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At least 163 records · Page 9Linked to original sources
PubMed2006

Hiv-specific secretory IgA in breast milk of HIV-positive mothers is not associated with protection against HIV transmission among breast-fed infants.

OBJECTIVES: To test whether secretory immunoglobulin A (sIgA) to human immunodeficiency virus (HIV) antigens in breast milk of HIV-positive women is associated with protection against HIV transmission among breast-fed infants. STUDY DESIGN: Nested, case-control design in which HIV-specific sIgA was measured in breast milk collected from 90 HIV-positive women enrolled in a study in Lusaka, Zambia. Milk samples were selected to include 26 HIV-positive mothers with infected infants (transmitters) and 64 mothers with uninfected infants (nontransmitters). RESULTS: HIV-specific sIgA was detected more often in breast milk of transmitting mothers (76.9%) than in breast milk of nontransmitting mothers (46.9%, P = .009). There were no significant associations between HIV-specific sIgA in breast milk and other maternal factors, including HIV RNA quantities in breast milk, CD4 count, and plasma RNA quantities. CONCLUSIONS: HIV-specific sIgA in breast milk does not appear to be a protective factor against HIV transmission among breast-fed infants.

Adult↗
PubMed2001

The effects of an HIV-1 immunogen (Remune) on viral load, CD4 cell counts and HIV-specific immunity in a double-blind, randomized, adjuvant-controlled subset study in HIV infected subjects regardless of concomitant antiviral drugs.

OBJECTIVE: We examined the activity of an HIV-1 immunogen (Remune) on viral load, CD4 cells and HIV-1 specific immunity. METHODS: Plasma and peripheral blood mononuclear cells were obtained in a predefined random subset of subjects (n = 252) from a multicentre, double-blind, adjuvant-controlled phase III clinical endpoint study. RESULTS: The subjects treated with the HIV-1 immunogen had a significantly greater decline in viral load at multiple time points (P < 0.05), a trend towards increased CD4+ T cell counts and significantly enhanced HIV-1 specific immune responses as measured by HIV-1 lymphocyte proliferation (P < 0.001) compared to the adjuvant control group. Furthermore, in the HIV-1 immunogen treated group, enhanced HIV-1 specific lymphocyte proliferative immune responses were associated with decreased HIV-1 plasma RNA. CONCLUSION: These results suggest that, in a predefined, random subset of subjects, a beneficial effect of the HIV-1 immunogen was observed on viral load, CD4+ T cells, and HIV-specific immunity. These differences were observed in a background of multiple drug therapies. Ongoing trials are evaluating the effect of the combination of this HIV-1 specific, immune-based therapy with potent antiviral drug therapy on virological outcomes.

AIDS Vaccines↗
PubMed1993

Regulation of HIV production by blood mononuclear cells from HIV-infected donors: II. HIV-1 production depends on T cell-monocyte interaction.

Cell-cell interactions induced between T cells and monocytes by certain soluble anti-CD3 monoclonal antibodies (MAbs) were previously shown to be required for high-level production of HIV-1 by peripheral blood mononuclear cells (PBMCs) from infected donors. Staphylococcal enterotoxin or superantigen (SAg) is another mitogen inducing monocytes-T cell interactions that exhibit potent induction of HIV-1 production. Antibodies to several adhesion molecules were used to test the requirements for T cell- and monocyte-associated adhesion molecules in HIV-1 production following activation with anti-CD3 or SAg. Blocking of either CD2-LFA-3, or CD18-ICAM-1, inhibited anti-CD3- or SAg-induced HIV-1 production by more than 90% without inhibiting CD4+ T cell proliferation. Inhibition of HIV production was observed when either the T cell or monocyte coreceptor was bound by MAbs to these adhesion molecules. Blocking of CD28-B7 interactions by soluble CTLA-4 fusion protein, a CD28 homolog, inhibited both HIV-1 production and CD4+ T cell proliferation. Fc binding was not required for HIV-1 inhibition by MAbs to CD2 and CD18, because Fab or F(ab')2 fragments of these MAbs inhibited HIV-1 production by more than 80%. A chimeric single-chain MAb to CD2 was produced, containing heavy and light chain variable regions from MAb 35.1 to CD2 linked to the constant regions of human IgG1 (CD2 SFv-Ig). This humanized CD2 SFv-Ig inhibited HIV-1 production by 30% to > 98%. These results thus indicate that simultaneous engagement of multiple adhesion pathways between T cells and monocytes are required for HIV production by patients PBMCs and may have implications for therapy of HIV infections.

Abatacept↗
PubMed1995

Analysis of trans-dominant mutants of the HIV type 1 Rev protein for their ability to inhibit Rev function, HIV type 1 replication, and their use as anti-HIV gene therapeutics.

