🔬 Other

Inclusion Body Myositis

Also known as: IBM, Sporadic Inclusion Body Myositis (sIBM)

Inclusion Body Myositis (IBM) is a rare, acquired muscle disease characterized by progressive muscle weakness and wasting, predominantly affecting the muscles of the thighs, forearms, and fingers. It is the most common acquired muscle disease in people over the age of 50. The condition progresses slowly over years, leading to significant disability.

ICD-10: G72.4 Orphanet: 606 OMIM: 600737
👥 1-9 / 1,000,000 Prevalence
🔬 25 Active Trials

Inclusion Body Myositis is a rare disease that makes your muscles weak, especially in your legs, arms, and fingers. It happens mostly to older people and gets worse slowly over time. Doctors can help you stay strong with exercises and sometimes medicines, but there is no cure.

Signs & Symptoms

  • Progressive muscle weakness
  • Muscle wasting (atrophy)
  • Dysphagia (difficulty swallowing)
  • Knee extension weakness
  • Finger flexor weakness
  • Foot drop
  • Asymmetric weakness
  • Decreased grip strength
  • Fatigue
  • Muscle pain (myalgia) - less common

Treatment Options

THERAPY FDA Approved

Physical Therapy

SUPPORTIVE
THERAPY FDA Approved

Occupational Therapy

SUPPORTIVE
THERAPY FDA Approved

Speech Therapy

SUPPORTIVE
MEDICATION FDA Approved

Intravenous Immunoglobulin (IVIg)

MODERATELY EFFECTIVE
MEDICATION FDA Approved

Immunosuppressants (e.g., Methotrexate, Azathioprine)

MODERATELY EFFECTIVE
MEDICATION FDA Approved

Corticosteroids (e.g., Prednisone)

MODERATELY EFFECTIVE
MEDICATION

Alemtuzumab

EXPERIMENTAL

Diagnosis

  • Physical examination
  • Muscle biopsy (gold standard; reveals rimmed vacuoles and amyloid deposits)
  • Electromyography (EMG)
  • Blood tests (Creatine kinase levels may be mildly elevated)
  • MRI of muscles

History

Inclusion Body Myositis was first described as a distinct entity in the 1960s and 1970s, differentiating it from other inflammatory myopathies like polymyositis. The identification of rimmed vacuoles and amyloid deposits in muscle biopsies led to its recognition as a unique disease with a distinct pathophysiology.

Recent Breakthroughs

2022

Identification of novel autoantibodies in IBM patients

Research has identified novel autoantibodies targeting specific muscle proteins in a subset of IBM patients, potentially providing new diagnostic and therapeutic targets.

2023

Clinical trial of experimental drug targeting muscle inflammation shows promise

A phase II clinical trial of an experimental drug targeting muscle inflammation in IBM patients demonstrated improvements in muscle strength and function in some participants.