Immunosuppressive properties of methotrexate: apoptosis and clonal deletion of activated peripheral T cells

Methotrexate treatment affects effector but not regulatory T cells in juvenile idiopathic arthritis

OBJECTIVE

The balance between Treg and effector T cells (Teff) is crucial for immune regulation in JIA. How MTX, the cornerstone treatment in JIA, influences this balance in vivo is poorly elucidated. The aim of this study was to investigate quantitative and qualitative effects of MTX on Treg and Teff in JIA patients during MTX treatment.

METHODS

Peripheral blood samples were obtained from JIA patients at the start of MTX and 3 and 6 months thereafter. Treg numbers and phenotypes were determined by flow cytometry and suppressive function in allogeneic suppression assays. Teff proliferation upon stimulation with anti-CD3, activation status and intracellular cytokine production were determined by flow cytometry. Effector cell responsiveness to suppression was investigated in autologous suppression assays. Effector cell cytokines in supernatants of proliferation and suppression assays and in plasma were measured by cytokine multiplex assay.

RESULTS

MTX treatment in JIA did not affect Treg phenotype and function. Instead, MTX treatment enhanced, rather than diminished, CD4(+) and CD8(+) T cell proliferation of JIA patients after 6 months of therapy, independent of clinical response. Effector cells during MTX treatment were equally responsive to Treg-mediated suppression. MTX treatment did not attenuate Teff activation status and their capacity to produce IL-13, IL-17, TNF-α and IFN-γ. Similarly to Teff proliferation, plasma IFN-γ concentrations after 6 months were increased.

CONCLUSION

This study provides the novel insight that MTX treatment in JIA does not attenuate Teff function but, conversely, enhances T cell proliferation and IFN-γ plasma concentrations in JIA patients.

Skin-penetrating methotrexate alleviates imiquimod-induced psoriasiform dermatitis via decreasing IL-17-producing gamma delta T cells

Accumulating evidence has shown that the Toll-like receptor 7 agonist imiquimod (IMQ) induces psoriasiform skin inflammation in mice and that this inflammation is dependent on the IL-23/IL-17 axis. Moreover, it has been demonstrated that the main source of IL-17 is not Th17 but is dermal gamma delta (γδ) T cells in mouse psoriasiform skin. Recent advances in the understanding of immunopathogenesis of psoriasis led to an alteration in the treatment paradigm to the use of highly efficacious biologics. However, their high cost impedes the extensive use of these agents. Thus, inexpensive and safe medications are still considered valuable. In this study, we introduce the therapeutic efficacy of a newly formulated methotrexate (MTX), a chemical conjugate of MTX with cell permeable peptide, for the treatment of psoriasis. Topically applied skin-penetrating (SP)-MTX reduced the psoriasiform skin phenomenon, epidermal thickness and infiltrating immune cells into the dermis. IL-17A-producing dermal γδ T cells in the cellular infiltrate that contribute IL-23/IL-17 axis were well abrogated by SP-MTX. Furthermore, SP-MTX had no toxic effects on liver, kidney or myeloid cells, unlike systemic administration of MTX. In conclusion, topically applied SP-MTX ameliorated psoriasiform skin inflammation in mice with the criteria of clinical phenomenon, histopathology and immunology, without inducing systemic toxic effects.

Low expression of CD39 on regulatory T cells as a biomarker for resistance to methotrexate therapy in rheumatoid arthritis

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease characterized by joint destruction and severe morbidity. Methotrexate (MTX) is the standard first-line therapy of RA. However, about 40% of RA patients are unresponsive to MTX treatment. Regulatory T cells (Tregs, CD4(+)CD25(+)FoxP3(+)) are thought to play an important role in attenuating RA. To investigate the role of Tregs in MTX resistance, we recruited 122 RA patients (53 responsive, R-MTX; 69 unresponsive, UR-MTX) and 33 healthy controls. Three months after MTX treatment, R-MTX but not UR-MTX showed higher frequency of peripheral blood CD39(+)CD4(+)CD25(+)FoxP3(+) Tregs than the healthy controls. Tregs produce adenosine (ADO) through ATP degradation by sequential actions of two cell surface ectonucleotidases: CD39 and CD73. Tregs from UR-MTX expressed a lower density of CD39, produced less ADO, and had reduced suppressive activity than Tregs from R-MTX. In a prospective study, before MTX treatment, UR-MTX expressed a lower density of CD39 on Tregs than those of R-MTX or control (P < 0.01). In a murine model of arthritis, CD39 blockade reversed the antiarthritic effects of MTX treatment. Our results demonstrate that MTX unresponsiveness in RA is associated with low expression of CD39 on Tregs and the decreased suppressive activity of these cells through reduced ADO production. Our findings thus provide hitherto unrecognized mechanism of immune regulation in RA and on mode of action of MTX. Furthermore, our data suggest that low expression of CD39 on Tregs could be a noninvasive biomarker for identifying MTX-resistant RA patients.

Smoking and rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease caused by both genetic and environmental factors. Smoking has been implicated as one of the most important extrinsic risk factors for its development and severity. Recent developments have shed light on the pathophysiology of RA in smokers, including oxidative stress, inflammation, autoantibody formation and epigenetic changes. The association of smoking and the development of RA have been demonstrated through epidemiologic studies, as well as through in vivo and animal models of RA. With increased use of biological agents in addition to standard disease-modifying antirheumatic drugs (DMARDs), there has been interest in how smoking affects drug response in RA treatment. Recent evidence suggests the response and drug survival in people treated with anti-tumour necrosis factor (anti-TNF) therapy is poorer in heavy smokers, and possible immunological mechanisms for this effect are presented in the current paper.

