Methotrexate modulates the kinetics of adenosine in humans in vivo

The Role of Adenosine in Overcoming Resistance in Sarcomas

Resistance to systemic therapies in sarcomas poses a significant challenge to improving clinical outcomes. Recent research has concentrated on the tumor microenvironment's role in sarcoma progression and treatment resistance. This microenvironment comprises a variety of cell types and signaling molecules that influence tumor behavior, including proliferation, metastasis, and resistance to therapy. Adenosine, abundant in the tumor microenvironment, has been implicated in promoting immunosuppression and chemoresistance. Targeting adenosine receptors and associated pathways offers a novel approach to enhancing immune responses against tumors, potentially improving immunotherapy outcomes in cancers, including sarcomas. Manipulating adenosine signaling also shows promise in overcoming chemotherapy resistance in these tumors. Clinical trials investigating adenosine receptor antagonists in sarcomas have fueled interest in this pathway for sarcoma treatment. Ultimately, a comprehensive understanding of the tumor and vascular microenvironments, as well as the adenosine pathway, may open new avenues for improving treatment outcomes and overcoming resistance in sarcoma. Further studies and clinical trials are crucial to validate these findings and optimize therapeutic strategies, particularly for osteosarcoma. This study provides a literature review exploring the potential role of the adenosine pathway in sarcomas.

Combination of Methotrexate and Resveratrol Reduces Pro-Inflammatory Chemokines in Human THP-1 Cells

Introduction

Methotrexate (MTX) is a widely used anti-metabolite drug in cancer therapy, but its efficacy is often hindered by reactive oxygen species (ROS)-induced cellular toxicity. Resveratrol, a natural polyphenol, possesses antioxidant and anticancer properties. Therefore, this in vitro study aimed to investigate the synergistic anti-proliferative and anti-inflammatory effects of MTX and resveratrol in human THP-1 cells.

Methods

THP-1 cells were differentiated into macrophage-like cells using phorbol 12-myristate 13-acetate. In vitro experiments assessed the impact of various concentrations of MTX and resveratrol on cell viability and proliferation using the MTT assay. Concentration-effect curves were generated to elucidate their relationship. Gene expression was analyzed by RT-qPCR, while chemokine expression was measured via ELISA. Phagocytic and migratory activities were also evaluated.

Results

Differentiated THP-1 cells were treated with MTX and resveratrol and stimulated with dimethyl sulfoxide (DMSO) and lipopolysaccharide (LPS) as inflammatory stimuli. The combination of MTX and resveratrol exhibited an anti-proliferative effect in THP-1 cells (p = 0.03). The concentration-effect curve revealed IC50 values of 49.15 µg at 24 hours (R = 0.8236) and 2.029e-005 µg at 48 hours (R = 0.97) for MTX, and 20.17 µg at 48 hours (R = 1.000) and 55.38 µg at 96 hours (R = 0.9666) for resveratrol. Co-treatment with MTX and resveratrol significantly reduced mRNA and chemokine expression of CCL2, CCL3, CCL4, CCL5, and CXCL10 (p < 0.05). Moreover, decreased phagocytic and migratory activities were confirmed by phagocytosis and migration assays (p < 0.05).

Conclusion

The combination of MTX and resveratrol effectively attenuated pro-inflammatory activity in THP-1 cells, as evidenced by the downregulation of mRNA and chemokine expression. These findings suggest that the synergistic effects of MTX and resveratrol hold promise for enhancing cancer therapeutics.

Systematic review and network meta-analysis on the efficacy and safety of parmacotherapy for hand osteoarthritis

OBJECTIVE

Hand osteoarthritis poses a significant health challenge globally due to its increasing prevalence and the substantial burden on individuals and the society. In current clinical practice, treatment options for hand osteoarthritis encompass a range of approaches, including biological agents, antimetabolic drugs, neuromuscular blockers, anti-inflammatory drugs, hormone medications, pain relievers, new synergistic drugs, and other medications. Despite the diverse array of treatments, determining the optimal regimen remains elusive. This study seeks to conduct a network meta-analysis to assess the effectiveness and safety of various drug intervention measures in the treatment of hand osteoarthritis. The findings aim to provide evidence-based support for the clinical management of hand osteoarthritis.

METHODS

We performed a comprehensive search across PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials was conducted until September 15th, 2022, to identify relevant randomized controlled trials. After meticulous screening and data extraction, the Cochrane Handbook's risk of bias assessment tool was applied to evaluate study quality. Data synthesis was carried out using Stata 15.1 software.

RESULTS

21 studies with data for 3965 patients were meta-analyzed, involving 20 distinct Western medicine agents. GCSB-5, a specific herbal complex that mainly regulate pain in hand osteoarthritis, showed the greatest reduction in pain [WMD = -13.00, 95% CI (-26.69, 0.69)]. CRx-102, s specific medication characterized by its significant effect for relieving joint stiffness symptoms, remarkably mitigated stiffness [WMD = -7.50, 95% CI (-8.90, -6.10)]. Chondroitin sulfate displayed the highest incidence of adverse events [RR = 0.26, 95% CI (0.06, 1.22)]. No substantial variation in functional index for hand osteoarthritis score improvement was identified between distinct agents and placebo.

CONCLUSIONS

In summary, GCSB-5 and CRx-102 exhibit efficacy in alleviating pain and stiffness in HOA, respectively. However, cautious interpretation of the results is advised. Tailored treatment decisions based on individual contexts are imperative.

Partial Reversal of Anosmia Following Platinum-Based Chemotherapy in a Patient With Colorectal Adenocarcinoma

Platinum-based chemotherapy is known to cause taste and smell changes (TSCs) via a host of mechanisms, including altered receptor activity, saliva/mucus production, and induction of receptor destruction via mitotic inhibition. In the literature to date, these changes have primarily resulted in worsening of taste and smell. In this case report, we document the first instance of an individual regaining their sense of olfactory detection following treatment with oxaliplatin for colorectal adenocarcinoma. We theorize that the improvement in his sense of smell may have resulted from oxaliplatin-induced destruction of his nasal polyps through the caspase-9/procaspase-9 apoptotic pathway, a pathway shared with other mechanisms of nasal polyp destruction. These findings were supported by nasal endoscopy and sphenoid sinusoscopy, which demonstrated no clinical persistence of nasal polyps, in contrast to nasal endoscopy prior to chemotherapy which demonstrated persistent nasal polyposis. Objective smell testing post-treatment revealed a diminished ability to discriminate odors. Chemotherapy-induced TSCs play a key role in poor weight gain, food aversion, emotional distress, and an overall decrease in quality of life, and patients should be informed of these potential consequences prior to starting treatment. However, in patients with anosmia secondary to nasal polyposis, treatment with platinum-based chemotherapy may provide an additional therapeutic benefit. Further studies may help elucidate the potential therapeutic benefits of these agents in managing steroid-resistant polyposis for patients suffering from olfactory dysfunction.

Role of topical and systemic immunosuppression in aqueous-deficient dry eye disease

Immunosuppression in aqueous-deficient dry eye disease (ADDE) is required not only to improve the symptoms and signs but also to prevent further progression of the disease and its sight-threatening sequelae. This immunomodulation can be achieved through topical and/or systemic medications, and the choice of one drug over the other is determined by the underlying systemic disease. These immunosuppressive agents require a minimum of 6-8 weeks to achieve their beneficial effect, and during this time, the patient is usually placed on topical corticosteroids. Antimetabolites such as methotrexate, azathioprine, and mycophenolate mofetil, along with calcineurin inhibitors, are commonly used as first-line medications. The latter have a pivotal role in immunomodulation since T cells contribute significantly to the pathogenesis of ocular surface inflammation in dry eye disease. Alkylating agents are largely limited to controlling acute exacerbations with pulse doses of cyclophosphamide. Biologic agents, such as rituximab, are particularly useful in patients with refractory disease. Each group of drugs has its own side-effect profiles and requires a stringent monitoring schedule that must be followed to prevent systemic morbidity. A customized combination of topical and systemic medications is usually required to achieve adequate control, and this review aims to help the clinician choose the most appropriate modality and monitoring regimen for a given case of ADDE.

