Successful treatment of alveolar hypoventilation due to dermatomyositis with anti-tumour necrosis factor-alpha

The role of bDMARDs in idiopathic inflammatory myopathies: A systematic literature review

Idiopathic inflammatory myopathies (IIM) are a group of different conditions typically affecting striate muscle, lung, joints, skin and gastrointestinal tract. Treatment typically relies on glucocorticoids and synthetic immunosuppressants, but the occurrence of refractory, difficult to treat, manifestations, may require more aggressive treatment, borrowed from other autoimmune diseases, including biologic disease modifying drugs (bDMARDs). In this regard, we conducted a systemic literature review in order to depict the current evidence about the use of bDMARDs in IIM. A total of 78 papers, published during the last 21 years, were retrieved. The majority of patients was treated with TNF-α inhibitors, whose effectiveness was assessed particularly in recalcitrant striate muscle, skin and joints involvement. Rituximab, whose evidence is supported by a large number of real-life studies and trials, seems to be an excellent option in case of ILD and anti-synthetase syndrome, while Tocilizumab, despite not meeting primary and secondary endpoints in a recently published clinical trial, proved its effectiveness in rapidly progressing ILD. Similarly, Abatacept, studied in a phase IIb clinical trial with conflicting evidence, was reported to be effective in some case reports of refractory dermatomyositis. Less data exist for anti-IL1 and anti-IL23 agents, which were employed particularly for inclusion body myositis and severe skin disease, respectively. This study provides an organ-focused assessment of bDMARDs in IIM, which display encouraging results in the treatment of refractory subsets of disease.

The effects of infliximab in treating idiopathic inflammatory myopathies: A review article

Anti-TNF treatment may be useful for patients with idiopathic inflammatory myopathies (IIMs). The purpose of this study is to assess the efficacy of infliximab (IFX) in the management of IIMs. Two databases (ie, PubMed and China National Knowledge Infrastructure) were searched up to Nov 2020 for studies investigating skin lesions and muscular weakness in patients with IIMs treated with IFX. A total of 18 studies were included. One hundred and eighteen patients were identified, including 58 adult patients and 60 patients with juvenile dermatomyositis (JDM) treated with IFX. Among these patients, 110 (93%) patients with refractory cases. In addition to glucocorticoids, patients from 15/18 studies received immunosuppressant agents (ISAs) concomitantly with IFX, among which methotrexate (MTX) was most common. After treatment with IFX, skin lesions and muscle strength were improved in 67% of patients with DM and 75% of patients with JDM, respectively. Skin calcinosis was improved in 21/34 (62%) of patients with JDM. Only 55% (12/22) of patients with polymyositis exhibited improvements in muscle strength. Lastly, 40% (42/104) of patients reported adverse events. Current evidence appears to support the use of IFX in some patients with refractory IIMs, especially those with JDM. The most common adverse reaction was infection. Large, randomized-controlled studies should be carried out to confirm these findings.

Cytokines in immune-mediated inflammatory myopathies: cellular sources, multiple actions and therapeutic implications

The idiopathic inflammatory myopathies are a heterogeneous group of disorders characterised by diffuse muscle weakness and inflammation. A common immunopathogenic mechanism is the cytokine-driven infiltration of immune cells into the muscle tissue. Recent studies have further dissected the inflammatory cell types and associated cytokines involved in the immune-mediated myopathies and other chronic inflammatory and autoimmune disorders. In this review we outline the current knowledge of cytokine expression profiles and cellular sources in the major forms of inflammatory myopathy and detail the known mechanistic functions of these cytokines in the context of inflammatory myositis. Furthermore, we discuss how the application of this knowledge may lead to new therapeutic strategies for the treatment of the inflammatory myopathies, in particular for cases resistant to conventional forms of therapy.

