Hepatitis C virus populations in the plasma, peripheral blood mononuclear cells and cerebrospinal fluid of HIV/hepatitis C virus-co-infected patients.

BACKGROUND: Chronic hepatitis C virus (HCV) infection has occasionally been associated with diseases of the central nervous system, thus suggesting that the virus has a direct effect on cerebral function. OBJECTIVE: To investigate the presence and heterogeneity of HCV populations in the cerebrospinal fluid (CSF), plasma and peripheral blood mononuclear cells (PBMC) of HIV-infected and anti-HCV-positive patients. METHODS: Reverse transcriptase-polymerase chain reaction was used to detect HCV RNA in 21 paired CSF/plasma samples and 20 PBMC samples from HIV/HCV-positive patients. HCV was genotyped by means of a hybridization assay, and its compartmental heterogeneity was analysed by cloning the related amplicons. RESULTS: All of the plasma samples, 14 out of 20 PBMC samples and five out of 21 CSF samples were positive for HCV RNA. Of the five patients with HCV-positive CSF, two had the same genotype in the plasma/CSF/PBMC samples, two had a different genotype in the CSF from that in plasma and PBMC, and one had the same genotype in paired CSF/plasma samples. An analysis of the HCV populations showed that two patients seemingly infected with the same genotype in different compartments harbored mixed infection in the CSF but not in the plasma and PBMC samples. CONCLUSIONS: These findings of different HCV genetic diversification in different compartments suggest that CSF is an independent site of viral replication and persistence.

Few modifications of the Cobas Amplicor HIV Monitor 1.5 test allow reliable quantitation of HIV-1 proviral load in peripheral blood mononuclear cells.

Recent studies have suggested that monitoring the amount of HIV provirus in peripheral blood mononuclear cells (PBMCs) may be a useful end point for HAART where, in combination with plasma viral load, it provides additional information as to the possibility of virus eradication. In the present study, a modified version of the Cobas Amplicor HIV-1 Monitor test (CAHIM), currently used to quantify plasma viremia, have been evaluated to also measure the amount of proviral DNA in PBMCs. The analytical and clinical performance of the modified CAHIM test was assessed by quantifying different amounts of a standard HIV-DNA preparation obtained from the 8E5 cell line and by analysing 165 patients and controls samples. In these experiments, the modified test, that showed a linear dynamic range from 1.7 to 4.7 log10 copies/10(6) cells (r = 0.99) with a maximum CV of 20%, proved able to detect and quantify HIV-DNA in all but one clinical samples, with concentrations varying from 1.3 to 3.8 log10 copies/10(6) cells. During anti-retroviral treatment, the assay revealed different proviral DNA time courses associated with viral load changes and inversely correlated with CD4+ cells count. As expected, HIV-DNA was always detectable even when plasma viremia fell below the CAHIM cut-off. The modified CAHIM test specificity was confirmed by testing 20 HIV-negative samples in triplicates. Taken together, the data showed that the modified CAHIM test can be used to monitor HIV proviral DNA changes during HAART and can help in investigating further the clinical use of this marker.