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

Precision Medicine in Rheumatology: The Promise of Ultrasound-Guided Synovial Biopsy, Barriers to Its Implementation in the United States, and Proposed Solutions

PURPOSE OF REVIEW

In the clinical evaluation of inflammatory arthritis and the research into its pathogenesis, there is a growing role for the direct analysis of synovial tissue. Over the years, various biopsy techniques have been used to obtain human synovial tissue samples, and there have been progressive improvements in the safety, tolerability, and utility of the procedure.

RECENT FINDINGS

The latest advancement in synovial tissue biopsy techniques is the use of ultrasound imaging to guide the biopsy device, along with evolution in the characteristics of the device itself. While ultrasound guided synovial biopsy (UGSB) has taken a strong foothold in Europe, the procedure is still relatively new to the United States of America (USA). In this paper, we describe the expansion of UGSB in the USA, elucidate the challenges faced by rheumatologists developing UGSB programs in the USA, and describe several strategies for overcoming these challenges.

Intensive training programme for ultrasound-guided minimally invasive synovial tissue biopsy on knees and wrists in different phases of inflammation

OBJECTIVES

To develop an intensive training programme for ultrasound (US)-guided synovial tissue (ST) biopsy on knees and wrists in inflammatory arthritis and to assess the learning curve, patient tolerability, sample quality and trainees' expectations.

METHODS

Active or remission rheumatoid arthritis patients were enrolled. Nine trainees joined the 4-month programme in a centre experienced in performing US-guided ST biopsies consisting of four sequential phases: (1) observation, (2) performance of guided step-by-step phases, (3) execution of the whole procedure on paired joints (knees or wrists) of the same patient in parallel with the trainer and (4) performance of the procedure autonomously. Sample representativity was assessed by histology, and procedure-related adverse events were recorded. Before and after the programme, trainees' expectations and perceptions were collected.

RESULTS

328 ST biopsy procedures were included. The rate of trainees' informative samples was: (1) comparable to the trainers in active and remission knees, but lower in active wrists (70% for trainees vs 100% for trainers, p=0.06) in phase 3; (2) excellent on active knees and wrists (91.9% and 90.9% respectively) but lower (77.6%, p=0.0089) on remission knees in phase 4. Procedures performed by trainees did not affect patient tolerability. Trainees' expectations about procedure-related invasiveness and pain infliction decreased while the difficulty of procedure execution on active wrists and remission knees remained perceived as moderately difficult.

CONCLUSIONS

This intensive training programme develops advanced skills in the performance of US-guided ST biopsy on knees and wrists, yielding high-quality specimens available for basic and translational studies on inflammatory joint diseases.

Stratification of biological therapies by pathobiology in biologic-naive patients with rheumatoid arthritis (STRAP and STRAP-EU): two parallel, open-label, biopsy-driven, randomised trials

BACKGROUND

Despite highly effective targeted therapies for rheumatoid arthritis, about 40% of patients respond poorly, and predictive biomarkers for treatment choices are lacking. We did a biopsy-driven trial to compare the response to rituximab, etanercept, and tocilizumab in biologic-naive patients with rheumatoid arthritis stratified for synovial B cell status.

METHODS

STRAP and STRAP-EU were two parallel, open-label, biopsy-driven, stratified, randomised, phase 3 trials done across 26 university centres in the UK and Europe. Biologic-naive patients aged 18 years or older with rheumatoid arthritis based on American College of Rheumatology (ACR)-European League Against Rheumatism classification criteria and an inadequate response to conventional synthetic disease-modifying antirheumatic drugs (DMARDs) were included. Following ultrasound-guided synovial biopsy, patients were classified as B cell poor or B cell rich according to synovial B cell signatures and randomly assigned (1:1:1) to intravenous rituximab (1000 mg at week 0 and week 2), subcutaneous tocilizumab (162 mg per week), or subcutaneous etanercept (50 mg per week). The primary outcome was the 16-week ACR20 response in the B cell-poor, intention-to-treat population (defined as all randomly assigned patients), with data pooled from the two trials, comparing etanercept and tocilizumab (grouped) versus rituximab. Safety was assessed in all patients who received at least one dose of study drug. These trials are registered with the EU Clinical Trials Register, 2014-003529-16 (STRAP) and 2017-004079-30 (STRAP-EU).

