Abnormalities of peripheral nerve in patients with human immunodeficiency virus infection.

The purpose of this study was to assess systematically morphology of peripheral nerves from patients with human immunodeficiency virus infection (acquired immunodeficiency syndrome [AIDS] and AIDS-related complex) examined at autopsy. Sural nerve specimens were taken from 25 patients (mean age 44 years) and evaluated by routine procedures used in our laboratory. In 13 cases no detectable abnormality was seen. Twelve patients (48%) showed loss of myelinated fibers with disproportionately greater loss of large myelinated fibers. Three of these patients showed severe myelinated fiber loss; 2 had no documented symptoms and no other known predisposing factors for a peripheral neuropathy. Changes suggestive of wallerian degeneration were occasionally seen, as were epineurial and endoneurial inflammatory infiltrates. Segmental demyelination was not identified in any nerve examined. Electron microscopy revealed thickened basement membranes around small blood vessels, Schwann cells, and fibroblasts. Peripheral nerve abnormalities in patients with AIDS or ARC are frequent and their pathogenesis remains unclear.