Hepatosplenic Hodgkin lymphoma without lymphadenopathy following reversible methotrexate-associated lymphoproliferative disorder

Lymphoproliferative disorders (LPDs) occur more frequently in rheumatoid arthritis (RA) patients treated with immunosuppressive agents than in the non-RA population. However, the various forms of disease progression have not yet been elucidated in detail. We encountered a case of Epstein-Barr virus (EBV)-positive atypical polymorphous LPD in the cervical and intraabdominal lymph nodes with hepatosplenomegaly in an 88-year-old female with RA who had taken infliximab and methotrexate (MTX) for six years. Although spontaneous remission occurred following the withdrawal of infliximab and MTX, reversible LPD evolved into hepatosplenic Hodgkin lymphoma without lymphadenopathy presenting as a cholestatic febrile illness. Our findings suggest that the recurrent lesions of MTX-associated LPDs may not always coincide with the primary lesion and may present unexplained findings based on various extranodal diseases.

Analysis of humoral immune response of animals exposed to bacterial antigens

From the Aeromonas hydrophila strain, five different types of antigens such as heat killed antigen, whole cell antigen, heat killed antigen with antiserum, whole cell antigen with antiserum and nucleotide antigens were prepared and injected into the experimental fish (Catla catla) groups for the study of immunomodulation. Analysis of immunogenicity of antigens against the fish Catla catla was estimated. The A. hydrophila produced β hemolytic pattern on the blood agar plate. B lymphocyte counts using rosette forming assay revealed a significant decrement in pathogens exposed fishes as compared to controls. Fishes exposed to pathogenic strains (1/10^th sublethal concentration) for 3 weeks showed a reduction in PFC. The effect or pathogenic antigens in direct spleenic plaque forming cells (1 g M producing cells) showed a reduction in the secondary plaque forming cell in the first 3 weeks and a time- and dose-dependent decrease in primary and secondary PFC response. A remarkable observation enhancement in B cell production due to immune complex of antigens was noted in the present study. The enhancement of this type of immune responses confirms the potential of immune complexes to be used as vaccines.

LD-aminopterin in the canine homologue of human atopic dermatitis: a randomized, controlled trial reveals dosing factors affecting optimal therapy

Background

Options are limited for patients with atopic dermatitis (AD) who do not respond to topical treatments. Antifolate therapy with systemic methotrexate improves the disease, but is associated with adverse effects. The investigational antifolate LD-aminopterin may offer improved safety. It is not known how antifolate dose and dosing frequency affect efficacy in AD, but a primary mechanism is thought to involve the antifolate-mediated accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). However, recent in vitro studies indicate that AICAR increases then decreases as a function of antifolate concentration. To address this issue and understand how dosing affects antifolate efficacy in AD, we examined the efficacy and safety of different oral doses and schedules of LD-aminopterin in the canine model of AD.

Methods and Findings

This was a multi-center, double-blind trial involving 75 subjects with canine AD randomized to receive up to 12 weeks of placebo, once-weekly (0.007, 0.014, 0.021 mg/kg) or twice-weekly (0.007 mg/kg) LD-aminopterin. The primary efficacy outcome was the Global Score (GS), a composite of validated measures of disease severity and itch. GS improved in all once-weekly cohorts, with 0.014 mg/kg being optimal and significant (43%, P<0.01). The majority of improvement was seen by 8 weeks. In contrast, GS in the twice-weekly cohort was similar to placebo and worse than all once-weekly cohorts. Adverse events were similar across all treated cohorts and placebo.

Conclusions

Once-weekly LD-aminopterin was safe and efficacious in canine AD. Twice-weekly dosing negated efficacy despite having the same daily and weekly dose as effective once-weekly regimens. Optimal dosing in this homologue of human AD correlated with the concentration-selective accumulation of AICAR in vitro, consistent with AICAR mediating LD-aminopterin efficacy in AD.

Myelosuppressive and hepatotoxic potential of leflunomide and methotrexate combination in a rat model of rheumatoid arthritis

BACKGROUND

Safety of the combination of leflunomide and methotrexate was examined in several studies with inconclusive results. The present study was designed to compare the efficacy and safety of the combination of leflunomide and methotrexate in adjuvant-induced arthritis (AIA) in rats focusing on immunosuppressive and hepatotoxic effects.

METHODS

Eighty four rats were divided into seven groups. Group 1: Sham control, group 2: the vehicle control, group 3: methotrexate group, group 4-5: leflunomide (5 and 10mg/kg/day) groups, group 6-7: combination 1 and 2 [methotrexate+leflunomide (5 and 10mg/kg/day)] groups, respectively.

RESULTS

The current results indicated that combination therapies improved the ankle circumference and clinical scores compared to monotherapies; histopathological examination confirmed these findings. The myelosuppressive effect of leflunomide (10mg/kg/day) was comparable to that produced by methotrexate as indicated by the complete blood count and bone marrow cellularity; however their combination resulted in greater toxicity. Furthermore, methotrexate greatly affected the splenic histopathology compared to leflunomide and the combination therapy produced a greater effect compared to leflunomide not methotrexate. Differently, assessment of the hepatotoxic potential of the two drugs highlighted that leflunomide induced a dose-dependent increase in the fibrosis score which was higher in their magnitude than that induced by methotrexate. Leflunomide (10mg/kg/day) and combination 2 groups showed the greatest degree of liver fibrosis.

CONCLUSIONS

In rats with AIA, current drug combinations provided higher therapeutic benefit compared to monotherapies, however, greater toxicities were observed. Therefore, continuous monitoring of hematologic parameters and liver function will be recommended in clinical settings.

Update on research and clinical translation on specific clinical areas: From bench to bedside: How insight in immune pathogenesis can lead to precision medicine of severe juvenile idiopathic arthritis

Despite the enormous progress in the treatment of juvenile idiopathic arthritis (JIA), innovations based on true bench-to-bedside research, performed in JIA patients, are still scarce. This chapter describes novel developments in which clinical innovations go hand in hand with basic discoveries. For the purpose of this review, we will mainly focus on developments in severe forms of JIA, most notably systemic JIA and polyarticular JIA. However, also in less severe forms of JIA, such as oligoarticular JIA, better insight will help to improve diagnosis and treatment. Facilitating the transition from bench to bedside will prove crucial for addressing the major challenges in JIA management. If successful, it will set new standards for a safe, targeted and personalized therapeutic approach for children with JIA.

