CD40L-Dependent Pathway Is Active at Various Stages of Rheumatoid Arthritis Disease Progression.

The inflammatory CD40-CD40L pathway is implicated in various autoimmune diseases, but the activity status of this pathway in various stages of rheumatoid arthritis (RA) progression is unknown. In this study, we used gene signatures of CD40L stimulation derived from human immature dendritic cells and naive B cells to assess the expression of CD40-downstream genes in synovial tissues from anti-citrullinated protein Ab-positive arthralgia, undifferentiated arthritis (UA), early RA, and established RA cohorts in comparison with healthy donors. Interestingly, the expression of CD40LG and active full-length CD40 was increased in the disease tissues, whereas that of a dominant-negative CD40 isoform was decreased. Gene set variation analysis revealed that CD40L-responsive genes in immature dendritic cells and naive B cells were significantly enriched in synovial tissues from UA, early RA, and established RA patients. Additionally, CD40L-induced naive B cell genes were also significantly enriched in synovial tissues from arthralgia patients. In our efforts to characterize downstream mediators of CD40L signaling, we have identified GPR120 and KDM6B as novel components of the pathway. In conclusion, our data suggest that therapeutic CD40-CD40L blocking agents may prove efficacious not only in early and established RA, but also in inhibiting the progression of the disease from arthralgia or UA to RA.

A Treat-to-Target Strategy Preserves Work Capacity in a Rheumatoid Arthritis Inception Cohort Treated With Combination Conventional DMARD Therapy.

OBJECTIVES: Quantification of work disability in patients with early rheumatoid arthritis (RA) receiving conventional DMARDs according to a treat-to-target strategy. METHODS: This is a retrospective cohort analysis of RA patients who received combination conventional DMARDs, escalated to achieve DAS28(ESR) remission and completed an annual work and arthritis questionnaire. Random effect mixed modeling was used to assess associations between average hours worked per week (HWPW), and baseline prognostic factors. HWPW were compared with matched population averages. Cox proportional hazards modeling was employed to evaluate associations between permanent loss of employment and treatment response, disease and demographic factors. RESULTS: Work data from 135 patients working at baseline and 137 working at any point followed for up to 14 years (range 1-14) were available for analysis. The mean age was 45 years, 70% were female, and 70% and 68% were seropositive for rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP), respectively. Men worked more hours than women; there was a highly significant association between working hours lost and increasing age (0.28 hours, P = 0.04) and female gender (11.92 hours, P < 0.001). HWPW were maintained over the study time comparable to the general population (loss of 0.78 vs. 0.24 HWPW). EULAR good responders at 6 months were more likely to be working at 10 years compared to those with moderate/no response. Permanent loss of employment and baseline age were strongly associated for anti-CCP positive participants (P = 0.04). CONCLUSIONS: Treat-to-target combination conventional DMARD therapy maintains work capacity, particularly in good responders, comparable to the general population. Improving treatment response in moderate/no responders early in disease may increase work retention.

Replication of association of the apolipoprotein A1-C3-A4 gene cluster with the risk of gout.

OBJECTIVE: Gout is associated with dyslipidaemia. Association of the apolipoprotein A1-C3-A4 gene cluster with gout has previously been reported in a small study. To investigate a possible causal role for this locus in gout, we tested the association of genetic variants from APOA1 (rs670) and APOC3 (rs5128) with gout. METHODS: We studied data for 2452 controls and 2690 clinically ascertained gout cases of European and New Zealand Polynesian (Maori and Pacific) ancestry. Data were also used from the publicly available Atherosclerosis Risk in Communities study (n = 5367) and the Framingham Heart Study (n = 2984). Multivariate adjusted logistic and linear regression was used to test the association of single-nucleotide polymorphisms with gout risk, serum urate, triglyceride and high-density lipoprotein cholesterol (HDL-C). RESULTS: In Polynesians, the T-allele of rs670 (APOA1) increased (odds ratio, OR = 1.53, P = 4.9 × 10(-6)) and the G-allele of rs5128 (APOC3) decreased the risk of gout (OR = 0.86, P = 0.026). In Europeans, there was a strong trend to a risk effect of the T-allele for rs670 (OR = 1.11, P = 0.055), with a significant protective effect of the G-allele for rs5128 being observed after adjustment for triglycerides and HDL-C (OR = 0.81, P = 0.039). The effect at rs5128 was specific to males in both Europeans and Polynesians. Association in Polynesians was independent of any effect of rs670 and rs5128 on triglyceride and HDL-C levels. There was no evidence for association of either single-nucleotide polymorphism with serum urate levels (P ⩾ 0.10). CONCLUSION: Our data, replicating a previous study, supports the hypothesis that the apolipoprotein A1-C3-A4 gene cluster plays a causal role in gout.

