Transcriptomic profiling and immuno-histological characterization of synovial biopsies in juvenile idiopathic arthritis (JIA) suggest two broad categories, with significant overlap with rheumatoid arthritis (RA).

OBJECTIVES: To characterize transcriptomic profiles and immune cell composition and distribution in Juvenile Idiopathic Arthritis (JIA) synovial biopsies, assess for associations of these features with clinical parameters, and compare JIA and Rheumatoid Arthritis (RA) synovial features. METHODS: RNASeq was performed on 24 samples, with pathway analysis and inference of relative abundance of immune cell subsets based on gene expression data. Two multiplex fluorescence immunohistochemistry (IHC) panels were performed on 28 samples (including 13 on which RNASeq was performed), staining for CD206- classical and CD206+ non-classical macrophages, CD8+ and CD4+ T and B lymphocytes. Data were compared to a published series of early RA synovial biopsies. RESULTS: Pathway analysis of the (n=339) most variably expressed genes identified a B and plasma cell signature as the main driver of heterogeneity in JIA synovia, with strong overlap between JIA and RA synovitis. Multiplex IHC confirmed heterogeneity of immune cell infiltration. M1-like macrophage rich synovial lining was associated with greater lining hypertrophy and higher pan (CD45+) immune and CD8+ T cell infiltration. CONCLUSION: Our study indicates significant similarities between JIA and RA synovitis. Similar to RA, JIA synovia may be broadly categorized into two groups: (i) those with an inflammatory/adaptive immune transcriptomic signature, M1-like macrophage and CD8+ T cell infiltration and thicker, M1-like macrophage rich synovial lining, and (ii) those with an M2-like macrophage transcriptomic signature, greater M2/M1-like macrophage ratios and thinner, M2-like macrophage rich synovial lining. Synovial features were not significantly associated with clinical parameters, likely due to group size and heterogeneity.

Disease activity drives transcriptomic heterogeneity in early untreated rheumatoid synovitis.

OBJECTIVES: Transcriptomic profiling of synovial tissue from patients with early, untreated rheumatoid arthritis (RA) was used to explore the ability of unbiased, data-driven approaches to define clinically relevant subgroups. METHODS: RNASeq was performed on 74 samples, with disease activity data collected at inclusion. Principal components analysis (PCA) and unsupervised clustering were used to define patient clusters based on expression of the most variable genes, followed by pathway analysis and inference of relative abundance of immune cell subsets. Histological assessment and multiplex immunofluorescence (for CD45, CD68, CD206) were performed on paraffin sections. RESULTS: PCA on expression of the (n=894) most variable genes across this series did not divide samples into distinct groups, instead yielding a continuum correlated with baseline disease activity. Two patient clusters (PtC1, n=52; PtC2, n=22) were defined based on expression of these genes. PtC1, with significantly higher disease activity and probability of response to methotrexate therapy, showed upregulation of immune system genes; PtC2 showed upregulation of lipid metabolism genes, described to characterise tissue resident or M2-like macrophages. In keeping with these data, M2-like:M1-like macrophage ratios were inversely correlated with disease activity scores and were associated with lower synovial immune infiltration and the presence of thinner, M2-like macrophage-rich synovial lining layers. CONCLUSION: In this large series of early, untreated RA, we show that the synovial transcriptome closely mirrors clinical disease activity and correlates with synovial inflammation. Intriguingly, lower inflammation and disease activity are associated with higher ratios of M2:M1 macrophages, particularly striking in the synovial lining layer. This may point to a protective role for tissue resident macrophages in RA.

Should We Use bDMARDs as an Induction Therapy in Early and Severe Rheumatoid Arthritis? Results at 5 years from the ERA UCLouvain Brussels Cohort.