The Clinical Significance of Salusins in Systemic Sclerosis-A Cross-Sectional Study

Background: Systemic sclerosis (SSc) is a connective tissue disease manifesting with progressive fibrosis of the skin and internal organs. Its pathogenesis is strictly associated with vascular disfunction and damage. Salusin-α and salusin-β, endogenous peptides regulating secretion of pro-inflammatory cytokines and vascular smooth muscle proliferation, may potentially play a role in SSc pathogenesis. Objectives: The aim of this study was to assess the concentration of salusins in sera of patients with SSc and healthy controls and to evaluate correlations between the salusins levels and selected clinical parameters within the study group. Materials and methods: 48 patients with SSc (44 women; mean age, 56.4, standard deviation, 11.4) and 25 adult healthy volunteers (25 women; mean age, 55.2, standard deviation, 11.2) were enrolled. All patients with SSc were treated with vasodilators and twenty-seven of them (56%) also received immunosuppressive therapy. Results: Circulating salusin-α was significantly elevated in patients with SSc in comparison to healthy controls (U = 350.5, p = 0.004). Patients with SSc receiving immunosuppression had higher serum salusin-α concentrations compared with those without immunosuppressive therapy (U = 176.0, p = 0.026). No correlation was observed between salusins concentrations and skin or internal organ involvement parameters. Conclusions: Salusin-α, a bioactive peptide mitigating the endothelial disfunction, was elevated in patients with systemic sclerosis receiving vasodilators and immunosuppressants. Increased salusin-α concertation may be associated with the initiation of atheroprotective processes in patients with SSc managed pharmacologically, which requires verification in future studies.

Comorbidities of sarcoidosis

Sarcoidosis is a heterogeneous disease, which can affect virtually every body organ, even though lungs and intra thoracic lymph nodes are almost universally affected. The presence of noncaseating granulomas is the histopathological hallmark of the disease, and clinical picture depends on the organs affected. Data about interaction between sarcoidosis and comorbidities, such as cardiovascular and pulmonary diseases, autoimmune disorders, malignancy and drug-related adverse events are limited. Several lung conditions can be associated with sarcoidosis, such as pulmonary hypertension and fibrosis, making it difficult sometimes the differentiation between complications and distinctive pathologies. Their coexistence may complicate the diagnosis of sarcoidosis and contribute to the highly variable and unpredictable natural history, particularly if several diseases are recognised. A thorough assessment of specific disorders that can be associated with sarcoidosis should always be carried out, and future studies will need to evaluate sarcoidosis not only as a single disorder, but also in the light of possible concomitant conditions.Key messagesComorbidities in sarcoidosis are common, especially cardiovascular and pulmonary diseases.In the diagnostic workup, a distinction must be made between sarcoidosis-related complaints and complaints caused by other separate disorders. It can be very difficult to distinguish between complications of sarcoidosis and other concomitant conditions.The coexistence of multiple conditions may complicate the diagnosis of sarcoidosis, affect its natural course and response to treatment.

Methotrexate Inhibits T Cell Proliferation but Not Inflammatory Cytokine Expression to Modulate Immunity in People Living With HIV

Inflammation associated with increased risk of comorbidities persists in people living with HIV (PWH) on combination antiretroviral therapy (ART). A recent placebo-controlled trial of low-dose methotrexate (MTX) in PWH found that numbers of total CD4 and CD8 T cells decreased in the low-dose MTX arm. In this report we analyzed T cell phenotypes and additional plasma inflammatory indices in samples from the trial. We found that cycling (Ki67+) T cells lacking Bcl-2 were reduced by MTX but plasma inflammatory cytokines were largely unaffected. In a series of in vitro experiments to further investigate the mechanisms of MTX activity, we found that MTX did not inhibit effector cytokine production but inhibited T cell proliferation downstream of mTOR activation, mitochondrial function, and cell cycle entry. This inhibitory effect was reversible with folinic acid, suggesting low-dose MTX exerts anti-inflammatory effects in vivo in PWH largely by blocking T cell proliferation via dihydrofolate reductase inhibition, yet daily administration of folic acid did not rescue this effect in trial participants. Our findings identify the main mechanism of action of this widely used anti-inflammatory medicine in PWH and may provide insight into how MTX works in the setting of other inflammatory conditions.

Adenosine: a partially discovered medicinal agent

Background

A plethora of chemicals exists in human body which can alter physiology in one way or other. Scientists have always been astounded by such abilities of chemicals but as the technology advances, even the chemical which was once expected to be well known changes its status to not really well known. Adenosine is one of the chemicals which is in consonance with the aforementioned statements, although previous articles have covered vast information on role of adenosine in cardiovascular physiology, bacterial pathophysiology and inflammatory diseases. In this review we have discussed adenosine and its congeners as potential promising agents in the treatment of Huntington’s disease, post-traumatic stress disorder, erectile dysfunction, viral infections (SARS-CoV) and anxiety.

Main text

Adenosine is a unique metabolite of ATP; which serves in signalling as well. It is made up of adenine (a nitrogenous base) and ribo-furanose (pentose) sugar linked by β-N9-glycosidic bond. Adenosine on two successive phosphorylation forms ATP (Adenosine Triphosphate) which is involved in several active processes of cell. It is also one of the building blocks (nucleotides) involved in DNA (Deoxy-ribonucleic Acid) and RNA (Ribonucleic Acid) synthesis. It is also a component of an enzyme called S-adenosyl-L-methionine (SAM) and cyano-cobalamin (vitamin B-12). Adenosine acts by binding to G protein-coupled receptor (GPCR: A1, A2A, A2B and A3) carries out various responses some of which are anti-platelet function, hyperaemic response, bone remodelling, involvement in penile erection and suppression of inflammation. On the other hand, certain microorganisms belonging to genus Candida, Staphylococcus and Bacillus utilize adenosine in order to escape host immune response (phagocytic clearance). These microbes evade host immune response by synthesizing and releasing adenosine (with the help of an enzyme: adenosine synthase-A), at the site of infection.

Conclusion

With the recent advancement in attribution of adenosine in physiology and pathological states, adenosine and its congeners are being looked forward to bringing a revolution in treatment of inflammation, viral infections, psychiatric and neurodegenerative disorders.

CD38 in the age of COVID-19: a medical perspective

This medical review addresses the hypothesis that CD38/NADase is at the center of a functional axis (i.e., intracellular Ca2+ mobilization/IFNγ response/reactive oxygen species burst) driven by severe acute respiratory syndrome coronavirus 2 infection, as already verified in respiratory syncytial virus pathology and CD38 activity in other cellular settings. Key features of the hypothesis are that 1) the substrates of CD38 (e.g., NAD+ and NADP+) are depleted by viral-induced metabolic changes; 2) the products of the enzymatic activity of CD38 [e.g., cyclic adenosine diphosphate-ribose (ADPR)/ADPR/nicotinic acid adenine dinucleotide phosphate] and related enzymes [e.g., poly(ADP-ribose)polymerase, Sirtuins, and ADP-ribosyl hydrolase] are involved in the anti‐viral and proinflammatory response that favors the onset of lung immunopathology (e.g., cytokine storm and organ fibrosis); and 3) the pathological changes induced by this kinetic mechanism may be reduced by distinct modulators of the CD38/NAD+ axis (e.g., CD38 blockers, NAD+ suppliers, among others). This view is supported by arrays of associative basic and applied research data that are herein discussed and integrated with conclusions reported by others in the field of inflammatory, immune, tumor, and viral diseases.

CD38 in the age of COVID-19: a medical perspective

This medical review addresses the hypothesis that CD38/NADase is at the center of a functional axis (i.e., intracellular Ca²⁺ mobilization/IFNγ response/reactive oxygen species burst) driven by severe acute respiratory syndrome coronavirus 2 infection, as already verified in respiratory syncytial virus pathology and CD38 activity in other cellular settings. Key features of the hypothesis are that 1) the substrates of CD38 (e.g., NAD⁺ and NADP⁺) are depleted by viral-induced metabolic changes; 2) the products of the enzymatic activity of CD38 [e.g., cyclic adenosine diphosphate-ribose (ADPR)/ADPR/nicotinic acid adenine dinucleotide phosphate] and related enzymes [e.g., poly(ADP-ribose)polymerase, Sirtuins, and ADP-ribosyl hydrolase] are involved in the anti‐viral and proinflammatory response that favors the onset of lung immunopathology (e.g., cytokine storm and organ fibrosis); and 3) the pathological changes induced by this kinetic mechanism may be reduced by distinct modulators of the CD38/NAD⁺ axis (e.g., CD38 blockers, NAD⁺ suppliers, among others). This view is supported by arrays of associative basic and applied research data that are herein discussed and integrated with conclusions reported by others in the field of inflammatory, immune, tumor, and viral diseases.