FINDINGS

Between June 8, 2015, and July 4, 2019, 226 patients were randomly assigned to etanercept (n=73), tocilizumab (n=74), and rituximab (n=79). Three patients (one in each group) were excluded after randomisation because they received parenteral steroids in the 4 weeks before recruitment. 168 (75%) of 223 patients in the intention-to-treat population were women and 170 (76%) were White. In the B cell-poor population, ACR20 response at 16 weeks (primary endpoint) showed no significant differences between etanercept and tocilizumab grouped together and rituximab (46 [60%] of 77 patients vs 26 [59%] of 44; odds ratio 1·02 [95% CI 0·47-2·17], p=0·97). No differences were observed for adverse events, including serious adverse events, which occurred in six (6%) of 102 patients in the rituximab group, nine (6%) of 108 patients in the etanercept group, and three (4%) of 73 patients in the tocilizumab group (p=0·53).

INTERPRETATION

In this biologic-naive population of patients with rheumatoid arthrtitis, the dichotomic classification into synovial B cell poor versus rich did not predict treatment response to B cell depletion with rituximab compared with alternative treatment strategies. However, the lack of response to rituximab in patients with a pauci-immune pathotype and the higher risk of structural damage progression in B cell-rich patients treated with rituximab warrant further investigations into the ability of synovial tissue analyses to inform disease pathogenesis and treatment response.

FUNDING

UK Medical Research Council and Versus Arthritis.

Synovial biopsies for molecular definition of rheumatoid arthritis and treatment response phenotyping: where can we improve?

INTRODUCTION

The extensive knowledge gained in the cellular and molecular mechanisms underlying Rheumatoid Arthritis (RA) pathogenesis has led to therapeutic advances. However, up to 10-20% of patients fail to respond to multiple therapeutic agents being classified as multi-drugresistant. A key challenge moving forward will be the implementation of synovial biopsies in clinical practice to facilitate the shift from the current trial-and-error strategy toward new forms of clinical trials. Biomarker-driven trials have the potential to improve drug selection and patient stratification, reduce economic costs and unnecessary drug-related toxicity.

AREAS COVERED

This special report explores the clinical and research applications of synovial biopsy, the advancement in the molecular pathobiology of RA to better understand disease pathogenesis and treatment response, and the way forward for the paradigm shift needed.

EXPERT OPINION

In the current era of highly targeted biologic drugs which have dramatically transformed the outlook of RA patients, the use of synovial biopsy represents a valuable practical tool to dissect disease pathogenesis and, consequently, treatment response. In the near future, it is hoped that technological advances will allow for speeding up synovial molecular analysis and that the design of new biomarker-driven trials will enable the allocation of patients to more effective treatment.

Image-guided synovial biopsy with a focus on infection

Image-guided biopsy of the synovium is a relatively uncommon but safe procedure with a high-diagnostic yield in the correct clinical scenario. Whilst surgical and arthroscopic techniques are still commonly performed and remain the gold standard, they are more invasive, expensive and not widely available. Ultrasound and X-ray-guided synovial biopsy are being increasingly performed by radiologists to diagnose both native and periprosthetic joint infection (PJI) to guide surgical and microbiological management. The purpose of this review article is to present the historical background to synovial biopsy particularly related to potential joint infection, including common and uncommon pathogens encountered, sampling techniques and pitfalls, focusing mainly on its role in PJI and its role in patient pathways and decision-making within a joint infection multi-disciplinary framework.

Best practices for ultrasound-guided synovial biopsy in the United States

The target organ in many forms of inflammatory arthritis is the synovium. However, synovial tissue has historically been perceived as either difficult to obtain or of little practical value. Ultrasound-guided synovial biopsy [UGSB] is a safe and well-tolerated bedside procedure that is established in Europe and rapidly growing in popularity in the United States. The technique can be mastered by rheumatologists who are already experienced in ultrasound-guided procedures such as joint aspirations. The USGB procedure allows the proceduralist to access small, medium, and large joints and is inexpensive and less invasive compared to surgical alternatives. The relative ease of obtaining this tissue, along with recent research suggesting that synovium may have more clinical and investigational utility than previously thought, has led clinicians and researchers to a new appreciation of the role of synovial biopsy in both the clinical and research setting. In this manuscript, the authors present recommendations on best practices for ultrasound-guided synovial biopsy in the United States, based on our initial training with well-established experts overseas and our own subsequent collective experience in performing numerous synovial biopsies in the United States over the past 7 years for both clinical and research indications. We envision a future where UGSB is more frequently incorporated in the standard diagnostic workup of arthritis and drives novel research initiatives.

