Neuromuscular disorders associated with hepatitis B virus infection.

Approximately 400 million worldwide are chronically infected with the hepatitis B virus (HBV). During the course of illness, approximately 20% of patients develop disease manifestations outside the liver. Neuropathy develops in approximately 5% of patients with chronic HBV infection and rarely during acute HBV infection. The pathogenesis of the various HBV-associated neuropathy syndromes possibly involves deposition of immune complexes in nerves or blood vessel walls. Direct viral infection of nerves has not been demonstrated. Management entailed supportive care with antiviral and immunomodulatory treatment as clinically indicated. Rare cases of muscle disease, mostly inflammatory myopathy, have been associated with HBV infection. Presumably, HBV-associated antigens trigger immune mechanisms directed against components of muscle tissue. There is no evidence of replicative virus infection of muscle fibers. Management entailed immunomodulatory treatment, occasionally with anti-HBV therapy. Physicians should be aware that HBV infection has the potential to trigger presumed immune-mediated neuromuscular syndromes.