Polymorphism of genes involved in methotrexate pathway: Predictors of response to methotrexate therapy in Indian rheumatoid arthritis patients

INTRODUCTION

The adenosine pathway is one of the ways through which methotrexate (MTX) ameliorates inflammation. We therefore explored an association of polymorphism of genes involved in adenosine and MTX metabolic pathways with response to MTX.

METHODS

Association of polymorphism in 7 genes (rs2236225 [MTHFD1 1958G>A], rs17602729 [AMPD1 G>A], rs1127354 [ITPA C>A], rs1431131 [TGFBR2 A>T], rs2372536 [ATIC C>G], rs11188513 [ENTPD1 C>T] and rs5751876 [ADORA2A T>C]) with efficacy of MTX was studied in Indian rheumatoid arthritis (RA) patients. The patients, classified by European League Against Rheumatology (EULAR)/American College of Rheumatology (ACR) 2010 criteria, were DMARD (disease-modifying antirheumatic drug)-naïve, with Disease Activity Score (DAS28) >3.2. After 4 months of MTX monotherapy, patients were classified as responders (R) or non-responders (NR) based on EULAR response criteria. Genotyping was done by TaqMan 5' nuclease assay and association of gene polymorphisms with response to MTX was determined by Chi-squared test.

RESULTS

Two hundred and twenty-six patients (86% female, median age 40 [interquartile range, IQR = 17.25] years), with disease duration of 24 (IQR = 38.25) months and DAS28-C-reactive protein score of 4.61 (IQR = 1.34) were enrolled. After therapy, 186 patients were classified as R and 40 as NR. GG genotype of ATIC (P = .01, odds ratio [OR] 2.56, 95% CI, 1.04-6.30) and CC genotype of ITPA (P = .009, OR 1.34, 95% CI 1.02-1.76) genes were found to be associated with the response. On binary logistic regression analysis, GG genotype of ATIC and CC of ITPA genes were independent predictors of the response.

CONCLUSION

Polymorphisms of ATIC and ITPA genes alone or with clinical variables were associated with response to MTX therapy in Indian RA patients.

Metformin alleviates memory and hippocampal neurogenesis decline induced by methotrexate chemotherapy in a rat model

Methotrexate (MTX) is a chemotherapeutic drug commonly used to treat cancers that has an adverse effect on patients' cognition. Metformin is a primary treatment for type 2 diabetes mellitus that can pass through the blood-brain barrier. Metformin has neuroprotective actions, which can improve memory. In the present study, we examined the ability of metformin in MTX chemotherapy-generated cognitive and hippocampal neurogenesis alterations. Male Sprague-Dawley rats were allocated into control, MTX, metformin, preventive, and throughout groups. MTX (75 mg/kg/day) was given intravenously on days 7 and 14 of the study. Metformin (200 mg/kg/day) was injected intraperitoneally for 14 days. Some of the MTX-treated rats received co-treatment with metformin once a day for either 14 (preventive) or 28 days (throughout). After treatment, memory ability was evaluated using novel object location and novel object recognition tests. Ki67 (proliferating cells), BrdU (survival cells), and doublecortin (immature neurons, DCX) positive cells in the subgranular zone (SGZ) of the hippocampal dentate gyrus were quantified. We found that reductions of cognition, the number of proliferating and survival cells and immature neurons in the SGZ were ameliorated in the co-treatment groups, which suggests that metformin can prevent memory and hippocampal neurogenesis impairments induced by MTX in adult rats.

The influence of coffee intake and genetics on adenosine pathway in rheumatoid arthritis

Aim: We studied the influence of coffee consumption on the therapeutic effect of methotrexate (MTX) in patients with rheumatoid arthritis (RA) sorted according to ADORA2A genotypes. Patients & methods: 82 RA patients were dichotomized according to caffeine intake with a threshold of 700 mg/week. Disease activity score 28 (DAS28) was applied (>3.2: high; <3.2: low or remission). Patients were genotyped using quantitative PCR allelic discrimination. Results: We found significantly higher risk of RA in patients with higher caffeine intake and the CT genotype of ADOARA2A rs2298383, rs3761422 and rs2267076 SNPs. The CC genotype of ADORA2A rs2236624 SNP in patients with lower caffeine intake treated with MTX is significantly protective. Conclusion: ADORA2A genotypes and coffee intake influence risk of RA and efficacy of it MTX treatment.

Are gene polymorphisms related to adverse events of methotrexate in patients with rheumatoid arthritis? A retrospective cohort study based on an updated meta-analysis

Aims:

We performed an updated meta-analysis to verify correlations between gene polymorphisms and adverse events in methotrexate (MTX)-treated rheumatoid arthritis (RA) patients. Then, we conducted a retrospective cohort study of Han Chinese in China.

Methods:

Relevant studies were collected from the PubMed database and the EMBASE database until December 2017. Pre-allele, dominant, recessive, codominant, and homozygotic models were applied. In addition, a retrospective cohort study enrolling 162 RA patients treated with MTX was conducted. Single nucleotide polymorphism (SNP) genotyping was analyzed by PCR and product sequencing.

Results:

A total of 39 studies were included in 20 meta-analyses; meta-analysis showed a significant association between MTX-related toxicity and 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C>T(rs1801133) polymorphism in East Asian RA patients, and significant associations were observed between MTX-related toxicity and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC) 347C>G (rs2372536), reduced folate carrier 1 (RFC-1) 80G>A (rs1051266), and adenosine triphosphate-binding cassette B1 (ABCB1) 3435C>T(rs1045642) polymorphisms in European RA patients but not in East Asian RA patients. Moreover, in our retrospective cohort study, ATIC 347C>G(rs2372536) and ABCB1 3435C>T(rs1045642) polymorphisms were not associated with MTX-related toxicity. However, a significant association was observed between MTX-related toxicity and RFC-1 80G>A (rs1051266) polymorphism in Chinese Han RA patients.

Conclusion:

Evidence-based results suggest that the MTHFR 677C>T(rs1801133), ATIC 347C>G(rs2372536), RFC-1 80G>A (rs1051266), ABCB1 3435C>T(rs1045642) polymorphisms are associated with MTX-related toxicity. Larger and more stringent study designs may provide more accurate findings for the effects of these SNPs on MTX-related toxicity, and larger sample-size studies of the Chinese Han population should be conducted for further validation.

Methotrexate and its mechanisms of action in inflammatory arthritis

Despite the introduction of numerous biologic agents for the treatment of rheumatoid arthritis (RA) and other forms of inflammatory arthritis, low-dose methotrexate therapy remains the gold standard in RA therapy. Methotrexate is generally the first-line drug for the treatment of RA, psoriatic arthritis and other forms of inflammatory arthritis, and it enhances the effect of most biologic agents in RA. Understanding the mechanism of action of methotrexate could be instructive in the appropriate use of the drug and in the design of new regimens for the treatment of RA. Although methotrexate is one of the first examples of intelligent drug design, multiple mechanisms potentially contribute to the anti-inflammatory actions of methotrexate, including the inhibition of purine and pyrimidine synthesis, transmethylation reactions, translocation of nuclear factor-κB (NF-κB) to the nucleus, signalling via the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway and nitric oxide production, as well as the promotion of adenosine release and expression of certain long non-coding RNAs.

Role of allopurinol and febuxostat in the amelioration of dextran-induced colitis in rats

Ulcerative colitis is a chronic auto-inflammatory disorder confined to the colorectal region. It is challenging to find an absolute treatment and current therapy aims to ameliorate symptoms, decrease relapses and prevent prognosis of colorectal cancer. In the present study, we investigated the possible action of xanthine oxidase inhibitors in murine colitis model by measuring different indicative parameters and comparing the results to those of the reference sulfasalazine. Also, we compared the effects of combining sulfasalazine and allopurinol to each drug alone. Dextran Sodium Sulfate (DSS) is used in this study to induce ulcerative colitis in male wistar rats as it is known to be the closest model that mimics human ulcerative colitis. Allopurinol was given prior to colitis induction by four days and febuxostat for six days before induction with DSS (5% w/v) and continue to give them concomitantly during the induction.Il-1β, malondialdehyde, reduced glutathione (GSH), xanthine oxidase, and superoxide dismutase were measured in colonic tissue. We also measured concentrations of IL-1β, Il-6 and uric acid in serum. Allopurinol dose-dependently ameliorated biochemical injuries. Febuxostat has shown better results than allopurinol and sulfasalazine, and this is the first study to demonstrate this.