Regarding Arthroscopy: Can Orthopedists and Rheumatologists Be Friends?

BACKGROUND/OBJECTIVE

Rheumatologists' interest in arthroscopy began before the 1980s, when many era practitioners began to take up the procedure in earnest. Some of the important players in pre-World War II explorations of arthroscopy were rheumatologists, and the father of modern arthroscopy Makei Watanabe counted many rheumatologists among his postwar students, who were publishing about arthroscopic insights into rheumatic conditions in the 1960s and 1970s. We chose to review this evolution to demonstrate the diverging interests of rheumatologists and orthopedists in arthroscopy and emphasize the chances for reconciliation and cooperation. Methods involve our personal recollection and review of the literature.

RESULTS

Guidelines for the practice of arthroscopy were published by the American Rheumatism Association (now the American College of Rheumatology) 7 years before similar guidelines appeared from the Arthroscopy Association of North America. American rheumatologists ceased arthroscopy when controlled trials showed no effect in osteoarthritis beyond placebo and biologics for synovitis virtually eliminated situations in which synovectomy might be considered. The research potential of arthroscopy has been realized mainly by European rheumatologists, although the ultrasound-guided biopsy is supplanting arthroscopy as means to secure synovium for investigation, despite the advantages of the latter, such as the ability to obtain larger amounts of tissue, select tissue based on macroscopic appearance, sample multiple area in the same joint, and deliver the potentially therapeutic effect of washout. New miniscopes suitable for office use could restore some of the lagging interest in arthroscopy for investigation. Orthopedists have generally been resistant to rheumatologists doing arthroscopy but would not be sharing any turf with rheumatologists using the miniscope.

CONCLUSIONS

We hope that we orthopedists and rheumatologists could be friends as we enter this new phase of arthroscopy as we use the technique for different purposes.

EULAR points to consider for minimal reporting requirements in synovial tissue research in rheumatology

BACKGROUND

Synovial tissue research has become widely developed in several rheumatology centres, however, large discrepancies exist in the way synovial tissue is handled and, more specifically, how data pertaining to biopsy procedure, quality check and experimental results are reported in the literature. This heterogeneity hampers the progress of research in this rapidly expanding field. In that context, under the umbrella of European Alliance of Associations for Rheumatology, we aimed at proposing points to consider (PtC) for minimal reporting requirements in synovial tissue research.

METHODS

Twenty-five members from 10 countries across Europe and USA met virtually to define the key areas needing evaluation and formulating the research questions to inform a systematic literature review (SLR). The results were presented during a second virtual meeting where PtC were formulated and agreed.

RESULTS

Study design, biopsy procedures, tissue handling, tissue quality control and tissue outcomes (imaging, DNA/RNA analysis and disaggregation) were identified as important aspects for the quality of synovial tissue research. The SLR interrogated four databases, retrieved 7654 abstracts and included 26 manuscripts. Three OPs and nine PtC were formulated covering the following areas: description of biopsy procedure, overarching clinical design, patient characteristics, tissue handling and processing, quality control, histopathology, transcriptomic analyses and single-cell technologies.

CONCLUSIONS

These PtC provide guidance on how research involving synovial tissue should be reported to ensure a better evaluation of results by readers, reviewers and the broader scientific community. We anticipate that these PtC will enable the field to progress in a robust and transparent manner over the coming years.

Impact of synovial biopsy procedures and disease-specific aspects on synovial tissue outcome: a systematic literature review informing the EULAR points to consider for the minimal reporting requirements in synovial tissue research in rheumatology

BACKGROUND

The aim of this work was to summarise the literature evaluating the impact of biopsy procedures, tissue handling, tissue quality and disease-specific aspects including joint biopsied and disease stage, on synovial tissue outcome.

