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A randomized, controlled clinical trial was started in the pre-HAART era to compare the efficacy of zidovudine (AZT) and interferon-alpha (IFN-alpha) either alone or in combination to reduce HIV viremia, maintain CD4(+) cell count, and decrease time to AIDS progression and death. The purpose of the current study was to compare the effects of AZT and IFN on HIV load using modern technology. One hundred and eighty patients with CD4(+) counts above 500 cells/mm(3) were randomized to receive AZT alone, IFN-alpha alone, or AZT and IFN-alpha in combination. CD4(+) cell count and HIV load at baseline and at the last follow-up visit were compared, and time to AIDS or death was calculated by treatment group. At a mean follow-up of 45 weeks, the mean change in log HIV RNA was -0.06 for the AZT alone group, -0.47 for the AZT plus IFN-alpha group (P = 0.01 versus AZT group), and -0.35 for the IFN-alpha alone group (P = 0.02 versus AZT group). There was no significant difference among groups in change in total CD4(+) count or in time to AIDS or death. Since treatment with IFN-alpha produces significant decreases in HIV load, additional studies of IFN-alpha as part of a combination regimen are warranted.

In order to obtain HIV-1 primary isolates in settings with limited access to donor PBMCs, a culture method was developed where patient PBMCs infected with HIV-1 were cultured together with U87.CD4 cells. Using this non-laborious method, it is possible to harvest virus solely on the basis of syncytia formation and circumventing monitoring of viral replication by CA-p24 ELISA. Primary isolates from 23 out of 33 patients (70%) were isolated successfully. From PCR amplification and sequencing of the V1V5 region of the viral gp120 envelope gene, primary isolates were compared with variants obtained from plasma and PBMCs of 13 patients. The primary isolates of seven patients (54%) resembled closely the plasma viral quasispecies, whereas different variants were isolated from the other patients (46%). Three patients harboured a dual infection, while this remained unnoticed from sequencing the plasma or PBMC compartment. The primary isolates were highly infectious for TZM-bl cells and could infect CD4-enriched lymphocytes. This study demonstrates that it is possible to grow viral isolates using a non-laborious and simple method. These isolates may be used in the field for studies on antiretroviral therapy or for vaccine trials. (C) 2010 Elsevier B.V. All rights reserved

This study evaluated correlation and agreement between version 3 of the Quantiplex human immunodeficiency virus type 1 (HIV-1) RNA assay (v3 branched DNA [bDNA]) and a sensitized Amplicor HIV-1 Monitor assay (reverse transcription [RT]-PCR) for the measurement of HIV RNA. Three hundred eighteen samples from 59 randomly selected, HIV-1-seropositive persons on various drug protocols from the National Institute of Allergy and Infectious Diseases HIV outpatient clinic were studied. The results indicate that v3 bDNA and RT-PCR are highly correlated (r 5 0.98) and are in good agreement (mean difference in log10 copies/ml 6 2 standard deviations 5 0.072 6 0.371). The relationship between values obtained by both assays is given by the following equation: log10v3 bDNA 52 0.0915 1 1.0052 z log10RT-PCR. This represents a 1.026-fold difference between log10RT-PCR values and log10v3 bDNA values. The use of highly active antiretroviral therapy in patients with human immunodeficiency virus type 1 (HIV-1) infection has resulted in an increase in the number of CD4 1 T lymphocytes as well as in a reduction in plasma virus load (2, 4‐6). In order to assess the magnitude of viral load reduction and the occurrence of rebound virus due to drug failure or noncompliance, it is necessary to use as sensitive a viral quantitation assay as is available. There are two widely used techniques to achieve these ends: the Amplicor HIV-1 Monitor assay (reverse transcription [RT]-PCR) and the Quantiplex HIV-1 RNA assay (branched DNA [bDNA]). The Amplicor HIV-1 Monitor assay is an in vitro nucleic acid target amplification (PCR) test for the quantitation of HIV-1 RNA in human plasma, while the Quantiplex HIV-1 RNA assay is a signal amplification nucleic acid probe assay for HIV-1 quantitation. The most current versions of these assays have a quantitative detection limit of 50 copies (3, 7, 8, 11). Because patients may be tested with both of these assays at some point in their treatment, it is useful to determine how the resulting values are related to each other and, ideally, to develop some formula for their comparison. We hypothesize that tests designed to measure the same thing, albeit in different ways, will show a quantifiable relationship to each other; not only will they correlate, but they will show agreement. Previous reports comparing Amplicor with Quantiplex version 2.0 have indicated that although the results show a high correlation, they show poor agreement (9, 10). In this study, we compared two of the commercially available assays for the measurement of HIV RNA, the Quantiplex version 3 assay (3) and a sensitized version of the HIV-1

Experimental conditions affecting the successful propagation of HIV-1 from the plasma of seropositive individuals were examined. It was determined that whole blood samples collected with lithium heparin as the anticoagulant, immediate plasma separation, and immediate culturing were best suited for obtaining viable virus from plasma. Virus was isolated by infecting fresh phytohemagglutinin-stimulated normal donor peripheral blood mononuclear cells (PBMCs) with plasma followed by weekly cocultivation with new target cells. The plasma virus isolation rate was the greatest and HIV-1 titers were the highest for those individuals with less than 200 CD4+ cells/mm3 and decreased as the level of CD4+ cells approached normal values. We were able to obtain positive cultures from 29.5% of those patients with CD4+ counts greater than 500/mm3. HIV-1 titers in plasma also correlated with high serum p24 antigen levels when serum was treated with glycine to dissociate antigen-antibody complexes.