Methotrexate reduces inflammatory cell numbers, expression of monokines and of adhesion molecules in synovial tissue of patients with rheumatoid arthritis

[Low-dose methotrexate: Indications and side effects, particularly in cases of diffuse interstitial pneumonia]

INTRODUCTION

Methotrexate (MTX) is a folate antagonist used as an immunosuppressant in a number of conditions, including rheumatoid arthritis (RA). Low-dose MTX (MTX-LD) is associated with a risk of haematological, hepatic, gastrointestinal and pulmonary toxicity, which may up until now have limited its use.

STATE OF THE ART

In RA, data from retrospective cohorts have reported a possible excess risk of methotrexate toxicity in cases of underlying interstitial lung disease (ILD). However, recent prospective and retrospective multicentre studies have found no such increased risk, and have reassuringly concluded that MTX-LD can be prescribed in cases of RA-associated ILD (RA-ILD).

PERSPECTIVES AND CONCLUSIONS

Current recommendations are not to delay the introduction of MTX in patients with RA at risk of developing ILD or in the presence of RA-ILD with mild to moderate respiratory impairment.

Untargeted metabolic profiling of high-dose methotrexate toxicity shows alteration in betaine metabolism

Cardiotoxicity is a well-established adverse effect of several drugs across multiple therapeutic indications. It is particularly prevalent following anticancer therapy. In order to evaluate the changes in cellular metabolism associated with methotrexate cardiotoxicity, we treated Wistar rats with a single high dose of methotrexate (HDMTX), and after five days, the animals were sacrificed. We then analyzed the cardiotoxicity parameters in serum like Cardiac enzymes(CK-MB, Troponin T, ALP), Inflammatory markers (TNF-α and IL-6), oxidative stress markers (NO, NOX-2), histopathology and cardiac tissue with the goal of identifying a metabolic signature of cardiotoxicity using discovery-based metabolomics. The biochemical parameters for cardiac enzymes, oxidative stress and inflammatory markers showed a significant increase in all three categories in rats treated with HDMTX. These findings were mirrored in the histopathological analysis confirming cardiotoxicity due to HDMTX. The results showed a total of 95 metabolites that were found to be significantly (p < 0.05) modulated: either up- or downregulated in the HDMTX-treated group when compared with the control group. Using integrated pathway analysis we found these metabolites were associated with many important cardiac tissue metabolic pathways, such as the malate aspartate shuttle, taurine and hypotaurine metabolism, betaine metabolism, spermidine biosynthesis, and homocysteine degradation. Among them, L-arginine, homocysteine, and betaine were significantly upregulated, suggesting their possible association with cardiac tissue injury. Overall, we provided evidence for using untargeted metabolomics to identify novel metabolites associated with HDMTX cardiac toxicity.

Unveiling Novel Drug Targets and Emerging Therapies for Rheumatoid Arthritis: A Comprehensive Review

Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disease, that causes joint damage, deformities, and decreased functionality. In addition, RA can also impact organs like the skin, lungs, eyes, and blood vessels. This autoimmune condition arises when the immune system erroneously targets the joint synovial membrane, resulting in synovitis, pannus formation, and cartilage damage. RA treatment is often holistic, integrating medication, physical therapy, and lifestyle modifications. Its main objective is to achieve remission or low disease activity by utilizing a "treat-to-target" approach that optimizes drug usage and dose adjustments based on clinical response and disease activity markers. The primary RA treatment uses disease-modifying antirheumatic drugs (DMARDs) that help to interrupt the inflammatory process. When there is an inadequate response, a combination of biologicals and DMARDs is recommended. Biological therapies target inflammatory pathways and have shown promising results in managing RA symptoms. Close monitoring for adverse effects and disease progression is critical to ensure optimal treatment outcomes. A deeper understanding of the pathways and mechanisms will allow new treatment strategies that minimize adverse effects and maintain quality of life. This review discusses the potential targets that can be used for designing and implementing precision medicine in RA treatment, spotlighting the latest breakthroughs in biologics, JAK inhibitors, IL-6 receptor antagonists, TNF blockers, and disease-modifying noncoding RNAs.

Serum Cytokine Profiles in Patients with Rheumatoid Arthritis Before and After Treatment with Methotrexate

Rheumatoid arthritis (RA) is an inflammatory autoimmune illness affecting around 1% of the population globally. Cytokines have a crucial role in the pathogenesis of RA. The objectives of the present study were to compare the serum cytokine profiles between methotrexate (MTX)-treated and MTX-naive RA patient groups, MTX-treated RA patient group and healthy controls, and MTX-naive RA patient group and healthy controls. Enzyme linked immunosorbent assay (ELISA) kits were used to quantify the serum concentrations of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-17, IL-6, interferon-gamma (IFN-γ), and IL-10 in 80 RA patients (48 MTX treated and 32 MTX naive) and 80 healthy controls. For all cytokine assays, absorbance was measured at 450 nm using a microplate reader (Bio-Rad). Independent sample t-test was used to compare the serum cytokine concentrations between the study groups using SPSS version 25. MTX-treated RA patient group had significantly reduced serum levels of TNF-α (36.13 ± 17.64 versus 45.82 ± 23.07, *P = 0.037), IL-17 (307.85 ± 151.74 versus 435.42 ± 241.19, **P = 0.006), and IFN-γ (414.93 ± 212.13 versus 527.15 ± 269.61, *P = 0.041) compared to MTX-naive RA patients. Both MTX-treated and MTX-naive RA patient groups had significantly high serum levels of TNF-α, IL-1β, IL-17, IL-6, IFN-γ, and IL-10 when compared to healthy controls (***P < 0.001). Downregulation of the serum concentrations of certain key cytokines, viz. TNF-α, IL-17, and IFN-γ, demonstrates the anti-inflammatory effect of MTX in RA patients.

Endothelial Cell Adhesion Molecules- (un)Attainable Targets for Nanomedicines

Endothelial cell adhesion molecules have long been proposed as promising targets in many pathologies. Despite promising preclinical data, several efforts to develop small molecule inhibitors or monoclonal antibodies (mAbs) against cell adhesion molecules (CAMs) ended in clinical-stage failure. In parallel, many well-validated approaches for targeting CAMs with nanomedicine (NM) were reported over the years. A wide range of potential applications has been demonstrated in various preclinical studies, from drug delivery to the tumor vasculature, imaging of the inflamed endothelium, or blocking immune cells infiltration. However, no NM drug candidate emerged further into clinical development. In this review, we will summarize the most advanced examples of CAM-targeted NMs and juxtapose them with known traditional drugs against CAMs, in an attempt to identify important translational hurdles. Most importantly, we will summarize the proposed strategies to enhance endothelial CAM targeting by NMs, in an attempt to offer a catalog of tools for further development.

Tocilizumab decreases T cells but not macrophages in the synovium of patients with rheumatoid arthritis while it increases the levels of serum interleukin-6 and RANKL

OBJECTIVES

Our knowledge about the effect of tocilizumab (TCZ) on the synovium in rheumatoid arthritis (RA) is limited. The aim of this study was to investigate the effect of TCZ on citrullination and on inflammation in the synovial tissue and in the peripheral blood.