The effect of carbohydrate moiety structure on the immunoregulatory activity of lactoferrin in vitro

The aim of this study was to evaluate the immunoregulatory effects of recombinant human lactoferrin (rhLF) in two in vitro models: (1) the secondary humoral immune response to sheep erythrocytes (SRBC); and (2) the mixed lymphocyte reaction (MLR). We compared the non-sialylated glycoform of rhLF as expressed by glycoengineered Pichia pastoris with one that was further chemically sialylated. In an earlier study, we showed that sialylated rhLF could reverse methotrexate-induced suppression of the secondary immune response of mouse splenocytes to SRBC, and that the phenomenon is dependent on the interaction of lactoferrin (LF) with sialoadhesin (CD169). We found that the immunorestorative activity of sialylated rhLF is also dependent on its interaction with the CD22 antigen, a member of the immunoglobulin superfamily that is expressed by B lymphocytes. We also demonstrated that only sialylated rhLF was able to inhibit the MLR reaction. MLR was inhibited by bovine lactoferrin (bLF), a glycoform that has a more complex glycan structure. Desialylated bLF and lactoferricin, a bLF-derived peptide devoid of carbohydrates, did not express such inhibitory activity. We showed that the interaction of LF with sialic acid receptors is essential for at least some of the immunoregulatory activity of this glycoprotein.

Pediatric ulcerative colitis: a practical guide to management

Ulcerative colitis (UC) is a chronic inflammatory disorder of the gastrointestinal tract of unknown etiology that frequently presents in the pediatric population. The evaluation of pediatric UC involves excluding infection, and a colonoscopy that documents the clinical and histologic features of chronic colitis. Initial management of mild UC is typically with mesalamine therapy for induction and maintenance. Moderate UC is often initially treated with oral prednisone. Depending on disease severity and response to prednisone, maintenance options include mesalamine, mercaptopurine, azathioprine, infliximab, or adalimumab. Severe UC is typically treated with intravenous corticosteroids. Corticosteroid nonresponders should either undergo a colectomy or be treated with second-line medical rescue therapy (infliximab or calcineurin inhibitors). The severe UC patients who respond to medical rescue therapy can be maintained on infliximab or thiopurine, but 1-year remission rates for such patients are under 50 %. These medications are discussed in detail along with the initial work-up and a treatment algorithm.

The effects of prednisone and steroid-sparing agents on decay accelerating factor (CD55) expression: implications in myasthenia gravis

Decay accelerating factor (DAF) expression at the muscle endplate is an important defence against complement-mediated damage in myasthenia gravis. Previously we implicated the c.-198C>G DAF polymorphism with the development of treatment-resistant myasthenia-associated ophthalmoplegia by showing that the C>G DAF polymorphism prevented lipopolysaccharide-induced upregulation of lymphoblast DAF. We postulated that drugs used in myasthenia gravis may increase the susceptibility of extraocular muscles to complement-mediated damage and studied their effects on endogenous DAF using patient-derived lymphoblasts as well as mouse myotubes. We show that prednisone repressed C>G DAF expression in lymphoblasts and increased their susceptibility to cytotoxicity. Methotrexate, but not azathioprine or cyclosporine, increased DAF in C>G lymphoblasts. In mouse myotubes expressing wild-type Daf, prednisone also repressed Daf expression. Although cyclosporine, azathioprine, and methotrexate increased muscle Daf levels when used alone, upon co-treatment with prednisone only azathioprine maintained myotube Daf levels close to basal. Therefore, prednisone negatively influences DAF expression in C>G lymphoblasts and in myotubes expressing wild-type Daf. We speculate that myasthenic individuals at risk of developing the ophthalmoplegic complication, such as those with C>G DAF, may have inadequate endogenous levels of complement regulatory protein protection in their extraocular muscle in response to prednisone, increasing their susceptibility to complement-mediated damage.

Patients with systemic sclerosis present increased DNA damage differentially associated with DNA repair gene polymorphisms

OBJECTIVE

Patients with systemic sclerosis (SSc) exhibit increased toxicity when exposed to genotoxic agents. In our study, we evaluated DNA damage and polymorphic sites in 2 DNA repair genes (XRCC1 Arg399Gln and XRCC4 Ile401Thr) in patients with SSc.

METHODS

A total of 177 patients were studied for DNA repair gene polymorphisms. Fifty-six of them were also evaluated for DNA damage in peripheral blood cells using the comet assay.

RESULTS

Compared to controls, the patients as a whole or stratified into major clinical variants (limited or diffuse skin involvement), irrespective of the underlying treatment schedule, exhibited increased DNA damage. XRCC1 (rs: 25487) and XRCC4 (rs: 28360135) allele and genotype frequencies observed in patients with SSc were not significantly different from those observed in controls; however, the XRCC1 Arg399Gln allele was associated with increased DNA damage only in healthy controls and the XRCC4 Ile401Thr allele was associated with increased DNA damage in both patients and controls. Further, the XRCC1 Arg399Gln allele was associated with the presence of antinuclear antibody and anticentromere antibody. No association was observed between these DNA repair gene polymorphic sites and clinical features of patients with SSc.

CONCLUSION

These results corroborate the presence of genomic instability in SSc peripheral blood cells, as evaluated by increased DNA damage, and show that polymorphic sites of the XRCC1 and XRCC4 DNA repair genes may differentially influence DNA damage and the development of autoantibodies.

Tuberculosis of spine: current views in diagnosis and management

Tuberculosis is the chronic consumptive disease and currently the world's leading cause of death. Tuberculous spondylitis is a less common yet the most dangerous form of skeletal tuberculosis. The recent re-emergence of Mycobacterium tuberculosis (M. tuberculosis) hints at a possible resurgence of tuberculosis in the coming years. This article discusses the clinical manifestations, diagnosis and treatment of tuberculous spondylitis, and updates material that the author has previously published on the subject. Treatment should be individualized according to different indications which is essential to recovery. A treatment model is suggested on the basis of the author's vast personal experiences.

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.

