Insights Into the Pathology and Treatment of Spondyloarthritis: From the Bench to the Clinic

MicroRNAs in Axial Spondylarthritis: an Overview of the Recent Progresses in the Field with a Focus on Ankylosing Spondylitis and Psoriatic Arthritis

Purpose of Review

To highlight the recent discoveries and lines of evidence on the role of microRNAs in ankylosing spondylitis (AS) and psoriatic arthritis (PsA), focusing on their expression profiling and mechanisms of action.

Recent Findings

AS and PsA are chronic inflammatory musculoskeletal diseases with axial manifestations and represent an excellent model for studying microRNAs contribution to the disease pathogenesis, particularly through immunomodulation, inflammation, and bone remodelling, or their value as candidate diagnostic and prognostic biomarkers.

Summary

MicroRNAs are single-stranded nucleotides able to regulate gene expression. They are a key component of the epigenetic machinery, involved in physiological and pathological processes. The contribution of microRNAs in AS and PsA (such as miR-29a in regulating bone metabolism) is highlighted by several works in the field but their utility as possible markers must be still confirmed, particularly in larger patients’ cohorts.

The influence of gut microbiome on bone health and related dietary strategies against bone dysfunctions

The link between the gut microbiome and bone health has begun to attract widespread interest in recent years. The gut microbiome are vital in many diseases involving bone loss. Probiotics, prebiotics, and dietary supplements have been suggested to protect bone health by altering the composition of the gut microbiota. Notably, studying the relationship between the gut microbiome and bone health can provide a basis for the prevention and treatment of bone diseases. This review focuses on the link between the gut microbiome and bone diseases, exploring current knowledge of the mechanisms by which gut bacteria affect bone health. In addition, the influences of dietary supplements on the interactions between the gut microbiome and bone health are discussed. This knowledge will promote new ideas for gut microbiota-mediated dietary interventions in patients with bone diseases.

Ixekizumab in the treatment of psoriatic arthritis

Psoriatic arthritis (PsA) is a heterogeneous chronic rheumatic disorder with numerous phenotypic facets. A better in deep understanding of the pathophysiologic mechanisms leading to psoriasis and PsA has contributed to the introduction of novel therapeutic agents. IL-17 is at the heart and a critical factor in the onset of PsA. Ixekizumab, a high-affinity monoclonal antibody against IL-17 A, has been approved by the US FDA in March 2016 for baseline psoriasis and Dec 2017 for PsA; by the EMA in April 2016 and January 2018, respectively. This article reviews the published data relating to ixekizumab efficacy and safety in the PsA treatment.

Validation of the Simple Psoriatic Arthritis Screening (SiPAS) questionnaire in a Turkish psoriatic population

OBJECTIVES

Screening of psoriatic arthritis (PsA) in patients with psoriasis (PsO) is critical for the prevention of irreversible joint erosions, deformity, and disability. The SiPAS questionnaire is a short, simple and useful tool designed to screen PsA. This study aimed to evaluate validity of the SiPAS questionnaire in Turkish patients with PsO.

MATERIALS AND METHODS

The Turkish translation of SiPAS was sent to us by the developer authors of the original index. Subjects were recruited from dermatology outpatient clinics. All patients' demographic parameters and SiPAS questionnaire results were recorded. After patients completed the questionnaire they were assessed by a rheumatologist according to standard protocol which included a complete history, detailed physical examination, laboratory tests and Classification for Psoriatic Arthritis (CASPAR) criteria. Receiver operating characteristics (ROC) were assessed to obtain sensitivity and specificity of the Turkish version of the SiPAS questionnaire.

RESULTS

One hundred and thirty subjects were recruited into the study. The mean age of subjects were 43.5 years and the 55.4% of subjects were female. Of these, after rheumatologic evaluation 42 patients were diagnosed as PsA. The area under the ROC curve was 0.994 which means as excellent predictor and optimum cut-off threshold to discriminate patients diagnosed with PsA was 3 according to this ROC curve analysis. The overall sensitivity and specificity based on cut-off threshold of 3, were 97.6% and 94.3%, respectively.