METHODS

15 patients with RA underwent synovial biopsy before and 8 weeks after TCZ initiation. Clinical evaluation was performed at baseline and at 8 weeks. Using immunohistochemistry, we evaluated the expression of CD68, CD3, CD20, osteoprotegerin (OPG) and receptor activator for nuclear factor-κB ligand (RANKL) before and after treatment with TCZ. We also analysed the expression of protein arginine deiminase (PAD)-2 and PAD-4 enzymes in the synovial tissue and protein citrullination patterns with the help of anticitrullinated protein antibody (ACPA) clones 1325:04C03 and 1325:01B09. Serum levels of interleukin-6 (IL-6), IL-8, RANKL, OPG and C-terminal crosslinked telopeptide type II collagen were measured by ELISA. Paired-wise Wilcoxon signed-rank test was used to compare median values before and after treatment.

RESULTS

Disease activity in patients was reduced from baseline to 8 weeks. Although PAD-2 and PAD-4 expressions remained unchanged after TCZ treatment, the binding of one ACPA clone decreased in the synovial tissue. TCZ did not affect the number of CD68+ macrophages or CD20+ B cells but induced significant decrease in the number of CD3+ T cells. RANKL and OPG expression remained unchanged in the synovial tissue. A significant increase in the levels of IL-6 and RANKL was observed in the serum. This increase was statistically significant in patients who responded to TCZ (achieving Clinical Disease Activity Index low disease activity or remission) but not in non-responders.

CONCLUSIONS

TCZ reduced synovial T-cell counts but not macrophages. A significant increase of serum IL-6 was observed in responders.

Immune response in LPD during methotrexate administration (MTX-LPD) in rheumatoid arthritis patients

Methotrexate (MTX) is known as a first-line synthetic disease-modifying anti-rheumatic drug (DMARD) for the treatment of rheumatoid arthritis (RA). Although the risk of LPD development increases by RA inflammation itself, observation of spontaneous regression of LPD after MTX discontinuation lead to the theory of lymphomagenic role of MTX. In this review, we focused on the several immune response involved in LPD that developed under MTX administration in RA patients.

Surfactant-Free, Self-Assembled Nanomicelles-Based Transdermal Hydrogel for Safe and Targeted Delivery of Methotrexate against Rheumatoid Arthritis

Methotrexate (MTX) is the first line agent for therapy against rheumatoid arthritis (RA); however, orally its efficacy is hampered by poor solubility, less permeability, short plasma half-life, and reduced bioavailability. Meanwhile, parenteral formulations are associated with severe adverse effects. In an attempt to improve the efficacy of MTX, we synthesized polycaprolactone-polyethylene glycol-polycaprolactone (PCL-PEG-PCL) triblock copolymer by a ring-opening copolymerization reaction and used it as a carrier for the fabrication of MTX-loaded nanomicelles. Surfactant-free, self-assembled nanomicelles were prepared by nanoprecipitation technique and optimized through central composite design. The optimized nanomicelles exhibited a size distribution of 31 nm and an encapsulation efficiency of 91%. In vitro, the nanomicelles exhibited hemocompatibility, sustained release, and significantly high uptake in lipopolysaccharide activated macrophages. To facilitate application on the skin, optimized nanomicelles were loaded into a Carbopol 934-based hydrogel with eucalyptus oil as a penetration enhancer. Eucalyptus oil significantly improved the permeation of nanomicelles through the skin (p < 0.001). When the hydrogel was applied on the RA mice model, nanomicelles exhibited preferentially highest accumulation in the inflamed joints than other organs. As compared with the free MTX, MTX nanomicelles significantly improved the pharmacokinetic (4.34-fold greater half-life, 3.68-fold higher AUC_0-t, and 3.15-fold higher mean residence time) and pharmacodynamic profile ascertained through low inflammatory cytokines expression, improved oxidation protection, recovered behavioral responses, and radiological analysis. MTX nanomicelles-based hydrogel also significantly reduced the hepatotoxicity and did not activate the immune system. These results suggest that the MTX-loaded nanomicelles-based transdermal hydrogel can prove to be a promising agent against RA.

Mécanisme d'action du méthotrexate dans le traitement de la polyarthrite rhumatoïde

Le méthotrexate est utilisé dans le traitement de la polyarthrite rhumatoïde (PR) depuis les années 1980 et est souvent à ce jour le médicament de première intention pour le traitement de la PR. Dans cette revue, nous examinons plusieurs hypothèses pour expliquer le mécanisme à l'origine de l'efficacité du méthotrexate dans la PR. Celles-ci comprennent l'antagonisme du folate, la signalisation par l'adénosine, la génération d'espèces réactives de l'oxygène (ROS), la diminution des molécules d'adhérence, la modification des profils cytokiniques et l'inhibition des polyamines, entre autres. Actuellement, la signalisation par l'adénosine est probablement l'explication la plus largement acceptée du mécanisme du méthotrexate dans la PR, car le méthotrexate augmente les taux d'adénosine et suite à l'engagement de l'adénosine avec ses récepteurs extracellulaires, une cascade intracellulaire est activée et favorise un état antiinflammatoire global. Outre ces hypothèses, nous examinons le mécanisme du méthotrexate dans la PR sous l'angle de ses effets indésirables et considérons certains des nouveaux marqueurs génétiques de l'efficacité et de la toxicité du méthotrexate dans la PR. Enfin, nous discutons brièvement du mécanisme du méthotrexate en association avec un traitement de la PR par un inhibiteur du TNF-. En fin de compte, en trouvant une explication claire de la voie et du mécanisme conduisant à l'efficacité du méthotrexate dans la PR, il pourrait exister un moyen de formuler des thérapies plus puissantes avec moins d'effets secondaires.

Methotrexate an Old Drug with New Tricks

Methotrexate (MTX) is the first line drug for the treatment of a number of rheumatic and non-rheumatic disorders. It is currently used as an anchor disease, modifying anti-rheumatic drug in the treatment of rheumatoid arthritis (RA). Despite the development of numerous new targeted therapies, MTX remains the backbone of RA therapy due to its potent efficacy and tolerability. There has been also a growing interest in the use of MTX in the treatment of chronic viral mediated arthritis. Many viruses—including old world alphaviruses, Parvovirus B19, hepatitis B/C virus, and human immunodeficiency virus—have been associated with arthritogenic diseases and reminiscent of RA. MTX may provide benefits although with the potential risk of attenuating patients’ immune surveillance capacities. In this review, we describe the emerging mechanisms of action of MTX as an anti-inflammatory drug and complementing its well-established immunomodulatory activity. The mechanisms involve adenosine signaling modulation, alteration of cytokine networks, generation of reactive oxygen species and HMGB1 alarmin suppression. We also provide a comprehensive understanding of the mechanisms of MTX toxic effects. Lastly, we discussed the efficacy, as well as the safety, of MTX used in the management of viral-related rheumatic syndromes.