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.

Successful Treatment of Necrotizing Retinitis with Epstein-Barr Virus-Positive Ocular Fluid by Intravitreal Methotrexate Injection

PURPOSE

To present a case of necrotizing retinitis with Epstein-Barr virus (EBV)-positive ocular fluid in a patient with sudden unilateral vision loss, which was successfully treated with intravitreal methotrexate (MTX) injections.

METHODS

Retrospective case report.

RESULTS

An 83-year-old female who had been on methylprednisolone for 20 years due to interstitial pneumonia developed vitreous opacity and extensive necrotizing retinitis with retinal hemorrhage sparing the posterior pole in the left eye. Multiplex polymerase chain reaction (PCR) for viral DNA using vitreous sample was positive for EBV but negative for herpes simplex virus, varicella-zoster virus, and cytomegalovirus. Real-time PCR detected EBV-DNA in aqueous humor but not in peripheral blood sample. Serologic testing was negative for Toxoplasma gondii, syphilis, and HIV. The patient did not respond to systemic ganciclovir or acyclovir. Subsequent treatment with intravitreal MTX resulted in immediate clinical improvement correlating with a decrease in copy number of EBV-DNA.

CONCLUSION

Intravitreal MTX may be an effective treatment option for patients with necrotizing retinitis and EBV-positive ocular fluid not responding to conventional antiviral therapy.

Role of methotrexate chronotherapy in collagen-induced rheumatoid arthritis in rats

Aim

To explore the circadian rhythm of serum interleukin (IL)-6 in collagen-induced arthritis (CIA) rats and compare the safety and effectiveness of methotrexate (MTX) administered traditionally and via chronotherapy.

Methods

CIA rat models were immunized with bovine type II collagen. Serum IL-6 levels in normal and CIA rats were measured at 2, 6, 10, 14, 18, or 22 h after the light was turned on (HALO). MTX was administered to 6 HALO/18 HALO experimental groups of Wistar rats once daily according to the IL-6 rhythm. The control groups (positive, negative, and normal) were given MTX or an equal volume of phosphate buffered saline (PBS) once a week simultaneously. Arthritis score, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C reactive protein (CRP) levels in the serum were measured by enzyme-linked immunosorbent assay (ELISA). Histological changes in the ankle joint were analyzed.

Results

After 6 weeks of treatment, arthritis scores in the experimental group were lower than in the control group. The expression of TNF-α, IL-6, and CRP was lower in the 18 HALO group than in the control or 6 HALO groups. Histopathology scores in the experimental groups were lower than in the control group (p < 0.05).

Conclusion

The plasma IL-6 levels in CIA rats were higher than in normal rats and showed significant circadian rhythm. Daily administration of MTX is more potent than weekly administration. The therapeutic index of rheumatoid arthritis (RA) may be improved with MTX therapy based on the IL-6 circadian rhythm.

A novel combination of astilbin and low-dose methotrexate respectively targeting A2AAR and its ligand adenosine for the treatment of collagen-induced arthritis

Methotrexate (MTX) is widely used for rheumatoid arthritis (RA) treatment with frequently serious adverse effects. Therefore, combination of low-dose MTX with other drugs is often used in clinic. In this study, we investigated the improvement of astilbin and low-dose MTX combination on collagen-induced arthritis in DBA/1J mice. Results showed that the clinic score, incidence rate, paw swelling, pathological changes of joints and rheumatoid factors were more alleviated in combination therapy than MTX or astilbin alone group. Elevated antibodies (IgG, IgG1, IgG2a, IgM and anti-collagen IgG) and pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, IFN-γ and IL-17A) in serum were significantly inhibited, while anti-inflammatory cytokine, IL-10, was enhanced by combination therapy. Further studies indicated that combination therapy significantly decreased Th1 and Th17 cell differentiation and increased Treg cell differentiation. Mechanisms analysis demonstrated combination therapy greatly inhibited Con A-activated MAPK and inflammatory transcriptional signals. Moreover, MTX activated adenosine release and astilbin specifically up-regulated A_2A adenosine receptor (A_2AAR) expression simultaneously, which most probably contributed to the synergistic efficacy of combination therapy. ZM241385, a specific antagonist of A_2AAR, greatly blocked the effects of combination therapy on T cell functions and downstream pathways. All these findings suggest that astilbin is a valuable candidate for low-dose MTX combined therapy in RA via increasing A_2AAR/adenosine system and decreasing ERK/NFκB/STATs signals.

The plausible association of MTHFR and ADORA2A polymorphisms with nodules in rheumatoid arthritis patients treated with methotrexate

OBJECTIVE

The treatment of rheumatoid arthritis (RA) patients with methotrexate (MTX) is linked to the development or progression of rheumatoid nodules. The aim of this study was to determine whether folate and adenosine pathways-related single nucleotide polymorphisms might be predictive of increased nodule formation in RA patients treated with oral MTX.

METHODS

A total of 185 Caucasian RA patients were enrolled in this cross-sectional study, all of whom fulfilled the 1987 RA criteria of the American College of Rheumatology; each patient had a history of MTX treatment.

RESULTS

A higher frequency of the MTHFR 1298AA genotype was found in 17 (70.8%) of 24 patients with general nodules [odds ratio (OR)=3.08, 95% confidence interval (CI): 1.20-7.69] and in 14 (73.7%) of 19 patients who developed nodules during MTX treatment (OR=3.55, 95% CI: 1.22-10.32). In contrast, a negative association with nodules during MTX treatment (OR=0.29, 95% CI: 0.08-1.10) was found for 19 (79.2%) patients with the TT genotype (rs2298383) in the adenosine A2a receptor gene (ADORA2A). However, the significance did not remain upon correction for multiple testing. The combination of MTHFR 1298AA along with ADORA2A rs2298383 CC or CT genotypes occurring in one-third of RA patients showed a higher frequency of general nodules 15/59 (25.4%) as well as developing nodules during MTX treatment 13/59 (22.0%) in comparison with the overall studied group: 24/185 (13.0%) and 19/185 (10.3%), respectively.

CONCLUSION

This exploratory study indicates for the first time a plausible association of adenosine and folate pathways single nucleotide polymorphisms in nodules' etiopathogenesis.

Low-dose methotrexate in sickle-cell disease: a pilot study with rationale borrowed from rheumatoid arthritis

Background

Inflammation is a major feature of sickle cell disease (SCD). Low-dose methotrexate (MTX) has long been used in chronic inflammatory diseases. This pilot study examined the MTX effect on acute vaso-occlusive pain crises (VOC) in SCD patients.

Methods

Fourteen adults on hydroxyurea with severe and refractory VOC received one intramuscular injection of 10 mg of MTX per week for 12 weeks. A single weekly dose of 5 mg of leucovorin was administered orally 48 h after each MTX injection. The primary outcome was reduction in number/intensity of acute pain episodes. The secondary outcomes were improvement of quality of life (QOL) and reduction of the inflammatory status.

Results

MTX did not significantly change the median VOC frequency (12 before vs 10.5 during treatment, P = 0.6240) or the median McGill pain index (45 at week 0 vs 39.5 at week 12, P = 0.9311). However, there was a decrease of ≥50% in chronic pain resulting from avascular osteonecrosis (AVN) in 5 out of 7 patients with radiologic evidence of AVN, with the perception of longer pain-free periods. There was a 44.4% median gain in physical function in the SF-36 QOL questionnaire (P = 0.0198). MTX treatment up-regulated two C-X-C motif chemokines (CXCL), CXCL10 (P = 0.0463) and CXCL12 (P < 0.0001), without significant effect on 14 additional plasma inflammatory markers. Adverse events: One individual had fever of unknown origin. Respiratory tract infections were recorded in five patients. Among the latter, one also had dengue fever and another had a central venous line infection and died of pneumonia and septic shock. Three patients with previous history of hydroxyurea-induced hematological toxicity developed low blood platelet counts while receiving simultaneously MTX and hydroxyurea.

