Inclusion body myositis: advancements in diagnosis, pathomechanisms, and treatment.

OBJECTIVE

To review new advances in inclusion body myositis (IBM) and discuss them in light of current knowledge on diagnosis, pathomechanisms, and treatment perspectives.

RESULTS

IBM is a treatment refractory inflammatory myopathy in middle-aged patients that leads to a slow, relentlessly progressive muscle weakness, and atrophy. Recent data collections suggest that mortality in IBM patients is somewhat elevated compared with the general population. One major risk factor for death is severe dysphagia, which can now be determined by a novel real-time MRI technique. Recently, proposed diagnostic criteria with a combination of clinical and histopathological features have improved sensitivity and specificity. cytosolic 5'-nucleotidase 1A antibodies have been characterized in IBM patients and their pathophysiologic role has recently been studied. New inflammatory pathomechanisms have been identified in IBM muscle and may help to design novel treatment strategies. A broad spectrum of immunosuppressive and immunomodulatory trials have been conducted, but - so far- no effective treatment is available. Current therapeutic attempts aim to block the myostatin pathway or restore the protein homeostasis.

CONCLUSIONS

The expanding knowledge of the complex disease, the refinement of diagnostic criteria, and developments in diagnostic procedures are expected to foster the much needed design of new treatment approaches for future clinical trials.