Neurometabolic Remodeling in Chronic Hiv Infection: a Five-Year Follow-up Multi-Voxel Mrs Study

Area of Science:

• Neuroscience
• Medical Imaging
• Infectious Diseases

Background:

• Long-term effects of continuous antiretroviral therapy (cART) on HIV-associated neurological changes are not well understood.
• Neuromyelitis optica (NMO) is an autoimmune demyelinating disease affecting the central nervous system.
• HIV infection can lead to chronic neurological injury and neuroinflammation, even with effective treatment.

Purpose of the Study:

• To assess longitudinal changes in neurometabolic profiles and neurocognitive performance in HIV-positive individuals on cART over five years.
• To investigate the relationship between neurometabolic changes and neurocognitive function in this cohort.
• To explore potential indicators of brain plasticity and persistent neuroinflammation.

Main Methods:

• Utilized multi-voxel 2D proton magnetic resonance spectroscopy (¹H-MRS) at 3T to analyze neurometabolites (NAA, Cr, Cho, mI) in specific brain regions.
• Assessed neurocognitive performance synchronously with MRS measurements over a five-year follow-up period.
• Analyzed longitudinal changes in metabolite ratios (e.g., NAA/Cr, mI/Cr) and neurocognitive scores using the Wilcoxon signed-rank test.

Main Results:

• A significant longitudinal increase in the N-acetyl-aspartate (NAA)/creatine (Cr) ratio was observed in 5 out of 12 analyzed brain voxels, with trends in three more.
• The myoinositol (mI)/creatine (Cr) ratio significantly increased in 4 out of 12 voxels.
• A trend towards increased choline (Cho)/creatine (Cr) ratio was noted in one voxel, and a significant increase in another.

Conclusions:

• Progressive increases in NAA/Cr ratios correlate with improved neurocognitive performance, suggesting brain plasticity despite chronic HIV-related neuronal injury.
• Rising mI/Cr ratios may indicate glial proliferation and ongoing neuroinflammation not fully controlled by cART.
• These findings highlight the dynamic changes in the HIV-affected brain under long-term therapy and the need for continued monitoring.