Methotrexate therapy in asthma increases T cell susceptibility to corticosteroid inhibition

Pharmacological targeting of allergen-specific T lymphocytes

Allergic disorders are the result of a complex pathophysiology, involving major cellular lineages and a multitude of humoral factors of the innate and adaptive immune system, and have the tendency to involve multiple organs. Consequently, even standard pharmacological treatment of allergies is rarely specific but usually targets more than one pathway/cellular system at a time. Accordingly, many of the classic anti-allergic drugs have a critical impact also on T helper cells, which are pivotal not only during the sensitization but also the maintenance phase of allergic diseases. Recent years have seen a dramatic increase of novel drugs with the potency to interfere, more or less specifically, with T lymphocyte function, which might, possibly together with classic anti-allergic drugs, help harnessing one of the central cellular players in allergic responses. A major theme in the years to come will be a thoughtful combination of previously established with recently developed treatment modalities.

Specificity and sensitivity of glucocorticoid signaling in health and disease

Endogenous glucocorticoids regulate a variety of physiologic processes and are crucial to the systemic stress response. Glucocorticoid receptors are expressed throughout the body, but there is considerable heterogeneity in glucocorticoid sensitivity and induced biological responses across tissues. The immunoregulatory properties of glucocorticoids are exploited in the clinic for the treatment of inflammatory and autoimmune disorders as well as certain hematological malignancies, but adverse side effects hamper prolonged use. Fully understanding the molecular events that shape the physiologic effects of glucocorticoid treatment will provide insight into optimal glucocorticoid therapies, reliable assessment of glucocorticoid sensitivity in patients, and may advance the development of novel GR agonists that exert immunosuppressive effects while avoiding harmful side effects. In this review, we provide an overview of mechanisms that affect glucocorticoid specificity and sensitivity in health and disease, focusing on the distinct isoforms of the glucocorticoid receptor and their unique regulatory and functional properties.

Weekly low-dose methotrexate for reduction of Global Initiative for Asthma Step 5 treatment in severe refractory asthma: study protocol for a randomized controlled trial

BACKGROUND

Patients with chronic severe asthma (CSA) have a crippling disease and current available treatments are not satisfactory. Thus, management of CSA remains a major unmet need. Although the evidence from existing randomized controlled trials fails to support a definite role for immunomodulatory drugs in these patients due to major methodologic drawbacks, findings with low-dose methotrexate (MTX) are encouraging. However, larger and well-designed clinical trials are required to establish the beneficial role of MTX in CSA, and for the detection of the key characteristics of those who are going to respond to this drug.

METHODS/DESIGN

Patients will be recruited from the accessible asthmatic patients lists of tertiary referral centers. All patients will meet the stringent diagnostic criteria for CSA, including the requirement for the regular use of Global Initiative for Asthma (GINA) Global Strategy for Asthma Management and Prevention Step 5 medications (oral prednisone and/or omalizumab). The experimental design of the proposed study will take the form of a double-blind parallel-randomized placebo-controlled trial consisting of a total of eight visits, including run-in and run-out periods. Patients will be randomly allocated to receive either MTX or a matched placebo once a week as an add-on therapy to their existing medication after run-in. Physiological, laboratory and clinical assessments will be measured regularly throughout the study and compared with baseline assessments.

DISCUSSION

We expect that MTX will reduce Step 5 medications dosage in patients with CSA without compromising the overall disease control. Improvement in several indicators of asthma severity and control will be also investigated.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02124226 (assigned 25 April 2014).

New treatments for severe treatment-resistant asthma: targeting the right patient

Guidelines for asthma management focus on the use of combination inhaled treatment with corticosteroids and longacting β-agonists for symptomatic asthma. In more severe disease, other drugs such as leukotriene blockers and slow-release oral theophylline are added, with oral corticosteroids and anti-immunoglobulin E treatment with omalizumab for the most severe cases of asthma. Once-daily longacting β-agonists and inhaled corticosteroids are being developed. Longacting muscarinic antagonists might also provide additive benefit. New approaches are needed for the treatment of severe asthma, but patients need to be endotyped so that they can be directed for specific treatments. This Review focuses on the role of eosinophilic and neutrophilic inflammation, the attributes of chronic airflow obstruction, and the notion of corticosteroid insensitivity because potential targets for treatment have started to emerge from such analyses. How the best phenotypic or even better, the best endotypic responder with each new treatment, can be established will also be discussed. Newer treatments for asthma will emerge from better endotyping, leading to personalised medicine in asthma.

Methotrexate: can it be a choice for nasal polyposis in aspirin exacerbated respiratory disease?