Methotrexate induces apoptosis in nasal polyps via caspase cascades and both mitochondria-mediated and p38 mitogen-activated protein kinases/Jun N-terminal kinase pathways

BACKGROUND

Methotrexate (MTX) is a very effective treatment for chronic inflammatory diseases that induces apoptosis in nasal polyps (NPs). However, the precise apoptotic pathway in NPs remains unclear. The aim of this study was to identify the apoptotic signaling pathways activated by MTX in NPs.

METHODS

NP tissues were organ cultured using an air-liquid interface method. Cultures were maintained in the presence or absence of MTX (10 or 100 μM) for 24 hours. To investigate apoptotic signaling in NPs, we performed reverse transcription-polymerase chain reaction and Western blotting.

RESULTS

MTX-treated NPs contained significantly increased amounts of the active forms of caspase 8, caspase 9, and caspase 3 and displayed increased cleavage of poly(ADP-ribose) polymerase. Expression of the proapoptotic molecules Bax and Bad at the mRNA and protein levels and of the activated molecules p-Bad and tBid was significantly higher in MTX-treated NPs than in nontreated NPs. In contrast, expression of the antiapoptotic molecule Bcl-2 at the mRNA and protein levels was significantly lower in MTX-treated NPs than in nontreated NPs. Expression of the phosphorylated forms of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) was significantly higher in MTX-treated NPs than in nontreated NPs. In contrast, expression of the phosphorylated form of Akt was significantly lower in MTX-treated NPs than in nontreated NPs.

CONCLUSION

MTX induces apoptosis in NPs via caspase cascades and both mitochondria-mediated and p38 MAPK/JNK pathways. We suggest that MTX can be used to treat NPs.

Low-dose methotrexate results in the selective accumulation of aminoimidazole carboxamide ribotide in an erythroblastoid cell line

Therapeutic and toxic response to low-dose methotrexate (MTX) in the treatment of autoimmune disease continues to be highly variable, resulting in a critical need to identify predictive biomarkers of response. Biomarker development has been hampered by an incomplete understanding of the molecular pharmacology of low-dose MTX. To address this issue, accumulation of the substrates for aminoimidazole carboxamide ribonucleotide transformylase (AICART) and thymidylate synthase (TS) was measured as markers of pharmacological activity of MTX in an erythroblastoid cell line. A 115-fold increase in the AICART substrate and anti-inflammatory mediator, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranosyl 5'-monophosphate (ZMP), was observed following exposure to 10 nM MTX but subsequently decreased with increasing MTX concentrations, declining to baseline levels with 1000 nM MTX. In contrast, the TS substrate, 2'-deoxyuridine 5'-monophosphate disodium salt (dUMP), displayed concentration-dependent accumulation, increasing 29-, 342-, and 471-fold over baseline with 10, 100, and 1000 nM MTX, respectively. Cellular levels of dUMP correlated with levels of the parent drug (MTX-PG1; r = 0.66, P < 0.001) and its polyglutamates (MTX-PG2-6) (r = 0.81, P < 0.001), whereas cellular levels of ZMP were only moderately correlated with MTX-PG1 (r = 0.34, P < 0.01). In contrast, accumulation of ZMP at 10 nM MTX was associated with a 2.9-fold increase in the AICART inhibitor dihydrofolate (DHF), represented primarily by long-chain DHF polyglutamates. Selectivity, defined as the ratio of ZMP to dUMP, was maximal following exposure to 6 nM MTX. Characterizing the range of MTX concentrations that selectively promote ZMP accumulation while preserving pyrimidine biosynthesis may lead to optimization of low-dose MTX therapy.

Methotrexate therapy leading to a rapid progression of a previously indolent prostate cancer: is immunosuppression to blame?

Methotrexate therapy has been associated with occurrence and/or accelerated progression of malignancies. We describe a patient who developed widespread bone metastases of a previously confined to the prostate gland prostate cancer shortly after starting methotrexate therapy for rheumatoid arthritis and large granular lymphocyte leukemia. We believe an immunosuppressive milieu brought on by the methotrexate use in this case is responsible for the rapid progression of prostate cancer leading to the patient's demise. To the best of our knowledge, no association has been made to date between the therapy with methotrexate and a fulminant course of a previously indolent prostate cancer. Given its utilization in a variety of benign and malignant conditions and the ageing population, caution is advised with the use of this agent, especially in the presence of an underlying malignancy.

Esophageal sarcoidosis: a review of cases and an update

Sarcoidosis is a chronic disorder that can virtually affect any organ system in the body. Histologically, it is characterized by the presence of T lymphocytes, mononuclear phagocytes, and noncaseating granulomas. Most commonly affected are the intrathoracic structures, with 90% of the reported cases involving the lungs. Esophageal involvement in sarcoidosis is extremely rare. Dysphagia is the most common presentation in these patients and can be attributed to various mechanisms such as direct esophageal wall infiltration, extrinsic compression, cranial neuropathy, and brainstem involvement. A thorough online literature review revealed only 23 reported cases of esophageal involvement in sarcoidosis. This paper reviews these reported cases in detail along with newer diagnostic and treatment options, including direction of future therapy.

Treatment of early diffuse systemic sclerosis skin disease

Diffuse systemic sclerosis carries a high morbidity and mortality. The Prospective Registry of Early Systemic Sclerosis (PRESS), a multicentre incident cohort study of patients with early diffuse cutaneous systemic sclerosis, has the goal of advancing the understanding of disease pathogenesis and identifying novel biomarkers. In this review, PRESS investigators discuss the evidence pertaining to the more commonly used treatments for early diffuse SSc skin disease including methotrexate, mycophenolate, cyclophosphamide, azathioprine, and intravenous immunoglobulin. This review highlights the unmet need for effective treatment in early diffuse SSc as well as its more rigorous study. Nonetheless, the PRESS investigators aim to decrease intra- and inter-institutional variability in prescribing in order to improve the understanding of the clinical course of early diffuse SSc skin disease.

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.

The immunosuppressed traveler

This article reviews the normal immune response to vaccines. It describes the effect of different immunosuppressive therapies (glucocorticoids, inhibitors of calcineurin and mTOR, azathioprine, mycophenolate acid, methotrexate, depleting and nondepleting monoclonal antibodies, and tumor necrosis factor antagonists) on critical steps in the cellular and humoral immune responses to vaccines. The impact of age-related involution of thymus and bone marrow on the immune reconstitution in allogeneic hematopoietic cell transplant recipients and human immunodeficiency virus is covered. A practical approach to vaccinating and preparing travelers with severe immunosuppression is proposed.

