[Muscular involvement in HIV infection]

Skeletal muscle involvement may occur at all stages of HIV-infection and represents the first manifestation of the disease in some patients. We usually classify muscle involvement in HIV-infected patients in one of the following categories: (1) HIV-associated myopathy, a myopathy that meets the criteria for polymyositis in a majority of patients, and those for acquired nemaline myopathy in some; (2) zidovudine myopathy, a reversible mitochondrial myopathy; (3) the HIV-wasting syndrome and other AIDS-associated cachexias; (4) opportunistic infections and tumoral infiltrations of the skeletal muscle; (5) vasculitic processes and iron pigment deposits; (6) HIV-associated myasthenia gravis and (7) rhabdomyolysis. Immunohistology for major histocompatibility complex class I antigen and histochemical reaction for cytochrome c oxidase are helpful in correct classification of a myopathy as HIV polymyositis or zidovudine myopathy.