Editorial: Advances in Pathogenesis, Etiology, and Therapies for Ankylosing Spondylitis

miRNAs dysregulation in ankylosing spondylitis: A review of implications for disease mechanisms, and diagnostic markers

Epigenetic processes, including non-coding RNA, histone modifications, and DNA methylation, play a vital role in connecting the environment to the development of a disorder, especially when there is a favorable genetic background. Ankylosing Spondylitis (AS) is a chronic type of spinal arthritis that highlights the significance of epigenetics in diseases related to autoimmunity and inflammation. MicroRNAs (miRNAs) are small non-coding RNAs that are involved in both normal and aberrant pathological and physiological gene expression. This study focuses on the pathophysiological pathways to clarify the role of miRNAs in AS. We have conducted a thorough investigation of the involvement of miRNAs in several processes, including inflammation, the production of new bone, T-cell activity, and the regulation of pathways such as BMP, Wnt, and TGFβ signaling. Undoubtedly, miRNAs play a crucial role in enhancing our comprehension of the pathophysiology of AS, and their promise as a therapeutic strategy is quickly expanding.

The efficacy of tofacitinib combined with bDMARDs in the treatment of ankylosing spondylitis patients with inadequate response to bDMARDs: a retrospective study

INTRODUCTION

Ankylosing spondylitis(AS) is a chronic inflammatory rheumatic disease primarily affecting the spine and sacroiliac joints. While biologic disease-modifying antirheumatic drugs(bDMARDs) and targeted synthetic DMARDs(tsDMARDs) are popular treatments for AS, there is limited research on their combined use. This study examined a cohort of AS patients who demonstrated inadequate response to bDMARDs and subsequently initiated combination therapy with tofacitinib in conjunction with bDMARDs, assessing both the efficacy and safety profile of this therapeutic approach.

METHODS

In this study, we retrospectively collected the electronic medical records (EMR) of 15 adult patients with AS who were admitted to the Fourth Affiliated Hospital Zhejiang University School of Medicine between January 2018 and June 2022. All patients had received at least one bDMARD treatment for more than three months and still exhibited moderate to high disease activity. Tofacitinib 5 mg bid was added to their original biological treatment. Treatment was continued for a minimum of 12 weeks following the initiation of combination therapy. Changes in ASDAS-CRP and BASDAI scores at week 12 were collected and analyzed from baseline, while changes in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) at weeks 4, 8, and 12 were also collected and analyzed.

RESULTS

After 12 weeks of treatment, the overall ASDAS-CRP score decreased significantly from a baseline of 3.82 ± 1.47 (2.83 ~ 4.99) to 1.47 ± 0.48 (0.75 ~ 2.44), with remission achieved by 7 patients (46.7%) and low disease activity achieved by 5 patients (33.3%). The overall BASDAI score also showed significant improvement, decreasing from a baseline of 5.11 ± 1.42 (3.25 ~ 7 0.75) to 1.28 ± 0.70(0.20 ~ 2.55). Additionally, both ESR and CRP levels decreased significantly during the course of treatment without any reported adverse events leading to discontinuation.

CONCLUSION

To a certain extent, our findings provide some evidence supporting the efficacy and safety of the combination of bDMARD and JAK inhibitor tofacitinib in AS patients with inadequate response to bDMARD monotherapy. It effectively controls disease activity while maintaining a relatively low and manageable incidence of adverse events. Further prospective randomized controlled trials with large sample sizes are anticipated to provide evidence-based medical support.