Coran A, Sukhotnik I. Dietary transforming growth factor-beta 2 (TGF-β2) supplementation reduces methotrexate-induced intestinal mucosal injury in a rat

BACKGROUND/AIMS

Dietary supplementation with transforming growth factor-beta (TGF-β) has been proven to minimize intestinal damage and facilitate regeneration after mucosal injury. In the present study, we evaluated the effects of oral TGF-β2 supplementation on intestinal structural changes, enterocyte proliferation and apoptosis following methotrexate (MTX)-induced intestinal damage in a rat and in a cell culture model.

METHODS

Caco-2 cells were treated with MTX and were incubated with increasing concentrations of TGF-β2. Cell apoptosis was assessed using FACS analysis by annexin staining and cell viability was monitored using Trypan Blue assay. Male rats were divided into four experimental groups: Control rats, CONTR- TGF-β rats were treated with diet enriched with TGF-β2, MTX rats were treated with a single dose of methotrexate, and MTX- TGF-β rats were treated with diet enriched with TGF-β2. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined at sacrifice. Real Time PCR and Western blot were used to determine bax and bcl-2 mRNA, p-ERK, β-catenin, IL-1B and bax protein expression.

RESULTS

Treatment of MTX-pretreated Caco-2 cells with TGF-B2 resulted in increased cell viability and decreased cell apoptosis. Treatment of MTX-rats with TGF-β2 resulted in a significant increase in bowel and mucosal weight, DNA and protein content, villus-height (ileum), crypt-depth (jejunum), decreased intestinal-injury score, decreased level of apoptosis and increased cell proliferation in jejunum and ileum compared to the untreated MTX group. MTX-TGF-β2 rats demonstrated a lower bax mRNA and protein levels as well as increased bcl-2 mRNA levels in jejunum and ileum compared to MTX group. Treatment with TGF-β2 also led to increased pERK, IL-1B and β-catenin protein levels in intestinal mucosa.

CONCLUSIONS

Treatment with TGF-β2 prevents mucosal-injury, enhances p-ERK and β-catenin induced enterocyte proliferation, inhibits enterocyte apoptosis and improves intestinal recovery following MTX-induced intestinal-mucositis in rats.

Dietary folic acid promotes survival of Foxp3+ regulatory T cells in the colon

Dietary compounds as well as commensal microbiota contribute to the generation of a unique gut environment. In this study, we report that dietary folic acid (FA) is required for the maintenance of Foxp3+ regulatory T cells (Tregs) in the colon. Deficiency of FA in the diet resulted in marked reduction of Foxp3+ Tregs selectively in the colon. Blockade of folate receptor 4 and treatment with methotrexate, which inhibits folate metabolic pathways, decreased colonic Foxp3+ Tregs. Compared with splenic Tregs, colonic Tregs were more activated to proliferate vigorously and were highly sensitive to apoptosis. In colonic Tregs derived from mice fed with a FA-deficient diet, expression of anti-apoptotic molecules Bcl-2 and Bcl-xL was severely decreased. A general reduction of peripheral Tregs was induced by a neutralizing Ab against IL-2, but a further decrease by additional FA deficiency was observed exclusively in the colon. Mice fed with an FA-deficient diet exhibited higher susceptibility to intestinal inflammation. These findings reveal the previously unappreciated role of dietary FA in promotion of survival of Foxp3+ Tregs that are in a highly activated state in the colon.

Concomitant therapy with methotrexate and anti-TNF-α in pediatric patients with refractory crohn's colitis: a case series

BACKGROUND

Crohn's colitis refractory to anti-tumor necrosis factor alpha (TNF-α) therapy is commonly seen in tertiary care centers for pediatric inflammatory bowel disease (IBD). We report our experience in managing pediatric refractory Crohn's colitis with concomitant use of methotrexate and anti-TNF-α therapy.

METHODS

We reviewed records from 2007 to 2010 at the Mayo Clinic pediatric IBD center. We included all patients with Crohn's disease (CD) failing anti-TNF-α therapy who then received concomitant methotrexate. The primary endpoint was clinical remission, defined as inactive disease in accordance with the short pediatric CD activity index (PCDAI). The secondary endpoint was last day of follow-up.

RESULTS

Fourteen patients with CD received concomitant methotrexate and anti-TNF-α treatment (age, mean [range], 15.7 [6-20] years; standard deviation [SD], 3.4 years). Mean age at diagnosis was 12.5 years (range, 3-17 years; SD, 3.83 years). The male-to-female ratio was 10:4. All patients had moderate to severe disease activity using the short PCDAI and had predominately Crohn's colitis. Twelve patients were previously treated with thiopurines (85.7%). Seven patients (50%) were in clinical remission within an average of 6 weeks postmethotrexate induction. Five patients (35.7%) experienced adverse events including nausea and headache, yet only one discontinued therapy due to adverse events. Infection with Clostridium difficile was common, complicating therapy in four patients (28.6%).

CONCLUSIONS

Concomitant use of methotrexate and anti-TNF-α therapy is a promising option for children with refractory Crohn's colitis.

Non-Fas(CD95/APO1)-mediated apoptosis of activated T cells inhibits the development of atherosclerosis

Atherosclerosis is a chronic systemic inflammatory disease. The innate and adaptive immune response might be involved in atherogenesis. Methotrexate (MTX) induces apoptosis of activated T cells by a CD95-independent pathway. The aim of this study was to analyse the effect of immunomodulation by MTX in the development of early atherosclerotic vascular lesions in an animal model. Four-week old male C57BL6 LDL-receptor-deficient mice were fed a diet rich in saturated fat (82%) and cholesterol (2.8%). Thirty animals were given a weekly intramuscular injection of MTX, establishing three subgroups: 10, 30 and 50 mg/kg. Ten further mice were used as an immunocompetent control group. Aortic thickening was significantly inhibited in all MTX-treated groups compared with the control group at 30 days (0.46 ± 0.003 mm(2) in the control group vs 0.31 ± 0.002, 0.14 ± 0.009 and 0.16 ± 0.006 mm(2) in the low-, intermediate- and high-dose group, respectively; P = 0.01) and at 60 days. The aortic lumen/total area ratio was also increased in the MTX-treated groups (0.82 ± 0.06 in the control group vs 0.88 ± 0.07, 0.86 ± 0.05 and 0.88 ± 0.04, respectively; P = 0.02). Immunosuppression by MTX inhibits the development of atherosclerotic lesions in arterial vessels in mice, which highlights the crucial role of the immune system in atherogenesis.