CONCLUSIONS

The Turkish version of the SiPAS questionnaire is a simple useful, time-saving and valid tool for screening PsA in patients diagnosed with PsO with its high sensitivity and specificity. A SiPAS score ≥3 is an indication for referral to a rheumatologist.

Insight into the Quality of Life of Patients with Ankylosing Spondylitis: Real-World Data from a US-Based Life Impact Survey

INTRODUCTION

We aim to assess the real-world, US patient-reported impact of ankylosing spondylitis (AS) on quality of life (QOL) across physical, discomfort, social, and emotional domains.

METHODS

Demographic and QOL data were collected from a random sample of patients associated with the Spondylitis Association of America (SAA) from July to December 2017. QOL measures were based on the Evaluation of Ankylosing Spondylitis Quality of Life (EASi-QoL) questionnaire. The survey evaluated AS impact on the physical domain on the day of survey participation and impact on the discomfort, social, and emotional domains within the week before participation. A 3:1 (male to female) weighting was performed to reflect the reported prevalence of AS in US adults.

RESULTS

Of 820 respondents who completed the survey, 716 self-reported receiving an AS diagnosis from their doctor and were included in this analysis (mean age, 55.5 years; 46.9% male). The mean total EASi-QoL score was 28.9 (weighted); overall, 33.7%, 31.7%, and 34.7% of respondents, respectively, reported a low (EASi-QoL score 0-17), a medium (18-35), and a high (≥ 36) impact of AS on QOL. The physical domain was most impacted; 41.9% of respondents had an EASi-QoL score ≥ 10 (weighted). Women were significantly more likely than men to report a high impact of AS on all QOL domains. Biologic users reported an impact on QOL comparable with the impact on QOL of nonsteroidal anti-inflammatory drug use. AS also impacted lifestyle characteristics, including career choice and sports participation.

CONCLUSION

AS negatively impacted all QOL domains analyzed. The incorporation of subjective measures of disease into disease evaluation should be considered.

FUNDING

Novartis Pharmaceuticals Corporation and UCB, Inc. Plain language summary available for this article.

Fecal transplants in spondyloarthritis and uveitis: ready for a clinical trial?

PURPOSE OF REVIEW

The intestinal microbiome is thought to play a role in the pathogenesis of inflammatory bowel disease (IBD). There are many shared clinical manifestations between IBD and spondyloarthritis (SpA), of which the most common are peripheral arthritis and uveitis. Clinical overlap along with similar genetics between these diseases suggests a possible shared pathogenetic mechanism, which might center on the intestinal microbiota. In this review, we discuss the available evidence that SpA is a microbiome-driven disease and indicate how SpA-associated uveitis could be tied to gut dysbiosis. We conclude by discussing different treatment paradigms targeting the intestinal microbiome for SpA.

RECENT FINDINGS

Recent studies support the growing evidence of the intestinal microbiome as a crucial player in SpA disease pathogenesis. There is emerging evidence that the gut microbiome may play a causative role in uveitis.

SUMMARY

The field is beginning to discover a new level of understanding how the intestinal microbiome is involved in SpA. Treatment methods to alter intestinal microbiota to treat SpA-related diseases are still in its infancy.

Validation of the Toronto Psoriatic Arthritis Screen II (TOPAS II) questionnaire in a Turkish population

OBJECTIVE

To evaluate the TOPAS II questionnaire validation in a Turkish population.

METHODS

The Turkish translation of ToPAS II was sent to us by the developer authors of the original index. Subjects were recruited from dermatology, physical medicine and rehabilitation, and rheumatology outpatient clinics. All patients' demographic parameters and ToPAS II questionnaire results were recorded. After patients completed the questionnaire they were assessed by a rheumatologist according to a standard protocol which includes a complete history, detailed physical examination, laboratory tests and CASPAR criteria. Receiver operating characteristics (ROC) assessed to obtain sensitivity and specificity of Turkish version of ToPAS II questionnaire.

RESULTS

One hundred and fifty subjects were recruited in the study. The mean age of subjects was 41.07 years (SD 12.59) and the 58% of subjects were female. There were 46 subjects from psoriasis group, 43 subjects from psoriatic arthritis (PsA) group, 41 subjects from physical medicine and rehabilitation group and 20 subjects from rheumatology (non-PsA) group. The area under the ROC curve was 0.99 which means as excellent predictor and optimum cut-off threshold to discriminate patients diagnosed with PsA was 8 according to this ROC curve analysis. The overall sensitivity and specificity based on cut-off threshold of 8, were 95.8 and 98%, respectively.