METHODS

Two reviewers independently identified eligible studies according to the Patients, Intervention, Comparator and Outcome framework obtained for five research questions formulated during the first EULAR task force meeting to produce points to consider (PtC) for minimal reporting requirements in synovial tissue studies. The databases explored were Medline, Embase, CENTRAL and Cinhal. The risk of bias of each study was evaluated using an adapted version of the Joanna Briggs Institute checklist for analytical cross-sectional studies.

RESULTS

Of the 7654 records yielded, 75 full texts were assessed, leading to the inclusion of 26 manuscripts in the systematic literature review (SLR). Two papers assessed the impact of biopsy procedures on the quality and quantity of tissue retrieved alongside patient tolerability; six papers focused on synovial tissue variability. Four papers studied the impact of sample handling or randomisation and 14 assessed the impact of disease stage and state, namely early or established active rheumatoid arthritis and remission on histopathological and transcriptomic results.

CONCLUSIONS

This SLR informs the EULAR PtC for minimal reporting requirements in synovial tissue research in rheumatology. Characteristics related to the study design, population, sample handling, randomisation and analysis can affect the final synovial tissue outcome in the studies reviewed. Thus, accurate reporting of these factors is required in order to ensure the scientific validity of manuscripts describing synovial tissue outcomes.

Value of imaging to guide interventional procedures in rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

OBJECTIVES

To summarise current data on the value of imaging to guide interventional procedures in patients with rheumatic and musculoskeletal disease (RMDs) informing an European Alliance of Associations for Rheumatology taskforce.

METHODS

A systematic literature review was conducted to retrieve prospective and retrospective studies published in English and comparing different (imaging) techniques, different settings and procedural protocols to guide interventions in patients with RMDs. MEDLINE, EMBASE, the Cochrane Library and Epistemonikos databases were searched through October 2021. Risk of bias (RoB) was assessed using the Cochrane RoB tool for randomised trials V.2 (ROB2), the RoB tool for Non-Randomised Studies of Interventions and the appraisal tool for cross-sectional studies.

RESULTS

Sixty-six studies were included (most with moderate/high RoB); 49 were randomised controlled trials, three prospective cohort studies and 14 retrospective studies. Fifty-one studies compared either one imaging technique with another imaging technique, or with palpation-guided interventions. Ultrasound (US) was most frequently studied (49/51), followed by fluoroscopy (10/51). Higher accuracy was found for US or fluoroscopy compared with palpation-guided interventions. Studies comparing different imaging techniques (12/51) did not endorse one specific method. Different settings/equipment for imaging-guided procedures (eg, automatic vs manual syringes) were investigated in three studies, reporting heterogeneous results. Fifteen studies compared different imaging-guided procedures (eg, intra-articular vs periarticular injections).

CONCLUSION

Higher accuracy of needle positioning at joints and periarticular structures was seen in most studies when using imaging (especially US) guidance as compared with palpation-guided interventions with the limitation of heterogeneity of data and considerable RoB.

Title Current Status of the Search for Biomarkers for Optimal Therapeutic Drug Selection for Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by destructive synovitis. It is significantly associated with disability, impaired quality of life, and premature mortality. Recently, the development of biological agents (including tumor necrosis factor-α and interleukin-6 receptor inhibitors) and Janus kinase inhibitors have advanced the treatment of RA; however, it is still difficult to predict which drug will be effective for each patient. To break away from the current therapeutic approaches that could be described as a “lottery,” there is an urgent need to establish biomarkers that stratify patients in terms of expected therapeutic responsiveness. This review deals with recent progress from multi-faceted analyses of the synovial tissue in RA, which is now bringing new insights into diverse features at both the cellular and molecular levels and their potential links with particular clinical phenotypes.

The Crucial Questions on Synovial Biopsy: When, Why, Who, What, Where, and How?

In the majority of joint diseases, changes in the organization of the synovial architecture appear early. Synovial tissue analysis might provide useful information for the diagnosis, especially in atypical and rare joint disorders, and might have a value in case of undifferentiated inflammatory arthritis, by improving disease classification. After patient selection, it is crucial to address the dialogue between the clinician and the pathologist for adequately handling the sample, allowing identifying histological patterns depending on the clinical suspicion. Moreover, synovial tissue analysis gives insight into disease progression helping patient stratification, by working as an actionable and mechanistic biomarker. Finally, it contributes to an understanding of joint disease pathogenesis holding promise for identifying new synovial biomarkers and developing new therapeutic strategies. All of the indications mentioned above are not so far from being investigated in everyday clinical practice in tertiary referral hospitals, thanks to the great feasibility and safety of old and more recent techniques such as ultrasound-guided needle biopsy and needle arthroscopy. Thus, even in rheumatology clinical practice, pathobiology might be a key component in the management and treatment decision-making process. This review aims to examine some essential and crucial points regarding why, when, where, and how to perform a synovial biopsy in clinical practice and research settings and what information you might expect after a proper patient selection.