Conclusions

Although MTX did not reduce acute VOC frequency/intensity, it decreased chronic pain and led to QOL improvement.

Trial registrationhttp://www.who.int/ictrp/en/ and http://www.ensaiosclinicos.gov.br, RBR-2s9xvn, 19 December 2016, retrospectively registered

Electronic supplementary material

The online version of this article (doi:10.1186/s40164-017-0078-1) contains supplementary material, which is available to authorized users.

MethotrexaTE THerapy in ST-Segment Elevation MYocardial InfarctionS

Purpose:

Methotrexate is an anti-inflammatory drug that has been shown to have anti-ischemic effects. Our aim was to evaluate if methotrexate could reduce infarct size in patients with ST-segment elevation myocardial infarction (STEMI).

Methods:

We randomly assigned patients with STEMI to receive either methotrexate or placebo. Primary outcome was infarct size determined by calculating the area under the curve (AUC) for creatine kinase (CK) release. Secondary outcomes were AUC of CK MB (CK-MB) and AUC of troponin I; peak CK, peak CK-MB, and troponin I; B-type natriuretic peptide (BNP) level, high-sensitivity C-reactive protein (hsCRP) result, and erythrocyte sedimentation rate (ESR); left ventricular ejection fraction (LVEF); thrombolysis in myocardial infarction (TIMI) frame count; Killip score; mortality and reinfarction incidence; and incidence of adverse reactions.

Results:

We included 84 patients. Median AUC of CK was 78 861.0 in the methotrexate group and 68 088.0 in the placebo group ( P = .10). Patients given methotrexate and placebo exhibited, respectively, median AUC for CK-MB of 9803.4 and 8037.0 ( P = .42); median AUC for troponin of 3691.1 and 2132.6 ( P = .09); peak CK of 2806.0 and 2147.0 ( P = .05); peak CK-MB of 516.0 and 462.3 ( P = .25); and peak troponin of 121.0 and 85.1 ( P = .06). At 3 months, LVEF was lower in patients who received methotrexate (49.0% ± 14.1%) than in patients given placebo (56.4% ± 10.0%; P = .01). There were no differences in hsCRP, ESR, BNP, Killip scores, TIMI frame count, reinfarction, and mortality rates. There was a higher median serum glutamic–pyruvic transaminase levels in the methotrexate group.

Conclusion:

Methotrexate did not reduce infarction size and worsened LVEF at 3 months ( Clinicaltrials.gov identifier NCT01741558).

The Folate Cycle As a Cause of Natural Killer Cell Dysfunction and Viral Etiology in Type 1 Diabetes

The folate pathway is critical to proper cellular function and metabolism. It is responsible for multiple functions, including energy (ATP) production, methylation reactions for DNA and protein synthesis and the production of immunomodulatory molecules, inosine and adenosine. These play an important role in immune signaling and cytotoxicity. Herein, we hypothesize that defects in the folate pathway in genetically susceptible individuals could lead to immune dysfunction, permissive environments for chronic cyclical latent/lytic viral infection, and, ultimately, the development of unchecked autoimmune responses to infected tissue, in this case islet beta cells. In the context of type 1 diabetes (T1D), there has been a recent increase in newly diagnosed cases of T1D in the past 20 years that has exceeded previous epidemiological predictions with yet unidentified factor(s). This speaks to a potential environmental trigger that adversely affects immune responses. Most research into the immune dysfunction of T1D has focused on downstream adaptive responses of T and B cells neglecting the role of the upstream innate players such as natural killer (NK) cells. Constantly, surveilling the blood and tissues for pathogens, NK cells remove threats through direct cytotoxic responses and recruitment of adaptive responses using cytokines, such as IL-1β and IFN-γ. One long-standing hypothesis suggests viral infection as a potential trigger for the autoimmune response in T1D. Recent data suggest multiple viruses as potential causal agents. Intertwined with this is an observed reduced NK cell enumeration, cytotoxicity, and cytokine signaling in T1D patients. Many of the viruses implicated in T1D are chronic latent/lysogenic infections with demonstrated capacity to reduce NK cell response and number through mechanisms that resemble those of pregnancy tolerance. Defects in the folate pathway in T1D patients could result in decreased immune response to viral infection or viral reactivation. Dampened NK responses to infections result in improper signaling, improper antigen presentation, and amplified CD8⁺ lymphocyte proliferation and cytotoxicity, a hallmark of beta cell infiltrates in patients with T1D onset. This would suggest a critical role for NK cells in T1D development linked to viral infection and the importance of the folate pathway in maintaining proper NK response.

Cutting Edge: Adenosine A2a Receptor Signals Inhibit Germinal Center T Follicular Helper Cell Differentiation during the Primary Response to Vaccination

Adenosine A2a receptor (A2aR) signaling acts as a barrier to autoimmunity by promoting anergy, inducing regulatory T cells, and inhibiting effector T cells. However, in vivo effects of A2aR signaling on polyclonal CD4 T cells during a primary response to foreign Ag has yet to be determined. To address this problem, we immunized mice with peptide Ag 2W1S coupled to PE in CFA and treated with the selective A2aR agonist CGS-21680 (CGS). 2W1S:I-A^b-specific tetramer-binding CD4 T cells did not become anergic or differentiate into Foxp3⁺ regulatory T cells. Additionally, CGS treatment did not inhibit Th1 or Th17 differentiation. However, CGS did abrogate germinal center T follicular helper cells, and blunted PE-specific germinal center B cell responses. The use of A2aR-deficient CD4 T cells established that this CGS effect was T cell intrinsic. Therefore, this study has identified a unique role for A2aRs in regulating CD4 T cell differentiation during vaccination.

Moving toward personalized medicine in rheumatoid arthritis: SNPs in methotrexate intracellular pathways are associated with methotrexate therapeutic outcome

AIM

Evaluate the potential of selected SNPs as predictors of methotrexate (MTX) therapeutic outcome.

PATIENTS & METHODS

In total, 35 SNPs in 14 genes involved in MTX intracellular pathways and Phase II reactions were genotyped in 233 rheumatoid arthritis (RA) patients treated with MTX. Binary logistic regressions were performed by genotype/haplotype-based approaches. Non-Response- and Toxicity-Genetic Risk Indexes (Non-RespGRI and ToxGRI) were created.

RESULTS

MTX nonresponse was associated to eight genotypes and three haplotypes: MTHFR rs1801131 AA and rs1801133 TT; MS rs1805087 AA; MTRR rs1801394 A carriers; ATIC rs2372536 C carriers, rs4673993 T carriers, rs7563206 T carriers and rs12995526 T carriers; CC for GGH rs3758149 and rs12681874; CGTTT for ATIC combination 1; and CTTTC for ATIC combination 2. From overall Non-RespGRI patients with indexes 6-8 had more than sixfold increased risk for MTX nonresponse than those patients with indexes 0-5. MTX-related toxicity was associated to five genotypes and two haplotypes: ATIC rs2372536 G carriers, rs3821353 T carriers, rs7563206 CC and rs12995526 CC; ADORA2A rs2267076 T; CTTCC for ATIC combination 1; and TC for ADORA2A rs2267076 and rs2298383. From overall ToxGRI, patients with indexes 3-4 had more than sevenfold increased risk for MTX-related toxicity than those patients with indexes 1-2.

CONCLUSION

Genotyping may be helpful to identify which RA patients will not benefit from MTX treatment and, consequently, important to personalized medicine in RA. Nevertheless, further studies are required to validate these findings.

Methotrexate-mediated activation of an AMPK-CREB-dependent pathway: a novel mechanism for vascular protection in chronic systemic inflammation

AIMS

Premature cardiovascular events complicate chronic inflammatory conditions. Low-dose weekly methotrexate (MTX), the most widely used disease-modifying drug for rheumatoid arthritis (RA), reduces disease-associated cardiovascular mortality. MTX increases intracellular accumulation of adenosine monophosphate (AMP) and 5-aminoimidazole-4-carboxamide ribonucleotide which activates AMP-activated protein kinase (AMPK). We hypothesised that MTX specifically protects the vascular endothelium against inflammatory injury via induction of AMPK-regulated protective genes.