INTRODUCTION: This study sought to analyze the benefit of an early induction therapy with a biological disease-modifying anti-rheumatic drugs (bDMARD) during the first year of treatment with a 5-year follow-up in early rheumatoid arthritis (ERA). METHODS: We included ERA patients from the UCLouvain Brussels cohort who met the American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) 2010 classification criteria and were naïve to DMARDs. ERA patients were divided into two groups according to whether they received an induction bDMARD therapy or a standard therapy with methotrexate (MTX). Clinical response after the induction treatment at 6 and 12 months followed by a MTX maintenance therapy at 36 and 60 months was evaluated. RESULTS: Data from 470 ERA patients were collected, 189 received a bDMARD and 281 initiated MTX alone. In the bDMARD group, disease activity and HAQ were higher at baseline. A total of 391 patients were followed up to 5 years. We then divided each group into two subgroups according to the last treatment they received at 5 years: bDMARD > MTX (n = 95), bDMARD > bDMARD (n = 59); MTX > MTX (n = 134), MTX > bDMARD (n = 103). During the induction, we observed a clinical response with a large number of patients achieving DAS28-CRP remission. According to a treat-to-target (T2T) approach, remission rate was stable on MTX monotherapy or rescued by the addition or prolongation of a bDMARD. Interestingly, bDMARD followed by a MTX maintenance therapy experienced a stable and sustained DAS28-CRP remission rate in 53% of the ERA patients at year 5. CONCLUSIONS: Long-term remission is an achievable goal in ERA. Our results suggest that a bDMARD induction therapy followed by MTX maintenance therapy could be an interesting option.

Severe treatment-induced inflammatory polyarthritis in advanced melanoma patients: 2 case reports.

Immune checkpoint inhibitors (ICI) and targeted therapies form the therapeutic mainstay for v-Raf murine sarcoma viral oncogene homolog B V600-mutated metastatic melanoma. Both treatment regimens can cause inflammatory arthritis. The reported incidence of treatment-induced inflammatory arthritis is low, though presumably underestimated due to lack of awareness, clear definitions and uniform grading systems. Nevertheless, recognition is important as inflammatory arthritis can become chronic and thus affect the quality of life beyond treatment. In this short communication, we present two patients with metastatic melanoma treated with ICI and targeted therapies who develop severe polyarthritis. Based on their clinical discourse we describe standard inflammatory arthritis treatment modalities and more advanced immunomodulatory treatment options with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) or biologic DMARDs (bDMARDs). Long-term immunosuppressive treatment with glucocorticoids or DMARDs in this setting raises concerns about antitumour response and potential carcinogenic risk. Current literature on this topic is scarce, heterogeneous and retrospective. Prospective analysis of cancer patients treated with DMARDs is needed to clearly address these concerns.

ImmunoStart: preparing patients for immunosuppression.

OBJECTIVES: Patients with immune-mediated inflammatory disease (IMID) present an increased risk of infection. Here, we present the concept of a preventive consultation called ImmunoStart and the first results of its implementation in the care pathway of patients with IMID. METHODS: Relevant information about vaccination history, tuberculosis exposure and other infectious risks were collected through blood sampling, complete anamnesis, chest X-ray and Mantoux test. During the ImmunoStart consultation, vaccination schedules, specific treatments and risk considerations were discussed. RESULTS: Between October 2016 and February 2020, 437 patients were seen at an ImmunoStart consultation, mainly referred by rheumatologists (56%), dermatologists (25%) and gastroenterologists (18%). A total of 421 (96%) patients needed at least one vaccine (a mean of 3.3 vaccines per patient). Live attenuated vaccine was indicated for 45 patients (10%), requiring them to reduce or interrupt their immunosuppressive drug(s). Ninety-two patients (21%) were treated for latent tuberculosis infection. CONCLUSION: This preventive consultation provides a centralized and systematic setting for the direct management of patients with IMID in need of vaccination, treatment of latent disease and specific advice regarding their immunomodulating treatments.

Common Transcriptomic Effects of Abatacept and Other DMARDs on Rheumatoid Arthritis Synovial Tissue.