Will rheumatologists ever pick up the arthroscope again?

Conditions prompting physicians and surgeons first adapting endoscopes to peer into joints were mainly the sort of synovial conditions that would concern today's rheumatologists. Rheumatologists were among the pre-World War II pioneers developing and documenting arthroscopy. The post-War father of modern arthroscopy, Watanabe, found rheumatologists among his early students, who took back the technique to their home countries, teaching orthopedists and rheumatologists alike. Rheumatologists described and analyzed the intra-articular features of their common diseases in the '60s and '70s. A groundswell of interest from academic rheumatologists in adapting arthroscopy grew considerably in the '90s with development of "needle scopes" that could be used in an office setting. Rheumatologists helped conduct the very trials the findings of which reduced demand for their arthroscopic services by questioning the efficacy of arthroscopic debridement in osteoarthritis (OA) and also developing biological compounds that greatly reduced the call for any resective intervention in inflammatory arthropathies. The arthroscope has proven an excellent tool for viewing and sampling synovium and continues to serve this purpose at several international research centers. While cartilage is now imaged mainly by magnetic resonance imaging, some OA features - such as a high prevalence of visible calcinosis - beg further arthroscopy-directed investigation. A new generation of "needle scopes" with far superior optics awaits future investigators, should they develop interest.

BIOlogical Factors that Limit sustAined Remission in rhEumatoid arthritis (the BIO-FLARE study): protocol for a non-randomised longitudinal cohort study

BACKGROUND

Our knowledge of immune-mediated inflammatory disease (IMID) aetiology and pathogenesis has improved greatly over recent years, however, very little is known of the factors that trigger disease relapses (flares), converting diseases from inactive to active states. Focussing on rheumatoid arthritis (RA), the challenge that we will address is why IMIDs remit and relapse. Extrapolating from pathogenetic factors involved in disease initiation, new episodes of inflammation could be triggered by recurrent systemic immune dysregulation or locally by factors within the joint, either of which could be endorsed by overarching epigenetic factors or changes in systemic or localised metabolism.

METHODS

The BIO-FLARE study is a non-randomised longitudinal cohort study that aims to enrol 150 patients with RA in remission on a stable dose of non-biologic disease-modifying anti-rheumatic drugs (DMARDs), who consent to discontinue treatment. Participants stop their DMARDs at time 0 and are offered an optional ultrasound-guided synovial biopsy. They are studied intensively, with blood sampling and clinical evaluation at weeks 0, 2, 5, 8, 12 and 24. It is anticipated that 50% of participants will have a disease flare, whilst 50% remain in drug-free remission for the study duration (24 weeks). Flaring participants undergo an ultrasound-guided synovial biopsy before reinstatement of previous treatment. Blood samples will be used to investigate immune cell subsets, their activation status and their cytokine profile, autoantibody profiles and epigenetic profiles. Synovial biopsies will be examined to profile cell lineages and subtypes present at flare. Blood, urine and synovium will be examined to determine metabolic profiles. Taking into account all generated data, multivariate statistical techniques will be employed to develop a model to predict impending flare in RA, highlighting therapeutic pathways and informative biomarkers. Despite initial recruitment to time and target, the SARS-CoV-2 pandemic has impacted significantly, and a decision was taken to close recruitment at 118 participants with complete data.

DISCUSSION

This study aims to investigate the pathogenesis of flare in rheumatoid arthritis, which is a significant knowledge gap in our understanding, addressing a major unmet patient need.

TRIAL REGISTRATION

The study was retrospectively registered on 27/06/2019 in the ISRCTN registry 16371380 .