Effects of prednisolone on energy and fat metabolism in patients with rheumatoid arthritis: tissue-specific insulin resistance with commonly used prednisolone doses.

OBJECTIVE: Glucocorticoids can cause postprandial hyperglycaemia, but the effects on postprandial energy and fat metabolism are uncertain. We investigated the effects of acute and chronic low-dose prednisolone on fasting and postprandial energy expenditure and substrate metabolism. DESIGN: An open interventional and cross-sectional study was undertaken. PATIENTS AND MEASUREMENTS: Eighteen patients who had not taken oral glucocorticoids for ≥6 months were studied before and after 7 days prednisolone (6 mg/day) to assess the acute effects of prednisolone. Baseline data from patients, not on glucocorticoids, were compared with 18 patients on long-term prednisolone (6·5 ± 1·8 mg/day for >6 months) to assess the chronic effects. Energy expenditure and substrate oxidation were measured using indirect calorimetry before and after a mixed meal. Adipocyte insulin resistance index and insulin-mediated suppression of NEFA were calculated from fasting and postprandial insulin and NEFA concentrations. RESULTS: There were no significant differences in resting energy expenditure or diet-induced thermogenesis with prednisolone. Acute (-2·1 ± 6·2 vs -16·3 ± 4·8 mg/min, P = 0·01) and chronic (-1·4 ± 2·8 vs -16·3 ± 4·8 mg/min, P = 0·01) prednisolone attenuated postprandial suppression of fat oxidation. Chronic (31·6 ± 3·8 vs 17·0 ± 3·3, P = 0·007), but not acute, prednisolone increased adipocyte insulin resistance index. However, insulin-mediated suppression of NEFA was not significantly different after acute or chronic prednisolone. CONCLUSIONS: Prednisolone does not alter energy expenditure. However, even at low doses, prednisolone exerts adverse effects on fat metabolism, which could exacerbate insulin resistance and increase cardiovascular risk. Attenuated postprandial suppression of fat oxidation, but not lipolysis, suggests that prednisolone causes greater insulin resistance in skeletal muscle than in adipocytes.

Effect of acute and chronic glucocorticoid therapy on insulin sensitivity and postprandial vascular function.

OBJECTIVE: Postprandial hyperglycaemia is associated with increased arterial stiffness and cardiovascular events. Low-dose prednisolone causes insulin resistance that typically manifests as postprandial hyperglycaemia. We investigated whether prednisolone causes postprandial vascular dysfunction in a cohort of patients with rheumatoid arthritis. DESIGN: An open interventional and cross-sectional study was undertaken. PATIENTS AND MEASUREMENTS: Eighteen subjects with rheumatoid arthritis who had not taken oral glucocorticoids for ≥6 months were studied before and after prednisolone 6 mg/day for 7 days to determine the acute effects of prednisolone. Pre-prednisolone data were compared to 18 subjects with rheumatoid arthritis taking long-term (>6 months) prednisolone (6·5 ± 1·8 mg/day) to assess the chronic effects of prednisolone. Augmentation index (by applanation tonometry) and reactive hyperaemia index (by peripheral artery tonometry) were measured before and after a mixed-meal (10 kcal/kg, 45% carbohydrate, 15% protein, 40% fat). Insulin sensitivity was estimated by the Matsuda index and sympathetic nervous system activity from urinary noradrenaline excretion. RESULTS: Matsuda index was lower after acute (2·0 ± 1·0 vs 3·6 ± 1·1, P = 0·01) and chronic (1·9 ± 1·0 vs 3·6 ± 1·1, P = 0·04) prednisolone. Postprandial augmentation index was lower after acute prednisolone (2551 ± 197 vs 2690 ± 272%*min, P ≤ 0·001), but not chronic prednisolone. There were no significant differences in reactive hyperaemia index with acute or chronic prednisolone. Noradrenaline excretion was lower after acute (54 ± 8 vs 93 ± 23 nmol/6 h, P = 0·02), but not chronic, prednisolone. CONCLUSIONS: Prednisolone-induced insulin resistance is not associated with postprandial vascular dysfunction in patients with rheumatoid arthritis. Reduced sympathetic activity may contribute to the reduction in postprandial arterial stiffness with acute prednisolone.