Objectives: Our goal was to assess for the histological and transcriptomic effects of abatacept on RA synovia, and to compare them with previously published data from four other DMARDs: tocilizumab, rituximab, methotrexate, and adalimumab. Methods: Synovial tissue was obtained using ultrasound-guided biopsy from affected joints of 14 patients, before and 16 weeks after treatment with subcutaneous abatacept 125 mg weekly. Paraffin-sections were stained and scored for CD3+, CD20+, and CD68+ cell infiltration. Transcriptional profiling was performed using GeneChip Human Genome U133 Plus 2.0 arrays (Affymetrix) and analyzed on Genespring GX (Agilent). Pathway analyses were performed on Genespring GX, Metascape, and EnrichR. Results: Gene expression analysis identified 304 transcripts modulated by abatacept in synovial tissue. Downregulated genes were significantly enriched for immune processes, strongly overlapping with our findings on other therapies. Data were pooled across these studies, revealing that genes downregulated by DMARDs are significantly enriched for both T-cell and myeloid leukocyte activation pathways. Interestingly, DMARDs seem to have coordinate effects on the two pathways, with a stronger impact in good responders to therapy as compared to moderate and non-responders. Conclusion: We provide evidence that the effects of five DMARDs on the RA synovium culminate in the same pathways. This confirms previous studies suggesting the existence of common mediators downstream of DMARDs, independent of their primary targets.

Paired Rheumatoid Arthritis Synovial Biopsies From Small and Large Joints Show Similar Global Transcriptomic Patterns With Enrichment of Private Specificity TCRB and TCR Signaling Pathways.

Objectives: We explored histological and transcriptomic profiles of paired synovial biopsies from rheumatoid arthritis (RA) patients, in order to assess homogeneity in synovial tissue at the individual level. Methods: Synovial biopsies were performed simultaneously in one small and one large joint per patient using needle-arthroscopy for the knee and ultrasound-guided biopsy for the hand or wrist. Synovium from individuals with osteoarthritis was used as controls. Paraffin-embedded samples were stained for CD3, CD20, and CD68. Total RNA was hybridized on high-density microarrays. TCRB variable sequences were obtained from synovial and blood RNA samples. Results: Twenty paired biopsies from 10 RA patients with active disease were analyzed. Semi-quantification of histological markers showed a positive correlation for synovial hyperplasia, inflammatory infiltrates and CD3-positive T cells between pairs. Pairwise comparison of transcriptomic profiles showed similar expression of RA-related molecular pathways (TCR signaling, T cell costimulation and response to TNFα). T cells clonotypes were enriched in all but one joints compared to blood, regardless of the magnitude of T cell infiltration. Enriched clonotypes were shared between pairs (23-100%), but this was less the case in pairs of joints displaying weaker T cell signatures and more pronounced germinal center-like transcriptomic profiles. Conclusion: Cellular and molecular alterations in RA synovitis are similar between small and large joints from the same patient. Interindividual differences in magnitude of T cell infiltrates and distribution of enriched T cell clonotypes support the concept of distinct synovial pathotypes in RA that are associated with systemic versus local antigen-driven activation of T cells.

[Inflammatory arthritides pathotypes]. / Pathotypes des rhumatismes ­inflammatoires.

The pathophysiology of the inflammatory arthritides (IA) is complex and the result of interactions between genetic and environmental factors, leading to -in the case of seropositive rheumatoid arthritis-a breach of immune tolerance and subsequent development of joint and systemic manifestations. Regardless of the exact site of the initial immune dysregulation, the synovial membrane is the main target of IA. The heterogeneity of the clinical phenotypes is even more evident on the histological level (pathotypes), which in turn renders research on disease mechanisms more complicated. This article focusses on the various pathotypes of IA.

La physiopathologie des rhumatismes inflammatoires est complexe et résulte de l'interaction entre facteurs génétiques et environnementaux, qui aboutissent, dans le cas de la polyarthrite rhumatoïde séropositive, à une perte de tolérance immunitaire puis au développement d'atteintes articulaires et systémiques. Indépendamment du lieu de naissance du conflit immunologique initial, la membrane synoviale est la cible principale des rhumatismes inflammatoires. L'hétérogénéité des phénotypes des patients est encore plus prononcée au niveau histologique (pathotypes), ce qui rend l'étude des mécanismes pathogéniques impliqués plus compliquée. Dans cet article, nous nous sommes donc intéressés aux différents pathotypes des arthrites inflammatoires.

Ultrasound-Guided Synovial Biopsies of Wrists, Metacarpophalangeal, Metatarsophalangeal, Interphalangeal Joints, and Tendon Sheaths.