Application of paclitaxel in low non-cytotoxic doses supports vaccination with melanoma antigens in normal mice

Chemotherapeutic agents such as paclitaxel applied in ultra-low, non-cytotoxic doses were previously shown to stimulate dendritic cell activity and anti-tumor immune responses upon vaccination in mouse transplantable tumor models. However, the mechanisms of these alterations-termed chemoimmunomodulation or chemomodulation-are still not clear. This study investigated the effect of paclitaxel applied in ultra-low, non-cytotoxic doses on the efficiency of immunization of healthy C57BL/6 mice with the peptide derived from tyrosinase related protein (TRP)-2 as a model melanoma antigen. Using an IFNγ ELISPOT assay, it was found that administration of 1 mg paclitaxel/kg in combination with the peptide vaccination strongly increased the frequencies of TRP-2 specific spleen T-cells as compared to levels due to the vaccination alone. This was associated with a significant decrease in the levels of regulatory T-cells (T(reg)) and immature myeloid cells (known as a counterpart of myeloid derived suppressor cells [MDSC] in healthy mice). Such impairments of potential immunosuppressive cells were found to correlate with a strong increase in the amount of effector CD8+ and CD4+ T-cells in the bone marrow and spleen. Furthermore, in paclitaxel-treated mice, a significant augmentation of natural killer (NK) cell numbers in the bone marrow and their ability to produce IFNγ were observed. In addition, the level of NK-T-cells in the lymph nodes was also increased. It is suggested that paclitaxel applied in ultra-low, non-cytotoxic doses may potentially enhance the efficacy of anti-tumor vaccinations by neutralizing immunosuppressive T(reg) and MDSC populations in tumor-bearing hosts.

Analysis of SF and plasma cytokines provides insights into the mechanisms of inflammatory arthritis and may predict response to therapy

OBJECTIVES

Biologic drugs have revolutionized the care of RA, but are expensive and not universally effective. To further understand the inflammatory mechanisms underlying RA and identify potential biomarkers predicting response to therapy, we measured multiple cytokine concentrations in SF of patients with inflammatory arthritides (IAs) and, in a subset of patients with RA, correlated this with response to TNF-α inhibition.

METHODS

SF from 42 RA patients and 19 non-RA IA patients were analysed for 12 cytokines using a multiplex cytokine assay. Cytokines were also measured in the plasma of 16 RA patients before and following treatment with anti-TNF-α. Data were analysed using Mann-Whitney U-test, Spearman's rank correlation and cluster analysis with the Kruskal-Wallis test with Dunn's post-test analysis.

RESULTS

RA SF contained significantly elevated levels of IL-1β, IL-1ra, IL-2, IL-4, IL-8, IL-10, IL-17, IFN-γ, G-CSF, GM-CSF and TNF-α compared with other IA SF. RA patients who did not respond to anti-TNF therapy had elevated IL-6 in their SF pre-therapy (P < 0.05), whereas responders had elevated IL-2 and G-CSF (P < 0.05). Plasma cytokine concentrations were not significantly modulated by TNF inhibitors, with the exception of IL-6, which decreased after 12 weeks (P < 0.05).

CONCLUSIONS

Cytokine profiles in RA SF vary with treatment and response to therapy. Cytokine concentrations are significantly lower in plasma than in SF and relatively unchanged by TNF inhibitor therapy. Concentrations of IL-6, IL-2 and G-CSF in SF may predict response to TNF inhibitors.

Effects of methotrexate on vascular endothelial growth factor, angiopoietin 1, and angiopoietin 2 in nasal polyps

BACKGROUND

Methotrexate (MTX) is a very effective treatment for chronic inflammatory diseases, which are often associated with increased angiogenesis. Angiogenesis is dependent on a perfectly coordinated balance between endogenous-positive and -negative regulatory factors, including vascular endothelial growth factor (VEGF) and the angiopoietins (Ang). The aim of this study was to investigate the effects of MTX on levels of VEGF, Ang-1, and Ang-2 in organ-cultured nasal polyps (NPs).

METHODS

To determine the effects of MTX, NP tissues were cultured using an air-liquid interface method. Cultures were maintained in the absence or presence of MTX (10 or 100 micromoles) for 24 hours. Hematoxylin and eosin, and TUNEL (terminal deoxynucleotidyl transferase [Tdt]-mediated dUTP-biotin nick-end labeling) staining were performed to observe apoptosis. Enzyme-linked immunosorbent assay was used to quantify tissue concentrations of VEGF, Ang-1, and Ang-2.

RESULTS

MTX treatment resulted in marked alterations in inflammatory cells, especially eosinophils. In contrast, the mucosal epithelium, microvessels including arterioles, veins and capillaries, and fibroblasts maintained their structure. TUNEL(+) cells (apoptotic cells) were seen in the MTX-treated specimens. The more induction of TUNEL(+) cells was observed 100-micromolar MTX-treated specimens. VEGF and Ang-1 levels were significantly lower, and Ang-2 levels were significantly higher in NPs treated with 100-micromolar MTX than in nontreated NPs (p < 0.01).

CONCLUSION

MTX may inhibit the growth of NPs via local regulation of VEGF, Ang-1, and Ang-2 protein levels. We suggest that MTX can be used to treat NPs.