General synovitis score and immunologic synovitis score reflect clinical disease activity in patients with advanced stage rheumatoid arthritis

The purpose of this study was to investigate the relationship between clinical disease activity in patients with advanced stage rheumatoid arthritis (RA) on treatment with Disease Modifying Antirheumatic Drugs (DMARDs) and histopathological scores of synovial inflammation. To this end, synovial biopsies of 62 RA patients who underwent surgery for either synovectomy or total joint arthroplasty were assessed by a general synovitis score (GSS) and an immunologic synovitis score (IMSYC). The clinical disease activity index (CDAI) was significantly correlated with both the GSS and the IMSYC (r = 0.65, p = <0.001, r = 0.68, p = <0.001). Compared to patients with moderate and high disease activity, there was a significantly lower expression of T cell (CD3), B cell (CD20) and neutrophil (CD15) markers in synovial tissue of patients with low activity, but similar expression of the macrophage marker CD68. Subgroup analyses revealed no differences between small and large joints, seropositive and seronegative RA and patients with or without prednisolone treatment. However, we found a significantly stronger correlation of CDAI with IMSYC in patients undergoing arthroplasty (r = 0.82) than in patients undergoing synovectomy (r = 0.55). In addition, there was a stronger correlation of CDAI with GSS in patients treated with methotrexate (r = 0.86) than in patients with TNFα blockade (r = 0.55). In summary, the present study demonstrates that the histopathological scores GSS and IMSYC in general reflect clinical disease activity in patients with advanced stage rheumatoid arthritis, but that there is some heterogeneity between subgroups of patients within the cohort. In the future, molecular characterization of synovial inflammatory cell populations, including plasma cell infiltrates, will help to further defined clinically important subtypes of RA and treatment response.

Serum Biomarkers for Prediction of Response to Methotrexate Monotherapy in Early Rheumatoid Arthritis: Results from the SWEFOT Trial

OBJECTIVE

To investigate baseline levels of 12 serum biomarkers that constitute a multibiomarker disease activity test, as predictors of response to methotrexate (MTX) in patients with early rheumatoid arthritis (eRA).

METHODS

In 298 patients from the Swedish Pharmacotherapy (SWEFOT) clinical trial, baseline serum levels of 12 proteins were analyzed for association with disease activity based on the 28-joint count Disease Activity Score (DAS28) after 3 months of MTX monotherapy using uni-/multivariate logistic regression. Primary outcome was low disease activity (LDA; DAS28 ≤ 3.2).

RESULTS

Of 298 patients, 104 achieved LDA after 3 months on MTX. Four of the 12 biomarkers [C-reactive protein (CRP), leptin, tumor necrosis factor receptor I (TNF-RI), and vascular cell adhesion molecule 1 (VCAM-1)] significantly predicted LDA based on stepwise logistic regression analysis. Dichotomization of patients using receiver-operating characteristic curve analysis-based cutoffs for these biomarkers showed significantly higher proportions with LDA among patients with lower versus higher levels of CRP or leptin (40% vs 23%, p = 0.004, and 40% vs 25%, p = 0.011, respectively), as well as among those with higher versus lower levels of TNF-RI or VCAM-1 (43% vs 27%, p = 0.004, and 41% vs 25%, p = 0.004, respectively). Combined score based on these biomarkers, adjusted for known predictors of LDA (smoking, sex, and age), associated with decreased chance of LDA (adjusted OR 0.45, 95% CI 0.32-0.62).

CONCLUSION

Low baseline levels of CRP and leptin, and high baseline levels of TNF-RI and VCAM-1 were associated with LDA after 3 months of MTX therapy in patients with eRA. Combination of these 4 biomarkers increased accuracy of prediction. [Trial registration number: NCT00764725].

Liquid biopsies to guide therapeutic decisions in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic, immune-mediated inflammatory disease that has transitioned from a debilitating disease to a chronic, controllable disease. This has been possible due to the introduction of new treatment strategies like "treat-to-target," in which the clinician treats the patient aggressively enough to reach low disease activity or remission, and the introduction of new therapeutic agents, such as biological therapies, which can lead to the prevention of damage by early diagnosis and initiation of treatment. Attention is now being directed toward identifying the optimal treatment for each patient, one that will be the most efficient and have the least number of side effects. Much work has been done to find serologic and synovial biomarkers of response to various RA treatments. Proteomics, genomics and, in the past few years, metabolomics, have all been used in the quest of identifying these biomarkers. Blood-based liquid biopsies provide a minimally invasive alternative to synovial biopsies to identify cellular and molecular signatures that can be used to longitudinally monitor response and allow for personalized medicine approach. Liquid biopsies are comprised of cell-free DNA, immune circulating cells, and extracellular vesicles, and are being increasingly and successfully used in the field of oncology for diagnosis, progression, prognosis, and prediction of response to treatment. Recently, researchers have also begun investigating the usefulness of liquid biopsies in the field of rheumatology; in this review, we will focus on the potential of liquid biopsy blood samples as biomarkers of response to treatment in patients with RA.

Methotrexate mechanism in treatment of rheumatoid arthritis

Methotrexate has been used in treatment of rheumatoid arthritis (RA) since the 1980s and to this day is often the first line medication for RA treatment. In this review, we examine multiple hypotheses to explain the mechanism of methotrexate efficacy in RA. These include folate antagonism, adenosine signaling, generation of reactive oxygen species (ROS), decrease in adhesion molecules, alteration of cytokine profiles, and polyamine inhibition amongst some others. Currently, adenosine signaling is probably the most widely accepted explanation for the methotrexate mechanism in RA given that methotrexate increases adenosine levels and on engagement of adenosine with its extracellular receptors an intracellular cascade is activated promoting an overall anti-inflammatory state. In addition to these hypotheses, we examine the mechanism of methotrexate in RA from the perspective of its adverse effects and consider some of the newer genetic markers of methotrexate efficacy and toxicity in RA. Lastly, we briefly discuss the mechanism of additive methotrexate in the setting of TNF-α inhibitor treatment of RA. Ultimately, finding a clear explanation for the pathway and mechanism leading to methotrexate efficacy in RA, there may be a way to formulate more potent therapies with fewer side effects.

Mechanism of action of methotrexate in rheumatoid arthritis, and the search for biomarkers

The treatment and outcomes of patients with rheumatoid arthritis (RA) have been transformed over the past two decades. Low disease activity and remission are now frequently achieved, and this success is largely the result of the evolution of treatment paradigms and the introduction of new therapeutic agents. Despite the rapid pace of change, the most commonly used drug in RA remains methotrexate, which is considered the anchor drug for this condition. In this Review, we describe the known pharmacokinetic properties and putative mechanisms of action of methotrexate. Consideration of the pharmacodynamic perspective could inform the development of biomarkers of responsiveness to methotrexate, enabling therapy to be targeted to specific groups of patients. Such biomarkers could revolutionize the management of RA.