Ultrasound-guided synovial biopsy (UGSB) is a minimally-invasive procedure which allows quality synovial tissue retrieval. In this article, we will discuss overarching principles of the procedure performed in wrists, metacarpophalangeal (MCP), metatarsophalangeal (MTP), interphalangeal joints (IP), and tendon sheaths, including basic sonoanatomy, entry site and biopsy technique, as well as special considerations for each structure whenever relevant.

US-Guided Biopsies: Overarching Principles.

Gathering synovial tissue from any swollen joint especially in early arthritis patients is critical for good quality research and to obtain further insight into the pathophysiology of inflammatory joint diseases. Multiplying biopsy sites is a challenge in terms of the techniques needed for each different joint but also in terms of safety and tolerability. It is important to provide the best care especially in very early arthritis patients who have only had the disease for a few months. This review discusses the minimal requirements applying to antiseptic techniques for the operator's hands, patient preparation, local anesthesia, and post-procedure care.

Standardisation of synovial biopsy analyses in rheumatic diseases: a consensus of the EULAR Synovitis and OMERACT Synovial Tissue Biopsy Groups.

BACKGROUND: The aim of this global collaboration was to develop a consensual set of items for the analysis of synovial biopsies in clinical practice and translational research through the EULAR Synovitis Study Group (ESSG) and OMERACT Synovial Tissue Biopsy Group. METHODS: Participants were consulted through a modified Delphi method. Three sequential rounds occurred over 12 months. Members were sent a written questionnaire containing items divided into two parts. Items were identified and formulated based on a scoping review. The first part of the questionnaire referred to synovial biopsies in clinical practice including five subsections, and the second part to translational research with six subsections. Every participant was asked to score each item on a 5-point Likert scale. Items with a median score above 3.5 and a ≥ 70% agreement were selected for the next round. The last round was conducted orally at EULAR in June 2017. RESULTS: Twenty-seven participants from 19 centers were contacted by email. Twenty participants from 17 centers answered. Response rates for next rounds were 100%. For the first part relating to clinical practice, 20/44 items (45.5%) were selected. For the second part relating to translational research, 18/43 items (41.9%) were selected for the final set. CONCLUSIONS: We herein propose a consensual set of analysis items to be used for synovial biopsies conducted in clinical practice and translational research.

Patient-reported outcomes and safety in patients undergoing synovial biopsy: comparison of ultrasound-guided needle biopsy, ultrasound-guided portal and forceps and arthroscopic-guided synovial biopsy techniques in five centres across Europe.

BACKGROUND: We present a European multicenter study, comparing safety data and patient-reported outcomes (PRO) from patients undergoing synovial biopsy using ultrasound-guided needle biopsy (US-NB), ultrasound-guided portal and forceps (US-P&F) or arthroscopic-guided (AG) procedures. OBJECTIVES: To describe safety and PRO data on joint indices of pain, stiffness and swelling before and after biopsy, procedural discomfort, joint status compared with before biopsy and willingness to undergo a second biopsy for each technique and compare the three techniques. To evaluate the impact on PRO and safety data of corticosteroid therapy as part of the biopsy procedure and sequential biopsy procedures. METHODS: Data were collected on the day of biopsy and 7-14 days postprocedure. Joint pain, swelling and stiffness indices were recorded as 0-100 mm Visual Analogue Scale; qualitative outcome variables on five-point Likert scales. Groups were compared with linear regression, adjusting for disease activity, corticosteroid therapy and prebiopsy PRO value and accounting for repeated measurements. RESULTS: A total of 524 synovial biopsy procedures were documented (402 US-NB, 65 US-P&F and 57 AGSB). There were eight adverse events (1.5%) with no difference between biopsy methods (p=0.55). All PROs were improved 2 weeks postprocedure, and there were no differences in postbiopsy change in PROs between biopsy methods. Corticosteroid administration, whether intramuscular (n=62) or intra-articular (n=38), did not result in more adverse events (p=0.81) and was associated with reduction in postbiopsy swelling (p<0.01). Sequential biopsy procedures (n=103 patients) did not result in more adverse events (p=0.61) or worsening in PRO data. CONCLUSION: Overall, our results do not suggest a significant difference in safety or patient tolerability between US-NB, US-P&F and AGSB sampling. Further, corticosteroid therapy as part of the biopsy procedure and sequential biopsies is safe and well tolerated in patients.