Total Raltegravir Concentrations in Cerebrospinal Fluid Exceed the 50-Percent Inhibitory Concentration for Wild-Type HIV-1

HIV Neurobehavioral Research Center, University of California-San Diego, 220 Dickinson, Suite B, #8208, San Diego, CA 92103, USA.
Antimicrobial Agents and Chemotherapy (Impact Factor: 4.48). 09/2010; 54(12):5156-60. DOI: 10.1128/AAC.00507-10
Source: PubMed


HIV-associated neurocognitive disorders continue to be common. Antiretrovirals that achieve higher concentrations in cerebrospinal
fluid (CSF) are associated with better control of HIV and improved cognition. The objective of this study was to measure total
raltegravir (RAL) concentrations in CSF and to compare them with matched concentrations in plasma and in vitro inhibitory concentrations. Eighteen subjects with HIV-1 infection were enrolled based on the use of RAL-containing regimens
and the availability of CSF and matched plasma samples. RAL was measured in 21 CSF and plasma pairs by liquid chromatography-tandem
mass spectrometry, and HIV RNA was detected by reverse transcription-PCR (RT-PCR). RAL concentrations were compared to the
50% inhibitory concentration (IC50) for wild-type HIV-1 (3.2 ng/ml). Volunteers were predominantly middle-aged white men with AIDS and without hepatitis C virus
(HCV) coinfection. The median concurrent CD4+ cell count was 276/μl, and 28% of CD4+ cell counts were below 200/μl. HIV RNA was detectable in 38% of plasma specimens and 4% of CSF specimens. RAL was present
in all CSF specimens, with a median total concentration of 14.5 ng/ml. The median concentration in plasma was 260.9 ng/ml,
with a median CSF-to-plasma ratio of 0.058. Concentrations in CSF correlated with those in with plasma (r2, 0.24; P, 0.02) but not with the postdose sampling time (P, >0.50). RAL concentrations in CSF exceeded the IC50 for wild-type HIV in all specimens by a median of 4.5-fold. RAL is present in CSF and reaches sufficiently high concentrations
to inhibit wild-type HIV in all individuals. As a component of effective antiretroviral regimens or as the main antiretroviral,
RAL likely contributes to the control of HIV replication in the nervous system.

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