Methotrexate affects HMGB1 expression in rheumatoid arthritis, and the downregulation of HMGB1 prevents rheumatoid arthritis progression

High-mobility group box 1 (HMGB1) is associated with the development of rheumatoid arthritis (RA). Recent studies have shown that methotrexate (MTX) may inhibit the expression of HMGB1. This study examined whether HMGB1 might be involved in the treatment of RA using MTX. Synovial tissues were collected from RA patients who were treated with MTX for at least 6 months (RA-MTX group, 7 cases) and from those without MTX treatment (RA-noMTX group, 7 cases). Additionally, patients with osteoarthritis (OA group, 7 cases) were used as controls. The expression and locations of HMGB1 in the tissues were detected using real-time PCR, western blot, and immunohistochemistry. Additionally, OA-fibroblast-like synoviocytes (FLSs) and RA-FLSs were isolated and cultured, and the expression of HMGB1 was reduced in these cells by transfection with HMGB1 siRNA. Cell proliferation, migration, and invasion abilities were detected. Furthermore, the effects of HMGB1 on matrix metalloproteinase (MMP)-2 and MMP-13 were measured using western blot analysis. At the tissue level, HMGB1 expression in synovial membrane did not differ significantly between the OA and RA-MTX groups, but was significantly lower in these groups than in the RA-noMTX group. In cell experiments, the cell doubling time in the RA-FLS HMGB1 siRNA group was significantly extended compared with that in the RA-FLS negative control (NC)-siRNA group. The amount of cell migration and invasion in the RA-FLS HMGB1 siRNA group was significantly lower compared with that in the NC-siRNA group; the MMP-2 and MMP-13 expression levels were also lower. These results showed that MTX reduced HMGB1 expression in RA synovial tissues, and through the downregulation of HMGB1 expression in tissues, MTX may slow disease progression of RA.

Methotrexate treatment provokes apoptosis of proliferating keratinocyte in psoriasis patients

Psoriasis is a chronic inflammatory skin disease characterized by hyper proliferation of keratinocytes. Recent data show that the epidermis thickening in psoriasis may be related to imbalance of homeostasis caused by abnormal apoptotic process. Maintenance of keratinocyte apoptotic process is very important in psoriasis. Methotrexate (MTX) has been used for many years to restore the normal skin in psoriasis condition. However, the exact mechanism of MTX in psoriasis condition is poorly understood. The aim of this study was to examine the role of MTX on keratinocyte apoptosis pathway in psoriasis patients. A total of 58 psoriasis vulgaris patients were recruited for this study. Nonlesional skin biopsies served as control. Skin biopsies of psoriatic patients were collected and analyzed for cytosolic, mitochondria and total cytochrome c by ELISA. Expression of caspase-9, NFκBp65, pAkt1 by western blot, real-time PCR and immunohistochemical analysis of c-FLIP protein was analyzed in nonlesional and lesional skin biopsies before (day 0) and after (at the end of 6 and 12 weeks) MTX treatment. After MTX treatment, a significant increase in cytochrome c was observed when compared with before MTX treatment in psoriasis patients (p < 0.001). Protein and gene expression of cleaved caspase-9 were significantly increased after MTX treatment, whereas the expression of Bcl-xL, c-FLIP, NFκBp65, pAkt1 significantly downregulated after MTX treatment. In conclusion, these results showed that intrinsic apoptotic pathway induced by MTX eventually adds the beneficial therapeutic role of MTX in psoriasis by controlling the acanthosis.

Control of autoimmune inflammation by celastrol, a natural triterpenoid

Celastrol is a bioactive compound derived from traditional Chinese medicinal herbs of the Celastraceae family. Celastrol is known to possess anti-inflammatory and anti-oxidant activities. Our studies have highlighted the immunomodulatory attributes of celastrol in adjuvant-induced arthritis (AA), an experimental model of human rheumatoid arthritis (RA). RA is an autoimmune disease characterized by chronic inflammation of the synovial lining of the joints, leading eventually to tissue damage and deformities. Identification of the molecular targets of celastrol such as the NF-κB pathway, MAPK pathway, JAK/STAT pathway and RANKL/OPG pathway has unraveled its strategic checkpoints in controlling arthritic inflammation and tissue damage in AA. The pathological events that are targeted and rectified by celastrol include increased production of pro-inflammatory cytokines; an imbalance between pathogenic T helper 17 and regulatory T cells; enhanced production of chemokines coupled with increased migration of immune cells into the joints; and increased release of mediators of osteoclastic bone damage. Accordingly, celastrol is a promising candidate for further testing in the clinic for RA therapy. Furthermore, the results of other preclinical studies suggest that celastrol might also be beneficial for the treatment of a few other autoimmune diseases besides arthritis.

Is there a role of synovial biopsy in drug development?

Rheumatoid arthritis (RA) is an autoimmune disease which causes significant pain, joint deformity, functional disability. The pathological hallmark of RA is inflammation of the synovium characterized by involvement of inflammatory and resident stromal cells, soluble mediators and signalling pathways leading to irreversible joint destruction. The treatment goal in RA has evolved over the last decade towards a target of disease remission that is achieved in less than a third of patients in clinical trials. The lack of therapeutic response to current treatments is suggestive of alternative drivers of RA pathogenesis that might serve as promising therapeutic targets. There are data to justify the use of synovial tissue in early drug development. Synovial tissue represents an appropriate compartment to be studied in patients with inflammatory arthritis and provides information that is distinct from peripheral blood. Modern techniques have made the procedure much more accessible and ultrasound guided biopsies represent a safe and acceptable option. Advances in analytic technologies allowing transcriptomic level of analysis can provide unique inside to target organ/tissue following the exposure to investigational medicinal product. However, there are still caveats with regard to both the choice of technique and analytical methods. Therefore the significance of synovial biopsy remains to be determined in future clinical trials. The aim of the current debate is to explore the potential for accessing and evaluating synovial tissue in early drug development, to summarize lessons we have learned from clinical trials and to discuss the challenges that have arisen so far.

Decrease of CD68 Synovial Macrophages in Celastrol Treated Arthritic Rats

Background

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease characterized by cellular infiltration into the joints, hyperproliferation of synovial cells and bone damage. Available treatments for RA only induce remission in around 30% of the patients, have important adverse effects and its use is limited by their high cost. Therefore, compounds that can control arthritis, with an acceptable safety profile and low production costs are still an unmet need. We have shown, in vitro, that celastrol inhibits both IL-1β and TNF, which play an important role in RA, and, in vivo, that celastrol has significant anti-inflammatory properties. Our main goal in this work was to test the effect of celastrol in the number of sublining CD68 macrophages (a biomarker of therapeutic response for novel RA treatments) and on the overall synovial tissue cellularity and joint structure in the adjuvant-induced rat model of arthritis (AIA).

Methods

Celastrol was administered to AIA rats both in the early (4 days after disease induction) and late (11 days after disease induction) phases of arthritis development. The inflammatory score, ankle perimeter and body weight were evaluated during treatment period. Rats were sacrificed after 22 days of disease progression and blood, internal organs and paw samples were collected for toxicological blood parameters and serum proinflammatory cytokine quantification, as well as histopathological and immunohistochemical evaluation, respectively.

Results

Here we report that celastrol significantly decreases the number of sublining CD68 macrophages and the overall synovial inflammatory cellularity, and halted joint destruction without side effects.

