Synovial biopsies in inflammatory arthritis: precision medicine in rheumatoid arthritis

Enhancing Endogenous Hyaluronic Acid in Osteoarthritic Joints with an Anti-Inflammatory Supramolecular Nanofiber Hydrogel Delivering HAS2 Lentivirus

Osteoarthritis (OA) management remains challenging because of its intricate pathogenesis. Intra-articular injections of drugs, such as glucocorticoids and hyaluronic acid (HA), have certain limitations, including the risk of joint infection, pain, and swelling. Hydrogel-based therapeutic strategies have attracted considerable attention because of their enormous therapeutic potential. Herein, a supramolecular nanofiber hydrogel is developed using dexamethasone sodium phosphate (DexP) as a vector to deliver lentivirus-encoding hyaluronan synthase 2 (HAS2) (HAS2@DexP-Gel). During hydrogel degradation, HAS2 lentivirus and DexP molecules are slowly released. Intra-articular injection of HAS2@DexP-Gel promotes endogenous HA production and suppresses synovial inflammation. Additionally, HAS2@DexP-Gel reduces subchondral bone resorption in the anterior cruciate ligament transection-induced OA mice, attenuates cartilage degeneration, and delays OA progression. HAS2@DexP-Gel exhibited good biocompatibility both in vitro and in vivo. The therapeutic mechanisms of the HAS2@DexP-Gel are investigated using single-cell RNA sequencing. HAS2@DexP-Gel optimizes the microenvironment of the synovial tissue by modulating the proportion of synovial cell subpopulations and regulating the interactions between synovial fibroblasts and macrophages. The innovative nanofiber hydrogel, HAS2@DexP-Gel, effectively enhances endogenous HA production while reducing synovial inflammation. This comprehensive approach holds promise for improving joint function, alleviating pain, and slowing OA progression, thereby providing significant benefits to patients.

High-grade synovitis associates with clinical markers and response to therapy in chronic inflammatory arthritis: post hoc analysis of a synovial biomarkers prospective cohort study

Background

Inflammatory arthritis (IAs), such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA), are characterized by the presence of chronic synovitis. The Krenn's synovitis score (KSS), a simple tool detectable by haematoxylin/eosin staining of synovial biopsy samples, allows the discrimination between high-grade and low-grade synovitis. The aim of this study was to identify the clinical associations of KSS and to evaluate the relationship between high-grade synovitis and treatment response in IA patients.

Methods

Clinical, laboratory and ultrasound data were retrieved from RA and PsA patients recruited in the prospective MATRIX cohort study. Inclusion criteria were age≥18 years, RA or PsA diagnosis, and presence of active disease with eligibility to start/modify therapy. Patients underwent ultrasound-guided synovial biopsy of one of the most involved joints before starting/modifying treatment according to treat-to-target strategy. The samples were analysed by an expert pathologist for KSS calculation. Univariable and multivariable logistic regression analyses were performed to evaluate the relationship between KSS and baseline variables. The association between KSS and treatment response at 24 weeks of follow-up was investigated in univariable logistic regression analysis.

Results

53 patients, 34 RA and 19 PsA, completed 24 weeks of follow-up after synovial biopsy. Patients were either treatment naïve (N=6, 11%), csDMARDs-experienced (N=46, 87%) or b/tsDMARDs-experienced (N=20, 38%). Median KSS was 6.00 (Q1-Q3 4.00-7.00) in RA and 4.00 (3.00-6.00) in PsA (p=0.040), and inflammatory infiltrates score was significantly higher in RA than in PsA patients (median 3.00 vs 2.00, p=0.021). In multivariable analysis, synovial effusion in the biopsied joint (OR 9.26, 95%CI 2.12-53.91) and erythrocyte sedimentation rate (ESR) (OR 1.04, 95%CI 1.01-1.08) associated with high KSS. High-grade synovitis significantly associated with a higher probability of achieving DAS28 remission, ACR20/50 response, and Boolean2.0 remission, independently from diagnosis.

