Evaluation of the Synovial Effects of Biological and Targeted Synthetic DMARDs in Patients with Psoriatic Arthritis: A Systematic Literature Review and Meta-Analysis

The aims of this systematic literature review (SLR) were to identify the effects of approved biological and targeted synthetic disease modifying antirheumatic drugs (b/tsDMARDs) on synovial membrane of psoriatic arthritis (PsA) patients, and to determine the existence of histological/molecular biomarkers of response to therapy. A search was conducted on MEDLINE, Embase, Scopus, and Cochrane Library (PROSPERO:CRD42022304986) to retrieve data on longitudinal change of biomarkers in paired synovial biopsies and in vitro studies. A meta-analysis was conducted by adopting the standardized mean difference (SMD) as a measure of the effect. Twenty-two studies were included (19 longitudinal, 3 in vitro). In longitudinal studies, TNF inhibitors were the most used drugs, while, for in vitro studies, JAK inhibitors or adalimumab/secukinumab were assessed. The main technique used was immunohistochemistry (longitudinal studies). The meta-analysis showed a significant reduction in both CD3+ lymphocytes (SMD -0.85 [95% CI -1.23; -0.47]) and CD68+ macrophages (sublining, sl) (SMD -0.74 [-1.16; -0.32]) in synovial biopsies from patients treated for 4-12 weeks with bDMARDs. Reduction in CD3+ mostly correlated with clinical response. Despite heterogeneity among the biomarkers evaluated, the reduction in CD3+/CD68+sl cells during the first 3 months of treatment with TNF inhibitors represents the most consistent variation reported in the literature.

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.

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.

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.

EULAR recommendations for the reporting of ultrasound studies in rheumatic and musculoskeletal diseases (RMDs)

OBJECTIVE

To produce European League Against Rheumatism (EULAR) recommendations for the reporting of ultrasound studies in rheumatic and musculoskeletal diseases (RMDs).

METHODS

Based on the literature reviews and expert opinion (through Delphi surveys), a taskforce of 23 members (12 experts in ultrasound in RMDs, 9 in methodology and biostatistics together with a patient research partner and a health professional in rheumatology) developed a checklist of items to be reported in every RMD study using ultrasound. This checklist was further refined by involving a panel of 79 external experts (musculoskeletal imaging experts, methodologists, journal editors), who evaluated its comprehensibility, feasibility and comprehensiveness. Agreement on each proposed item was assessed with an 11-point Likert scale, grading from 0 (total disagreement) to 10 (full agreement).

RESULTS

Two face-to-face meetings, as well as two Delphi rounds of voting, resulted in a final checklist of 23 items, including a glossary of terminology. Twenty-one of these were considered 'mandatory' items to be reported in every study (such as blinding, development of scoring systems, definition of target pathologies) and 2 'optional' to be reported only if applicable, such as possible confounding factors (ie, ambient conditions) or experience of the sonographers.

CONCLUSION

An EULAR taskforce developed a checklist to ensure transparent and comprehensive reporting of aspects concerning research and procedures that need to be presented in studies using ultrasound in RMDs. This checklist, if widely adopted by authors and editors, will greatly improve the interpretability of study development and results, including the assessment of validity, generalisability and applicability.

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.

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.

Synovial Tissue Biopsy Collection by Rheumatologists: Ready for Clinical Implementation?

Synovial tissue from arthritis patients is increasingly used for both basic pathophysiological and clinical translational research. This development has been spurred by the development of biotechnological techniques for analysis of complex tissues and the validation of ultrasound guided biopsies for easier tissue sampling. This increasing use of synovial tissue raises questions on standardization of methodologies for tissue processing and cellular & molecular analyses. Furthermore, it raises the question if synovial tissue biopsy analysis may be more widely implemented in clinical practice, what are the methodological hurdles for implementation and what are the lessons that can be learned from previous experience. This will be the focus of this review.

Needle Biopsy Adequacy in the Era of Precision Medicine and Value-Based Health Care

CONTEXT.—

Needle biopsy of diseased tissue is an essential diagnostic tool that is becoming even more important as precision medicine develops. However, the capability of this modality to efficiently provide samples adequate for diagnostic and prognostic analysis remains quite limited relative to current diagnostic needs. For physicians and patients, inadequate biopsy frequently leads to diagnostic delay, procedure duplication, or insufficient information about tumor biology leading to delay in treatment; for health systems, this results in substantial incremental costs and inefficient use of scarce specialized diagnostic resources.

OBJECTIVE.—

To review current needle biopsy technology, devices, and practice with a perspective to identify current limitations and opportunities for improvement in the context of advancing precision medicine.

