Targeting inflammatory pathways in axial spondyloarthritis.

The triggers and pathogenesis of axial spondyloarthritis (axSpA) are not yet completely understood. However, therapeutic agents targeting tumor necrosis factor-α and interleukin-17 inflammatory pathways have proven successful in suppressing many of the clinical symptoms and signs of axSpA, giving us an indication of which pathways are responsible for initiating and maintaining the inflammation. The mechanisms that eventuate in syndesmophytes and ankyloses are less clear. This review addresses these two critical pathways of inflammation, discussing their nature and these factors that may activate or enhance the pathways in patients with axSpA. In addition, genetic and other markers important to the inflammatory pathways implicated in axSpA are explored, and prognostic biomarkers are discussed. Treatment options available for the management of axSpA and their associated targets are highlighted

Uveitis in spondyloarthropathies

Background: Uveitis is associated with several systemic disorders. It may be the initial presentation or manifestation of a systemic disease. It is the most common ocular complication and is sometimes the earliest manifestation of spondyloarthropathies. This study aimed to review the current literature on spondyloarthropathies and associated uveitis. Methods: A narrative review was performed using various combinations of the keywords spondyloarthropathies, seronegative spondylarthritis-related uveitis, and human leukocyte antigen-associated uveitis using PubMed/MEDLINE and Google Scholar from January 1, 2000, to September 30, 2022. We describe the disease mechanisms, genetics, and classification of spondyloarthropathies, the clinical patterns of their related ocular diseases, and the current modalities for the management of their ocular or systemic manifestations. Results: Seronegative spondyloarthropathies are a group of rheumatic disorders including ankylosing spondylitis, reactive arthritis, psoriatic arthritis, inflammatory bowel disease-related spondyloarthropathy, juvenile-onset spondyloarthritis, and undifferentiated spondyloarthritis. These are characterized by enthesitis in the absence of serum rheumatoid factor and have a strong association with human leukocyte antigen B27. The clinical courses and features of spondyloarthropathies are remarkably diverse. Ocular inflammation is common in spondyloarthropathies, often precedes the onset or diagnosis of systemic disease, and responds well to topical therapy. Timely diagnosis of systemic diseases may improve quality of life and help avoid ocular and skeletal complications. Recurrence of ocular inflammation is frequent; on occasion, it may be associated with etanercept administration. Conclusions: Eye care professionals should be able to recognize spondyloarthropathies, manage ocular disease, and collaborate with related specialties for modification of systemic treatment if associated with ocular complications. Timely referral and early management could attenuate or prevent ocular or systemic morbidities associated with spondyloarthropathies

Aberrant expression of shared master-key genes contributes to the immunopathogenesis in patients with juvenile spondyloarthritis

Association of juvenile spondyloarthritis (jSpA) with the HLA-B27 genotype is well established, but there is little knowledge of other genetic factors with a role in the development of the disease. To date, only a few studies have tried to find those associated genes by obtaining expression profiles, but with inconsistent results due to various patient selection criteria and methodology. The aim of the present study was to identify and confirm gene signatures and novel biomarkers in highly homogeneous cohorts of untreated and treated patients diagnosed with jSpA and other forms of juvenile idiopathic arthritis (JIA) according to ILAR criteria. For the purposes of the research, total RNA was isolated from whole blood of 45 children with jSpA and known HLA genotype, 11 children with oligo- and polyarticular forms of JIA, as well as 12 age and sex matched control participants without diagnosis of inflammatory disease. DNA microarray gene expression was performed in 11 patients with jSpA and in four healthy controls, along with bioinformatical analysis of retrieved data. Carefully selected differentially expressed genes where analyzed by qRT-PCR in all participants of the study. Microarray results and bioinformatical analysis revealed 745 differentially expressed genes involved in various inflammatory processes, while qRT-PCR analysis of selected genes confirmed data universality and specificity of expression profiles in jSpA patients. The present study indicates that jSpA could be a polygenic disease with a possible malfunction in antigen recognition and activation of immunological response, migration of inflammatory cells and regulation of the immune system. Among genes involved in these processes TLR4, NLRP3, CXCR4 and PTPN12 showed almost consistent expression in study patients diagnosed with jSpA. Those genes and their products could therefore potentially be used as novel biomarkers, possibly predictive of disease prognosis and response to therapy, or even as a target for new therapeutic approaches

