Inclusion Body Myositis Treatment & Management

Updated: Jun 08, 2018
  • Author: Michael P Collins, MD; Chief Editor: Nicholas Lorenzo, MD, MHA, CPE  more...
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Treatment

Medical Care

No definitive treatment has been proven effective for s-IBM.

Early anecdotal reports documented the failure of patients to respond to steroids, methotrexate, azathioprine, and cyclophosphamide. Subsequent clinical studies of various immunosuppressive or immunomodulatory therapies have largely been disappointing. [95] Individual responses, functional improvement, or mild regional improvement in strength have been reported, but sustained remission and improvement in whole-body strength have not been demonstrated. [96]

  • A long-term observational study of a large cohort of patients in Paris and Oxford found that immunosuppressive treatments do not ameliorate sporadic inclusion body myositis and could modestly exacerbate the progression of disability. However, the results from this study are limited due to the semi-retrospective nature of data collection and possible bias in patients selected for immunosuppressive treatment. [97]

  • An open-label study of high-dose prednisone in 8 patients showed no improvement in strength or functional disability scores despite a decrease in creatine phosphokinase (CPK) and inflammatory cell infiltration. Posttreatment muscle biopsy samples showed increased vacuole formation and amyloid deposition, suggesting that mechanisms other than the inflammatory response play a role in disease propagation. [98]

  • A randomized, controlled study of oxandrolone in 19 patients reported a regional improvement in upper extremity strength, but only borderline improvement in whole-body strength. [99]

  • A randomized, controlled study of methotrexate in 44 patients likewise showed no improvement in strength despite a significant decrease in CPK levels. [100]

  • An early small, uncontrolled study reported improvement in strength in 4 patients following intravenous immunoglobulin (IVIg) treatment. [101] However, subsequent larger and placebo-controlled studies have failed to duplicate these results. [102, 23, 103] Two studies suggest some benefit in patients with severe dysphagia. [104, 105] A subsequent controlled study of IVIg in combination with prednisone likewise showed no treatment response despite a reduction in endomysial inflammation. [106]

  • An open-label, randomized study of anti-T-lymphocyte globulin treatment followed by 12 months of oral methotrexate (vs methotrexate alone) reported regional improvement in distal upper extremity strength, but continued deterioration of the proximal muscle groups. [107]

  • Beta interferon-1a at standard (30 µg IM/wk) and high-dosage (60 µg IM/wk) regimens were found to be well tolerated but produced no significant improvement in muscle strength or muscle mass. [108, 109]

  • A pilot trial of etanercept, a tumor necrosis factor (TNF) alpha blocker, did not show significant benefit in composite muscle strength scores at 6 months. However, with 12 months of treatment, slight improvement in grip strength was noted. [110] . A double-blinded, randomized, placebo-controlled study is currently underway to assess the efficacy of etanercept treatment in patients with IBM.

  • A study of alemtuzumab, a T-cell–depleting monoclonal antibody, involved 13 patients who underwent infusion of 0.3 mg/kg/d for 4 days. It reported slowed disease progression, improvement of strength in some patients, and reduction in endomysial inflammation. [111] This preliminary study holds promise for future studies.

  • Follistatin, an antagonist of the myostatin pathway, has been shown to produce a dramatic increase in muscle mass in animals. [112] These results are promising for future gene therapy trials to improve muscle mass in patients with neuromuscular disease.

  • Arimoclomol, a heat shock protein (HSP) coinducer may slow down the process of protein misfolding and aggregation. A study of its safety and efficacy in IBM is underway.

  • Lithium is an inhibitor of the glycogen synthase kinase (GSK) enzyme, the latter of which is involved in the development of phosphorylated tau (p-tau). A recent study has shown that in biopsied s-IBM muscle fibers, GSK3b activity is increased, with increased ABPP phosphorylation. Treatment with lithium showed decreased GSK3b activity, decreased amounts of total and phosphorylated ABPP and AB oligomers, and increased proteosomal function. [113] These findings suggest that treatment of patients with s-IBM with lithium may be beneficial.

  • Empiric therapies include coenzyme Q10, carnitine, and antioxidants. They may provide benefit to some patients, but, to date, none of these has been studied in a controlled clinical trial.

  • Routine follow-up visits at intervals contingent upon the progression and severity of involvement are indicated to assess the patient's strength, tolerance of exertion, and compromise in occupation or activities of daily living. Hicks has outlined a strategy for care of patients with inflammatory myopathies, including s-IBM. [114]

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Surgical Care

Muscle biopsy is performed for diagnosis.

Severe dysphagia may require cricopharyngeal myotomy or placement of a gastrostomy tube. Chemodenervation with botulinum toxin A injection into the upper esophageal sphincter has also been shown to be of benefit. [115]

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Consultations

Depending on degree of weakness, physical therapy or physiatry consultation may be useful in optimizing the patient's abilities.

If dysphagia occurs, referral to a speech therapist would be of benefit for instruction regarding swallowing techniques and aspiration precautions. In patients with severe dysphagia, referral to ear, nose, and throat (ENT) specialist is indicated for consideration of botulinum toxin injections or cricopharyngeal myotomy.

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Diet

No dietary modification is required in most cases unless symptomatic dysphagia occurs.

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Activity

Appropriate activity level depends on the condition of the patient.

Strength training and exercise regimens have been subjects of debate, given concerns that physical activity might instigate increased muscle breakdown and inflammation. However, 3 recent studies have shown that an exercise program can be instituted safely. [116, 89, 117] In the study by Arnardottir, 6 of 7 patients reported a subjective positive effect on muscle function after a 12-week exercise regimen. [89] No improvement or deterioration in strength was observed, and no increase in inflammation was noted in pretreatment and posttreatment muscle biopsy specimens. In the study by Johnson, 7 patients underwent a combined aerobic and functional exercise regimen. [117] The patients exhibited improved aerobic and functional exercise capacity and strength without significant increase in creatine kinase.

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