Diagnosis and Treatment of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory condition primarily affecting the axial bone and sacroiliac joints. Its etiology is complicated and involves genetic variables, demographic factors (age of onset, gender, ethnicity, family history), and environmental variables. It typically manifests in males in their third decade. Galen is credited with first recognizing it, according to historical traditions, but it was not until the 19th century that specific diagnostic criteria were developed. The human leukocyte antigen B27 (HLA-B27) variation, around 20% of the genetic risk, is currently the most significant gene associated with AS susceptibility. Over 100 genes have been connected to AS susceptibility. Clinical signs of AS include stiffness and inflammation in the back, eye inflammation, aortitis (inflammation of the aorta), and spinal ankylosis that impacts posture and fatigue. The dagger sign and sacroiliitis on radiographs, in particular, are crucial for diagnosis. Early inflammatory alterations can be found using modern diagnostic tools such as MRI, and the HLA-B27 gene can help confirm the diagnosis. Overall, 80-95% of people with AS have the HLA-B27 marker. Furthermore, although non-specific, elevated inflammatory markers, such as C-reactive protein and erythrocyte sedimentation rate, offer supporting evidence. Over time, treatment paradigms have seen significant change. First-line treatments such as non-steroidal anti-inflammatory drugs are no longer the only options, even though disease-modifying anti-rheumatic drugs and biologics, especially tumor necrosis factor blockers, have been developed. Physical therapy, which emphasizes consistent exercise, stretches, and posture maintenance, is extremely helpful in managing AS. Surgical interventions can be required in extreme situations. The significance of the interleukin 23/17 axis in the disease cascade has been demonstrated by recent research. Furthermore, a deeper comprehension of the genetic landscape, mainly the functions of non-HLA-B27 loci, may open the door for more specialized therapies. Early diagnosis and interdisciplinary therapies can improve patient outcomes and quality of life as our understanding of AS grows.

Associations of the circulating levels of cytokines with risk of ankylosing spondylitis: a Mendelian randomization study

Background

Observational studies have shown that changes in circulating cytokine/growth factor levels occur throughout the initiation and progression of ankylosing spondylitis (AS), yet whether they are etiologic or downstream effects remains unclear. In this study, we performed a summarized-level bidirectional Mendelian randomization (MR) analysis to shed light on the causal relationship between the two.

Methods

Genetic instrumental-variables (IVs) associated with circulating cytokine/growth factor levels were derived from a genome-wide association study (GWAS) of 8,293 European individuals, whereas summary data for the AS were obtained from a FinnGen GWAS of 166,144 participants. We used the inverse-variance-weighted (IVW) method as the main analysis for causal inference. Furthermore, several sensitivity analyses (MR-Egger, weighted median, MR-PRESSO and Cochran's Q test) were utilized to examine the robustness of the results. Finally, reverse MR analysis was performed to assess reverse causality between AS and circulating cytokine/growth factor levels.

Results

After Bonferroni correction, circulating levels of Cutaneous T-cell attracting (CTACK) and Monocyte specific chemokine 3 (MCP-3) were positively associated with a higher risk of AS (odds ratio [OR]: 1.224, 95% confidence interval [95% Cl]: 1.022 ~ 1.468, P = 0.028; OR: 1.250, 95% Cl: 1.016 ~ 1.539, P = 0.035). In addition, elevated circulating levels of Basic fibroblast growth factor (FGF-basic), Granulocyte colony-stimulating factor (G-CSF) and MCP-3 was considered a consequence of AS disease (β = 0.023, P = 0.017; β = 0.017, P = 0.025; β = 0.053, P = 0.025). The results of the sensitivity analysis were generally consistent.

Conclusion

The present study supplies genetic evidence for the relationship between circulating cytokine levels and AS. Targeted interventions of specific cytokines may help to reduce the risk of AS initiation and progression.

Frontiers of ankylosing spondylitis research: an analysis from the top 100 most influential articles in the field

Ankylosing spondylitis (AS) is a chronic inflammatory disease that frequently results in disability. It has a negative impact on patients' quality of life and puts an enormous budgetary and societal burden on society. The most effective treatment for AS has grown to be a significant issue worldwide. In order to pinpoint research focus and trends in this region, we performed a bibliometric analysis of the top 100 cited papers in this study. We searched the Science Citation Index Expanded (SCI-Expanded) on the Web of Science (WOS) and selected the top 100 cited papers based on AS. The pertinent literature from various years, journals, nations/regions, institutions, authors, keywords, and references were then examined. To construct knowledge maps, we used the VOSviewer, CiteSpace, and Scimago Graphica programs. Excel was then used to compile the information from the pertinent literature that we had retrieved, and we were able to make predictions about the focus and trends that were currently occurring in the field. Between 1999 and 2019, the top 100 cited papers appeared in 23 journals from 36 different nations and regions. Annals of the rheumatic diseases published the majority of the articles, while Lancet had the highest average number of citations per paper. Germany contributed the most publications, followed by the Netherlands and the USA. In terms of the total number of publications, Rheumazentrum Ruhrgebiet contributed the most papers, followed by University Hospital Maastricht and Leiden University. The three major categories are Rheumatology, Medicine, General & Internal, and Genetics & Heredity, whereas the top 5 co-occurrence of keywords included rheumatoid arthritis, double-blind, disease activity, efficacy, and infliximab. The cluster analysis results indicate that inflammation and immunology, safe and effective therapies, and placebo-controlled trials may be focus and trends for future AS research. Bibliometric analysis can swiftly and visually identify the focus and boundaries of AS research. Our findings imply that inflammation and immunology, safe and effective therapies, and placebo-controlled trials may be focus and trends for future AS research.