Differential action of 3-hydroxyanthranilic acid on viability and activation of stimulated lymphocytes

Lymphocytes proliferation after antigen-driven activation leads to an increase in cell count, which could last some week, until apoptosis mechanisms allow the homeostatic control of the system. During the first days of this stimulation, activated lymphocytes display high resistance to apoptosis and to most immunosuppressive drugs. According to the literature, few compounds have been described to kill recently activated cells, by inhibiting metabolic processes fundamental to proliferation. The aim of our work was to evaluate comparatively these different compounds, in order to identify the best strategy to kill cells that have undergone proliferation, while sparing the repertoire of resting cells. After preliminary experiments, 3-HAA and bortezomib were selected as the most suitable compounds for our purposes. The possible synergic effect of 3-HAA with bortezomib or with manganese ions was also assessed. 3-HAA was confirmed to be the most reliable pharmacologic approach to inhibit proliferation with acceptable toxicity on resting cells. While in the case of PHA stimulation 3-HAA led to death of most lymphocytes, only a minor percentage of cells were killed after allo-stimulation, suggesting that the effect is proportional to the percentage of stimulated lymphocytes. Manganese ions further enhanced this effect, while results with bortezomib seemed to be less consistent. These results deserve further investigations to develop new procedures for targeting activated cells with pharmacological approaches.

Increased sensitivity to apoptosis induced by methotrexate is mediated by JNK

OBJECTIVE

Low-dose methotrexate (MTX) is an effective therapy for rheumatoid arthritis (RA), yet its mechanism of action is incompletely understood. The aim of this study was to explore the induction of apoptosis by MTX.

METHODS

Flow cytometry was performed to assess changes in the levels of intracellular proteins, reactive oxygen species (ROS), and apoptosis. Quantitative polymerase chain reaction was performed to assess changes in the transcript levels of select target genes in response to MTX.

RESULTS

MTX did not directly induce apoptosis but rather "primed" cells for markedly increased sensitivity to apoptosis via either mitochondrial or death receptor pathways, by a JNK-dependent mechanism. Increased sensitivity to apoptosis was mediated, at least in part, by MTX-dependent production of ROS, JNK activation, and JNK-dependent induction of genes whose protein products promote apoptosis. Supplementation with tetrahydrobiopterin blocked these MTX-induced effects. Patients with RA who were receiving low-dose MTX therapy expressed elevated levels of the JNK target gene, jun.

CONCLUSION

Our results support a model whereby MTX inhibits reduction of dihydrobiopterin to tetrahydrobiopterin, resulting in increased production of ROS, increased JNK activity, and increased sensitivity to apoptosis. The finding of increased jun levels in patients with RA receiving low-dose MTX supports the notion that this pathway is activated by MTX in vivo and may contribute to the efficacy of MTX in inflammatory disease.

A single-blinded trial of methotrexate versus azathioprine as steroid-sparing agents in generalized myasthenia gravis

Background

Long-term immunosuppression is often required in myasthenia gravis (MG). There are no published trials using methotrexate (MTX) in MG. The steroid-sparing efficacy of azathioprine (AZA) has been demonstrated after 18-months of starting therapy. However, AZA is considered expensive in Africa. We evaluated the steroid-sparing efficacy of MTX (17.5 mg weekly) compared with AZA (2.5 mg/kg daily) in subjects recently diagnosed with generalized MG by assessing their average monthly prednisone requirements.

Methods

The primary outcome was the average daily prednisone requirement by month between the two groups. Prednisone was given at the lowest dose to manage MG symptoms and adjusted as required according to protocol. Single-blinded assessments were performed 3-monthly for 2-years to determine the quantitative MG score and the MG activities of daily living score in order to determine those with minimal manifestations of MG.

Results

Thirty-one subjects (AZA n = 15; MTX n = 16) satisfied the inclusion criteria but only 24 were randomized. Baseline characteristics were similar. There was no difference between the AZA- and MTX-groups in respect of prednisone dosing (apart from months 10 and 12), in quantitative MG Score improvement, proportions in sustained remission, frequencies of MG relapses, or adverse reactions and/or withdrawals. The MTX-group received lower prednisone doses between month 10 (p = 0.047) and month 12 (p = 0.039). At month 12 the prednisone dose per kilogram bodyweight in the MTX-group (0.15 mg/kg) was half that of the AZA-group (0.31 mg/kg)(p = 0.019).

Conclusions

This study provides evidence that in patients with generalized MG methotrexate is an effective steroid-sparing agent 10 months after treatment initiation. Our data suggests that in generalized MG methotrexate has similar efficacy and tolerability to azathioprine and may be the drug of choice in financially constrained health systems.

Trial registration

SANCTR:DOH-27-0411-2436

TNF-α Antagonists and Immunization

Tumor necrosis factor (TNF) antagonists have proven to be very effective in the treatment of several autoimmune-mediated inflammatory diseases. The two classes of TNF antagonists-soluble TNF receptors and TNF monoclonal antibodies-have several important structural, pharmacokinetic, and functional differences. TNF antagonists interfere at different steps in the immune response to infections and vaccines. The immune response to pneumococcal polysaccharide vaccines is impaired in patients treated with methotrexate with some additional immunosuppressive effect of TNF antagonists. The secondary immune responses to inactivated and live attenuated vaccines, such as yellow fever vaccine, during treatment with TNF antagonists is mostly adequate despite significantly lower antibody levels. Little is known about the primary immune response to inactivated travel-related vaccines, but it is likely to be poor. Primary vaccination with live attenuated vaccines of patients receiving TNF antagonists should be avoided at all times.

An aqueous birch leaf extract of Betula pendula inhibits the growth and cell division of inflammatory lymphocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Leaf extracts of Betula pendula have been traditionally used for the treatment of patients with rheumatoid arthritis (RA) or osteoarthritis.

AIM OF THE STUDY

We investigated the anti-proliferative capacity of an aqueous leaf extract of Betula pendula (BPE) on human primary lymphocytes in vitro, because activated lymphocytes play a major role in the initiation and maintenance of RA.