Impact of a multidisciplinary approach in enteropathic spondyloarthritis patients

Spondyloarthritis (SpA) and inflammatory bowel disease (IBD) are chronic autoinflammatory diseases that partially share the genetic predisposition and the unchecked inflammatory response linking the gut to the joints. The coexistence of both conditions in patients and the increased cross-risk ratios between SpA and IBD strongly suggest a shared pathophysiology. The prevalence of Enteropathic-related Spondyloarthritis (ESpA) in IBD patients shows a wide variation and may be underestimated. It is well accepted that the management of joint pain requires rheumatological expertise in conjunction with gastroenterologist assessment. In this view, we aimed at assessing, in a prospective study performed in a combined Gastro-Intestinal and Rheumatologic "GI-Rhe" clinic: (1) the prevalence of ESpA and other rheumatologic diseases in IBD patients with joint pain; (2) the features of the ESpA population; and (3) the diagnostic delay and the potential impact of the combined assessment. From November 2012 to December 2014, IBD patients with joint pain referring to a dedicated rheumatologist by the IBD-dedicated gastroenterologist were enrolled. Clinical and biochemical evaluations, joint involvement and disease activity assessment, diagnostic delay, and treatment were recorded. IBD patients (n = 269) with joint pain were jointly assessed in the "GI-Rhe" Unit. A diagnosis of ESpA was made in 50.5% of IBD patients with joint pain. ESpA patients showed a peripheral involvement in 53% of cases, axial in 20.6% and peripheral and axial in 26.4% of cases. ESpA patients had a higher prevalence of other autoimmune extra-intestinal manifestations and received more anti-TNF treatment compared with IBD patients. A mean diagnostic delay of 5.2. years was revealed in ESpA patients. Patients with joint disease onset in the 2002-2012 decade had reduced diagnostic delay compared with those with onset in the 1980-1990 and 1991-2001 decades. Diagnostic delay was further reduced for patients with joint onset in the last two years in conjunction with the establishment of the GI-Rhe clinic. Multidisciplinary approach improved management of rheumatic disorders in IBD patients allowing a more comprehensive care

Loss and gain of bone in spondyloarthritis: what drives these opposing clinical features?

The breadth of bone lesion types seen in spondyloarthritis is unprecedented in medicine and includes increased bone turnover, bone loss and fragility, osteitis, osteolysis and erosion, osteosclerosis, osteoproliferation of soft tissues adjacent to bone and spinal skeletal structure weakness. Remarkably, these effects can be present simultaneously in the same patient. The search for a potential unifying cause of effects on the skeleton necessarily focuses on inflammation arising from the dysregulation of immune response to microorganisms, particularly dysregulation of TH17 lymphocytes, and the dysbiosis of established gut and other microbiota. The compelling notion that a common antecedent pathological mechanism affects existing bone and tissues with bone-forming potential (entheses), simultaneously with variable effect in the former but bone-forming in the latter, drives basic research forward and focuses our awareness on the effects on these bone mechanisms of the increasing portfolio of targeted immunotherapies used in the clinic