Ultrasound-Guided Synovial Biopsy: A Review

Ultrasound-guided synovial biopsy is a safe, well-tolerated, and effective method to collect good-quality synovial tissue from all types of joints for clinical and research purposes. Although synovial biopsy cannot be used to distinguish between types of inflammatory rheumatic disease, analysis of synovial tissue has led to remarkable advances in the understanding of the pathobiology of rheumatoid arthritis and other inflammatory rheumatic diseases. Synovitis is the hallmark of these diseases; hence, accessing the core of the pathological process, synovial tissue, provides an opportunity to gather information with potential diagnostic and prognostic utility.

Arthroscopic Guided Synovial Biopsies

Synovial tissue can be safely and reliably collected for research and clinical purposes using arthroscopy. This technique offers the obvious advantage of allowing direct visualization, and targeted biopsy of specific areas of interest within the joint, as well as for the collection of tissue which will include a lining layer. Much has been learnt by studying the synovium retrieved using this technique concerning the pathobiology of inflammatory arthritis. Furthermore, recent evidence suggests that the tissue retrieved may enable the identification of unique pathotypes that will allow for a precise approach to treatment selection in individual patients. Although ultrasound guided techniques for sampling synovial tissue have gained in popularity over the last decade, both methodologies are expected to compliment each other, each having unique benefits and drawbacks. We present here a detailed description of the arthroscopy technique reporting on our collective experience at two centers in Europe.

Synovial biopsies in clinical practice and research: current developments and perspectives

Synovial biopsy techniques have developed and widely expanded over the past few years, in particular due to the development of ultrasound-guided procedures. This article reviews the different techniques, clinical applications, and the latest advances in translational research as well as current challenges and perspectives. The first part focuses on different techniques available for biopsy, along with their feasibility, success rate, tolerance, and training requirements. In the second part, clinical applications are described. Data on diagnostic performances are reported, especially regarding septic arthritis. Translational research applications are described and explained in the final part, from the early histological studies and the first description of pathotype to more recent technologies involving -omics. Latest developments involving single-cell RNA sequence analysis have allowed the discovery of new cell subpopulations with remarkable roles in RA pathophysiology. These studies pave the ground for the discovery of new therapeutic targets and the implementation of personalized therapy in RA.

Key Point •This review provides an overview of synovial biopsy techinques and applications especially in clinical and translational research.

Arthroscopy in rheumatology: where have we been? Where might we go?

The aim of our manuscript is to illustrate the past, present and future role of rheumatologists performing arthroscopy. Doctors first began adapting endoscopes to inspect joints to assess synovial conditions that concern rheumatologists. Rheumatologists were among the pioneers developing arthroscopy. Students of the father of modern arthroscopy, Watanabe, included rheumatologists, who taught others once home. Rheumatologists assessed the intra-articular features of their common diseases in the 60s and 70s. Improvements in instrumentation and efforts by a few orthopaedists adapted a number of common joint surgical procedures for arthroscopy. Interest from rheumatologists in arthroscopy grew in the 90s with ‘needle scopes’ used in an office setting. Rheumatologists conducting the first prospective questioning arthroscopic debridement in OA and developing biological compounds reduced the call for arthroscopic interventions. The arthroscope has proven an excellent tool for viewing and sampling synovium, which continues to at several international centres. Some OA features—such as calcinosis—beg further arthroscopic investigation. A new generation of ‘needle scopes’ with far superior optics awaits future investigators.

Efficacy, Safety, and Sample Quality of Ultrasound-Guided Synovial Needle Biopsy in Clinical Practice and Research: A Prospective Observational Study

OBJECTIVE

To study the efficacy, tolerability, safety, and sampling variation of ultrasound (US)-guided synovial biopsies performed in clinical practice and research.

METHODS

We included all patients who had a US-guided synovial needle biopsy from November 2013 to January 2018. Patients were evaluated for procedure safety and tolerability. Usefulness of synovial biopsy was considered based on contribution for achieving the proposed aims. We analyzed samples for presence and quality of synovial tissue, synovitis score/grade, and pathotype. Variation across patients, samples, section levels, and sampling order was assessed.