Conclusions

Our results validate celastrol as a promising compound for the treatment of arthritis.

Prediction of Response to Therapy for Autoimmune/Inflammatory Diseases Using an Activated Macrophage-Targeted Radioimaging Agent

The ability to select patients who will respond to therapy is especially acute for autoimmune/inflammatory diseases, where the costs of therapies can be high and the progressive damage associated with ineffective treatments can be irreversible. In this article we describe a clinical test that will rapidly predict the response of patients with an autoimmune/inflammatory disease to many commonly employed therapies. This test involves quantitative assessment of uptake of a folate receptor-targeted radioimaging agent ((99m)Tc-EC20) by a subset of inflammatory macrophages that accumulate at sites of inflammation. Murine models of four representative inflammatory diseases (rheumatoid arthritis, inflammatory bowel disease, pulmonary fibrosis, and atherosclerosis) show markedly decreased uptake of (99m)Tc-EC20 in inflamed lesions upon initiation of successful therapies, but no decrease in uptake upon administration of ineffective therapies, in both cases long before changes in clinical symptoms can be detected. This predictive capability should reduce costs and minimize morbidities associated with failed autoimmune/inflammatory disease therapies.

Complex Primary Human Cell Systems for Drug Discovery

Phenotypic or biofunctional assays play an important role in drug discovery by helping to bridge the gap between high-throughput, target-based screening assays used for compound identification and more physiologically relevant in vivo disease models used for preclinical development. We have developed a standardised panel of phenotypic assays using primary human cells and co-cultures that model tissue and disease biology for characterization of drug leads. Here we show application of these assays for characterisation of clinical stage kinase inhibitors for rheumatoid arthritis, the recently approved JAK kinase inhibitor, tofacitinib, and the SYK kinase inhibitor, fostamatinib. We demonstrate how profiling in this assay panel can relate to clinical effects, both efficacy and safety related.

Methotrexate: an old new drug in autoimmune disease

Methotrexate (MTX) is currently considered, among disease-modifying anti-rheumatic drugs (DMARDs), the 'anchor-drug' in the treatment of rheumatoid arthritis. In the last 25 years, there has been a marked expansion in the use of MTX in different inflammatory diseases. Its low cost, associated to a good long-term efficacy and safety profile, justifies the use of MTX as a first-line disease-modifying drug or alternatively, a steroid-sparing medication in this field of medicine. Although new emerging options, including biological treatments, are being established in the therapeutic scenario, the good cost/benefit ratio of MTX supports the choice of this drug in combination with these newer therapies, enhancing the efficacy of these combination therapies and decreasing the risk of potential side effects.

Antiangiogenic effect of methotrexate and PUVA on psoriasis

Vascular endothelial growth factor (VEGF) is important factor for angiogenesis in psoriasis. Methotrexate and psoralen and ultraviolet light A (PUVA) mainly target the T cell-mediated immunopathology of psoriasis. Our work aimed at estimating VEGF mRNA in psoriatic patients and investigating whether the standard therapeutic modalities (methotrexate and PUVA) exert their antiangiogenic activity through altering VEGF levels. Twenty-four chronic plaque psoriasis patients were enrolled. Patients were divided into two groups (12 patients each); group A received intramuscular methotrexate and group B was treated by PUVA three times/week in a PUVA 1000 cabin for 10 weeks each. Twelve healthy volunteers served as controls. A skin biopsy was taken from lesional skin before and after treatment for RT-PCR detection of VEGF mRNA. Capillary perfusion scanning using LASER Doppler perfusion imaging was performed on the same psoriatic plaque before and after treatment and was also done for the controls. Following both methotrexate and PUVA, a significant reduction in the amount of VEGF mRNA (P < 0.001 and P = 0.002, respectively) and capillary perfusion (P = 0.002) occurred. These reductions were significantly higher in the methotrexate group (P < 0.001 and  P = 0.001, respectively) than in the PUVA group. The percentage of clinical improvement in the examined psoriatic plaque was significantly positively correlated with the percentage of reduction in the amount of VEGF mRNA (r = 0.850, P < 0.001) and the percentage of reduction in the capillary perfusion (r = 0.684, P < 0.001). Both modalities may exert an antiangiogenic effect. Methotrexate appears to have possibly a more potent antiangiogenic effect than PUVA.

Circulating CD4+CD161+ T lymphocytes are increased in seropositive arthralgia patients but decreased in patients with newly diagnosed rheumatoid arthritis

Improved understanding of the immune events discriminating between seropositive arthralgia and clinical synovitis is of key importance in rheumatology research. Ample evidence suggests a role for Th17 cells in rheumatoid arthritis. We hypothesized that CD4+CD161+ cells representing Th17 lineage cells may be modulated prior to or after development of clinical synovitis. Therefore, in a cross-sectional study, we investigated the occurrence of CD4+CD161+ T-cells in seropositive arthralgia patients who are at risk for developing rheumatoid arthritis and in newly diagnosed rheumatoid arthritis patients. In a prospective study, we evaluated the effect of methotrexate treatment on circulating CD4+CD161+ T-cells. Next, we assessed if these cells can be detected at the level of the RA joints. Precursor Th17 lineage cells bearing CD161 were found to be increased in seropositive arthralgia patients. In contrast, circulating CD4+CD161+T-cells were decreased in newly diagnosed rheumatoid arthritis patients. The decrease in CD4+CD161+ T-cells correlated inversely with C-reactive protein and with the 66 swollen joint count. Methotrexate treatment led to normalization of CD4+CD161+ T-cells and reduced disease activity. CD4+CD161+ T cells were readily detected in synovial tissues from both early and late-stage rheumatoid arthritis. In addition, synovial fluid from late-stage disease was found to be enriched for CD4+CD161+ T-cells. Notably, synovial fluid accumulated CD4+CD161+T-cells showed skewing towards the Th1 phenotype as evidenced by increased interferon-γ expression. The changes in peripheral numbers of CD4+CD161+ T-cells in seropositive arthralgia and early rheumatoid arthritis and the enrichment of these cells at the level of the joint predict a role for CD4+CD161+ T-cells in the early immune events leading to clinical synovitis. Our findings may add to the development of RA prediction models and provide opportunities for early intervention.

Impact of methotrexate on oxidative stress and apoptosis markers in psoriatic patients

Methotrexate (MTX), a cytotoxic chemotherapeutic agent, is considered an effective drug in the treatment of psoriasis. The aim of this study was to find out whether the effect of MTX treatment in psoriasis is due to oxidative stress-induced apoptosis. Psoriasis vulgaris patients (58 in number) were recruited for this study. Healthy volunteers (45 in number) served as control. Samples of psoriatic patients were collected and analyzed for total reactive oxygen species (ROS), malondialdehyde (MDA) levels, nitrite, nitrate levels and the activities of antioxidants like superoxide dismutase (SOD), catalase (CAT) and total antioxidant status (TAS) and also the protein expression of caspase-3, before (Day 0) and after (at the end of 6 and 12 weeks) MTX treatment. Our results show a significant increase in tissue ROS and plasma MDA after MTX treatment when compared with before MTX treatment in psoriasis patients (p < 0.001). The levels of serum nitrite and nitrate were decreased significantly after MTX treatment (p < 0.001). The activities of plasma SOD, TAS and serum CAT levels were decreased, but not significantly after 12 weeks of treatment. The expression of caspase-3 was increased after MTX treatment. In conclusion, MTX induce apoptosis through oxidative stress by reducing NO and increasing caspase-3 levels. MTX-induced apoptosis may account for the beneficial effect of MTX treatment in psoriasis patients, which is characterized by acanthosis.