Janus kinase inhibitors: a new tool for the treatment of axial spondyloarthritis

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease involving the spine, peripheral joints, and entheses. This condition causes stiffness, pain, and significant limitation of movement. In recent years, several effective therapies have become available based on the use of biologics that selectively block cytokines involved in the pathogenesis of the disease, such as tumor necrosis factor-α (TNFα), interleukin (IL)-17, and IL-23. However, a significant number of patients show an inadequate response to treatment. Over 10 years ago, small synthetic molecules capable of blocking the activity of Janus kinases (JAK) were introduced in the therapy of rheumatoid arthritis. Subsequently, their indication extended to the treatment of other inflammatory rheumatic diseases. The purpose of this review is to discuss the efficacy and safety of these molecules in axSpA therapy

Ankylosing Spondylitis Pathogenesis and Pathophysiology

The pathogenesis and pathophysiology of Ankylosing Spondylitis (AS) is complex and remains only partially understood. Contributory genes including a variety of HLA-B27 subset genes and many other non-HLA genes are implicated in the literature. Novel genes and gene–gene interactions being a continuously evolving area of AS research. Dysregulation of the enteric microbiome with a corresponding aberrant immunological response is recognised in research. Certain infectious agents are thought to play a role. A variety of other influences including environmental exposures, dietary and lifestyle factors and sex hormones appear to play a role in AS pathogenesis. There is emerging evidence that that pathophysiological response in AS is an elaborate combination of both autoinflammatory and autoimmune components, however the IL-17/IL-23 pathway remains the major pathway in AS according to studies to date. The specific mechanisms that lead to characteristic clinical features of AS including sacroiliitis, spondylitis, ankylosis, uveitis and other extra articular manifestations remain occult. Further research to establish these is ongoing

Ankylosing spondylitis: genomic and functional characterization of candidate genes and their repercussion in clinical practice