DATA SOURCES.—

PubMed searches of fine-needle aspiration and core needle biopsy devices and similar technologies were made generally, by tissue site, and by adequacy as well as by health economics of these technologies.

CONCLUSIONS.—

Needle biopsy adequacy can be improved by recognizing the importance of this diagnostic tool by promoting common criteria for needle biopsy adequacy; by optimizing needle biopsy procedural technique, technologies, clinical practice, professional education, and quality assurance; and by bundling biopsy procedure costs with downstream diagnostic modalities to provide better accountability and incentives to improve the diagnostic process.

Synovial Tissue Biopsy Research

Synovial tissue is a key structure in diarthrodial joints and is the primary target of inflammation in autoimmune arthritis. The study of synovial tissue has developed significantly in the last two decades as arthroscopic and ultrasonographic techniques have allowed visualization and access to synovial biopsy. Further progress in synovial tissue processing and analysis has improved studies of disease pathogenesis, biomarker discovery, and molecular therapeutic targeting with increasingly specialized analytical and technological approaches. In September 2018 the first course on Synovial Tissue Biopsies was convened in Brussels, in this Mini Review these approaches will be described and I will summarize how synovial tissue research advanced.

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.

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.

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.

Transcriptional Profiling of Synovial Macrophages Using Minimally Invasive Ultrasound-Guided Synovial Biopsies in Rheumatoid Arthritis

OBJECTIVE

Currently, there are no reliable biomarkers for predicting therapeutic response in patients with rheumatoid arthritis (RA). The synovium may unlock critical information for determining efficacy, since a reduction in the numbers of sublining synovial macrophages remains the most reproducible biomarker. Thus, a clinically actionable method for the collection of synovial tissue, which can be analyzed using high-throughput strategies, must become a reality. This study was undertaken to assess the feasibility of utilizing synovial biopsies as a precision medicine-based approach for patients with RA.

METHODS

Rheumatologists at 6 US academic sites were trained in minimally invasive ultrasound-guided synovial tissue biopsy. Biopsy specimens obtained from patients with RA and synovial tissue from patients with osteoarthritis (OA) were subjected to histologic analysis, fluorescence-activated cell sorting, and RNA sequencing (RNA-seq). An optimized protocol for digesting synovial tissue was developed to generate high-quality RNA-seq libraries from isolated macrophage populations. Associations were determined between macrophage transcriptional profiles and clinical parameters in RA patients.

RESULTS

Patients with RA reported minimal adverse effects in response to synovial biopsy. Comparable RNA quality was observed from synovial tissue and isolated macrophages between patients with RA and patients with OA. Whole tissue samples from patients with RA demonstrated a high degree of transcriptional heterogeneity. In contrast, the transcriptional profile of isolated RA synovial macrophages highlighted different subpopulations of patients and identified 6 novel transcriptional modules that were associated with disease activity and therapy.

CONCLUSION

Performance of synovial tissue biopsies by rheumatologists in the US is feasible and generates high-quality samples for research. Through the use of cutting-edge technologies to analyze synovial biopsy specimens in conjunction with corresponding clinical information, a precision medicine-based approach for patients with RA is attainable.

Success Rate and Utility of Ultrasound-guided Synovial Biopsies in Clinical Practice

OBJECTIVE

The utility of synovial biopsy in increasing our understanding of the pathogenesis of inflammatory arthropathies, as well as in evaluating treatments, is well established. Ultrasound (US) allows synovial assessment and therefore assists in biopsying synovial tissue in a safe and well-tolerated manner. This study's objectives were to (1) determine the rate of success in retrieving synovial tissue using US guidance, (2) describe the indications for US-guided synovial biopsies in the clinical setting, (3) determine how frequently the synovial biopsy can lead to a clear diagnosis, and (4) assess the quality of the synovial tissue obtained using this technique.

METHODS

Synovial biopsies of small and large joints were performed under US guidance between February 2007 and December 2014 using a semiautomatic core biopsy needle. The biopsy procedure was considered successful if synovial tissue was found at histological examination.

RESULTS

Seventy-four patients with undifferentiated arthritis underwent 76 synovial biopsies. The success rate in retrieving synovial tissue was 81.6% (62/76). One patient taking acetyl salicylic acid at 75 mg at the time of the biopsy presented with hemarthrosis 48 h after the procedure, which resolved following simple arthrocentesis. A definitive diagnosis was achieved in 16% of the patients where synovial tissue was sampled successfully.

CONCLUSION

US-guided synovial biopsies in clinical practice can be performed safely on patients with undifferentiated arthritis and with heterogeneous presentations. The rate of success in acquiring synovial tissue is high. The procedure usually retrieves quality tissue and leads to a definite diagnosis in a significant minority of patients.