Publication Abstract Display
Type: Poster
Title: Highly precise measurements of HIV DNA in CSF and blood by droplet digital PCR.
Authors: Oliveira M, Gianella S, Letendre S, Scheffler K, Kosakovsky Pond S, Smith D, Strain M, Ellis R
Date: 02-23-2015
Abstract:Background: We investigated associations between HIV DNA reservoir dynamics in cerebrospinal fluid (CSF) and blood in subjects with or without antiretroviral therapy (ART), to better understand the dynamics of these critical targets for eradication, and to gauge how well the HIV DNA reservoir in anatomic compartments can be predicted by measurements in peripheral blood. Methods: We analyzed paired peripheral blood mononuclear cells (PBMC) and CSF cell pellets from 29 chronically HIV infected subjects with or without ART. Genomic DNA was extracted from PBMC using silica-based columns, while CSF cell pellets were directly lysed. Levels of HIV DNA (pol gene) were measured by digital droplet PCR (ddPCR) and normalized to cell numbers measured with RPP30. Non-parametric tests of associations between levels of HIV DNA and RNA in CSF and blood were carried out. Results: We investigated 20 subjects with undetectable HIV RNA (<50 copies/ml in blood plasma and CSF) and 9 subjects with detectable HIV RNA (median of 4.22 log10 HIV RNA in blood and 4.11 log10 HIV RNA in CSF). The median CD4 count was 498 (interquartile range [IQR]: 362-637). Patients on ART were mostly on regimens including a protease-inhibitor (86%)) had a median time of ART exposure of 6.2 years (IQR: 4.6-11.6) and a median CNS penetration effectiveness (CPE) value of 7 (IQR: 7-7.8). HIV DNA was detected in 19 (66%) CSF pellets, including 10 (50%) samples in which HIV RNA was undetectable in CSF. HIV DNA levels in CSF cells positively correlated with HIV DNA levels in PBMC (P=0.03) and with HIV RNA in CSF (P=0.05) but not with the number of CSF leukocytes. Levels of HIV DNA in PBMC positively correlated with HIV RNA levels in blood (p=0.001). Similarly, the levels of HIV RNA significantly correlated between both compartments (P<0.0001). Interestingly, while levels of HIV DNA in blood were significantly lower in subjects on suppressive ART compared to untreated participants (P=0.01), HIV DNA levels in CSF did not differ between treated and untreated participants. Conclusions: Levels of HIV DNA and RNA correlated within and between blood and CSF compartments. However, suppressive ART was associated with lower HIV DNA levels in blood but not in CSF cells, despite relatively high CPE values. The HIV DNA reservoir in the CNS may not be effectively targeted with highly potent ART.

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