Ultrastructural findings in the cochlea of AIDS cases

Neurotologic manifestations associated with the human immunodeficiency virus (HIV-1) are poorly understood. Eight temporal bones of acquired immunodeficiency syndrome (AIDS) cases were dissected and investigated ultrastructurally to determine if pathogens and pathologic changes were present within the cochlea. Extracellular viral-like particles with morphologic characteristics of HIV-1 were identified on the tectorial membrane in three cases. Numerous viral-like particles with cores appeared trapped within lacunae along the tectorial membrane in one specimen. Intracellular viral-like particles, appearing essentially similar to identified HIV-1 particles of infected lymphocyte cultures, were found within the cytoplasm of connective tissue cells. These same cells had gradients of enlarged viral envelopes forming cisterns that contained cores and varying amounts of cistern particulate. Some sectioned profiles of enlarged cytoplasmic cisterns revealed the attachment and inward protrusion of the core from the cistern wall. Other ultrastructural findings included cytoplasmic globular-dense particulate bodies, aggregates of smaller viral-like particles, and mitochondrial changes. This demonstration of prominent viral-like particles and cochlear pathology may help to explain the neurotologic manifestations associated with HIV-1 infection.