MATERIALS AND METHODS

Lymphocyte proliferation and cell division was measured by the activity of mitochondrial dehydrogenases and by using the membrane-permeable dye carboxyfluorescein diacetate succinimidyl ester (CFSE), respectively. Apoptosis was analyzed by surface staining of phosphatidylserine and intracellular activation of effector caspases 3 and 7 in comparison to the drug methotrexate using flow cytometric and photometrical analysis. In addition, the impact of the extract on cell cycle distribution was investigated by propidium iodide staining of DNA. For the bioassays BPE concentrations of 10-160 μg/mL were investigated. A phytochemical analysis, using LC-MS and HPLC, was conducted to identify the polyphenolic constituents of the birch leaf extract.

RESULTS

Leaf extracts of Betula pendula inhibited the growth and cell division (CD8(+): 40 μg/mL: 45%; 80 μg/mL: 60%; 160 μg/mL: 87%) (CD4(+): 40 μg/mL: 33%; 80 μg/mL: 54%; 160 μg/mL: 79%) of activated, but not of resting T lymphocytes in a significant dose-dependent manner. The inhibition of lymphocyte proliferation due to apoptosis induction (compared to untreated control: 40 μg/mL: 163%; 80 μg/mL: 240%; 160 μg/mL: 348%) and cell cycle arrest was comparable to that of methotrexate. LC-MS analyses showed that the extract contains different quercetin-glycosides.

CONCLUSION

Our results give a rational basis for the use of Betula pendula leaf extract for the treatment of immune disorders, like rheumatoid arthritis, by diminishing proliferating inflammatory lymphocytes.

Distinct effects of anti-tumor necrosis factor combined therapy on TH1/TH2 balance in rheumatoid arthritis patients

The immune balance in patients with rheumatoid arthritis (RA), a disease characterized by TH1 dominance, treated by the preferred combined anti-tumor necrosis factor (anti-TNF) and methotrexate (MTX) therapy was evaluated by assessing the chemokine and cytokine receptors as well as apoptosis induction. A meta-analysis of combined therapy by TNF blockers and MTX in 15 RA patients, MTX monotherapy in 20 RA patients, and 11 diagnosed but untreated RA patients was performed by assessing several immune markers in the whole lymphocyte population, as well as in specific CD4 cells, by both flow cytometry and image analysis. A significant downregulation of CXCR3 and IL-12 receptors (both TH1 markers) and a significant increase in the chemokine receptor CCR4 and, to a lesser extent, IL-4R (both TH2 markers) were found; a particularly marked increase was found in patients treated by combined therapy. This phenomenon was pronounced in CD4 cells and was accompanied by a high proportion of apoptotic cells. The therapeutic effect of MTX and TNF blockers may be due to apoptosis induction in lymphocytes infiltrating from the inflammation site and restoring the TH1/TH2 balance.

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.

Wild Panax ginseng (Panax ginseng C.A. Meyer) protects against methotrexate-induced cell regression by enhancing the immune response in RAW 264.7 macrophages

Many traditional herbal medicines have been re-evaluated to determine whether they enhance immune responses. In this study, the possible use of wild Panax ginseng (WPG) for enhancement of host immunity in chemotherapy was investigated. In the cell proliferation assay, WPG significantly enhanced the proliferation of RAW 264.7 macrophages and protected against cell regression in macrophages treated with methotrexate (MTX). WPG induced the production of nitric oxide and the expression of inducible nitric oxide synthase and cyclooxygense-2 mRNA. Furthermore, WPG enhanced the production of cytokines including interleukin (IL)-1alpha, IL-1beta, IL-6, tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor, and chemokines such as macrophage chemotactic protein-1 and regulated upon activation, normal T-cell expressed and secreted (RANTES), regardless of MTX co-administration. Taken together, these results provide the first evidence that WPG triggers immune responses through the prevention of macrophage cell regression caused by MTX and functional activation of macrophages.

Review article: the role of non-biological drugs in refractory inflammatory bowel disease

BACKGROUND

Up to one-third of patients with inflammatory bowel disease (IBD) do not respond to, or are intolerant of conventional immunosuppressive drugs. Although biological agents are alternative treatments, they may not be suitable or available to some patients.

AIM

To review the evidence for use of nonbiological drugs in the treatment of patients with IBD refractory to corticosteroids or thiopurines.

METHODS

A literature search was performed using PubMed for English language publications with predetermined search criteria to identify relevant studies.

RESULTS

Published evidence from uncontrolled series and controlled clinical trials has been used to produce a practical approach relevant to clinical practice which incorporates the indication, optimal dose, and side effects of various therapies including tacrolimus, methotrexate, thalidomide, tioguanine, mycophenolate mofotil, leucocyte apheresis, nutritional therapy, antibiotics, probiotics, allopurinol, rectal acetarsol and ciclosporin in the treatment of patients with refractory ulcerative colitis and Crohn's disease. Approaches to optimise thiopurine efficacy are also discussed.

CONCLUSIONS

Patients with IBD refractory to corticosteroids or thiopurines may respond to alternative anti-inflammatory chemical molecules, but the evidence base for many of these alternatives is limited and further trials are needed.

[Guidelines on the use of methotrexate in psoriasis]

Psoriasis, a chronic multifactorial inflammatory disease that develops in genetically predisposed individuals, affects approximately 1.5% of the Spanish population. This disease has a negative impact on patients' quality of life, and long-term therapy is often required to control the symptoms. In addition to the classical systemic treatments (methotrexate, acitretin, cyclosporine, and ultraviolet light), the group of drugs known as biologics (etanercept, infliximab, adalimumab, and ustekinumab) provides the dermatologist with an expanded therapeutic armamentarium, thereby improving the likelihood of controlling psoriasis in patients with severe and/or extensive disease. Methotrexate, a classic antipsoriatic drug, is still very useful either as single-drug therapy or in combination with other systemic drugs, particularly as a rescue therapy or combined with biologics. This article aims to establish the role of methotrexate in the treatment of psoriasis. We considered it of interest to develop guidelines for using methotrexate in the management of psoriasis with a view to ensuring the safe and proper use of this drug in the management of psoriasis. This document was developed by consensus among members of the Psoriasis Group of the Spanish Academy of Dermatology and Venereology.