTR region of the ERAP1 gene (rs13167972) was done by Sanger sequencing.

RESULTS

The results revealed that the AS occurred significantly in the age group of 20-35 years (p = 0.013). The BMI shows that the AS patients were overweighted males (p = 0.013) and the most predominant blood group in AS patients was O- (p = 0.002). The ESR and serum level of CRP were significantly raised in AS patient sera (< 0.001). The results of the receiver-operating characteristics curve analysis (ROC) revealed that the CRP (AUC: 0.995, cut-off: 2.48 mg/L, had 95% %sensitivity, 100% specificity, p < 0.001) is more discriminative than BMI (AUC: 0.300, cut-off: 46.91 kg, had 0% sensitivity, 100% specificity, p = 0.001), and ESR (AUC: 0.808, cut-off: 7.50 mm/hr, had 60% sensitivity, 88% specificity, p < 0.001) in distinguishing between AS patients and control group. The genotyping of the 3-UTR region of ERAP1 gene (rs13167972) result shows that the AG and GG genotypes are significantly occurring in AS patients (70%, OR: 2.33, 95%CI: 1.02-5.36, p = 0.04). The G allele is significantly occurring in AS patients (47%, OR: 2.07, 95CI%: 1.15-3.71, p = 0.01).

CONCLUSION

The AS occurred in young overweight males with blood group O-. The AG and GG genotypes are risk factors for AS development while the G allele is a risk factor that increases the chances for disease incidence.

Patient self-reported experience and satisfaction with golimumab and etanercept treatments for rheumatic diseases: A cohort study

Golimumab and etanercept both exhibit good efficacy in treating rheumatic diseases, while the patient self-reported measurement of treatment improvement and injection experience lacks sufficient evidence. Hence, this study aimed to compare the satisfaction with disease improvement and injection experience and the level of injection site reactions (ISRs) between golimumab-treated and etanercept-treated patients with rheumatic diseases. A total of 312 patients with rheumatic diseases were serially enrolled. Among them, 158 patients received golimumab (golimumab group); the other 154 patients were treated with etanercept (etanercept group) according to the actual disease status, physician advice, and patient willingness. Satisfaction with disease improvement was assessed using the 7-point Likert scale; satisfaction with injection experience and level of ISRs were both determined by the 5-point Likert scale. Satisfaction degrees with global injection experience (P = .025), injection device (P = .008), injection frequency (P = .010), and injection convenience (P = .003) were superior in the golimumab group to the etanercept group, while satisfaction degrees with global disease improvement, symptom relief, and speed of action did not vary (all P > .050) between the 2 groups. Discomfort (P = .005), swelling (P < .001), pain (P = .028), and burning (P = .035) levels were lower in the golimumab group than in the etanercept group. In addition, among 56 patients with a history of tumor necrosis factor inhibitor treatment before golimumab, 40 (71.4%) patients preferred golimumab to other tumor necrosis factor inhibitor. After switching to golimumab treatment, the level of ISRs in most patients was reduced or comparable. Golimumab achieves a satisfying injection experience and relieves the level of ISRs over etanercept in patients with rheumatic diseases.

Clinical features and fecal microbiota characteristics of patients with both ulcerative colitis and axial spondyloarthritis

BACKGROUND

The role of the intestinal microbiota in the pathogenesis of inflammatory bowel disease combined with axial spondyloarthritis (axSpA) is gaining widespread interest.

AIMS

This study was conducted to investigate the clinical and fecal microbiota characteristics of patients with both ulcerative colitis (UC) and axSpA.

METHODS

Clinical data were collected from patients with UC. Patients were divided into the axSpA and non-axSpA groups according to human leukocyte antigen-B27 serology and sacroiliac joint imaging results. We obtained fecal specimens from 14 axSpA and 26 non-axSpA patients. All samples underwent 16S ribosomal DNA sequencing.

RESULTS

Seventy-three patients with UC were included in this study, and the axSpA incidence was 19.2%. This incidence was significantly higher in patients with C-reactive protein > 10 mg/L. Firmicutes and Faecalibacterium abundances were decreased, and Proteobacteria and Escherichia_Shigella abundances were increased in the axSpA group compared with those of the non-axSpA group. Indicator analysis showed that Escherichia_Shigella was more likely to be an indicator species of axSpA. Additionally, many biosynthetic and metabolic pathways, including glutathione metabolism, fatty acid degradation, geraniol degradation, and biosynthesis of siderophore group nonribosomal peptides, were upregulated in the axSpA group.

CONCLUSION

Patients with UC have a high axSpA incidence, which may be related to the relative abundances of Escherichia_Shigella in these patients. The abundances of various biosynthetic and metabolic pathways of the fecal flora were upregulated in patients with axSpA.

The causal relationship between immune cells and ankylosing spondylitis: a bidirectional Mendelian randomization study

BACKGROUND

Ankylosing spondylitis (AS) is one of several disorders known as seronegative spinal arthritis (SpA), the origin of which is unknown. Existing epidemiological data show that inflammatory and immunological factors are important in the development of AS. Previous research on the connection between immunological inflammation and AS, however, has shown inconclusive results.

METHODS

To evaluate the causal association between immunological characteristics and AS, a bidirectional, two-sample Mendelian randomization (MR) approach was performed in this study. We investigated the causal connection between 731 immunological feature characteristic cells and AS risk using large, publically available genome-wide association studies.

RESULTS

After FDR correction, two immunophenotypes were found to be significantly associated with AS risk: CD14 - CD16 + monocyte (OR, 0.669; 95% CI, 0.544 ~ 0.823; P = 1.46 × 10-4; PFDR = 0.043), CD33dim HLA DR + CD11b + (OR, 0.589; 95% CI = 0.446 ~ 0.780; P = 2.12 × 10-4; PFDR = 0.043). AS had statistically significant effects on six immune traits: CD8 on HLA DR + CD8 + T cell (OR, 1.029; 95% CI, 1.015 ~ 1.043; P = 4.46 × 10-5; PFDR = 0.014), IgD on IgD + CD24 + B cell (OR, 0.973; 95% CI, 0.960 ~ 0.987; P = 1.2 × 10-4; PFDR = 0.021), IgD on IgD + CD38 - unswitched memory B cell (OR, 0.962; 95% CI, 0.945 ~ 0.980; P = 3.02 × 10-5; PFDR = 0.014), CD8 + natural killer T %lymphocyte (OR, 0.973; 95% CI, 0.959 ~ 0.987; P = 1.92 × 10-4; PFDR = 0.021), CD8 + natural killer T %T cell (OR, 0.973; 95% CI, 0.959 ~ 0.987; P = 1.65 × 10-4; PFDR = 0.021).

CONCLUSION

Our findings extend genetic research into the intimate link between immune cells and AS, which can help guide future clinical and basic research.