No evidence of a causal relationship between ankylosing spondylitis and cardiovascular disease: a two-sample Mendelian randomization study

Objective

Observational studies have suggested an increased risk of cardiovascular disease in individuals with ankylosing spondylitis. However, these studies are prone to confounding factors and reverse causality. To address these limitations, we conducted a Mendelian randomization study to assess the causal relationship between AS and CVD.

Methods

The study population comprises 9,069 individuals with ankylosing spondylitis and 509,093 individuals with either of six common cardiovascular diseases and a related indicator. Causal analysis using summary effect estimates and inverse variance weighting were employed as the main methods.

Results

The CAUSE analysis showed no evidence of a causal relationship between AS and CVD. The odds ratios for total CVD, heart failure, myocardial infarction, valvular heart disease, ischemic heart disease, and venous thromboembolism, Arterial stiffness index, were as follows: OR, 1.01; 95% confidence interval, 0.96-1.05; P = 0.91; OR, 1.03; 95% CI, 0.99-1.08; P = 0.50; OR, 0.94; 95% CI, 0.86-1.03; P = 0.53; OR, 0.99; 95% CI, 0.94-1.04; P = 0.99; OR, 0.98; 95% CI, 0.91-1.04; P = 0.94; OR, 0.98; 95% CI, 0.91-1.04; P = 0.99; β, -0.0019; 95% CI, 0.97-1.01; P = 0.99. The IVW and weighted median methods also yielded consistent results, and no heterogeneity or pleiotropy was found. Likewise, a reverse Mendelian randomization analysis did not uncover a heritable causal relationship between AS and CVD.

Conclusion

This Mendelian randomization study does not support a causal relationship between AS and CVD. Further research is needed to confirm this association.

Neuromyelitis optica spectrum disorder in a patient with ankylosing spondylitis: A case report

Neuromyelitis optica spectrum disorder is an autoimmune disease which tends to have other coexisting autoimmune or connective tissue diseases. However, coexisting with ankylosing spondylitis is rare. Here, we report a 57-year-old man with concomitant autoantibodies against aquaporin 4-positive neuromyelitis optica spectrum disorder and HLA-B27-positive ankylosing spondylitis.

Association of vascular endothelial growth factor serum levels with ankylosing spondylitis in Egyptian patients

Background

Ankylosing spondylitis (AS) is one of inflammatory rheumatic diseases which result in wide range of manifestations on the musculoskeletal system and axial joint specifically. Endothelial cell migration and proliferation, as well as subsequent neoangiogenesis and remodelling in autoimmune disorders, are pathogenic mechanisms that are fundamental to inflammation activation and angiogenesis. The development of advanced lesions is thought to involve vascular proliferation as well as vascular endothelial growth factor (VEGF), which serves a regulatory role. It was found that AS patients had increased serum levels of VEGF, which were linked to the disease activity.

Aim of the work

The purpose of this study is to measure serum VEGF levels in Egyptian AS patients and assess their relation to disease-related variables, including radiographic findings.

Results

VEGF serum levels showed a highly significant positive correlation with Bath Ankylosing Spondylitis Functional Index (BASFI) and modified Stroke Ankylosing Spondylitis Spinal Score (MSASS) (p < 0.001); also, there was a significant correlation between the VEGF values and the Ankylosing Spondylitis Disease Activity Index (ASDAS) and the New York x-ray sacroiliac score.