New onset of dermatomyositis/polymyositis during anti-TNF-α therapies: a systematic literature review

We performed a systematic search of databases from 1990 to 2013 to identify articles concerning the new onset of dermatomyositis/polymyositis (DM/PM) in patients treated with anti-TNF-α therapy. We retrieved 13 publications describing 20 patients where the new onset of DM/PM after anti-TNF-α therapy was recorded. 17 patients were affected by rheumatoid arthritis (RA), one by Crohn's disease, one by ankylosing spondilytis, and one by seronegative arthritis. In 91% of the cases antinuclear autoantibodies were detected after the introduction of anti-TNF-α therapy. In 6 patients antisynthetase antibodies were detected and other clinical findings as interstitial lung disease (ILD) were recorded. Improvement of DM/PM after anti-TNF suspension (with the concomitant use of other immunosuppressors) was recorded in 94% of cases. The emergence of DM/PM and antisynthetase syndrome seem to be associated with the use of anti-TNF-α agents, especially in patients with chronic inflammatory diseases (mainly RA) with positive autoantibodies before therapy initiation. In particular, physicians should pay attention to patients affected by RA with positive antisynthetase antibodies and/or history of ILD. In those cases, the use of the TNF-α blocking agents may trigger the onset of PM/DM or antisynthetase syndrome or may aggravate/trigger the lung disease.

Cutaneous dermatomyositis: an updated review of treatment options and internal associations

Dermatomyositis is a specific type of inflammatory myopathy with characteristic cutaneous findings. Patients may have skin disease without clinically apparent muscle disease, but this disorder is best thought of as a systemic process. Therefore, all patients with dermatomyositis skin lesions need appropriate evaluation for muscle disease, esophageal dysfunction, cardiopulmonary disease, and potential internal malignancy. There are many therapies that have been used for patients with dermatomyositis, but most are based upon case series or expert opinion rather than meta-analyses or randomized, placebo-controlled trials. Even those therapies that have been subjected to randomized, blinded, placebo-controlled trials include a mixture of patients with idiopathic inflammatory myopathy and do not utilize a validated assessment tool for measuring cutaneous disease responses. In this review, we discuss the therapies available as well as the internal associations with dermatomyositis.

A randomized, pilot trial of etanercept in dermatomyositis

OBJECTIVE

The aims of this pilot study were to assess (1) the safety and tolerability of etanercept in dermatomyositis (DM); (2) the feasibility and safety of a forced prednisone taper; and (3) outcome measures, including those recommended by the International Myositis Assessment Clinical Study (IMACS) group.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial of etanercept (50mg subcutaneously weekly) for 52 weeks in DM subjects. Subjects were tapered off prednisone in a standardized schedule as tolerated over the initial 24 weeks of the study. Principal outcomes included adverse events, time from randomization to treatment failure (inability to wean off prednisone on schedule), and average prednisone dosage after week 24.

RESULTS

Sixteen subjects were randomized, 11 to etanercept and 5 to placebo. There were no significant differences in adverse event rates between the treatment groups, although 5 etanercept-treated and 1 placebo-treated subjects developed worsening rash. All 5 subjects receiving placebo were treatment failures (median time to treatment failure 148 days). In contrast, 5 of 11 subjects in the etanercept arm were successfully weaned off prednisone; the median time to treatment failure in this group was 358 days (p = 0.0002). The median of the average prednisone dosage after week 24 was 29.2mg/day in the placebo group and 1.2mg/day in the etanercept group (p = 0.02). IMACS and other outcome measures demonstrated excellent test-retest reliability (intraclass correlation coefficients 0.79-0.99). There was no significant treatment effect on functional outcome.

INTERPRETATION

The findings of no major safety concerns and a steroid-sparing effect in our study suggest that further investigation of etanercept as a treatment for DM is warranted.

Idiopathic inflammatory myopathies: definition and management of refractory disease

Adult idiopathic inflammatory myopathies, commonly referred to as myositis, are a heterogeneous group of diseases with an autoimmune etiology. In this review, the authors are going to focus on myositis excluding inclusion body myositis. They will review the prognostic factors (for mortality and response to steroids), define refractory disease, introduce a new concept (presumed refractory disease), analyze definitions of active disease, damage and improvement criteria, and summarize therapeutic alternatives for refractory patients, based on different disease phenotypes.