RESUMO: Introdução: A espondilite anquilosante (EA) é uma doença inflamatória crónica caracterizada pela inflamação das articulações sacroilíacas e da coluna. A anquilose progressiva motiva uma deterioração gradual da função física e da qualidade de vida. O diagnóstico e o tratamento precoces podem contribuir para um melhor prognóstico. Neste contexto, a identificação de biomarcadores, assume-se como sendo muito útil para a prática clínica e representa hoje um grande desafio para a comunidade científica. Objetivos: Este estudo teve como objetivos: 1 - caracterizar a EA em Portugal; 2 - investigar possíveis associações entre genes, MHC e não-MHC, com a suscetibilidade e as características fenotípicas da EA; 3 - identificar genes candidatos associados a EA através da tecnologia de microarray. Material e Métodos: Foram recrutados doentes com EA, de acordo com os critérios modificados de Nova Iorque, nas consultas de Reumatologia dos diferentes hospitais participantes. Colecionaram-se dados demográficos, clínicos e radiológicos e colhidas amostras de sangue periférico. Selecionaram-se de forma aleatória, doentes HLA-B27 positivos, os quais foram tipados em termos de HLA classe I e II por PCR-rSSOP. Os haplótipos HLA estendidos foram estimados pelo algoritmo Expectation Maximization com recurso ao software Arlequin v3.11. As variantes alélicas dos genes IL23R, ERAP1 e ANKH foram estudadas através de ensaios de discriminação alélica TaqMan. A análise de associação foi realizada utilizando testes da Cochrane-Armitage e de regressão linear, tal como implementado pelo PLINK, para variáveis qualitativas e quantitativas, respetivamente. O estudo de expressão génica foi realizado por Illumina HT-12 Whole-Genome Expression BeadChips. Os genes candidatos foram validados usando qPCR-based TaqMan Low Density Arrays (TLDAs). Resultados: Foram incluídos 369 doentes (62,3% do sexo masculino, com idade média de 45,4 ± 13,2 anos, duração média da doença de 11,4 ± 10,5 anos). No momento da avaliação, 49,9% tinham doença axial, 2,4% periférica, 40,9% mista e 7,1% entesopática. A uveíte anterior aguda (33,6%) foi a manifestação extra-articular mais comum. Foram positivos para o HLA-B27, 80,3% dos doentes. Os haplótipo A*02/B*27/Cw*02/DRB1*01/DQB1*05 parece conferir suscetibilidade para a EA, e o A*02/B*27/Cw*01/DRB1*08/DQB1*04 parece conferir proteção em termos de atividade, repercussão funcional e radiológica da doença. Três variantes (2 para IL23R e 1 para ERAP1) mostraram significativa associação com a doença, confirmando a associação destes genes com a EA na população Portuguesa. O mesmo não se verificou com as variantes estudadas do ANKH. Não se verificou associação entre as variantes génicas não-MHC e as manifestações clínicas da EA. Foi identificado um perfil de expressão génica para a EA, tendo sido validados catorze genes - alguns têm um papel bem documentado em termos de inflamação, outros no metabolismo da cartilagem e do osso. Conclusões: Foi estabelecido um perfil demográfico e clínico dos doentes com EA em Portugal. A identificação de variantes génicas e de um perfil de expressão contribuem para uma melhor compreensão da sua fisiopatologia e podem ser úteis para estabelecer modelos com relevância em termos de diagnóstico, prognóstico e orientação terapêutica dos doentes. -----------ABSTRACT: Background: Ankylosing Spondylitis (AS) is a chronic inflammatory disorder characterized by inflammation in the spine and sacroiliac joints leading to progressive joint ankylosis and in progressive deterioration of physical function and quality of life. An early diagnosis and early therapy may contribute to a better prognosis. The identification of biomarkers would be helpful and represents a great challenge for the scientific community. Objectives: The present study had the following aims: 1- to characterize the pattern of AS in Portuguese patients; 2- to investigate MHC and non-MHC gene associations with susceptibility and phenotypic features of AS and; 3- to identify candidate genes associated with AS by means of whole-genome microarray. Material and Methods: AS was defined in accordance to the modified New York criteria and AS cases were recruited from hospital outcares patient clinics. Demographic and clinical data were recorded and blood samples collected. A random group of HLA-B27 positive patients and controls were selected and typed for HLA class I and II by PCR-rSSOP. The extended HLA haplotypes were estimated by Expectation Maximization Algorithm using Arlequin v3.11 software. Genotyping of IL23R, ERAP1 and ANKH allelic variants was carried out with TaqMan allelic discrimination assays. Association analysis was performed using the Cochrane-Armitage and linear regression tests as implemented in PLINK, for dichotomous and quantitative variables, respectively. Gene expression profile was carried out using Illumina HT-12 Whole-Genome Expression BeadChips and candidate genes were validated using qPCR-based TaqMan Low Density Arrays (TLDAs). Results: A total of 369 patients (62.3% male; mean age 45.4±13.2 years; mean disease duration 11.4±10.5 years), were included. Regarding clinical disease pattern, at the time of assessment, 49.9% had axial disease, 2.4% peripheral disease, 40.9% mixed disease and 7.1% isolated enthesopathic disease. Acute anterior uveitis (33.6%) was the most common extra-articular manifestation. 80.3% of AS patients were HLA-B27 positive. The haplotype A*02/B*27/Cw*02/DRB1*01/DQB1*05 seems to confer susceptibility to AS, whereas A*02/B*27/Cw*01/DRB1*08/DQB1*04 seems to provide protection in terms of disease activity, functional and radiological repercussion. Three markers (two for IL23R and one for ERAP1) showed significant single-locus disease associations. Association of these genes with AS in the Portuguese population was confirmed, whereas ANKH markers studied did not show an association with AS. No association was seen between non-MHC genes and clinical manifestations of AS. A gene expression signature for AS was established; among the fourteen validated genes, a number of them have a well-documented inflammatory role or in modulation of cartilage and bone metabolism. Conclusions: A demographic and clinical profile of patients with AS in Portugal was established. Identification of genetic variants of target genes as well as gene expression signatures could provide a better understanding of AS pathophysiology and could be useful to establish models with relevance in terms of susceptibility, prognosis, and potential therapeutic guidance