HIV-1 RNA levels in cerebrospinal fluid and plasma and their correlation with opportunistic neurological diseases in a Brazilian AIDS reference hospital.

Background: Plasma HIV RNA levels reflect systemic viral replication but in CNS it may occur relatively independent of systemic infection, yet clinical application of CSF HIV-1 RNA levels is less clear.

Objective: To compare CSF and plasma HIV-1 RNA levels of patients with different opportunistic neurological diseases to those without neurological disease, as well as to correlate these levels with the outcome of the disease and use of HAART.

Method: 97 patients who had lumbar puncture for routine work up of suspected neurological diseases, were divided in 2 groups: without neurological disease (23) and with neurological disease (74). NASBA was used for plasma and CSF HIV RNA.

Results: Median CSF viral load was higher in toxoplasmic encephalitis, cryptococcal meningitis, HIV dementia and neurological diseases without a defined etiology when compared to patients without neurological disease. There was no difference between plasma viral load in patients with and without neurological diseases. Median viral load was higher in plasma and CSF among patients who died when compared to those successfully treated. CSF and plasma viral load were lower in patients with opportunistic diseases on HAART than without HAART.

Conclusion: CSF viral load was higher in patients with any neurological disease, but this difference was not present in plasma viral load, suggesting that neurological disease influences more the CSF than plasma compartments. Notwithstanding different neurological diseases were not possible to be differentiated by the levels of CSF HIV-1.