Altered Glymphatic System in Middle-Aged cART-Treated Patients With HIV: A Diffusion Tensor Imaging Study

Area of Science:

• Neuroscience
• Immunology
• Radiology

Background:

• The brain's glymphatic system clears waste and maintains homeostasis.
• HIV infection and its treatment (cART) can impact brain function and lead to neurocognitive disorders (HAND).
• The precise role of the glymphatic system in HIV and HAND remains unclear.

Purpose of the Study:

• To investigate the impact of HIV and cART on the glymphatic system.
• To identify potential MRI biomarkers for HAND.
• To explore the relationship between glymphatic function, cART, and cognitive impairment in HIV patients.

Main Methods:

• Diffusion tensor image analysis along the perivascular space (ALPS) was used to assess glymphatic function in HIV patients on cART and healthy controls.
• Guided and unguided ALPS approaches were employed.
• MRI data were correlated with cognitive tests, CD4+ T-cell counts, and CD4+/CD8+ ratios.

Main Results:

• Glymphatic function, measured by the ALPS index, significantly increased in HIV patients on cART.
• Changes in glymphatic clearance correlated with attention, working memory, abstract/executive function, and learning/memory.
• Duration of cART was associated with cognitive performance.

Conclusions:

• MRI provides evidence of HIV-induced glymphatic system alterations.
• Increased glymphatic activity may be a compensatory response to HIV-related brain changes.
• ALPS index evaluation is clinically important for assessing glymphatic function and may offer therapeutic targets for HAND.