CONCLUSION

The Turkish version of ToPAS II has high sensitivity and specificity. It is simple, not time consuming and useful tool to screen for PsA in both patients with and without psoriasis.

Gut inflammation and microbiome in spondyloarthritis

Spondyloarthritis (SpA) is chronic inflammatory disease involving joints and the spine. Bowel inflammation is common in SpA, which may be classified as acute or chronic. Chronic gut inflammation is most common in SpA patients with axial involvement as compared to those presenting with peripheral involvement alone. The pathogenesis of gut inflammation in SpA could be explained by two factors-over-activation of immunological cells and altered gut microbiome. This is exemplified by SpA animal models, namely HLA-B27-expressing transgenic animals and SKG mice models. Immunological mechanisms include homing of activated T cells from gut into synovium, excess pro-inflammatory cytokines secretion by immune cells such as IL-23 and genetic variations in immunological genes. The evidence for role of gut microbiome in SpA is gradually emerging. Recently, metagenomic study of gut microbiome by sequencing of microbial nucleic acids has enabled identification of new microbial taxa and their functions in gut of patients with SpA. In SpA, the gut microbiome could emerge as diagnostic and prognostic marker of disease. Modulation of gut microbiome is slated to have therapeutic potential as well.

Health-related quality of life in patients with ankylosing spondylitis: a comprehensive review

Ankylosing spondylitis (AS) is a complex systemic rheumatological disease which often causes severe disability and impaired quality of life (QoL). We searched the PubMed/MEDLINE electronic database for available literature on QoL and its predictors in patients with AS. Recent evidence indicates that AS patients have poorer QoL compared to the general population, but similar to that of patients with other rheumatological disorders. Disease activity is one of the most powerful predictors of QoL, however latest advances in pharmacological treatment (namely, anti-TNF-α) along with physical exercise can minimize the effects of AS on QoL. Psychological distress symptoms contribute to impaired QoL both directly and indirectly by influencing disease activity. The impact of other psychosocial variables, however, is less studied and more prospective investigations are necessary, which could eventually lead to the development of psychosocial interventions that are personalized to this patient population.

Drug retention rates and treatment discontinuation among anti-TNF-α agents in psoriatic arthritis and ankylosing spondylitis in clinical practice

Objective. The study aim was to determine treatment persistence rates and to identify causes of discontinuation in psoriatic arthritis (PsA) and ankylosing spondylitis (AS) patients in clinical practice. Methods. Patients treated with adalimumab (ADA), etanercept (ETA), or infliximab (INF) were retrospectively included. Treatment persistence rates were analyzed by means of a stepwise logistic regression. Differences between therapy duration were assessed by means of an analysis of variance model (ANOVA), while a chi-square test was used to evaluate relationships between therapies and causes of treatment discontinuation and the administration of concomitant disease-modifying antirheumatic drugs (DMARDs) among therapies and types of disease considering completed courses of therapy versus courses that were discontinued. Results. 268 patients received a total of 353 anti-TNF treatment courses (97 ADA, 180 ETA, and 76 INF). Comparison among therapies showed significant difference regarding the treatment persistence rates due to the contrast between ETA and INF (P = 0.0062). We observed that 84.7% of patients were still responding after 6 months of follow-up. Comparison among diseases showed that there were significant differences between PsA and AS (P = 0.0073) and PsA and PsA with predominant axial involvement (P = 0.0467) in terms of duration of the therapy, while there were no significant differences with regard to the persistence rate. Conclusions. In this cohort, anti-TNF-α therapy was associated with high drug persistence rates. As in rheumatoid arthritis, switching to another anti-TNF-α agent can be an effective option when, during the treatment of AS or PsA, therapy is suspended because of inefficacy or an adverse event. Combination therapy with DMARDs was associated with a better persistence rate.