Tumor necrosis factor-alpha as a potential therapeutic target in idiopathic inflammatory myopathies

The cytokine, tumor necrosis factor alpha (TNFα), has been implicated in many aspects of immune system development, immune response regulation, and T cell-mediated tissue injury. TNFα plays a less well-defined role in the pathogenesis of the idiopathic inflammatory myopathy (IIM) group of disorders, and has been considered a potential therapeutic target. Observational studies of TNFα-blockade in (mostly refractory) IIM have yielded inconsistent beneficial results so that administration of these biological agents is presently deemed an unreliable alternative treatment strategy. Moreover, anti-TNFα therapy has the rare potential to trigger myositis in patients with rheumatoid arthritis, hinting at a pre-existing "overlap disorder". The full potential of TNFα-antagonism will be realized only if randomized controlled trials ascertain appropriate treatment regimens and identify patient subgroups most likely to benefit from such therapy.

Advances in the therapy of idiopathic inflammatory myopathies

PURPOSE OF REVIEW

To review progress in areas pertinent to the development of better therapies for the idiopathic inflammatory myopathies.

RECENT FINDINGS

New classification criteria for the idiopathic inflammatory myopathies have been proposed in an effort to define disease subsets with more uniform prognoses and responses to therapy. Diseases that may mimic the idiopathic inflammatory myopathies can be differentiated more accurately with molecular testing and biochemical and immunohistochemical analysis of muscle tissue. Advances in our understanding of the pathogenesis of the idiopathic inflammatory myopathies have served to identify potential new therapeutic targets. International collaborative study groups have reached consensus on outcome measures and on the optimal design of clinical trials in the idiopathic inflammatory myopathies. Tumor necrosis factor-alpha antagonists, rituximab, and the calcineurin inhibitors are being used to treat the idiopathic inflammatory myopathies, but their efficacy has not yet been tested in randomized clinical trials.

SUMMARY

Future advances in the development of therapies for the idiopathic inflammatory myopathies have been enabled by recent progress in myositis classification, differential diagnosis, basic science, and clinical trial design. Preliminary studies suggest that calcineurin inhibitors, tumor necrosis factor antagonists, and rituximab may be effective treatments.

[Recent research developments in polymyositis/dermatomyositis]

The idiopathic inflammatory myopathies, polymyositis (PM) and dermatomyositis (DM), are evaluated as systemic autoimmune diseases without the pathology determined. Past immunohistochemical findings suggested that the effector response is driven predominantly by CD4 T cells and by humoral immunity in DM, and by cytotoxic T cells in PM. However, histological observations of muscle tissue do not necessarily distinguish DM and PM. Thus, the two diseases including amyopathic DM might represent a spectrum of illness in which some patients suffer only from a muscle disease or from a skin disease. In comparison with research studies on other rheumatic diseases, there are much fewer research studies conducted on PM/DM. The relationship between PM and DM is not clear yet. We reviewed past clinical and basic research on the pathology of PM/DM, including research on relevant T cells, B cells and cytokines.

The treatment and prognosis of dermatomyositis: an updated review

Dermatomyositis (DM) is an idiopathic inflammatory myopathy. The mainstay of treatment for DM is oral corticosteroids. However, the dose and length of treatment is debated. Adding to the confusion, there have been no randomized controlled studies comparing the use of various corticosteroid doses and taper rates, and no controlled long-term studies assessing the hypothesis that, unlike systemic lupus erythematous, patients with DM can often achieve long-term remission off therapy. This literature review supports an approach that prednisone should be started at about 1 mg/kg/d, which is then tapered slowly based on the response. As patients respond differently to prednisone, additional therapies may be necessary. When to initiate these therapies requires clinical judgment. In addition, as we learn more about the pathophysiology of DM, newer medications that target specific mechanisms in the immune response may help us better treat the disease. Evidence-based data with long-term follow-up will allow for selection of the best treatment to maximize long-term remission, not simply short-term lowering of the systemic corticosteroid dose.