RESULTS

A total of 64 US-guided synovial biopsies were performed (n = 52 in clinical practice, n = 12 in research). Patient tolerability (70% no/mild discomfort) was remarkably high. There was no significant aggravation of symptoms or US synovitis in the biopsied joint. Procedures were overall safe, with few minor, 2 moderate, and no major adverse events. Usefulness of US-guided synovial biopsies was high, both in clinical practice (37% direct diagnostic impact, 100% positive/95% negative predictive values for infection) and in research (92% success). Synovial tissue was retrieved in 88% of biopsies, with a median of 75% gradable samples. There was significant variation in sample quality and synovitis features across patients and samples, but not between different section levels. Samples collected later in the procedure had a lower frequency of synovial tissue and were poorly concordant in pathotype with those collected earlier.

CONCLUSION

US-guided synovial needle biopsy is an effective, safe, and well-tolerated means to collect good quality synovial tissue for clinical and research purposes. Samples collected for different aims should be retrieved in parallel, rather than sequentially.

Safety and tolerability of ultrasound-guided synovial needle biopsy in Japanese arthritis patients

OBJECTIVES

We sought to clarify the safety and tolerability of ultrasound (US)-guided synovial needle biopsy in hand and knee joints in Japanese arthritis patients.

METHODS

A total of nine consecutive arthritis patients were recruited and scheduled for US-guided synovial needle biopsies. Patients completed a safety questionnaire and patient-reported outcomes (PRO) data of joint pain, stiffness, and swelling pre- and postbiopsy. We also recorded patients' characteristics and willingness to undergo a second biopsy by the same technique. All synovial needle biopsy samples were assessed with pathological and microbial examination to verify whether clinical evaluation was possible.

RESULTS

Five and 4 patients underwent US-guided biopsy from hand and knee joints, respectively. PRO data showed no significant differences in pain, swelling, or stiffness levels before and after biopsy, with a mean 11.8 samples collected per procedure. No significant complications, including joint infection, bleeding, or vasovagal signs, were reported. Histologically adequate synovial tissue was identified in 83 (78%) samples. We were able to submit the biopsy samples to pathological and bacterial analysis to exclude septic arthritis.

CONCLUSION

We demonstrated that a minimally invasive US-guided needle biopsy is a safe and well-tolerated procedure and the synovial tissue collected was of adequate quality for pathological analysis.

Transforming clinical trials in rheumatology: towards patient-centric precision medicine

Despite the success of targeted therapies in the treatment of inflammatory arthritides, the lack of predictive biomarkers drives a 'trial and error' approach to treatment allocation, leading to variable and/or unsatisfactory responses. In-depth characterization of the synovial tissue in rheumatoid arthritis, as well as psoriatic arthritis and spondyloarthritis, is bringing new insights into the diverse cellular and molecular features of these diseases and their potential links with different clinical and treatment-response phenotypes. Such progress raises the tantalizing prospect of improving response rates by matching the use of specific agents to the cognate target pathways that might drive particular disease subtypes in specific patient groups. Innovative patient-centric, molecular pathology-driven clinical trial approaches are needed to achieve this goal. Whilst progress is clearly being made, it is important to emphasize that this field is still in its infancy and there are a number of potential barriers to realizing the premise of patient-centric clinical trials.

[CME-Rheuma 21: Precision Medicine - Synovial Biopsy in Rheumatology]

CME-Rheuma 21: Precision Medicine - Synovial Biopsy in Rheumatology Abstract. Synovial biopsy is increasingly performed in the medicine of the musculoskeletal system. On the one hand it allows the in-depth diagnosis of unclear arthritides. On the other hand, there is an increasing body of publications showing that histology, immunohistochemistry and RNA analysis of synovial tissue may lead to subclassifications within rheumatoid arthritis. This in turn may have predictive value for the treatment response. We herein give a short overview of the joint biopsy technique, the basic evaluation of biopsy samples and the prospects of synovial biopsy.

Synovial biopsies in inflammatory arthritis: precision medicine in rheumatoid arthritis

Introduction: Synovial tissue (ST) is composed of a lining and sublining layer and is the target tissue involved in the inflammatory arthritides (IA), in which there is lining layer hyperplasia, inflammatory cell influx, macrophage recruitment and change in number and behavior of lining fibroblasts. Understanding synovial pathology has been critical in providing insights into pathogenetic mechanisms of disease and therapeutics. Pathobiological insights into ST have been underpinned by progress in molecular analytic methods; research in this area holds promise in individualizing treatment and optimizing response.Areas covered: We explore ST in IA and cover in-depth the utility of synovial biopsy and ST heterogeneity. We review recent advances in ST research and discuss implications with regards to therapeutic response. Finally, we provide perspectives on the identification of new drug targets and new diagnostic and prognostic markers.Expert opinion: ST holds the potential to individualize therapy by detecting biomarkers of diagnosis, therapeutic choice, and treatment modification in IA. Advances in molecular biology including high-throughput omics are likely to provide information that has hitherto remained unknown. ST analyzes pre- and post-treatment needs to be standard of care; only by routinely collecting and analyzing ST will we achieve the precision medicine outcomes described herein.