Limited effect of anti-rheumatic treatment on 15-prostaglandin dehydrogenase in rheumatoid arthritis synovial tissue

Introduction

Rheumatoid arthritis (RA) is a chronic inflammatory disease in which prostaglandin E₂ (PGE₂) displays an important pathogenic role. The enzymes involved in its synthesis are highly expressed in the inflamed synovium, while little is known about 15- prostaglandin dehydrogenase (15-PGDH) that metabolizes PGE₂. Here we aimed to evaluate the localization of 15-PGDH in the synovial tissue of healthy individuals or patients with inflammatory arthritis and determine the influence of common RA therapy on its expression.

Methods

Synovial tissue specimens from healthy individuals, psoriatic arthritis, ostheoarthritis and RA patients were immunohistochemically stained to describe the expression pattern of 15-PGDH. In addition, the degree of enzyme staining was evaluated by computer analysis on stained synovial biopsies from two groups of RA patients, before and after RA specific treatment with either intra-articular glucocorticoids or oral methotrexate therapy. Prostaglandins derived from the cyclooxygenase (COX) pathway were determined by liquid-chromatography mass spectrometry in supernatants from interleukin (IL) 1β-activated fibroblast-like synoviocytes (FLS) treated with methotrexate.

Results

15-PGDH was present in healthy and inflamed synovial tissue, mainly in lining macrophages, fibroblasts and vessels. Intra-articular glucocorticoids showed a trend towards reduced 15-PGDH expression in RA synovium (p = 0.08) while methotrexate treatment left the PGE₂ pathway unaltered both in biopsies ex vivo and in cultured FLS.

Conclusions

Early methotrexate therapy has little influence on the expression of 15-PGDH and on any of the PGE₂ synthesizing enzymes or COX-derived metabolites. Thus therapeutic strategies involving blocking induced PGE₂ synthesis may find a rationale in additionally reducing local inflammatory mediators.

Synovial tissue response to treatment in rheumatoid arthritis

The recognition of the synovial tissue, as the primary target of inflammation in RA, has driven research in this field, not only to clarify the disease pathogenesis but also to evaluate local changes in response to treatment. Special interest has been given to the identification of sensitive synovial biomarkers that could be of help in demonstrating proof of principle in early stages of drug development. Synovial sublining macrophages have been shown to correlate with scores for disease activity in cross-sectional studies. Moreover, decreased disease activity as measured by the disease activity score evaluated in 28 joints (DAS28) after effective treatment, has consistently been associated with a reduction of the number of CD68+ synovial sublining macrophages across different therapies. This observation highlights a possible final common pathway in the mechanism of action of various therapies and supports the notion that macrophages have a central role in RA pathogenesis.

When considering experimental therapies, the study of serial synovial biopsies in relatively small numbers of patients, in the context of proof of principle trials, successfully distinguished between effective and ineffective treatments. This attractive approach can be used during early drug development for screening proposes, supporting which new treatments have higher probability to be beneficial in a large scale clinical trial.

In this paper we review the effects of RA treatments on the synovial tissue, including targeted therapies, with particular attention to their effect on synovial biomarkers.

Effect of methotrexate on inflammatory cells redistribution in experimental adjuvant arthritis

The aim of this study was to evaluate the morphological changes in the spleen, the thymus and the knee joints of rats with experimental adjuvant arthritis induced by Mycobacterium butyricum in the incomplete Freund's adjuvant and the effect of treatment with methotrexate (MTX). Particular attention was aimed on the redistribution of granulocytes in the tissues during the inflammatory process. Clinical parameters, e.g., joint edema, body weight and of gamma glutamyl transferase (GGT) activity as an inflammatory marker, have also been determined. Induction of adjuvant arthritis caused a significant decrease in granulocyte number in the spleen and vice versa a significant increase in the knee joints, but without significant changes in the thymus. Treatment with methotrexate reversed this phenomenon by increasing the granulocyte number in the spleen and decreasing it in knee joints. MTX decreased the joint edema as well as the activity of GGT in the spleen, modified the size of the white pulp of the spleen and increased the cortex/medulla ratio in the thymus. The observed changes support the anti-inflammatory and immunomodulatory properties of MTX supporting its use as the first-line medication in patients with rheumatoid arthritis.

A personalized medicine approach to biologic treatment of rheumatoid arthritis: a preliminary treatment algorithm

RA is a syndrome consisting of different pathogenetic subsets in which distinct molecular mechanisms may drive common final pathways. Recent work has provided proof of principle that biomarkers may be identified predictive of the response to targeted therapy. Based on new insights, an initial treatment algorithm is presented that may be used to guide treatment decisions in patients who have failed one TNF inhibitor. Key questions in this algorithm relate to the question whether the patient is a primary vs a secondary non-responder to TNF blockade and whether the patient is RF and/or anti-citrullinated peptide antibody positive. This preliminary algorithm may contribute to more cost-effective treatment of RA, and provides the basis for more extensive algorithms when additional data become available.

Low dosages: new chemotherapeutic weapons on the battlefield of immune-related disease

Chemotherapeutic drugs eliminate tumor cells at relatively high doses and are considered weapons against tumors in clinics and hospitals. However, despite their ability to induce cellular apoptosis, chemotherapeutic drugs should probably be regarded more as a class of cell regulators than cell killers, if the dosage used and the fact that their targets are involved in basic molecular events are considered. Unfortunately, the regulatory properties of chemotherapeutic drugs are usually hidden or masked by the massive cell death induced by high doses. Recent evidence has begun to suggest that low dosages of chemotherapeutic drugs might profoundly regulate various intracellular aspects of normal cells, especially immune cells. Here, we discuss the immune regulatory roles of three kinds of chemotherapeutic drugs under low-dose conditions and propose low dosages as potential new chemotherapeutic weapons on the battlefield of immune-related disease.

Methotrexate--how does it really work?

Methotrexate remains a cornerstone in the treatment of rheumatoid arthritis and other rheumatic diseases. Folate antagonism is known to contribute to the antiproliferative effects that are important in the action of methotrexate against malignant diseases, but concomitant administration of folic or folinic acid does not diminish the anti-inflammatory potential of this agent, which suggests that other mechanisms of action might be operative. Although no single mechanism is sufficient to account for all the anti-inflammatory activities of methotrexate, the release of adenosine from cells has been demonstrated both in vitro and in vivo. Methotrexate might also confer anti-inflammatory properties through the inhibition of polyamines. The biological effects on inflammation associated with adenosine release have provided insight into how methotrexate exerts its effects against inflammatory diseases and at the same time causes some of its well-known adverse effects. These activities contribute to the complex and multifaceted mechanisms that make methotrexate efficacious in the treatment of inflammatory disorders.