Conclusion

Several markers of pro-inflammatory pathways associated with the presence of high-grade synovitis, and patients with higher KSS shared a higher probability of treatment targets achievement in the follow up. The integration of a simple and feasible tool like KSS in the clinical and prognostic stratification of patients with IA might help in intercepting patients with a disease more prone to respond to available treatment paradigms.

What Bedside Skills Could the Modern Rheumatologist Possess? Part II. "Certain Technical Procedures"

ABSTRACT

Rheumatologists have never been reluctant to adopt procedures that might enhance their diagnostic or therapeutic powers. Their propensity to penetrate the joints of the patients they were treating set them apart from the general internist. Since the 1980s, when a chance to look inside the joints they were treating attracted a few rheumatologists, other things that could be done at the bedside emerged with now an array of bedside procedures that could be part of a rheumatologist's skill set. Besides gains in diagnosis and/or therapy, each constitutes a chance to restore the physical contact between physician and patient, riven by factors of the last decade, such as electronic medical records and COVID. With such contact so important to satisfaction of the patient and physician alike, acquisition of proficiency in certain technical procedures described herein offers one path to begin restoring rheumatology to the richly fulfilling practice it once was.

Emerging biomedical imaging-based companion diagnostics for precision medicine

The tumor heterogeneity, which leads to individual variations in tumor microenvironments, causes poor prognoses and limits therapeutic response. Emerging technology such as companion diagnostics (CDx) detects biomarkers and monitors therapeutic responses, allowing identification of patients who would benefit most from treatment. However, currently, most US Food and Drug Administration-approved CDx tests are designed to detect biomarkers in vitro and ex vivo, making it difficult to dynamically report variations of targets in vivo. Various medical imaging techniques offer dynamic measurement of tumor heterogeneity and treatment response, complementing CDx tests. Imaging-based companion diagnostics allow for patient stratification for targeted medicines and identification of patient populations benefiting from alternative therapeutic methods. This review summarizes recent developments in molecular imaging for predicting and assessing responses to cancer therapies, as well as the various biomarkers used in imaging-based CDx tests. We hope this review provides informative insights into imaging-based companion diagnostics and advances precision medicine.

Role and mechanism of fibroblast-activated protein-α expression on the surface of fibroblast-like synoviocytes in rheumatoid arthritis

Fibroblast-activated protein-α (FAP) is a type II integrated serine protease expressed by activated fibroblasts during fibrosis or inflammation. Fibroblast-like synoviocytes (FLSs) in rheumatoid arthritis (RA) synovial sites abundantly and stably overexpress FAP and play important roles in regulating the cellular immune, inflammatory, invasion, migration, proliferation, and angiogenesis responses in the synovial region. Overexpression of FAP is regulated by the initial inflammatory microenvironment of the disease and epigenetic signaling, which promotes RA development by regulating FLSs or affecting the signaling cross-linking FLSs with other cells at the local synovium and inflammatory stimulation. At present, several treatment options targeting FAP are in the process of development. This review discusses the basic features of FAP expressed on the surface of FLSs and its role in RA pathophysiology and advances in targeted therapies.

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.

Synovial biopsy for establishing a definite diagnosis in undifferentiated chronic knee monoarthritis

BACKGROUND

Undifferentiated arthritis is a condition in which the problem cannot be classified into any definite diagnosis category. Various methods have been suggested to clarify the definite diagnosis in this class. The synovial biopsy is suggested as the last diagnostic approach to determine the precise histopathological diagnosis. In this study, we aimed to evaluate the efficacy of synovial biopsy for establishing a definite diagnosis in patients with undifferentiated chronic knee monoarthritis.

METHODS

The present retrospective case series was conducted in 2005 in the rheumatology research center of Shariati hospital and the 501 hospital in Tehran, Iran. The study included the synovial biopsy of patients with chronic knee monoarthritis who did not have a definite diagnosis after all the diagnostic steps before the synovial biopsy. Pathology slides of the patients' synovial biopsy were reevaluated with a senior expert pathologist.