The X-Linked Inhibitor of Apoptosis Protein Inhibitor Embelin Suppresses Inflammation and Bone Erosion in Collagen Antibody Induced Arthritis Mice.

OBJECTIVE: To investigate the effect of Embelin, an inhibitor of X-Linked Inhibitor of Apoptosis Protein (XIAP), on inflammation and bone erosion in a collagen antibody induced arthritis (CAIA) in mice. METHODS: Four groups of mice (n = 6 per group) were allocated: CAIA untreated mice, CAIA treated with Prednisolone (10 mg/kg/day), CAIA treated with low dose Embelin (30 mg/kg/day), and CAIA treated with high dose Embelin (50 mg/kg/day). Joint inflammation was evaluated using clinical paw score and histological assessments. Bone erosion was assessed using micro-CT, tartrate resistant acid phosphatase (TRAP) staining, and serum carboxy-terminal collagen crosslinks (CTX-1) ELISA. Immunohistochemistry was used to detect XIAP protein. TUNEL was performed to identify apoptotic cells. RESULTS: Low dose, but not high dose Embelin, suppressed inflammation as reflected by lower paw scores (P < 0.05) and lower histological scores for inflammation. Low dose Embelin reduced serum CTX-1 (P < 0.05) and demonstrated lower histological score and TRAP counting, and slightly higher bone volume as compared to CAIA untreated mice. XIAP expression was not reduced but TUNEL positive cells were more abundant in Embelin treated CAIA mice. CONCLUSION: Low dose Embelin suppressed inflammation and serum CTX-1 in CAIA mice, indicating a potential use for Embelin to treat pathological bone loss.

Leflunomide for inflammatory arthritis in end-stage renal disease on peritoneal dialysis: a pharmacokinetic and pharmacogenetic study.

OBJECTIVE: To study the pharmacokinetics and pharmacogenetics of leflunomide and document its efficacy and safety in the treatment of inflammatory arthritis in a patient with end-stage renal disease (ESRD) who was on peritoneal dialysis. CASE SUMMARY: Therapy for a 78-year-old man with ESRD who required peritoneal dialysis was started with leflunomide 10 mg/day for psoriatic arthritis. The dosage was increased to 20 mg/day after 3 months. Monitoring was continued until the patient's unexpected death from myocardial infarction at 8 months. Total and unbound teriflunomide (the active metabolite of leflunomide) concentrations were measured by liquid-chromatography-tandem mass spectrometry. Genotyping for CYP2C19 and ABCG2 polymorphisms, both known to influence teriflunomide pharmacokinetics, was also performed. DISCUSSION: Total concentrations of teriflunomide varied between 5.2 and 23.2 mg/L, while unbound concentrations varied between 0.0306 and 0.1468 mg/L. The unbound fraction varied between 0.367% and 0.71%. Teriflunomide was found in the dialysate at a concentration of 0.0981 mg/L. A single CYP2C19 loss of function allele was present, as was wild-type ABCG2. Leflunomide appeared to be therapeutically effective, as evidenced by a reduction in daily prednisolone dosage from 20 mg to 6mg; the Disease Activity Score in 28 joints (DAS28) was 5.46 at enrollment and 4.03 after 7 months. Health Assessment Questionnaire-Disability Index improved from 0.5 to 0.125 at 7 months. Numerous significant adverse events that were considered unrelated to leflunomide occurred. CONCLUSIONS: Dose adjustment for leflunomide does not appear to be required in the context of ESRD requiring peritoneal dialysis. We present novel evidence that a small amount of teriflunomide is removed by peritoneal dialysis. This case suggests that leflunomide is safe to use as therapy for inflammatory arthritis despite the presence of ESRD requiring peritoneal dialysis.

Transcriptomic profiling of programmed cell death 1 (PD-1) expressing T cells in early rheumatoid arthritis identifies a decreased CD4 + PD-1 + signature post-treatment.