Effects of methotrexate on plasma cytokines and cardiac remodeling and function in postmyocarditis rats

Excessive immune activation and inflammatory mediators may play a critical role in the pathogenesis of chronic heart failure. Methotrexate is a commonly used anti-inflammatory and immunosuppressive drug. In this study, we used a rat model of cardiac myosin-induced experimental autoimmune myocarditis to investigate the effects of low-dose methotrexate (0.1 mg/kg/d for 30 d) on the plasma level of cytokines and cardiac remodeling and function. Our study showed that levels of tumor necrosis factor-(TNF-)alpha and interleukin-6 (IL-6) are significantly increased in postmyocarditis rats, compared with the control rats. Methotrexate treatment reduced the plasma levels of TNF-alpha and IL-6 and increased IL-10 level, compared to saline treatment. In addition, postmyocarditis rats showed significant cardiac fibrosis characterized by increased myocardial collagen volume fraction, perivascular collagen area, and the ratio of collagen type I to type III, compared with the control rats. However, MTX treatment not only markedly attenuated cardiac fibrosis, diminished the left ventricular end-diastolic dimension, but also increased the left ventricular ejection fraction and fractional shortening. Collectively, these results suggest that low-dose methotrexate has ability to regulate inflammatory responses and improves cardiac function and hence contributes to prevent the development of postmyocarditis dilated cardiomyopathy.

Evaluation of arthroscopy and macroscopic scoring

INTRODUCTION

Arthroscopy is a minimally invasive technique for retrieving synovial biopsies in rheumatology during the past 20 years. Vital for its use is continual evaluation of its safety and efficacy. Important for sampling is the fact of intraarticular variation for synovial markers. For microscopic measurements scoring systems have been developed and validated, but for macroscopic evaluations there is a need for further comprehensive description and validation of equivalent scoring systems.

METHODS

We studied the complication rate and yield of arthroscopies performed at our clinic between 1998 and 2005. We also created and evaluated a macroscopic score set of instructions for synovitis.

RESULTS

Of 408 procedures, we had two major and one minor complication; two haemarthrosis and one wound infection, respectively. Pain was most often not a problem, but 12 procedures had to be prematurely ended due to pain. Yield of biopsies adequate for histology were 83% over all, 94% for knee joints and 34% for smaller joints. Video printer photographs of synovium taken during arthroscopy were jointly and individually reviewed by seven raters in several settings, and intra and inter rater variation was calculated. A macroscopic synovial scoring system for arthroscopy was created (Macro-score), based upon hypertrophy, vascularity and global synovitis. These written instructions were evaluated by five control-raters, and when evaluated individual parameters were without greater intra or inter rater variability, indicating that the score is reliable and easy to use.

CONCLUSIONS

In our hands rheumatologic arthroscopy is a safe method with very few complications. For knee joints it is a reliable method to retrieve representative tissue in clinical longitudinal studies. We also created an easy to use macroscopic score, that needs to be validated against other methodologies. We hope it will be of value in further developing international standards in this area.

Association of methotrexate and tumour necrosis factor antagonists with risk of infectious outcomes including opportunistic infections in the CORRONA registry

OBJECTIVE

To examine the association of methotrexate (MTX) and tumour necrosis factor (TNF) antagonists with the risk of infectious outcomes including opportunistic infections in patients with rheumatoid arthritis (RA).

METHODS

Patients with RA enrolled in the Consortium of Rheumatology Researchers of North America (CORRONA) registry prescribed MTX, TNF antagonists or other disease-modifying antirheumatic drugs (DMARDs) were included. The primary outcomes were incident overall and opportunistic infections. Incident rate ratios were calculated using generalised estimating equation Poisson regression models adjusted for demographics, comorbidities and RA disease activity measures.

RESULTS

A total of 7971 patients with RA were followed. The adjusted rate of infections per 100 person-years was increased among users of MTX (30.9, 95% CI 29.2 to 32.7), TNF antagonists (40.1, 95% CI 37.0 to 43.4) and a combination of MTX and TNF antagonists (37.1, 95% CI 34.9 to 39.3) compared with users of other non-biological DMARDs (24.5, 95% CI 21.8 to 27.5). The adjusted incidence rate ratio (IRR) was increased in patients treated with MTX (IRR 1.30, 95% CI 1.12 to 1.50) and TNF antagonists (IRR 1.52, 95% CI 1.30 to 1.78) compared with those treated with other DMARDs. TNF antagonist use was associated with an increased risk of opportunistic infections (IRR 1.67, 95% CI 0.95 to 2.94). Prednisone use was associated with an increased risk of opportunistic infections (IRR 1.63, 95% CI 1.20 to 2.21) and an increased risk of overall infection at doses >10 mg daily (IRR 1.30, 95% CI 1.11 to 1.53).

CONCLUSIONS

MTX, TNF antagonists and prednisone at doses >10 mg daily were associated with increased risks of overall infections. Low-dose prednisone and TNF antagonists (but not MTX) increased the risk of opportunistic infections.

Immunohistochemistry of the inflamed synovium

The development in the techniques for obtaining synovial tissue biopsy, especially through arthroscopy, have resulted in greater access to high-quality synovial tissue. The use of immunohistochemistry in arthritis research has greatly furthered our understanding of the varied immunological and biochemical pathways involved in inflammatory arthropathopies such as rheumatoid and psoriatic arthritis. Immunohistochemistry provides a strikingly visual narrative of the essential elements involved in inflammatory arthritis, from the infiltrating inflammatory cells (e.g., T-cells, macrophages, B-cells, and neutrophils), their products (e.g., cytokines, metalloproteinases) and their varied receptor molecules. This chapter describes the standard three-stage immunoperoxidase technique used in our laboratory and widely in the literature. Some problems that may be encountered and how they may be overcome are commented on. Also described is a method for dual-labeled immunofluoresence staining.

Microscopic measurement of inflammation in synovial tissue: inter-observer agreement for manual quantitative, semiquantitative and computerised digital image analysis

OBJECTIVES

To evaluate inter-observer agreement for microscopic measurement of inflammation in synovial tissue using manual quantitative, semiquantitative and computerised digital image analysis.

METHODS

Paired serial sections of synovial tissue, obtained at arthroscopic biopsy of the knee from patients with rheumatoid arthritis (RA), were stained immunohistochemically for T lymphocyte (CD3) and macrophage (CD68) markers. Manual quantitative and semiquantitative scores for sub-lining layer CD3+ and CD68+ cell infiltration were independently derived in 6 international centres. Three centres derived scores using computerised digital image analysis. Inter-observer agreement was evaluated using Spearman's Rho and intraclass correlation coefficients (ICCs).

RESULTS

Paired tissue sections from 12 patients were selected for evaluation. Satisfactory inter-observer agreement was demonstrated for all 3 methods of analysis. Using manual methods, ICCs for measurement of CD3+ and CD68+ cell infiltration were 0.73 and 0.73 for quantitative analysis and 0.83 and 0.78 for semiquantitative analysis, respectively. Corresponding ICCs of 0.79 and 0.58 were observed for the use of digital image analysis. All ICCs were significant at levels of p<0.0001. At each participating centre, use of computerised image analysis produced results that correlated strongly and significantly with those obtained using manual measurement.