RESULTS

Eighty patients with a mean age of 37.6 ± 17.32 years (range: 6-68) were included, of whom 50% were female. The gap time between the onset of knee monoarthritis and the decision-making for synovial biopsy was 14.34 ± 19.61 months. Histopathologic evaluations revealed non-specific synovitis in 65% of the patients and a definite diagnosis in 35%. The most common definite diagnosis was rheumatoid arthritis (9%), followed by septic arthritis (5%). The most common pathologic findings were endothelial proliferation (89%) and synovial proliferation (88%), and the most common infiltrating cell was lymphocyte (54%). Patients with non-specific synovitis were more likely to have neovascularization, cellular infiltration (p-value < 0.001), synovial proliferation, endothelial proliferation (p-value = 0.001), pannus formation (p-value = 0.009), and fibrosis (p-value = 0.022) compared to the patients with a definite pathologic diagnosis. However, age, gender, and the gap time between disease symptoms to synovial biopsy were not significantly different between the different groups of diagnosis (p-value > 0.05).

CONCLUSION

Non-specific synovitis remains the most common histopathologic finding, highlighting the importance of physician expert opinion for most of the patients with undifferentiated chronic knee monoarthritis. Studies with larger samples and immunohistochemistry analyses are needed to clarify this uncategorized entity further.

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.

Anti-inflammatory and osteoprotective effects of Chikusetsusaponin Ⅳa on rheumatoid arthritis via the JAK/STAT signaling pathway

BACKGROUND

Rheumatoid arthritis (RA) is a common autoimmune disease, for which no economical and safe target drug treatment is available. Chikusetsusaponin Ⅳa (CS-IVa), an active compound in Panax japonicus C.A. Mey, has a good anti-inflammatory effect, but whether this compound can serve as a targeted drug for RA and the corresponding therapeutic mechanism remain unclear.

PURPOSE

To investigate the anti-inflammatory and bone-protecting effects of CS-IVa on RA and the possible corresponding mechanisms of action.

METHODS

Biomarkers and underlying pathological mechanisms were examined by performing a bioinformatics analysis of RA synovial gene expression data profiles, and the feasibility of CS-IVa treatment for RA was predicted using molecular docking and molecular dynamics simulation techniques. Histomorphological and molecular biology techniques were used to verify the feasibility and molecular mechanism of CS-IVa treatment for RA in vivo using a collagen-induced arthritis (CIA) model.

RESULTS

CS-IVa alleviated symptoms and reduced the immune organ index, arthritis index, hind paw thickness, and number of swollen joints in the foot for CIA mice. Bioinformatics analysis suggested that interferon-gamma (IFN-γ), interleukin-1 β (IL-1β), and the Janus kinase/signal transduction and activator of transcription (JAK/STAT) pathway played important roles in the pathogenesis of RA. The results of molecular docking and molecular dynamics simulations showed that CS-IVa bound effectively to IFN-γ and IL-1β and that the combined pose has good stability and flexibility. The histomorphological results showed that CS-IVa reduced joint histopathology scores, OARSI scores, and TRAP-positive cell counts. Molecular biology analysis indicated that CS-IVa reduced the concentration of inflammatory factors in the peripheral serum of CIA mice and suppressed the mRNA expression of these factors in the spleen in a dose-dependent manner. The protein expression level of the JAK/STAT pathway was also inhibited by CS-IVa.

CONCLUSION

The results of the current study demonstrate a novel inhibitory effect of CS-IVa on inflammation and bone destruction in CIA mice, and the mechanism may be related to the JAK/STAT signaling pathway, which provides new insights into the development of CS-IVa as a therapeutic agent for RA.

During development of rheumatoid arthritis, intermetatarsal bursitis may occur before clinical joint swelling: a large imaging study in patients with clinically suspect arthralgia

Objectives

Intermetatarsal bursitis (IMB) represents juxta-articular synovial inflammation of the intermetatarsal bursae. Recent MRI studies identified IMB as feature of early RA, but whether IMB already occurs in the pre-arthritic phase is unknown. We performed a large MRI study in clinically suspect arthralgia (CSA) to assess the occurrence and prognostic value of IMB.