Programmed cell death protein 1 (PD-1)-expressing T cells are expanded in individuals with established rheumatoid arthritis (RA). However, little is known about their functional role in the pathogenesis of early RA. To address this, we investigated the transcriptomic profiles of circulating CD4+ and CD8+ PD-1+ lymphocytes from patients with early RA (n = 5) using fluorescence activated cell sorting in conjunction with total RNA sequencing. Additionally, we assessed for alterations in CD4+PD-1+ gene signatures in previously published synovial tissue (ST) biopsy data (n = 19) (GSE89408, GSE97165) before and after six-months of triple disease modifying anti-rheumatic drug (tDMARD) treatment. Comparisons of gene signatures between CD4+PD-1+ vs. PD-1- cells identified significant upregulation of genes including CXCL13 and MAF, and in pathways including Th1 and Th2, cross talk between dendritic cells and NK cells, B cell development and antigen presentation. Gene signatures from early RA ST before and after six-month tDMARD treatment revealed downregulation of the CD4+PD-1+ signatures following treatment, identifying a mechanism through which tDMARDs exert their effect by influencing T cell populations. Furthermore, we identify factors associated with B cell help that are enhanced in the ST compared with PBMCs, highlighting their importance in driving synovial inflammation.

Screening for diabetes in patients with inflammatory rheumatological disease administered long-term prednisolone: a cross-sectional study.

OBJECTIVE: The aim of the study was to assess the effect of long-term prednisolone on fasting and post-glucose load glucose concentration in patients with inflammatory rheumatological disease. We hypothesized that prednisolone would predominantly increase post-glucose load glucose concentration and that fasting glucose would have poor sensitivity as a screening test for diabetes in patients receiving chronic prednisolone therapy. METHODS: In a cross-sectional study of subjects with inflammatory rheumatological disease but without known diabetes, 60 subjects [age = 70 (±10) years, 62% female] who were receiving chronic (>6 months) prednisolone [6.5 (±2.1) mg/day] (Group 1) and 58 controls [age = 70 (±11) years, 62% female] who had not received oral glucocorticoids for at least 6 months (Group 2) underwent an oral glucose tolerance test. RESULTS: Fasting glucose was significantly lower [5.0 (±0.1) vs. 5.3 (±0.1) mmol/l, P = 0.02) and post-glucose load glucose concentration significantly higher [8.0 (±0.4) vs. 6.8 (±0.3) mmol/l, P = 0.02] in Group 1 than in Group 2. In a multiple regression analysis, glucocorticoid use (P = 0.004) and log CRP (P = 0.02) were independently associated with fasting glucose, while waist circumference (P = 0.01), but not glucocorticoid use, was independently associated with post-glucose load glucose concentration. A fasting glucose ≥5.6 mmol/l had 33 and 83% sensitivity for diabetes in Groups 1 and 2, respectively. CONCLUSION: There is discordance between a reduced fasting and increased post-glucose load glucose concentration in rheumatological patients on long-term prednisolone. Therefore fasting glucose has poor sensitivity to screen for diabetes in prednisolone-treated patients. Treatment of prednisolone-induced hyperglycaemia should be directed at the postprandial period. Trial registration. Australian New Zealand Clinical Trials Registry, http://www.anzctr.org.au/, ACTRN12607000540415.

Development of a novel recombinant biotherapeutic with applications in targeted therapy of human arthritis.

OBJECTIVE: To isolate recombinant antibodies with specificity for human arthritic synovium and to develop targeting reagents with joint-specific delivery capacity for therapeutic and/or diagnostic applications. METHODS: In vivo single-chain Fv (scFv) antibody phage display screening using a human synovial xenograft model was used to isolate antibodies specific to the microvasculature of human arthritic synovium. Single-chain Fv antibody tissue-specific reactivity was assessed by immunostaining of synovial tissues from normal controls and from patients with rheumatoid arthritis and osteoarthritis, normal human tissue arrays, and tissues from other patients with inflammatory diseases displaying neovasculogenesis. In vivo scFv antibody tissue-specific targeting capacity was examined in the human synovial xenograft model using both (125)I-labeled and biotinylated antibody. RESULTS: We isolated a novel recombinant human antibody, scFv A7, with specificity for the microvasculature of human arthritic synovium. We showed that in vivo, this antibody could efficiently target human synovial microvasculature in SCID mice transplanted with human arthritic synovial xenografts. Our results demonstrated that scFv A7 antibody had no reactivity with the microvasculature or with other cellular components found in a comprehensive range of normal human tissues including normal human synovium. Further, we showed that the reactivity of the scFv A7 antibody was not a common feature of neovasculogenesis associated with chronic inflammatory conditions. CONCLUSION: Here we report for the first time the identification of an scFv antibody, A7, that specifically recognizes an epitope expressed in the microvasculature of human arthritic synovium and that has the potential to be developed as a joint-specific pharmaceutical.