Nasal polyposis (NP) is considered a subgroup of chronic rhinosinusitis and is commonly associated with asthma, bronchiectasis, and cystic fibrosis. A certain subgroup of nasal polyposis is known as Aspirin Exacerbated Respiratory Disease (AERD), previously called Samter's Triad or aspirin triad, comprising polyposis, asthma, and aspirin hypersensitivity and makes up almost 10% of cases of NP. Therapy of NP involves a combination of medical and surgical treatments. However, recurrences are common, particularly in patients with asthma and aspirin hypersensitivity. Both topical and systemic corticosteroids form the mainstay of conservative therapy for NP as well as a primary treatment and prevention for recurrences. They have been shown to improve nasal breathing, rhinitis symptoms, and reduce the size of NP, along with the rate of recurrence. There is great concern about the adverse effects of systemic steroids, especially when long-term usage is necessary to maintain improvement. So far, no knowledge exists about the effects of methotrexate (MTX) on NP of the patients with asthma. We report two patients whose NP dramatically reduced in size after a course of MTX therapy administered as an additional treatment for their steroid- dependent asthma.

Effect of folic acid on methotrexate induction of sulfotransferases in rats

Our earlier investigation showed that MTX is an inducer of rat and human sulfotransferases. Here we report that folic acid treatment inhibited MTX induction of aryl sulfotransferase (AST-IV) in female rat liver and hydroxysteroid sulfotransferase (STa) in male rat liver. This is important for understanding the clinical mechanisms of MTX.

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

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

A rational approach to the management of severe refractory asthma

Severe refractory asthma is a heterogeneous condition with different patterns of severity and different reasons for loss of asthma control. The three main patterns include asthma with frequent exacerbations, asthma with irreversible airway obstruction, and asthma with reduced sensitivity or resistance to corticosteroids. Each of these patterns has distinct risk factors. The assessment of patients with severe asthma requires a systematic, diagnostic and management protocol. The majority of patients will benefit from thorough analysis and treatment of aggravating factors. In some patients with severe refractory asthma, in particular those with concomitant chronic rhinosinusitis, long-term administration of systemic corticosteroids may be necessary. In these patients all efforts should be directed towards reducing the dose of corticosteroids as much as possible. Although several corticosteroid-sparing agents and immunosuppressants have been proposed in the literature, none of these has gained complete acceptance in clinical practice, either because of limited efficacy or unacceptable adverse effects. Novel potent anti-inflammatory therapies aimed at reducing the need for systemic corticosteroids in patients with severe, refractory asthma are urgently needed.

Methotrexate therapy of oral corticosteroid-dependent asthmatics reduces serum immunoglobulins: correlation with clinical response to therapy

BACKGROUND

Concomitant methotrexate (MTX) therapy of oral corticosteroid (CS)-dependent asthmatics has been shown to spare CS therapy, but the mechanism is unknown. In a previous report, we showed that MTX increases T cell inhibition by CS. In this report we focus on effects of MTX on immunoglobulin concentrations and their possible clinical relevance.

OBJECTIVE

To monitor changes in circulating leucocytes and Ig in a group of these patients during MTX therapy, and to relate these changes to clinical 'response' as defined by oral CS reduction.

METHODS

Sixteen severe asthmatics dependent on oral prednisolone 15 (7.5-25) mg/day in addition to high dose inhaled CS were treated with MTX 15 mg intramuscularly, weekly for 28 weeks. Prednisolone dosages were maintained constant for 12 weeks then reduced systematically over the next 16 weeks provided that asthma control did not deteriorate. Patients were classified a priori as 'responders' or 'non-responders' to MTX (reduction of initial oral prednisolone requirement by >or=50% or <50%, respectively). Patients were followed-up for a further 12 weeks after MTX withdrawal. Serum Ig and differential blood leucocyte counts were measured at baseline, 12, 28 and 40 weeks.

RESULTS

MTX therapy allowed significant, but individually variable, reductions in oral prednisolone dosages (P<0.00001) without alteration of lung function or symptoms. This was associated with significant reductions in mean serum concentrations of Ig of all classes, which reversed following MTX withdrawal. Reductions in IgE and IgG were significantly greater in the MTX 'responders' as compared with 'non-responders', and changes in IgE, IgG and IgM correlated with changes in prednisolone requirements. Differential blood leucocyte counts showed no significant variation.

CONCLUSION

MTX therapy reduced oral CS requirements in these severe asthmatics to a degree which correlated with reduced circulating Ig but not lymphopaenia, suggesting a possible cause and effect relationship. These reductions might also contribute to the documented incidence of opportunistic infection in these circumstances.