Methods

A total of 577 consecutive CSA patients underwent contrast-enhanced MRI of the forefoot, metacarpophalangeal joints and wrist. MRIs were evaluated for subclinical synovitis/tenosynovitis/osteitis in line with the RA MRI scoring system (summed as RAMRIS inflammation) and for IMB. IMB was considered present if uncommon in the general population at the same location (i.e. size scored above the 95th percentile in age-matched symptom-free controls). The relation of IMB with other MRI-detected subclinical inflammation (synovitis/tenosynovitis/osteitis) was studied. Cox-regression assessed the association with clinical arthritis development during median 25 months follow-up. ACPA stratification was performed.

Results

At presentation with CSA, 23% had IMB. IMB was more frequent in ACPA-positive than ACPA-negative CSA (47% vs 19%, P < 0.001). Patients with IMB were more likely to also have subclinical synovitis [OR 3.4 (95% CI 1.8, 6.5)] and tenosynovitis [5.9(2.8, 12.6)]. IMB conferred higher risk of developing arthritis [HR 1.6(1.0–2.7) adjusted for other subclinical inflammation]. IMB-presence predicted arthritis development in ACPA-positive CSA [adjusted HR 2.2(1.0–4.7)], but not in ACPA-negative CSA-patients [0.8(0.4–1.7)].

Conclusion

Approximately a quarter of CSA patients have IMB, which is frequently accompanied by subclinical synovitis and tenosynovitis. IMB precedes development of clinical arthritis, particularly in ACPA-positive CSA. These results reinforce the notion that juxta-articular synovial inflammation is involved in the earliest phases of RA development.

Effective factors on Sharp Score in patients with rheumatoid arthritis: a retrospective study

Background

This study aims to describe the association between sharp score and clinical indexes, bone metabolism indexes, Disease Activity Score (DAS28) and sociodemographic factors in rheumatoid arthritis (RA).

Methods

Data were collected from the HIS (hospital information system), a national inpatient database in China, with information on the patients hospitalized during the period from 2012 to 2019. The association between sharp score and effective factors were identified using multinomial logistic regression and association rule mining (ARM).

Results

Three thousand eight hundred and forty patients were included: 82.66% males, 17.34% females, mean (SD) age 56.95 (12.68) years and symptom duration 3.45 (1.09) years. Spearman correlation analysis and Association rules analysis showed that there were significant positive correlations between sharp score and effective factors. Logistic regression analysis presented that erythrocyte sedimentation rate (ESR), high-sensitivity C-reactive protein (CRP), rheumatoid factor (RF) were risk factors of sharp score. In the analysis of individual outcomes, sex, age, symptom duration, DSA28 score, RF, ever drinker, and radiographic grading of hands were influence factors of sharp score.

Conclusion

Sharp score should be taken into consideration in formulating treatment strategies in RA.

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.

Geniposide downregulates the VEGF/SphK1/S1P pathway and alleviates angiogenesis in rheumatoid arthritis in vivo and in vitro

The VEGF/SphK1/S1P pathway is closely related to angiogenesis in rheumatoid arthritis (RA), but the precise underlying mechanisms are unclear at present. Here, we explored the involvement of the VEGF/SphK1/S1P cascade in RA models and determined the effects of GE intervention. Our results showed abnormal expression of proteins related to this pathway in RA synovial tissue. Treatment with GE effectively regulated the signal axis, inhibited angiogenesis, and alleviated RA symptoms. In vitro, TNF-ɑ enhanced the VEGF/SphK1/S1P pathway in a co-culture model of fibroblast-like synoviocytes (FLS) and vascular endothelial cells (VEC). GE induced downregulation of VEGF in FLS, restored the dynamic balance of pro-/antiangiogenic factors, and suppressed SphK1/S1P signaling in VEC, resulting in lower proliferation activity, migration ability, tube formation ability, and S1P secretion ability of VEC cells. Additionally, SphK1-specific small interfering RNA (siRNA) blocked the VEGF/SphK1/S1P cascade, which can effectively alleviate the stimulatory effect of FLS on VEC and further enhanced the therapeutic effect of GE. Taken together, our results demonstrate that GE suppresses the VEGF/SphK1/S1P pathway and alleviates the stimulation of VEC by FLS, thereby preventing angiogenesis and promoting therapeutic effects against RA.

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.