Differential expansion of T peripheral helper cells in early rheumatoid arthritis and osteoarthritis synovium.

OBJECTIVES: Programmed cell death protein 1 (PD-1)-expressing T cells are implicated in the pathogenesis of autoimmune inflammatory diseases such as rheumatoid arthritis. A subset of CXCR5- T cells, termed T peripheral helper (Tph) cells, which drive B cell differentiation, have been identified in ectopic lymphoid structures in established rheumatoid arthritis synovial tissue. Here, we aimed to characterise these in treatment-naïve, early rheumatoid arthritis to determine whether these cells accumulate prior to fully established disease. METHODS: Fresh dissociated tissue and peripheral blood mononuclear cell (PBMC) suspensions were stained with Zombie UV, followed by anti-CD45RO, PD-1, CD3, ICOS, CD8, CD4, CD20, CXCR5, TIGIT and CD38 antibodies prior to analysis. For histology, rheumatoid arthritis synovial sections were prepared for Opal multispectral immunofluorescence with anti-CD45RO, CD20, PD-1 and CXCR5 antibodies. Images were acquired on the Perkin Elmer Vectra V.3.0 imaging system and analysed using InForm Advanced Image Analysis software. RESULTS: Flow cytometry revealed T cell infiltration in the rheumatoid arthritis synovium with differential expression of PD-1, CD45RO, ICOS, TIGIT and CD38. We observed a higher frequency of PD1hiCXCR5- Tph in rheumatoid arthritis synovial tissue and PBMCs versus controls, and no significant difference in T follicular helper cell frequency. Microscopy identified a 10-fold increase of Tph cells in early rheumatoid arthritis synovial follicular and diffuse regions, and identified Tph adjacent to germinal centre B cells. CONCLUSIONS: These data demonstrate that PD-1hi Tph cells are present in early rheumatoid arthritis, but not osteoarthritis synovium, and therefore may provide a target for treatment of patients with early rheumatoid arthritis.

Esophageal adenocarcinoma and hypertrophic osteoarthropathy with improvement following resection of esophageal cancer.

Esophageal cancer usually presents late and carries a grave prognosis. Early diagnosis dramatically improves outcomes, and hence recognition of the varied presenting features, including hypertrophic osteoarthropathy (HOA), may be important. Hypertrophic osteoarthropathy is a rare manifestation of esophageal adenocarcinoma and indeed may herald the presence of this neoplasm, as it did in the case we present. A 59-year-old man presented with signs and symptoms suggestive of inflammatory wrist, ankle, and knee arthritis, and imaging revealed changes of HOA. He reported dysphagia mainly to solids, and endoscopic biopsy showed adenocarcinoma. Cancer resection treatment led to clinical resolution of his musculoskeletal symptoms. This case highlights the importance of recognition of HOA as a feature of this increasingly common cancer.

Apoptosis in the rheumatoid arthritis synovial membrane: modulation by disease-modifying anti-rheumatic drug treatment.

OBJECTIVES: RA is characterized at the synovial tissue level by synovial lining hyperplasia, angiogenesis and mononuclear cell infiltrates. A failure of apoptotic pathways may explain these pathological changes in RA synovial tissue. This study aims to demonstrate the presence of initiators and inhibitors of apoptosis in RA synovial tissue and the effect of treatment with DMARDs on apoptotic pathways in RA. METHODS: Synovial biopsy specimens were obtained at arthroscopy from 16 RA patients before and at 3- or 6-month intervals after commencing treatment with a DMARD. Apoptosis (by the terminal deoxynucleotidyl transferase mediated dUTP nick end labelling method and polyADP-ribose polymerase staining), proteins regulating apoptosis [Fas, FADD-like IL1b converting enzyme inhibitory protein (FLIP), Bcl-2, Survivin and X-linked inhibitor of apoptosis protein (XIAP)] and the presence of activated caspases (caspases 3 and 8) were detected by immunohistochemistry and quantified using image analysis and semiquantitative techniques. RESULTS: Fifteen patients responded to treatment, with an ACR response of > or =20%, 13 achieving an ACR response of > or =50% and 3 achieving an ACR remission. There was a significant reduction in SM macrophages and memory T cells, with an increase in fibroblast-like synovial lining cells following DMARD treatment. Apoptosis was not detected in the inflamed synovial tissue of RA patients before starting treatment, despite evidence of caspase activation, but was detectable after successful treatment with DMARDs. Inhibitors of activated caspases (FLIP, Survivin and XIAP) were detected in RA synovial tissue and were down-modulated with successful DMARD treatment. CONCLUSIONS: Apoptotic pathways are defective in RA synovial tissue from patients with active disease, despite the presence of activated caspases, possibly due to the abundant expression of inhibitors of the caspase pathway in RA synovial tissue. DMARD treatment can modulate apoptosis in the RA SM, which may lead to restoration of the SM architecture towards that of normal synovial tissue.

