Hippocampal involvement associated with human immunodeficiency virus encephalitis in Mexico

Area of Science:

• Neuropathology
• Infectious Diseases
• Neuroscience

Background:

• Acquired immunodeficiency syndrome (AIDS) can lead to central nervous system (CNS) complications.
• Human immunodeficiency virus encephalitis (HIVE) and opportunistic CNS infections are significant concerns in AIDS patients.
• The impact of these conditions on specific brain structures, like the hippocampal formation, requires further investigation.

Purpose of the Study:

• To review CNS alterations in deceased Mexican AIDS patients, focusing on hippocampal damage.
• To correlate neuropathological findings with clinical neurological and neurobehavioral manifestations.
• To assess the prevalence of HIVE and opportunistic CNS infections in this cohort.

Main Methods:

• Retrospective autopsy review of 19 deceased Mexican patients with AIDS.
• Histopathological examination with emphasis on the hippocampal formation.
• Immunohistochemical detection of gp41-positive microglial cells to identify HIVE.

Main Results:

• Of 19 patients, 9 (47%) had CNS opportunistic infections with HIVE, 3 (16%) had opportunistic infections without HIVE, and 2 (11%) had HIVE alone.
• All patients with neurological/neurobehavioral alterations showed evidence of HIVE and/or CNS opportunistic infections.
• HIVE, identified by gp41-positive microglial cells, was present in 11 (58%) patients, with the subiculum showing the most significant infiltration.

Conclusions:

• HIV-associated lesions in the hippocampal formation may explain selective neuronal damage in this limbic structure.
• Damage to hippocampal circuitry could be implicated in the cognitive alterations observed in HIVE.
• The prevalence of HIVE and CNS opportunistic infections in this study is comparable to other series using similar detection methods.