Conclusions

These findings and data illustrate the strong relationship between ASDAS and VEGF and the radiographic score in AS patients. ASDAS combined with VEGF not only is considered a tool for determining the level of disease activity only but also is considered as an indicator for the assessment of the syndesmophytes formation, which performs a crucial role in the prognosis and outcome in AS patients.

Implications and theragnostic potentials of circular RNAs in rheumatic diseases

Circular RNAs (circRNAs), a class of non-coding RNAs (ncRNAs), are highly stable and ubiquitous molecules that exhibit tissue-specific expression. Accumulating evidence has shown that aberrant expression of circRNAs can play a role in the pathogenesis of several diseases. Rheumatic diseases are a varied group of autoimmune and inflammatory disorders affecting mainly the musculoskeletal system. Notably, circRNAs, which are essential immune system gene modulators, are strongly linked to the occurrence and progression of autoimmune disorders. Here, we present and discuss the current findings concerning the roles, implications and theragnostic potentials of circRNAs in common rheumatic diseases, including ankylosing spondylitis (AS), osteoarthritis (OA), osteoporosis (OP), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Crohn's disease (CD), and gout. This review aims to provide new insights to support the development of novel diagnostic and therapeutic strategies for these disabling diseases.

A Predictive Disease Risk Model for Ankylosing Spondylitis: Based on Integrated Bioinformatic Analysis and Identification of Potential Biomarkers Most Related to Immunity

Background

The pathogenesis of ankylosing spondylitis (AS) is still not clear, and immune-related genes have not been systematically explored in AS. The purpose of this paper was to identify the potential early biomarkers most related to immunity in AS and develop a predictive disease risk model with bioinformatic methods and the Gene Expression Omnibus database (GEO) to improve diagnostic and therapeutic efficiency.

Methods

To identify differentially expressed genes and create a gene coexpression network between AS and healthy samples, we downloaded the AS-related datasets GSE25101 and GSE73754 from the GEO database and employed weighted gene coexpression network analysis (WGCNA). We used the GSVA, GSEABase, limma, ggpubr, and reshape2 packages to score immune data and investigated the links between immune cells and immunological functions by using single-sample gene set enrichment analysis (ssGSEA). The value of the core gene set and constructed model for early AS diagnosis was investigated by using receiver operating characteristic (ROC) curve analysis.

Results

Biological function and immune score analyses identified central genes related to immunity, key immune cells, key related pathways, gene modules, and the coexpression network in AS. Granulysin (GNLY), Granulysin (GZMK), CX3CR1, IL2RB, dysferlin (DYSF), and S100A12 may participate in AS development through NK cells, CD8⁺ T cells, Th1 cells, and other immune cells and represent potential biomarkers for the early diagnosis of AS occurrence and progression. Furthermore, the T cell coinhibitory pathway may be involved in AS pathogenesis.

Conclusion

The AS disease risk model constructed based on immune-related genes can guide clinical diagnosis and treatment and may help in the development of personalized immunotherapy.

Ankylosing spondylitis and glaucoma in European population: A Mendelian randomization study

Background

The relationship between ankylosing spondylitis (AS) and glaucoma in the European population remains unclear. In the present study, we applied a two-sample Mendelian randomization (MR) method to investigate their causal relationship.

Methods

MR analysis was conducted to validate the causal associations between AS with glaucoma using summary statistics from the genome-wide association studies of AS (9,069 cases and 13,578 control subjects) and glaucoma (8,591 cases and 210,201 control subjects). The inverse variance weighting method was performed to evaluate the causal relationship. The MR-Egger regression approach was applied to assess pleiotropy, while Cochran's Q test was used to analyze heterogeneity. Subgroup analysis was performed according to primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Results

The results of the MR study reveal a risk-increasing causal relationship between AS and glaucoma among European populations (OR = 1.35, 95%CI = 1.16-1.57, P = 8.81 × 10^-5). Pleiotropy and heterogeneity were not found in our study. In the subgroup analysis, AS was also causal with POAG (OR = 1.48, 95%CI = 1.17-1.86, P = 8.80 × 10^-4) and PACG (OR = 1.91, 95%CI = 1.03-3.51, P = 3.88 × 10^-2).