Nivolumab-induced synovitis is characterized by florid T cell infiltration and rapid resolution with synovial biopsy-guided therapy.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are associated with rheumatic and musculoskeletal immune-related adverse events (irAEs) in 5%-20% of patients. Currently, patients refractory to corticosteroids and conventional disease-modifying antirheumatic drugs (cDMARD) are treated with biological DMARDs (bDMARDs) targeting tumor necrosis factor α (TNFα) and interleukin-6, although without a clear biological rationale. Synovial tissue (ST) biopsy presents a valuable opportunity to investigate irAE pathogenesis and appropriately stratify bDMARD use in refractory irAE patients. CASE PRESENTATION: We provide the first report of comparative, parallel ST and synovial fluid (SF) analyses of severe, cDMARD-refractory, seronegative polyarthritis, classified as a grade 3 irAE occurring in response to nivolumab treatment for metastatic squamous cell lung cancer, in comparison with ST and SF from patients with untreated rheumatoid arthritis (RA). We investigated immunohistochemical labeling of ST cytokine expression as a biological rationale for selecting therapy. Flow cytometric analysis of lymphocytes from ST, SF and blood collected before and after synovial biopsy-guided therapy, in comparison with RA, were evaluated for insights into the immunopathogenesis of irAE. Immunolabeling of ST demonstrated an excess of TNFα cytokine expression. Subsequent treatment with infliximab resulted in resolution of inflammatory symptoms and a significant reduction in C reactive protein levels. Flow cytometric analysis of synovial infiltrates indicated absence of programmed cell death protein-1 (PD-1) receptor positivity despite cessation of nivolumab approximately 200 days prior to the analyzes. CONCLUSIONS: A deeper understanding of the immunopathogenetic basis of immune activation in irAEs is required in order to select therapy that is likely to be the most effective. This is the first report investigating parallel blood, ST and SF in ICI-induced severe rheumatic irAE. Use of a bDMARD directed by the dominant inflammatory cytokine achieved resolution of synovitis while maintaining cancer remission.

Vitamin D(2) supplementation induces the development of aortic stenosis in rabbits: interactions with endothelial function and thioredoxin-interacting protein.

Understanding of the pathophysiology of aortic valve stenosis (AVS) and finding potentially effective treatments are impeded by the lack of suitable AVS animal models. A previous study demonstrated the development of AVS in rabbits with vitamin D(2) and cholesterol supplementation without any hemodynamic changes in the cholesterol supplemented group alone. The current study aimed to determine whether AVS develops in an animal model with vitamin D(2) supplementation alone, and to explore pathophysiological mechanisms underlying this process. The effects of 8 weeks' treatment with vitamin D(2) alone (n=8) at 25,000 IU/4 days weekly on aortic valve structure and function were examined in male New Zealand white rabbits. Echocardiographic aortic valve backscatter (AV(BS)), transvalvular velocity, and transvalvular pressure gradient were utilized to quantitate changes in valve structure and function. Valvular histology/immunochemistry and function were examined after 8 weeks. Changes in valves were compared with those in endothelial function and in valvular measurement of thioredoxin-interacting protein (TXNIP), a marker/mediator of reactive oxygen species-induced oxidative stress. Vitamin D(2) treated rabbits developed AVS with increased AV(BS) (17.6+/-1.4 dB vs 6.7+/-0.8 dB, P<0.0001), increased transvalvular velocity and transvalvular pressure gradient (both P<0.01 via 2-way ANOVA) compared to the control group. There was associated valve calcification, lipid deposition and macrophage infiltration. Endothelial function was markedly impaired, and intravalvular TXNIP concentration increased. In this model, vitamin D(2) induces the development of AVS with histological features similar to those of early AVS in humans and associated endothelial dysfunction/redox stress. AVS development may result from the loss of nitric oxide suppression of TXNIP expression.

