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ABSTRACT Cells that actively transcribe HIV-1 have been defined as the “active viral reservoir” in HIV-infected individuals. However, important technical limitations have precluded the characterization of this specific viral reservoir during both treated and untreated HIV-1 infections. Here, we used a novel single-cell RNA fluorescence in situ hybridization-flow cytometry (FISH-flow) assay that requires only 15 million unfractionated peripheral blood mononuclear cells (PBMCs) to characterize the specific cell subpopulations that transcribe HIV RNA in different subsets of CD4+ T cells. In samples from treated and untreated HIV-infected patients, effector memory CD4+ T cells were the main cell population supporting HIV RNA transcription. The number of cells expressing HIV correlated with the plasma viral load, intracellular HIV RNA, and proviral DNA quantified by conventional methods and inversely correlated with the CD4+ T cell count and the CD4/CD8 ratio. We also found that after ex vivo infection of unstimulated PBMCs, HIV-infected T cells upregulated the expression of CD32. In addition, this new methodology detected increased numbers of primary cells expressing viral transcripts and proteins after ex vivo viral reactivation with latency reversal agents. This RNA FISH-flow technique allows the identification of the specific cell subpopulations that support viral transcription in HIV-1-infected individuals and has the potential to provide important information on the mechanisms of viral pathogenesis, HIV persistence, and viral reactivation. IMPORTANCE Persons infected with HIV-1 contain several cellular viral reservoirs that preclude the complete eradication of the viral infection. Using a novel methodology, we identified effector memory CD4+ T cells, immune cells preferentially located in inflamed tissues with potent activity against pathogens, as the main cells encompassing the transcriptionally active HIV-1 reservoir in patients on antiretroviral therapy. Importantly, the identification of such cells provides us with an important target for new therapies designed to target the hidden virus and thus to eliminate the virus from the human body. In addition, because of its ability to identify cells forming part of the viral reservoir, the assay used in this study represents an important new tool in the field of HIV pathogenesis and viral persistence.

Background: Lipoatrophy is the most stigmatizing side effect of stavudine therapy. We assessed the long-term effects of replacing stavudine with tenofovir in HIV-infected patients with lipoatrophy. Method: Prospective switch study. Sixty-two clinically stable patients with antiretroviral therapy (ART) containing stavudine, HIV-1 RNA <50 copies/mL, and lipoatrophy at least in the face on physical examination were included. All patients switched from stavudine to tenofovir without changing any other drug. Objective (malar ultasonography, bioelectrical impedance analysis) and subjective measures of lipoatrophy were assessed. Results: Median age at baseline was 40 years, 44 patients (71%) were male, and median time on stavudine was 4.8 years. Median malar fat thickness increased 0.8 mm (25%) 24 months after switching. Total fat mass increased 3.9 kg (21%). Plasma lactate levels decreased significantly, mainly in patients with baseline hyperlactatemia (from 3.05 to 1.19 mmol/L). Significant improvement in total cholesterol (−12%), triglycerides (−31%), and total cholesterol/HDL cholesterol ratio (−11%) was observed at Month 24. Conclusions: In this study, switching from stavudine to tenofovir maintained durable virologic suppression when the HAART regimen included a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor, led to a slow improvement of lipoatrophy, and improved the lipid profile and lactate levels with excellent tolerability. These results support the proactive change of stavudine to tenofovir. [ABSTRACT FROM AUTHOR]

Objectives To assess plasma steady-state pharmacokinetics (PK) of rifampicin, isoniazid, saquinavir and ritonavir in HIV and tuberculosis (TB) co-infected patients, and investigate potential interactions between TB drugs and protease inhibitors (PIs). Methods Open-label, single-arm, sequential PK study including 22 patients with HIV infection and TB. During the first 2 months, patients received rifampicin, isoniazid and pyrazinamide, with or without ethambutol (first PK study, n = 22). Then patients stopped pyrazinamide and ethambutol and started once-daily antiretroviral therapy (ART) with didanosine, lamivudine, ritonavir (200 mg) and saquinavir (1600 mg) (second PK study, n = 18). Patients stopped all TB drugs after 9 months continuing the same ART (third PK study, n = 15). Differences between TB drug parameters in the first and second PK studies, and between PI parameters in the second and third PK studies were used to assess interactions. Results Rifampicin and isoniazid pharmacokinetics did not change substantially with saquinavir and ritonavir. A significant 39.5%, 34.9% and 48.7% reduction in median saquinavir AUC0–24, Cmax and Ctrough, respectively, was seen with rifampicin and isoniazid. Ritonavir AUC0–24, Cmax and Ctrough decreased 42.5%, 49.6% and 64.3%, respectively, with rifampicin and isoniazid. Conclusions There was a significant interaction between saquinavir, ritonavir and rifampicin, with reduction in median plasma concentrations of saquinavir and ritonavir. Saquinavir should be given with caution in patients receiving rifampicin. Twice-daily dosing or higher saquinavir doses in once-daily administration should be tested to obtain more appropriate plasma levels. [ABSTRACT FROM AUTHOR]