Conclusion

The results of the MR analysis suggested a causal relationship between AS and glaucoma in the European population. Further studies are needed to identify the specific mechanism between these two diseases.

No Evidence to Support a Causal Relationship between Circulating Adiponectin Levels and Ankylosing Spondylitis: A Bidirectional Two-Sample Mendelian Randomization Study

Based on previous observational studies, the causal association between circulating adiponectin (CA) levels and ankylosing spondylitis (AS) risk remains unclear. Therefore, this study aims to investigate whether CA levels are related to the risk of AS. We carried out a bidirectional two-sample Mendelian randomization (MR) analysis to examine the causal correlation between CA levels and AS via published genome-wide association study (GWAS) datasets. Single-nucleotide polymorphisms (SNPs) related to CA levels were derived from a large GWAS that included 39,883 individuals of European descent. SNPs related to AS were obtained from the FinnGen consortium (2252 cases and 227,338 controls). The random-effects inverse variance weighted (IVW) method was the primary method utilized in our research. We also used four complementary approaches to improve the dependability of this study (MR-Egger regression, Weighted median, Weighted mode, and Simple mode). Random-effects IVW (odds ratio [OR], 1.00; 95% confidence interval [CI], 0.79-1.27, p = 0.984) and four complementary methods all indicated that genetically predicted CA levels were not causally related to the risk of AS. In reverse MR analysis, there is little evidence to support the genetic causality between the risk of AS and CA levels.

[Effectiveness analysis of MAKO robotic-arm assisted total hip arthroplasty via direct anterior approach for bony fused hips]

Objective

To investigate the effectiveness of MAKO robotic-arm assisted total hip arthroplasty (THA) via direct anterior approach (DAA) for bony fused hips in ankylosing spondylitis (AS).

Methods

Between June 2021 and January 2022, MAKO robotic-arm assisted THA via DAA was applied to treat 10 cases (12 hips) of AS with bony fused hips. There were 7 males and 3 females; the age ranged from 30 to 71 years, with an average age of 42.4 years. The duration of AS was 12-35 years, with an average of 21.4 years. The preoperative hip was ankylosed in flexion in 3 cases, with a flexion angle of 20°, 30°, 35°, respectively; 9 cases were ankylosed in extension. The operation time and complications were recorded; the visual analogue scale (VAS) score, Harris score, and Oxford hip scale (OHS) score before and after operation, and postoperative range of motion (flexion, extension, internal rotation, external rotation, adduction, and abduction) were used to evaluate the recovery of joint function; according to the postoperative anteroposterior X-ray film and CT scan of both hip joints, the abduction angle, anteversion angle, the difference between bilateral combined off-set and the lower limb length discrepancy were measured.

Results

The operation time ranged from 80 to 190 minutes (mean, 134.6 minutes). All 10 patients were followed up 5-11 months (mean, 7.4 months). There was no serious adverse events such as incision infection, deep vein thrombosis of lower extremities, hip redislocation, aseptic loosening of the prosthesis, or death. At 5 months after operation, the acetabular prosthesis angle of abduction was 37°-45° (mean, 40.3°), anteversion angle was 9°-20° (mean, 15.8°). The difference between bilateral combined off-set was 0-10 mm (mean, 4.3 mm); the lower limb length discrepancy was 0-12 mm (mean, 3.5 mm). At last follow-up, the average range of motion of the hip joint was 89.2° in flexion (range, 80°-100°), 1.7° in extension (range, -5°-10°), 7.1° in internal rotation (range, 0°-15°), 20.4° in external rotation (range, 10°-30°), 7.9° in adduction (range, 0°-20°), and 16.5° in abduction (range, 10°-25°). At last follow-up, the VAS score, Harris score, and OHS score significantly improved when compared with those before operation ( P<0.05).

Conclusion

The MAKO robotic-arm assisted THA via DAA can achieve satisfactory results in the treatment of AS with bony fused hip, which has the advantages of accurate prosthesis installation, soft tissue release, and less trauma during operation.