Immune checkpoint inhibitor PD-1 pathway is down-regulated in synovium at various stages of rheumatoid arthritis disease progression.

Immune checkpoint blockade with therapeutic anti-cytotoxic T lymphocyte-associated antigen (CTLA)-4 (Ipilimumab) and anti-programmed death (PD)-1 (Nivolumab and Pembrolizumab) antibodies alone or in combination has shown remarkable efficacy in multiple cancer types, concomitant with immune-related adverse events, including arthralgia and inflammatory arthritis (IA) in some patients. Herein, using Nivolumab (anti-PD-1 antagonist)-responsive genes along with transcriptomics of synovial tissue from multiple stages of rheumatoid arthritis (RA) disease progression, we have interrogated the activity status of PD-1 pathway during RA development. We demonstrate that the expression of PD-1 was increased in early and established RA synovial tissue compared to normal and OA synovium, whereas that of its ligands, programmed death ligand-1 (PD-L1) and PD-L2, was increased at all the stages of RA disease progression, namely arthralgia, IA/undifferentiated arthritis, early RA and established RA. Further, we show that RA patients expressed PD-1 on a majority of synovial tissue infiltrating CD4+ and CD8+ T cells. Moreover, enrichment of Nivolumab gene signature was observed in IA and RA, indicating that the PD-1 pathway was downregulated during RA disease progression. Furthermore, serum soluble (s) PD-1 levels were increased in autoantibody positive early RA patients. Interestingly, most of the early RA synovium tissue sections showed negative PD-L1 staining by immunohistochemistry. Therefore, downregulation in PD-1 inhibitory signaling in RA could be attributed to increased serum sPD-1 and decreased synovial tissue PD-L1 levels. Taken together, these data suggest that agonistic PD1 antibody-based therapeutics may show efficacy in RA treatment and interception.

Integrative analysis reveals CD38 as a therapeutic target for plasma cell-rich pre-disease and established rheumatoid arthritis and systemic lupus erythematosus.

BACKGROUND: Plasmablasts and plasma cells play a key role in many autoimmune diseases, such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This study was undertaken to evaluate the potential of targeting CD38 as a plasma cell/plasmablast depletion mechanism by daratumumab in the treatment of patients with RA and SLE. METHODS: RNA-sequencing analysis of synovial biopsies from various stages of RA disease progression, flow cytometry analysis of peripheral blood mononuclear cells (PBMC) from patients with RA or SLE and healthy donors, immunohistochemistry assessment (IHC) of synovial biopsies from patients with early RA, and ex vivo immune cell depletion assays using daratumumab (an anti-CD38 monoclonal antibody) were used to assess CD38 as a therapeutic target. RESULTS: We demonstrated that the plasma cell/plasmablast-related genes CD38, XBP1, IRF4, PRDM1, IGJ and TNFSF13B are significantly up-regulated in synovial biopsies from patients with arthralgia, undifferentiated arthritis (UA), early RA and established RA as compared to healthy controls and control patients with osteoarthritis. In addition, the highest CD38 expression was observed on plasma cells and plasmablasts compared to natural killer (NK) cells, classical dendritic cells (DCs), plasmacytoid DCs (pDCs) and T cells, in blood from healthy controls and patients with SLE and RA. Furthermore, IHC showed CD38 staining in the same region as CD3 and CD138 staining in synovial tissue biopsies from patients with early RA. Most importantly, our data show for the first time that daratumumab effectively depletes plasma cells/plasmablasts in PBMC from patients with SLE and RA in a dose-dependent manner ex vivo. CONCLUSION: These results indicate that CD38 may be a potential target for RA disease interception and daratumumab should be evaluated clinically for the treatment of both RA and SLE.

Arthroscopic guided synovial biopsy in rheumatology: current perspectives.

Synovial membrane (SM) pathology has provided valuable insights into our current understanding of immunopathological processes and treatment responses in the inflammatory arthritides. Amongst various methods of synovial biopsy, arthroscopic techniques remain the 'gold standard' owing to better sampling from sites of interest, particularly in patients with partially treated disease and from areas within joints that may be difficult to access using other techniques. Newer sophisticated techniques of SM membrane analyses allow assessment of differentially regulated pathways, the knowledge of which may help elucidate diagnostic and therapeutic targets in an attempt towards developing strategies for personalised medicine in the current era of targeted biologic therapies.