Inclusion body myositis and myopathies

Sporadic inclusion body myositis is a frequent, acquired, adult-onset vacuolar myopathy affecting proximal and distal muscles with a distinct, easily identifiable clinical pattern. Although its primary cause is still unknown, autoimmune, viral, and degenerative processes, alone or in combination, are being considered. A uniform and sustained therapeutic response using the currently available immunomodulatory agents has not yet been achieved. Hereditary, inherited noninflammatory rimmed vacuolar myopathies with similar histologic features, collectively called hereditary inclusion body myopathies, are being redefined with the use of molecular genetics. The implications of the recent advances in clinical and basic sciences are discussed in the present review.