METHODS/RESULTS

In the (NZW×BXSB)F1 murine model of inflammatory vasculopathy, MTX 1 mg/kg/week significantly reduced intramyocardial vasculopathy and attenuated end-organ damage. Studies of human umbilical vein endothelial cells (HUVEC) and arterial endothelial cells (HAEC) showed that therapeutically relevant concentrations of MTX phosphorylate AMPKα(Thr172), and induce cytoprotective genes including manganese superoxide dismutase (MnSOD) and haem oxygenase-1 (HO-1). These responses were preserved when HUVECs were pretreated with tumour necrosis factor-α to mimic dysfunctional endothelium. Furthermore, MTX protected against glucose deprivation-induced endothelial apoptosis. Mechanistically, MTX treatment led to cyclic AMP response element-binding protein (CREB)(Ser133) phosphorylation, while AMPK depletion attenuated this response and the induction of MnSOD and HO-1. CREB siRNA inhibited upregulation of both cytoprotective genes by MTX, while chromatin immunoprecipitation demonstrated CREB binding to the MnSOD promoter in MTX-treated EC. Likewise, treatment of (NZW×BXSB)F1 mice with MTX enhanced AMPKα(Thr172) phosphorylation and MnSOD, and reduced aortic intercellular adhesion molecule-1 expression.

CONCLUSIONS

These data suggest that MTX therapeutically conditions vascular endothelium via activation of AMPK-CREB. We propose that this mechanism contributes to the protection against cardiovascular events seen in patients with RA treated with MTX.

Ticagrelor Does Not Inhibit Adenosine Transport at Relevant Concentrations: A Randomized Cross-Over Study in Healthy Subjects In Vivo

BACKGROUND AND PURPOSE

In patients with myocardial infarction, ticagrelor reduces cardiovascular and sepsis-related mortality, and can cause dyspnea. It is suggested that this is caused by adenosine receptor stimulation, because in preclinical studies, ticagrelor blocks the nucleoside transporter and increases cellular ATP release. We now investigated the effects of ticagrelor on the adenosine system in humans in vivo.

EXPERIMENTAL APPROACH

In a double-blinded, placebo-controlled cross-over trial in 14 healthy subjects, we have tested whether ticagrelor (180 mg) affects adenosine- and dipyridamole-induced forearm vasodilation, as surrogates of nucleoside uptake inhibition and adenosine formation, respectively. Also, ex vivo uptake of adenosine and uridine in isolated red blood cells was measured. Primary endpoint was adenosine-induced vasodilation.

KEY RESULTS

Ticagrelor did not affect adenosine- or dipyridamole-induced forearm vasodilation. Also, ex vivo uptake of adenosine and uridine in isolated red blood cells was not affected by ticagrelor. In vitro, ticagrelor dose-dependently inhibited nucleoside uptake, but only at supra-physiological concentrations.

CONCLUSION AND IMPLICATIONS

In conclusion, at relevant plasma concentration, ticagrelor does not affect adenosine transport, nor adenosine formation in healthy subjects. Therefore, it is unlikely that this mechanism is a relevant pleiotropic effect of ticagrelor.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01996735.

Biological agents and respiratory infections: Causative mechanisms and practice management

Biological agents are increasingly being used to treat patients with immune-mediated inflammatory disease. In Japan, currently approved biological agents for patients with rheumatoid arthritis (RA) include tumor necrosis factor inhibitors, interleukin-6 receptor-blocking monoclonal antibody, and T-cell costimulation inhibitor. Rheumatologists have recognized that safety issues are critical aspects of treatment decisions in RA. Therefore, a wealth of safety data has been gathered from a number of sources, including randomized clinical trials and postmarketing data from large national registries. These data revealed that the most serious adverse events from these drugs are respiratory infections, especially pneumonia, tuberculosis, nontuberculous mycobacteriosis, and Pneumocystis jirovecii pneumonia, and that the most common risk factors associated with these respiratory infections are older age, concomitant corticosteroid use, and underlying respiratory comorbidities. Because of this background, in 2014, the Japanese Respiratory Society published their consensus statement of biological agents and respiratory disorders. This review summarizes this statement and adds recent evidence, especially concerning respiratory infections in RA patients, biological agents and respiratory infections, and practice management of respiratory infections in patients treated with biological agents. To decrease the incidence of infections and reduce mortality, we should know the epidemiology, risk factors, management, and methods of prevention of respiratory infections in patients receiving biological agents.

The effect of eplerenone on adenosine formation in humans in vivo: a double-blinded randomised controlled study

Background

It has been suggested that mineralocorticoid receptor antagonists have direct cardioprotective properties, because these drugs reduce mortality in patients with heart failure. In murine models of myocardial infarction, mineralocorticoid receptor antagonists reduce infarct size. Using gene deletion and pharmacological approaches, it has been shown that extracellular formation of the endogenous nucleoside adenosine is crucial for this protective effect. We now aim to translate this finding to humans, by investigating the effects of the selective mineralocorticoid receptor antagonist eplerenone on the vasodilator effect of the adenosine uptake inhibitor dipyridamole, which is a well-validated surrogate marker for extracellular adenosine formation.

Methods and Results

In a randomised, double-blinded, placebo-controlled, cross-over study we measured the forearm blood flow response to the intrabrachial administration of dipyridamole in 14 healthy male subjects before and after treatment with placebo or eplerenone (50 mg bid for 8 days). The forearm blood flow during administration of dipyridamole (10, 30 and 100 µg·min⁻¹·dl⁻¹) was 1.63 (0.60), 2.13 (1.51) and 2.71 (1.32) ml·dl⁻¹·min⁻¹ during placebo use, versus 2.00 (1.45), 2.68 (1.87) and 3.22 (1.94) ml·dl⁻¹·min⁻¹ during eplerenone treatment (median (interquartile range); P = 0.51). Concomitant administration of the adenosine receptor antagonist caffeine attenuated dipyridamole-induced vasodilation to a similar extent in both groups. The forearm blood flow response to forearm ischemia, as a stimulus for increased formation of adenosine, was similar during both conditions.

Conclusion

In a dosage of 50 mg bid, eplerenone does not augment extracellular adenosine formation in healthy human subjects. Therefore, it is unlikely that an increased extracellular adenosine formation contributes to the cardioprotective effect of mineralocorticoid receptor antagonists.

Trial Registration

ClinicalTrials.gov, NCT01837108

Serum Adenosine Deaminase Level is High But Not Related with Disease Activity Parameters in Patients with Rheumatoid Arthritis

Serum adenosine deaminase (ADA) has been previously proposed to predict disease activity in patients with rheumatoid arthritis (RA). The aim of this study was to investigate the level of serum ADA, and the relationship between ADA and disease activity markers, in a group of patients with RA.

A hundred and 10 patients with a diagnosis of RA were recruited from outpatient clinic of Rheumatology Unit. Demographic properties comprising age, gender, disease duration and drugs were recorded. Disease activity based on disease activity score (DAS)28-erythrocyte sedimentation rate (ESR) and DAS28- C reactive protein (CRP,) ESR, CRP levels, as well as pain by visual analog scale and rheumatoid factor (RF) were recorded. Serum ADA levels (IU/L) were determined in all RA patients and in 55 age and sex similar healthy control subjects.

Ninety-six female and 14 male RA patients with a mean age of 54.32±11.51, and with a mean disease duration of 11.5±9.13 years were included to the study. The control group comprised of 48 female and 7 male healthy subjects. 35.5% of the patients were on methotrexate (MTX) and 64.5% of patients were on combined DMARDs or combined MTX and anti-TNF therapies. The mean serum ADA level was statistically higher in RA patients than in control subjects (27.01±10.6 IU/L vs 21.8 ±9.9 IU/L). The mean values of ESR (23.2±14.8 mm/h), CRP (1.71±1.11mg/dL), pain by VAS (37.2±27.1), DAS28-ESR (2.72±0.77), DAS28 CRP (1.37±0.5) were not correlated with ADA levels (p>0.05).

Our results have shown that serum ADA levels are higher in RA patients than in controls but were not related with any of the disease activity markers. We conclude that ADA in the serum may not be a reliable biochemical marker to predict disease activity in patients with RA.

Intravitreal methotrexate in the management of presumed tuberculous serpiginous-like choroiditis

PURPOSE

To report on the use of intravitreal methotrexate (IVT MTX) as part of treatment of presumed tuberculous serpiginous-like choroiditis progressing despite the use of tuberculostatics.

