Correlation of neuromuscular pathology in acquired immune deficiency syndrome patients with cytomegalovirus infection and zidovudine treatment.

Peripheral nerve and skeletal muscle specimens from 115 autopsied adult AIDS patients were examined for types and incidence of histological abnormalities. Focal perivascular chronic inflammatory infiltrates featuring plasma cells were found in 85% of nerve and muscle specimens. These foci were specifically associated with cytomegalovirus (CMV)-infected capillary or venous endothelial cells in neuromuscular specimens of 31/115 patients, with increasing incidence in patients surviving longer with the diagnosis of AIDS. Neuromuscular CMV was identified histologically in 19% of AIDS patients with an AIDS-defining illness for 3 months or less, with the incidence increasing to 46% of patients who had the diagnosis for 2 years or longer. Vascular damage from CMV endothelial infection may result in regional ischemic and/or inflammatory damage to nerves, producing myelinated fiber loss and axonal degeneration, leading to denervation atrophy of myofibers found in skeletal muscle specimens in a majority of the patients. Myelinated fiber loss within the sural nerve was determined by morphometric quantitation for a subset of 50 patients, and correlated with the presence of histologically identifiable neuromuscular CMV, clinical history of zidovudine administration, and chemotherapy for alleviation of Kaposi's sarcoma. CMV infection and zidovudine treatment were both positively correlated with myelinated fiber loss, while Kaposi's sarcoma chemotherapy did not independently increase the incidence of myelinated fiber loss.