CONCLUSION

Strong inter-observer agreement was demonstrated for microscopic measurement of synovial inflammation in RA using manual quantitative, semiquantitative and computerised digital methods of analysis. This further supports the development of these methods as outcome measures in RA.

Methotrexate regulates the expression of glucocorticoid receptor alpha and beta isoforms in normal human peripheral mononuclear cells and human lymphocyte cell lines in vitro

MTX is an effective therapy for autoimmune-inflammatory diseases. The mechanisms that mediate these actions are not completely clear. It is accepted that many of these effects are mediated through the release of adenosine with the activation of the adenosine receptor A2. MTX is used as a steroid sparing agent. An improved in vitro GC cell sensitivity in GC insensitive asthma patients has been demonstrated after MTX treatment. Most GC actions are mediated by the GCR. The effect of MTX on GCRs expression has not been previously evaluated. Therefore, we evaluate if MTX regulates the expression of glucocorticoid receptors, increasing the expression of the active receptor (GCR alpha) and/or decreasing the expression of the dominant negative receptor (GCR beta). We show that MTX increases the mRNA and protein levels of GCR alpha and decreases or leaves unchanged the protein expression of the GCR beta in CEM cells in culture. This effect was also observed in other lymphocytes (Jurkat and Raji) and in PBMNC from healthy volunteers. We also show that upon MTX treatment PBMC from normal volunteers exhibit a higher sensitivity to DEX inhibition on LPS-induced TNF alpha release. To explore if these actions are mediated by adenosine through the adenosine receptor A2 we evaluate the effect of adenosine on the GCRs expression and the effect of an A2 receptor blocker (DMPX) on MTX effects on GCRs expression. Our results show that adenosine does not mimic and DMPX can enhance MTX effects on these receptors. We conclude that MTX increases the GCR alpha/GCR beta ratio of expression in lymphocytes which could mediate its previously reported effects in improving cell glucocorticoid sensitivity. These actions are not mediated by the adenosine receptor A2.

The effect of methotrexate (MTX) on expression of signalling lymphocytic activation molecule (SLAM) in patients with rheumatoid arthritis (RA) and its role in the regulation of cytokine production

OBJECTIVE

To investigate the effect of methotrexate (MTX) on cytokine production by activated CD4+ T-cells in patients with rheumatoid arthritis (RA).

METHODS

The effect of MTX on intracellular expression of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), and cell surface expression of signalling lymphocytic activation molecule (SLAM) from freshly isolated peripheral blood mononuclear cells (PBMCs), and after in vitro culture with or without MTX, was analysed with flow cytometry in 18 patients with RA and 20 healthy controls.

RESULTS

Intracellular expression of IFN-gamma and IL-4 on freshly isolated CD4+ T-cells was significantly higher in patients with RA than in the controls (p<0.05). Intracellular expression of both IFN-gamma and IL-4 after culture with MTX was significantly lower than those after culture without MTX in patients with RA. Although no significant difference was observed in SLAM expression on freshly isolated CD4+ T-cells between patients with RA and the controls, MTX significantly decreased SLAM expression on both activated IFN-gamma+ and IL-4+CD4+ T-cells in patients with RA.

CONCLUSION

In vitro modulation of the cytokine network by MTX, IFN-gamma, and IL-4 is one of the major targets for MTX, and production of IFN-gamma and IL-4 by PBMCs may be suppressed by SLAM on activated CD4+ T-cell in patients with RA.

Long term NSAID treatment inhibits COX-2 synthesis in the knee synovial membrane of patients with osteoarthritis: differential proinflammatory cytokine profile between celecoxib and aceclofenac

OBJECTIVE

To compare the effect of celecoxib with that of a classic non-steroidal anti-inflammatory drug (NSAID) on synovial inflammation and on the synovial expression of proinflammatory genes in patients with knee osteoarthritis (OA).

METHODS

30 patients with severe knee OA scheduled for total knee replacement surgery were included in a 3 month clinical trial. They were randomised to two groups: patients treated with celecoxib (CBX) (200 mg/24 h) and patients treated with aceclofenac (ACF) (100 mg/12 h). Those patients with OA who did not want to be treated with NSAIDs served as a control group. During knee surgery, synovial fluid (SF) and synovial membrane (SM) were collected. A SM specimen was fixed and embedded in paraffin and another part was frozen for molecular biology studies.

RESULTS

At the end of study both CBX and ACF treated patients showed a significant improvement in pain and knee function compared with controls. Both drugs significantly reduced prostaglandin E(2) (PGE(2)) SF concentration and down regulated COX-2 mRNA and protein expression at the SM. However, synovial macrophage infiltration (CD68 antigen staining) and expression of proinflammatory mediators, such as interleukin 1beta and tumour necrosis factor alpha, were decreased only by CBX treatment.

CONCLUSION

Both drugs improved joint pain and function, inhibited SF PGE(2) concentration, and induced a decrease in synovial COX-2 expression and synthesis not related to the tissue inflammatory status. These data suggest that PGE(2) blocking agents may decrease PGE(2) production not only by direct COX-2 inhibition but also by down regulating COX-2 expression and synthesis. However, CBX and ACF appear to have different anti-inflammatory profiles in controlling OA synovial macrophage infiltration and proinflammatory expression.

Synovial inflammation does not change in the absence of effective treatment: implications for the use of synovial histopathology as biomarker in early phase clinical trials in rheumatoid arthritis

OBJECTIVES

To determine the impact on synovial histopathology of changes in clinical disease activity in the absence of effective treatment.

METHODS

Twelve patients with active RA not receiving effective treatment were studied over a 14 week period. Synovial biopsy specimens obtained at baseline and week 14 were analysed by histology and immunohistochemistry.

RESULTS

Over the course of 14 weeks, there was a trend towards a decrease of the DAS28, with 7/12 patients being good or moderate DAS28 responders despite the absence of effective treatment. Patients' assessment of global disease activity and swollen joint count both decreased significantly. Histologically, there was a decrease of lining layer hyperplasia and lymphoid aggregates, a similar trend for vascularity, but there was no effect on global synovial infiltration. Accordingly, there was no decrease of the cellular infiltration with T lymphocytes (CD3, CD4, CD8), B lymphocytes (CD20), plasma cells (CD38), dendritic cells (CD1a, CD83), and even an increase of CD163+ sublining macrophages, with a similar trend for CD68+ sublining macrophages. The changes in DAS28 scores in these patients did not correlate with changes in histological variables, with the exception of an inverse correlation with plasma cells. Remarkably, even in the DAS28 responders, no significant changes in synovial inflammatory infiltration were noted.

CONCLUSIONS

Despite variations in global disease activity, synovial inflammatory infiltration did not change significantly in the absence of effective treatment. The lack of a placebo effect on synovial markers of treatment response such as sublining macrophages can facilitate conclusive early phase trials with small numbers of patients with RA.