METHODS

Case series of patients suffering from serpiginous-like choroiditis with positive tuberculin skin test who received IVT injections of MTX as part of treatment. Ocular disease was active despite the use of systemic tuberculostatic (isoniazid, rifampicin, pyrazinamide, and ethambutol), and choroidal lesions showed signs of progression. A single injection of IVT MTX (400 μg/0.1 mL) was administered in the eye with macular-threatening features. Change in visual acuity, appearance of the lesion, and staining patterns on angiography were among the main outcome measurements.

RESULTS

Three eyes from two patients were included. Both cases presented bilateral involvement with mild vitritis. In all three eyes, choroidal lesions healed within the first month after an IVT MTX injection with visual acuity improvement in two. No adverse reaction was related to the medication or to the procedure. Patients were followed for a mean of 13.5 months after being injected.

CONCLUSION

The use of IVT MTX seems effective in the management of the inflammatory component of tuberculous serpiginous-like choroiditis, whereas systemic tuberculostatics are aimed at controlling the infectious one.

The concomitant use of meloxicam and methotrexate does not clearly increase the risk of silent kidney and liver damages in patients with rheumatoid arthritis

We investigated whether the concomitant use of meloxicam and methotrexate might induce kidney and liver damages in patients with rheumatoid arthritis (RA). We enrolled 101 RA patients with normal kidney and liver functions taking meloxicam and methotrexate concomitantly for more than 6 months. Blood and urine tests were performed. Estimated glomerular filtration rate (eGFR) and liver stiffness measurement (LSM) were used for evaluating silent kidney and liver damages. Ultrasonography was also performed to exclude structural abnormalities. We adopted 90 mL/min/1.73 mm(2) and 5.3 kPa as the cutoff for an abnormal eGFR and LSM. The mean age (85 women) was 51.9 years. The mean eGFR was 97.0 mL/min/1.73 m(2) and the mean LSM was 4.7 kPa. The mean weekly dose of methotrexate was 13.4 mg. The mean weekly dose of methotrexate did not correlate with eGFR or LSM. Neither the cumulative dose of meloxicam or methotrexate nor the mean weekly dose of methotrexate showed the significant odds ratio or relative risk for abnormal eGFR and LSM values. The use of higher-dose MTX, above 15 mg per week, with meloxicam did not significantly increase the risk for abnormal LSM and eGFR (RR = 2.042, p = 0.185; RR = 0.473, p = 0.218). The concomitant use of meloxicam and MTX did not clearly increase the risk of silent kidney or liver damage in RA patients with normal laboratory results taking MTX and meloxicam concurrently for over 6 months.

Methotrexate and a spleen tyrosine kinase inhibitor cooperate to inhibit responses to peripheral blood B cells in rheumatoid arthritis

BACKGROUND

Selective disruption of the spleen tyrosine kinase (Syk) represents a novel strategy to control B-cell functional responses by inhibition of B-cell antigen receptor (BCR) signaling. PRT062607 (P505-15) is a highly selective small molecule Syk inhibitor that potently suppresses B-cell function in human and rodent blood, and reduces inflammation in rodent models of rheumatoid arthritis (RA).

AIMS

In this study, we sought to determine the potency of Syk inhibition by PRT062607 in whole blood from RA patients, and elucidate covariates that affect the potency of immune-regulation by this compound.

MATERIALS AND METHODS

Whole blood was collected from 30 patients diagnosed with RA as part of a single-center outpatient study. Disease severity, serum protein markers of inflammation, and co-medications were related to each other, and to PRT062607 activity in ex vivo Syk-mediated immune function assays.

RESULTS

We report here that PRT062607 exhibited greater potency in suppressing BCR mediated B-cell functional responses in whole blood from RA patients who received stable methotrexate (MTX) therapy. We demonstrate that the B-cell functional response to BCR ligation is influenced by cytokines and JAK/STAT signaling.

DISCUSSION

MTX is a known cytokine modulating agent, and this mechanism may act in concert with PRT062607 to control B-cell function.

CONCLUSION

These data have important implications for the co-administration of Syk inhibitors and MTX for the treatment of RA.

Methotrexate analogues display enhanced inhibition of TNF-α production in whole blood from RA patients

OBJECTIVES

Although methotrexate (MTX) is the anchor drug in the treatment of rheumatoid arthritis (RA), patients experience clinical resistance to MTX upon prolonged treatment. We explored whether new-generation antifolates elicit superior anti-inflammatory properties when compared to MTX, based on their capacity to inhibit tumour necrosis factor (TNF)-α production.

METHOD

T cells in whole blood from 18 RA patients (including MTX-naïve, MTX- responsive, and MTX non-responsive patients) and seven healthy volunteers were stimulated with αCD3/αCD28 antibodies and incubated ex vivo for 72 h with MTX and eight novel antifolate drugs with potentially favourable biochemical and pharmacological properties. Drug concentrations exerting 50% inhibition (IC-50) of TNF-α production (by enzyme-linked immunosorbent assay, ELISA) were determined as an estimate for their anti-inflammatory capacity. In addition, induction of T-cell apoptosis was evaluated by flow cytometry.

RESULTS

The new-generation antifolates PT523, PT644, raltitrexed, and GW1843 proved to be potent inhibitors of TNF-α production in activated T cells from all three groups of RA patients and from healthy volunteers. Based on IC-50 values, these antifolates were up to 10.3 times more potent than MTX. The anti-inflammatory effects were observed at drug concentrations that provoked suppression of T-cell activation and induction of apoptosis in 20-40% of activated T cells.

CONCLUSION

In an ex-vivo setting, novel antifolates elicited marked inhibition of TNF-α production in activated T cells from RA patients. Further clinical evaluation is warranted to investigate whether a low dosage of these antifolates can elicit immunosuppressive effects equivalent to MTX, and whether they are superior to MTX in patients who fail to respond to MTX.

CD73 is a phenotypic marker of effector memory Th17 cells in inflammatory bowel disease

Purinergic signaling and associated ectonucleotidases, such as CD39 and CD73, have been implicated in the pathogenesis of inflammatory bowel disease (IBD). CD39 is known to be a Treg memory cell marker, and here we determine the phenotype and function of CD73(+) CD4(+) T lymphocytes in patients with IBD. We describe elevated levels of CD73(+) CD4(+) T cells in the peripheral blood and intestinal lamina propria of patients with active IBD. The functional phenotype of these CD73(+) CD4(+) T cells was further determined by gene expression, ecto-enzymatic activity, and suppressive assays. Increased numbers of CD73(+) CD4(+) T cells in the periphery and lamina propria were noted during active inflammation, which returned to baseline levels following anti-TNF treatment. Peripheral CD73(+) CD4(+) T cells predominantly expressed CD45RO, and were enriched with IL-17A(+) cells. The CD73(+) CD4(+) cell population expressed higher levels of RORC, IL-17A, and TNF, and lower levels of FOXP3 and/or CD25, than CD73(-) CD4(+) T cells. Expression of CD73 by peripheral CD4(+) T cells was increased by TNF, and decreased by an anti-TNF monoclonal antibody (infliximab). In vitro, these peripheral CD73(+) CD4(+) T cells did not suppress proliferation of CD25(-) effector cells, and expressed higher levels of pro-inflammatory markers. We conclude that the CD73(+) CD4(+) T-cell population in patients with active IBD are enriched with cells with a T-helper type 17 phenotype, and could be used to monitor disease activity during treatment.

Methotrexate: new therapeutic approaches

Although the first study on the efficacy of methotrexate in the treatment of psoriasis was reported in 1958, scientific evidence for this indication has been scant until quite recently. We now have new data on the pharmacokinetics and mechanism of action of methotrexate and new subcutaneous formulations that have improved the bioavailability, efficacy, and ease of administration of the drug. The results of recent clinical trials comparing methotrexate with several biologic agents have shown it to be the first-line therapy among the classic systemic treatments for psoriasis. Moreover, the incremental cost-effectiveness ratio for subcutaneous methotrexate has been shown to be superior to that of ciclosporin, adalimumab, and infliximab.