Extraintestinal manifestations of inflammatory bowel disease: epidemiology, diagnosis, and management

Abstract Extraintestinal manifestations occur rather frequently in inflammatory bowel disease (IBD), e.g. ulcerative colitis (UC) and Crohn's disease (CD). The present paper provides an overview of the epidemiology, clinical characteristics, diagnostic process, and management of rheumatic, metabolic, dermatologic (mucocutaneous), ophthalmologic, hepatobiliary, hematologic, thromboembolic, urinary tract, pulmonary, and pancreatic extraintestinal manifestations related to IBD. Articles were identified through search of the PubMed and Embase databases, the Cochrane Library, and the web sites of the European Agency for the Evaluation of Medicinal Products (EMEA) and the US Food and Drug Administration (FDA) (cut-off date October 2009). The search terms 'Crohn's disease', 'inflammatory bowel disease', or 'ulcerative colitis' were combined with the terms 'adalimumab', 'anemia', 'arthritis', 'bronchiectasis', 'bronchitis', 'cutaneous manifestations', 'erythema nodosum', 'extraintestinal manifestations', 'hyperhomocysteinemia', 'infliximab', 'iridocyclitis', 'lung disease', 'ocular manifestations', 'osteomalacia', 'pancreatitis', 'primary sclerosing cholangitis', 'renal stones', 'sulfasalazine', 'thromboembolism', and 'treatment'. The search was performed on English-language reviews, practical guidelines, letters, and editorials. Articles were selected based on their relevance, and additional papers were retrieved from their reference lists. Since some of the diseases discussed are uncommon, valid evidence of treatment was difficult to obtain, and epidemiologic data on the rarer forms of extraintestinal manifestations are scarce. However, updates on the pathophysiology and treatment regimens are given for each of these disorders. This paper offers a current review of original research papers and randomized clinical trials, if any, within the field and makes an attempt to point out practical guidelines for the diagnosis and treatment of various extraintestinal manifestations related to IBD.

Epitope spreading initiates in the CNS in two mouse models of multiple sclerosis

Introduction

Mouse models of rheumatoid arthritis (RA) have proven critical for identifying genetic and cellular mechanisms of the disease. Upon discovering mice in our breeding colony that had spontaneously developed inflamed joints reminiscent of RA, we established the novel IIJ (inherited inflamed joints) strain. The purpose of this study was to characterize the histopathological, clinical, genetic and immunological properties of the disease.

Methods

To begin the IIJ strain, an arthritic male mouse was crossed with SJL/J females. Inheritance of the phenotype was then tracked by intercrossing, backcrossing and outcrossing to other inbred strains. The histopathology of the joints and extraarticular organ systems was examined. Serum cytokines and immunoglobulins (Igs) were measured by ELISA and cytometric bead array. Transfer experiments tested whether disease could be mediated by serum alone. Finally, the cellular joint infiltrate and the composition of secondary lymphoid organs were examined by immunohistochemistry and flow cytometry.

Results

After nine generations of intercrossing, the total incidence of arthritis was 33% (304 of 932 mice), with females being affected more than males (38% vs. 28%; P < 0.001). Swelling, most notably in the large distal joints, typically became evident at an early age (mean age of 52 days). In addition to the joint pathology, which included bone and cartilage erosion, synovial hyperproliferation and a robust cellular infiltration of mostly Gr-1⁺ neutrophils, there was also evidence of systemic inflammation. IL-6 was elevated in the sera of recently arthritic mice, and extraarticular inflammation was observed histologically in multiple organs. Total serum Ig and IgG1 levels were significantly elevated in arthritic mice, and autoantibodies such as rheumatoid factor and Ig reactive to joint components (collagen type II and joint homogenate) were also detected. Nevertheless, serum failed to transfer disease. A high percentage of double-negative (CD4^-CD8^-) CD3⁺ TCRα/β⁺ T cells in the lymphoid organs of arthritic IIJ mice suggested significant disruption in the T-cell compartment.

Conclusions

Overall, these data identify the IIJ strain as a new murine model of inflammatory, possibly autoimmune, arthritis. The IIJ strain is similar, both histologically and serologically, to RA and other murine models of autoimmune arthritis. It may prove particularly useful for understanding the female bias in autoimmune diseases.