Six-month prospective trial in early and long-standing rheumatoid arthritis: evaluating disease activity in the wrist through sequential synovial histopathological analysis, RAMRIS magnetic resonance score and EULAR-OMERACT ultrasound score

Introduction

Standardised scoring systems for rheumatoid arthritis (RA) joint disease activity include Larsen score for radiographs, rheumatoid arthritis magnetic resonance imaging score (RAMRIS) for MRI and using the European League Against Rheumatisms-Outcome Measures in Rheumatology (EULAR-OMERACT) score for ultrasound (US) images. The aim of this prospective study was to investigate the relationship between histological synovitis and radiological synovitis, assessed by conventional X-ray, US and MRI of the wrist radiocarpal joint.

Methods

20 patients with treatment naive early RA (ERA) and 20 with long-standing RA (LRA) were enrolled in a 6-month prospective study. Patients with RA underwent US-guided synovial biopsy, X-ray and US of the wrist at enrolment and 6 months. MRI at baseline and also at 6 months for the ERA group, and scored with the RAMRIS system. X-ray was scored by Larsen score and US by the EULAR-OMERACT system. Synovial biopsy inflammation was determined by the Krenn score.

Results

In the ERA group at baseline, Krenn score was correlated strongly with both US combined score (r = 0.77 p < 0.001) and MRI synovitis score (r = 0.85 p < 0.001), while uncorrelated at 6 months. In the LRA group at baseline, these scores correlated strongly (r = 0.83, p < 0.001) to moderately (r = 0.61, p = 0.002), and persisted at 6 months for US score (r = 0.81 p < 0.001). For all patients with RA, change in Krenn score between baseline and 6 months was correlated with both change in US combined score (r = 0.65, p < 0.001) and change in MRI synovitis score (r = 0.50, p = 0.03).

Conclusion

The MRI RAMRIS synovitis score and EULAR-OMERACT US scoring system are sensitive measures of histological synovitis in LRA and ERA. After 6 months, this correlation persists in the established RA group, but not in the ERA group. Overall, decreases in MRI/US synovitis are associated with reductions in histological synovitis. The study validates the use of MRI RAMRIS and EULAR-OMERACT US scores as surrogate markers of histological synovitis in established RA and early untreated RA.

Ultrasound-Guided Biopsies: Medium and Large Joints

Ultrasound-guided needle synovial biopsies are useful for clinical practice and research in rheumatology. With the emergence of personalized medicine for the treatment of inflammatory rheumatic diseases, it is predicted that this technique will be increasingly used in the near future. Standardized characterization of the technical aspects of ultrasound-guided needle synovial biopsies is needed in order to produce solid evidence on the safety and effectiveness of the technique.

Synovial tissue biopsy analysis: unlocking the hidden secrets to personalised medicine?

Rheumatoid arthritis is an immune-mediated inflammatory disease of the synovium. Yet we still lack robust tissue-specific (synovial) biomarkers that are able to guide clinical decisions and stratify patients according to their disease subgroup and predicted response to treatment. The EULAR Synovitis Study Group and the OMERACT synovial tissue biopsy (STB) Special Interests Group have undertaken a consensus exercise to identify factors that are important for the standardisation of STB handling and analytical procedures in two situations—clinical practice and translational research.

Synovial Tissue Sampling in Rheumatological Practice-Past Developments and Future Perspectives

Synovial biopsies are performed in routine clinical care in order to refine diagnosis as well as within a research setting. Progress in the development of minimally invasive synovial sampling methods in the last century has accelerated and facilitated novel insights into disease pathogenesis. This review discusses the development of synovial biopsy techniques as well as examining the three currently most commonly used approaches: arthroscopic, blind needle biopsy and ultrasound guided approaches. It also highlights major research advances driven through synovial research and considers future developments.

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.