Tumor necrosis factor-alpha in inflammatory myopathies: pathophysiology and therapeutic implications

OBJECTIVES

To present, in an organized fashion, data from the medical literature on the possible role of tumor necrosis factor (TNF)-alpha in the pathogenesis of dermatomyositis (DM) and polymyositis (PM), as well as recent clinical studies where TNF-inhibition was used as a treatment for myositis.

METHODS

PUBMED was searched from 1966 to the present using the terms: TNF-alpha, TNF-inhibitors, dermatomyositis, polymyositis, myositis, and inflammatory myopathy. In addition, relevant abstracts from major recent rheumatology meetings were retrieved.

RESULTS

Several studies that employed immunostaining and polymerase chain reaction analysis in muscle biopsy specimens from patients with inflammatory myopathies showed increased presence of TNF-alpha and its soluble receptors in inflamed muscle. One genetic study proposed an association between DM and the -308A TNF polymorphism. Abnormally high levels of TNF-alpha in the muscle may be directly toxic to myofibers, while preventing muscle regeneration. Furthermore, TNF-alpha may induce, or augment, the production of other pro-inflammatory cytokines such as interleukin (IL)-1, monocyte chemotactic protein-1, IL-6, and IL-8. These findings have prompted some investigators to use off-label, TNF-inhibitors in DM/PM patients, especially if they had failed corticosteroids, immune gamma-globulin, and traditional immunosuppressive agents. The results from these early, uncontrolled, studies have been promising.

CONCLUSION

TNF-alpha may have a role in the pathogenesis of the myositis and has emerged as a possible therapeutic target. Larger, carefully controlled studies are needed to confirm the results from early studies and clearly define the efficacy and safety of anti-TNF agents in the treatment of inflammatory myopathies.

Treatment of early and refractory dermatomyositis with infliximab: a report of two cases

The idiopathic inflammatory myopathies embody the largest group of acquired and potentially treatable causes of skeletal muscle weakness. The three major groups of this disorder are polymyositis (PM), dermatomyositis (DM), and inclusion body myositis. Corticosteroids continue to be the mainstay of initial treatment in the majority of cases of PM/DM. The treatment of refractory disease can be challenging despite the utilization of the medications currently available. We report two patients with refractory DM who were treated with infliximab. We describe their presentation, clinical course, treatment, and outcomes.

Polymyositis/dermatomyositis-associated lung disease: analysis of a series of 81 patients

The objective of this study was to assess the prevalence, clinical, histological and immunological characteristics, and the long-term outcome of polymyositis- (PM) and dermatomyositis- (DM) associated lung disease, and to define subgroups of lung-associated inflammatory myopathies. This retrospective study included 81 consecutive patients diagnosed with PM/DM. Pulmonary involvement was systematically investigated in relation to clinical symptoms by chest radiography, high resolution computed tomography and pulmonary function testing. Anti-synthetase autoantibodies (ASA) were analysed by ELISA and confirmed by protein and RNA immunoprecipitation methods. Statistical analyses were done with the Student t-test and Fisher exact test. Cumulative survival probabilities were estimated by the Kaplan-Meier method and Cox regression analysis. Fifty patients (61%) presented pulmonary involvement. Thirty-two (39%) had interstitial lung disease and five of them had devastating acute interstitial pneumonia with pneumomediastinum and an unfavorable prognosis. Histology showed diffuse alveolar damage in this subgroup and ASA were negative. Eighteen patients (22%) presented restrictive myopathic lung disease; in three of them respiratory muscles could not maintain ventilation. ASA were positive in 17 of the 50 patients (34%) and were significantly associated with interstitial lung disease (OR: 4.5 [95% CI: 1.3-15.3]), arthritis (OR: 6.0 [95% CI: 1.3-29.2]) and 'mechanic hands' (OR: 8.5 [95% CI: 1.7-41.4]); the presence of these autoantibodies did not imply worse survival prognosis. We concluded that clinical and immunological characteristics allowed the grouping of patients into different types of PM/DM lung-associated disease. Presence of ASA did not affect survival. ASA-negative patients with acute interstitial pneumonitis and pneumomediastinum had an unfavorable prognosis.