Maraviroc concentrations in cerebrospinal fluid in HIV-infected patients.

OBJECTIVE: To determine maraviroc (MVC) concentrations in cerebrospinal fluid (CSF) in HIV-infected patients. METHODS: Twelve CCR5+ HIV-1 adult antiretroviral-experienced patients receiving MVC-containing regimens for at least 1 month were enrolled. Both CSF and blood samples were taken around 12 hours after the last MVC dose. liquid chromatography tandem mass spectrometry was used to determine MVC concentrations, and HIV-1 viral load was determined by real-time polymerase chain reaction, (LOD, 40 copies/mL). RESULTS: Twelve blood and 12 CSF samples were collected. Median CD4 count was 281(120-759) cells per microliter, and median HIV-1 viral load was <40 copies per milliliter. Median time on MVC was 13.5 weeks (4-60). Nucleoside analogues (tenofovir/didanosine) were given in only 1 case. Median MVC concentrations in plasma were 124.75 (7.3-517) ng/mL. In all except one, CSF sample-receiving an erroneous MVC dose while taking concomitantly nevirapine-MVC concentrations [2.58 (<0.5-7.22) ng/mL] were within the EC(90) range (0.06-10.70). Median MVC CSF: plasma ratio was 0.022 (0.004-0.17), and when the free MVC plasma concentration was used, 0.094 (2.58-27.44). CSF viral load was <40 copies per milliliter in all 9 patients with undetectable plasma viral load. CONCLUSIONS: MVC achieves concentrations within the EC(90) range in CSF. All patients with undetectable plasma viral load although receiving nucleoside-sparing regimens including new drugs showed viral suppression in CSF.

Cerebrospinal fluid maraviroc concentrations in HIV-1 infected patients.

In order to assess the penetration of maraviroc to the central nervous system, we measured maraviroc concentrations in cerebrospinal fluid (CSF) and plasma. Concentrations were determined by liquid chromatography tandem mass spectrometry (lower limit of quantitation 1.25 ng/ml) in seven paired CSF and plasma samples. The median plasma maraviroc concentration was 94.9 ng/ml (range 21.4-478.0) and the median CSF concentration was 3.63 ng/ml (range 1.83-12.2). CSF samples exceeded the median EC90 for maraviroc (0.57 ng/ml) by at least three-fold. The CSF levels of maraviroc found in this study likely contribute to viral suppression in the CSF.

Enfuvirtide cerebrospinal fluid (CSF) pharmacokinetics and potential use in defining CSF HIV-1 origin.

BACKGROUND: Enfuvirtide is a potent inhibitor of systemic HIV-1 replication, but its penetration into the human central nervous system (CNS) has not been analysed. Here, we define cerebrospinal fluid (CSF) enfuvirtide pharmacokinetics and present a case illustrating the use of enfuvirtide as a probe to trace the origins of CSF HIV-1 quasispecies. METHODS: Enfuvirtide CSF pharmacokinetics were assessed in 18 CSF and plasma sample pairs from four HIV-1-infected individuals. Enfuvirtide levels were measured by liquid chromatography tandem mass spectrometry using known standards and controls that included spiked CSF samples from untreated, HIV-negative individuals. A segment of the gp41 coding region encompassing the heptad repeat HR-1 and HR-2 domains was amplified from selected CSF and plasma samples and independent clones sequenced to assess resistance-associated mutations. RESULTS: CSF and plasma samples obtained between 2 and 20 h after enfuvirtide injection showed plasma concentrations similar to previous reports (mean 3.687 SD +/- 1.828 mg/ml) with prolonged decay. By contrast, enfuvirtide in all CSF samples was below the assay detection limit of 0.025 mg/ml. In one individual, who developed a transient increase in CSF HIV-1 RNA, seven of seven CSF and plasma clones had identical enfuvirtide resistance-associated V38A mutations, suggesting that the CSF quasispecies derived from that of blood. CONCLUSIONS: Enfuvirtide penetration into CSF is negligible; thus, in clinical settings, where direct CNS drug exposure is crucial, this drug Is not likely to directly contribute to the local therapeutic effect. Enfuvirtide can be used as a tool to dissect the origin of the CNS virus.