Adenosine Deaminase Isoenzymes in the Diagnosis and Monitoring of Rheumatoid Arthritis

The aim of this study was determination of the catalytic activities of adenosine deaminase (ADA), ADA1 and ADA2 isoenzymes in the serum of patients suffering from rheumatoid arthritis (RA) who were and were not treated with methotrexate (MTX), and identification of the possibilities of using these biochemical parameters in diagnosing and monitoring the treatment effects in RA. Catalytic activities of total ADA (tADA) and ADA2 in serum were determined by a spectrophotometric method. A statistically significant correlation was found between the total ADA and ADA1 values, as well as between tADA and ADA2 in the serum of all patients suffering from RA. Determination of ADA1 and ADA2 isoenzyme catalytic activities in the serum of patients who might be suffering from RA improves the diagnostic value of total ADA catalytic activity determination. ADA2 catalytic activity in serum can be a useful biochemical marker in diagnosing and monitoring RA. Decrease in ADA1 isoenzyme catalytic activities in the serum of patients suffering from RA who were treated with MTX can help in the observation of MTX therapy effects.

Targeting adenosine receptors in the development of cardiovascular therapeutics

Adenosine receptor stimulation has negative inotropic and dromotropic actions, reduces cardiac ischemia-reperfusion injury and remodeling, and prevents cardiac arrhythmias. In the vasculature, adenosine modulates vascular tone, reduces infiltration of inflammatory cells and generation of foam cells, and may prevent the development of atherosclerosis as a result. Modulation of insulin sensitivity may further add to the anti-atherosclerotic properties of adenosine signaling. In the kidney, adenosine plays an important role in tubuloglomerular feedback and modulates tubular sodium reabsorption. The challenge is to take advantage of the beneficial actions of adenosine signaling while preventing its potential adverse effects, such as salt retention and sympathoexcitation. Drugs that interfere with adenosine formation and elimination or drugs that allosterically enhance specific adenosine receptors seem to be most promising to meet this challenge.

Genetic polymorphisms in key methotrexate pathway genes are associated with response to treatment in rheumatoid arthritis patients

We investigated the effect of Single Nucleotide Polymorphisms (SNPs) spanning 10 methotrexate (MTX) pathway genes, namely AMPD1, ATIC, DHFR, FPGS, GGH, ITPA, MTHFD1, SHMT1, SLC19A1 (RFC) and TYMS on the outcome of MTX treatment in a UK rheumatoid arthritis (RA) patient cohort. Tagging SNPs were selected and genotyping performed in 309 patients with predefined outcomes to MTX treatment. Of the 129 SNPs tested, 11 associations were detected with efficacy (p-trend ≤ 0.05) including four SNPs in the ATIC gene (rs12995526, rs3821353, rs7563206 and rs16853834), 6 SNPs in the SLC19A1 gene region (rs11702425, rs2838956, rs7499, rs2274808, rs9977268, rs7279445) and a single SNP within the GGH gene (rs12681874). Five SNPs were significantly associated with adverse events; three in the DHFR gene (rs12517451, rs10072026, and rs1643657) and two of borderline significance in the FPGS gene. The results suggest that genetic variations in several key MTX pathway genes may influence response to MTX in RA patients. Further studies will be required to validate these findings and if confirmed these results could contribute towards a better understanding of and ability to predict MTX response in RA.

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.

Folate Pathway Enzyme Gene Polymorphisms and the Efficacy and Toxicity of Methotrexate in Psoriatic Arthritis

Objective.

To determine the association between folate pathway gene polymorphisms and the effectiveness, toxicity, and drug survival of methotrexate (MTX) in psoriatic arthritis (PsA).

Methods.

Data were obtained from a longitudinal cohort of PsA patients evaluated according to a standard protocol. Data on duration of drug therapy, dose, side effects, and reasons for discontinuation are systematically recorded. Patients treated with MTX after clinic admission who had ≥ 3 swollen joints prior to initiating MTX therapy were selected for evaluation of effectiveness. Response to MTX treatment was assessed at 6 months. Data from all patients treated in the clinic with MTX were used in evaluation of toxicity and drug survival. The following single-nucleotide polymorphisms (SNP) were measured using the Sequenom platform: MTHFR 677C>T (rs1801133), MTHFR 1298A>C (rs1801131), DHFR −473T>C (rs1650697), DHFR 35289A>G (rs1232027), and RFC 80G>A (rs1051266). Fisher’s exact test, logistic regression, and Cox proportional hazard analyses were used to determine association.

Results.

Two hundred eighty-one patients were identified from the database. All patients were included in the analysis for side effects and drug survival, and 119 patients were included in the effectiveness analysis. The minor A allele of DHFR gene at +35289 was the only SNP demonstrating association with response to MTX therapy (OR 2.99, p = 0.02). Patients homozygous for the minor allele of MTHFR 677C/T (677TT) had more liver toxicity (Fisher exact test, p = 0.04).

Conclusion.

Polymorphisms of the DHFR gene may be associated with MTX efficacy. MTHFR 677TT may have a relationship with MTX-induced liver toxicity in PsA.

Disordered lymphoid purine metabolism contributes to the pathogenesis of persistent Borrelia garinii infection in mice

Extracellular ATP and adenosine are important regulators of immune responses; however, contribution of purinergic signaling to host defense during persistent microbial infections remains obscure. Lyme borreliosis is a common arthropod-borne infection caused by Borrelia burgdorferi sensu lato. In this study, we investigated whether lymphoid purinergic signaling contributes to the mechanisms by which borreliae species evade the immune system and trigger joint inflammation. Intracutaneous inoculation of Borrelia garinii to C3H/He mice induced symptomatic infection manifested in elevated levels of borrelia-specific IgG Abs, persistent spirochete dissemination into the tissues and joint swelling, as well as approximately 2- to 2.5-fold enlargement of draining lymph nodes with hyperplasia of B cell follicle area and L-selectin shedding from activated T lymphocytes. Purine catabolism was also activated in lymph nodes but not spleen and blood of infected C3H/He mice within the first 4 postinfection weeks, particularly manifested in transient upregulations of adenosine triphosphatase/ectonucleoside triphosphate diphosphohydrolase and ecto-5'-nucleotidase/CD73 on CD4(+)CD8(+) T lymphocytes and adenosine deaminase activity on B220(+) B lymphocytes. Compared with borrelia-susceptible C3H/He strain, lymphocytes from C57BL/6 mice displayed markedly enhanced adenosine-generating capability due to approximately three times higher ratio of ecto-5'-nucleotidase to adenosine deaminase. Borrelia-infected C57BL/6 mice efficiently eradicated the inoculated spirochetes at more chronic stage without any signs of arthritis. Strikingly, deletion of key adenosine-generating enzyme, ecto-5'-nucleotidase/CD73, was accompanied by significantly enhanced joint swelling in borrelia-infected CD73-deficient C57BL/6 mice. Collectively, these data suggest that insufficient basal adenosine level and/or pathogen-induced disordered lymphoid purine homeostasis may serve as important prerequisite for promotion of inflammatory responses and further host's commitment to persistence of bacterial infection and arthritis development.

Methotrexate in combination with sulfasalazine is more effective in rheumatoid arthritis patients who failed sulfasalazine than in patients naive to both drugs

OBJECTIVES

For pharmacological reasons, the effect of the combination of MTX and SSZ may be different in RA patients who are naïve to these drugs compared to patients with an insufficient response to one of them. Therefore, we compared the results of randomized controlled trials (RCTs) on the combination of MTX and SSZ in naïve patients and in patients with an insufficient response to SSZ.

METHODS

A systematic literature search was performed to identify RCTs that compared the MTX-SSZ combination to either drug alone. The databases MEDLINE and the Cochrane Clinical Trials registry were searched from 1966 up to April 2007. The efficacy of the single therapeutic agents or their combination was assessed using the mean change in the disease activity score (DAS) and the ACR improvement criteria.

RESULTS

Four RCTs were identified to compare the efficacy of the combination MTX-SSZ to the efficacy of either drug alone. Two parallel trials were performed with patients naïve to both drugs and two add-on trials were performed in SSZ failures. In the trials with naïve patients, the mean DAS changes for the combination MTX and SSZ pointed to a sub-additive efficacy. In the trials with patients who previously failed to SSZ, the mean DAS changes for the combination MTX and SSZ indicated additive efficacy.

CONCLUSIONS

In RA, addition of MTX to SSZ is a therapeutic option in SSZ failures, whereas combination of MTX and SSZ in DMARD-naïve patients has no added value.