Antiretroviral Treatment Alters Relationship between Mcp-1 and Neurometabolites in HIV Patients

Abstract

Objective

The relationships between neurometabolites and macrophage chemoattractant protein (MCP-1) in serum and cerebrospinal fluid (CSF) were evaluated in HIV patients before and after antiretroviral treatment. Design: Prior studies found higher CSF MCP-1 levels in patients with HIV-associated dementia compared to those in neuroasymptomatic. We hypothesized that CSF MCP-1 levels would correlate inversely to neuronal metabolites [including N-acetyl compounds, gluta-mate+glutamine, as assessed by principal component analyses (PCA)] and positively to glial metabolites (including myo-inositol and choline compounds).

Methods

Thirty-nine antiretroviral-naive HIV patients were evaluated prospectively with proton magnetic resonance spectroscopy (¹H MRS), and serum and CSF MCP-1 measurements prior to highly active antiretroviral therapy (HAART); 31 of these patients completed follow-up studies after 3 months of HAART but only 24 had follow-up CSF studies.

Results

After HAART, brain metabolites and clinical signs showed no change despite improvements in systemic (CD4 counts, plasma viral load, MCP-1) and CSF (viral load and MCP-1) variables. CSF, but not serum, MCP-1 levels correlated inversely with the neuronal component (from PCA) prior to treatment (r=-0.59, P=0.0008). Conversely, after 3 months of HAART, the glial component (from PCA) correlated positively with CSF MCP-1 levels (r=0.70, P=0.0002; ANCOVA interaction for treatment status, P=0.003).

Conclusions

These findings suggest that higher CSF MCP-1 levels are associated with neuronal dysfunction in untreated patients. After 3 months of HAART, the decreased systemic factors (viral burden, systemically derived MCP-1) no longer associate with neuronal dysfunction, but subjects with the strongest glial response in the brain continue to produce the highest levels of MCP-1.