Treatment of refractory polymyositis and dermatomyositis

A Narrative Review of Acthar Gel for the Treatment of Myositis

Idiopathic inflammatory myopathies (IIMs) are autoimmune disorders characterized by symmetric proximal muscle weakness and chronic inflammation, with an increased risk of morbidity and mortality. The current standard of care includes traditional immunosuppressive pharmacotherapies; however, some patients cannot tolerate or do not adequately respond to these therapies, highlighting the need for alternative treatments for refractory disease. Acthar^® Gel (repository corticotropin injection) is a naturally sourced mixture of adrenocorticotropic hormone analogs and other pituitary peptides that has been approved by the US Food and Drug Administration since 1952 for use in patients with two subgroups of IIMs, dermatomyositis (DM) and polymyositis (PM). However, it has not been routinely used in the treatment of IIMs. While Acthar may induce steroidogenesis, it also has a steroid-independent mechanism of action by exerting immunomodulatory effects through the activation of melanocortin receptors on immune cells, such as macrophages, B cells, and T cells. Recent clinical trials, retrospective analyses, and case reports add to the growing evidence suggesting that Acthar may be effective in patients with DM and PM. Here we review the current evidence supporting the safety and efficacy of Acthar for the treatment of refractory DM and PM.

Advantage of administering tacrolimus for improving prognosis of patients with polymyositis and dermatomyositis

AIM

The purpose of this study was to investigate the therapeutic advantage of administering tacrolimus (TAC) in patients with polymyositis (PM) and dermatomyositis (DM).

METHODS

We retrospectively analyzed the clinical outcomes after initiating treatment in 66 patients with PM/DM (28 PM and 38 DM). After initiating treatment, the prognosis was compared between patients who received TAC in combination with prednisolone (PSL) (the concomitant TAC group), and patients who were treated with PSL alone. The therapeutic efficacy of TAC was also evaluated for patients in the concomitant TAC group as well as patients who started additional TAC treatment after relapse (the additional TAC group), by analyzing clinical results, including serum creatine kinase (CK) levels, muscle strength and the daily dose of PSL.

RESULTS

Patients in the concomitant TAC group had significantly lower frequency of relapse and longer periods of remission than patients who were treated with PSL alone (P = 0.0001, P = 0.001, respectively). Significant decreases in CK levels were observed 1 month after starting TAC treatment in both the concomitant TAC group and the additional TAC group. Moreover, the significant effects of withdrawing PSL were also demonstrated in both groups.

CONCLUSION

Concomitant use of TAC with PSL clearly provides a favorable outcome in patients with DM/PM. Furthermore, additional treatment with TAC is useful for improving prognosis even after recurrence.

Evaluation of muscles affected by myositis using magnetic resonance elastography

INTRODUCTION

Idiopathic inflammatory myopathies (IIMs, or myositis) represent a group of autoimmune diseases that result in decreased muscle strength and/or endurance. Non-invasive tools to assess muscle may improve our understanding of the clinical and functional consequences of myopathies and their response to treatment. In this study we examine magnetic resonance elastography (MRE), a non-invasive technique that assesses the shear modulus (stiffness) of muscle, in IIM subjects.

METHODS

Nine subjects with active myositis completed the MRE protocol. Participants lay in a positioning device, and scans of the vastus medialis (VM) were taken in the relaxed state and at two contraction levels. Manual inversion was used to estimate the stiffness.

RESULTS

A significant reduction in muscle stiffness was seen in myositis subjects compared with healthy controls during the "relaxed" condition.

DISCUSSION

The use of non-invasive technologies such as MRE may provide greater understanding of the pathophysiology of IIM and improve assessment of treatment efficacy.

The use of cyclosporine in dermatology: part I

Cyclosporine is a calcineurin inhibitor that acts selectively on T cells. It has been used in dermatology since 1997 for its US Food and Drug Administration indication of psoriasis and off-label for various other inflammatory skin conditions, including atopic dermatitis, blistering disorders, and connective tissue diseases. In the last decade, many dermatologists have hesitated to use this important drug in their clinical practices because of its toxicity profile. The purpose of this article is to review the mechanism of action of cyclosporine and its current uses and dosing schedules. It is our goal to create a framework in which dermatologists feel comfortable and safe incorporating cyclosporine into their prescribing regimens.

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to describe the mechanism of action of cyclosporine, recognize the potential role of cyclosporine in dermatology and the evidence to support this role, and incorporate cyclosporine into his or her prescribing regimens.

Atheroprotective effects of methotrexate on reverse cholesterol transport proteins and foam cell transformation in human THP-1 monocyte/macrophages

OBJECTIVE

To determine whether methotrexate (MTX) can overcome the atherogenic effects of cyclooxygenase 2 (COX-2) inhibitors and interferon-gamma (IFNgamma), both of which suppress cholesterol efflux protein and promote foam cell transformation in human THP-1 monocyte/macrophages.

METHODS

Message and protein levels of the reverse cholesterol transport proteins cholesterol 27-hydroxylase and ATP-binding cassette transporter A1 (ABCA1) in THP-1 cells were evaluated by real-time polymerase chain reaction and immunoblot, respectively. Expression was evaluated in cells incubated in the presence or absence of the COX-2 inhibitor NS398 or IFNgamma, with and without MTX. Foam cell transformation of lipid-laden THP-1 macrophages was detected with oil red O staining and light microscopy.

RESULTS

MTX increased 27-hydroxylase message and completely blocked NS398-induced down-regulation of 27-hydroxylase (mean +/- SEM 112.8 +/- 13.1% for NS398 plus MTX versus 71.1 +/- 4.3% for NS398 alone; P < 0.01). MTX also negated COX-2 inhibitor-mediated down-regulation of ABCA1. The ability of MTX to reverse inhibitory effects on 27-hydroxylase and ABCA1 was blocked by the adenosine A2A receptor-specific antagonist ZM241385. MTX also prevented NS398 and IFNgamma from increasing transformation of lipid-laden THP-1 macrophages into foam cells.

CONCLUSION

This study provides evidence supporting the notion of an atheroprotective effect of MTX. Through adenosine A2A receptor activation, MTX promotes reverse cholesterol transport and limits foam cell formation in THP-1 macrophages. This is the first reported evidence that any commonly used medication can increase expression of antiatherogenic reverse cholesterol transport proteins and can counteract the effects of COX-2 inhibition. Our results suggest that one mechanism by which MTX protects against cardiovascular disease in rheumatoid arthritis patients is through facilitation of cholesterol outflow from cells of the artery wall.

Fidelity of gamma-glutamyl transferase (GGT) in differentiating skeletal muscle from liver damage

This study tested the hypothesis that gamma-glutamyl transferase (GGT) can be used as a reliable biomarker to distinguish skeletal muscle from liver damage. Twenty-eight Duchenne muscular dystrophy subjects with proven dystrophin gene mutations were enrolled. Included were 14 ambulatory and 14 nonambulatory patients with approximately half of each cohort taking corticosteroids. Twenty normal males served as controls. Initial blood samples for serum GGT and creatine kinase were taken between 8AM and 9AM and redrawn 8 hours later to test for variability. Between blood draws, subjects resumed normal activities in a play environment or could leave the clinic. Not a single duchenne muscular dystrophy patient showed a GGT outside the control range at any time point, while creatine kinase levels were 14 to 200 times normal. Validation of this finding is essential for management of patients with muscle disorders exposed to potentially hepatotoxic drugs for clinical management or monitoring subjects participating in clinical trials.