The HIV-1 rev gene product facilitates the transport of singly spliced and unspliced HIV-1 transcripts and is necessary for productive HIV-1 infection. On the basis of the previously described trans-dominant Rev mutant M10, four point mutants and one frameshift mutant of the Rev protein were constructed. The mutants were inserted into retroviral expression vectors and analyzed for their ability to inhibit Rev-mediated gene expression. Transient transfection systems were used to screen these new mutants, and each was shown to inhibit expression of a Rev-dependent CAT reporter plasmid. Inhibition of HIV-1 envelope gene expression was tested in the HeLa-T4 cell line and was also shown to be inhibited by the trans-dominant Rev mutants. Retroviral vector producer cell lines were constructed and used to transduce Rev trans-dominant genes into the human T-cell line SupT1. The engineered SupT1 cell lines were then challenged with HIV-1 IIIB and HIV-1 expression was monitored by Northern blot analysis and in situ hybridization. SupT1 cells expressing either a Rev point mutant or the frameshift mutant showed greatly reduced HIV-1 mRNA accumulation and the Rev-dependent singly spliced and unspliced HIV-1 mRNAs were reduced. The kinetics of viral replication following challenge of Rev trans-dominant-engineered SupT1 cells with both HIV-1 IIIB and MN strains was significantly reduced and cells were protected from viral lysis. Viruses that emerge late in infection from Rev trans-dominant-engineered cultures are not resistant to Rev-mediated inhibition. Last, trans-dominant Rev-mediated protection of human CD4+ lymphocytes from challenge with primary HIV-1 patient isolates confirms the potential utility of this system as an anti-HIV-1 gene therapy approach.

Amino Acid Sequence↗
PubMed2003

Population survey of CCR5 delta32, CCR5 m303, CCR2b 64I, and SDF1 3'A allele frequencies in indigenous Chinese healthy individuals, and in HIV-1-infected and HIV-1-uninfected individuals in HIV-1 risk groups.

The aim of this study is to determine in indigenous Chinese ethnic groups the frequencies of the chemokine (SDF1 3'A) and chemokine receptors (CCR5 delta32, CCR5 m303, and CCR2b 64I) HIV-1/AIDS restriction alleles. The study includes two cohorts; the first comprised 3165 indigenous healthy subjects representing eight ethnic groups: Han (n = 1406), Uygur (n = 316), Mongolia (n = 134), Hui (n = 386), Tibetan (n = 330), Zhuang (n = 378), Dai (n = 101), and Jingbo (n =114). The second cohort consisted of 330 HIV-1-infected (86 subjects infected by sexual transmission and 198 subjects infected by HIV-1-contaminated blood or by sharing injection equipment; the remaining 46 subjects said nothing about HIV-1 transmission) and 474 HIV-1-uninfected Han Chinese belonging to one of two HIV-1 high-risk groups: intravenous drug users (n = 215) and individuals with sexually transmitted diseases (n = 259). Genotypes for the four genes were obtained using PCR (CCR5 delta32) or PCR-restriction fragment length polymorphism. Randomly selected amplified PCR products were further confirmed by direct DNA sequencing. The variant allele frequencies were determined to be 0% to 3.48% for CCR5 delta32, 0% for CCR5 m303, 16.23% to 28.79% for CCR2b 64I, and 17.70% to 27.76% for SDF1 3'A in Chinese healthy individuals from eight ethnic groups. These findings show that allele frequencies differ among the eight Chinese ethnic groups for CCR5 delta32, CCR2b 64I, and SDF1 3'A and that the CCR5 m303 and CCR5 delta32 mutant alleles were absent or infrequent in Chinese, which may be helpful for studies of specific anti-HIV-1 vaccine trials and coreceptor inhibitor drug targets in Chinese populations. Furthermore, we observed no significant differences in allele or genotypic frequencies between HIV-1-infected and HIV-1-uninfected groups from the Han ethnic group. Our finding is the first reporting that there is likely no effect of the examined polymorphisms in our study on HIV-1 transmission in the Chinese Han population, However, the genetic effects of these and other AIDS-modifying polymorphisms on the pathogenesis and clinical outcome of HIV-1/AIDS diseases is under investigation in Chinese populations.

Adult↗
PubMed2005

The replicative fitness of primary human immunodeficiency virus type 1 (HIV-1) group M, HIV-1 group O, and HIV-2 isolates.

The main (M) group of human immunodeficiency virus type 1 (HIV-1) is responsible for the global AIDS epidemic while HIV-1 group O (outlier) and HIV type 2 are endemic only in west and central Africa. The failure of HIV-2 and especially HIV-1 group O to spread following the initial zoonotic jumps is not well understood. This study was designed to examine the relative replicative capacities between these human lentiviruses. A pairwise competition experiment was performed with peripheral blood mononuclear cells with eight HIV-2 isolates, 6 group O viruses, and 15 group M viruses of subtype A (2 viruses), B (5 viruses), C (4 viruses), D (2 viruses) and CRF01_AE (2 viruses). HIV-1 group M isolates of any subtype were typically 100-fold-more fit than group O or HIV-2 strains when competed in peripheral blood mononuclear cells from various humans. This order in replicative fitness was also observed when virus pairs were added to human dendritic cells and then cocultured with primary, quiescent T cells, which is the model for HIV-1 transmission. These results suggest that reduced replicative and transmission fitness may be contributing to the low prevalence and limited geographical spread of HIV-2 and group O HIV-1 in the human population.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Factors associated with HIV testing among HIV-positive and HIV-negative high-risk adolescents: the REACH Study. Reaching for Excellence in Adolescent Care and Health.

OBJECTIVE: To describe human immunodeficiency virus (HIV) testing patterns among high-risk, uninfected adolescents and HIV-infected adolescents, and factors associated with testing. METHODS: HIV-infected adolescents (N = 246) and high-risk, uninfected adolescents (N = 141) at 15 sites nationwide were asked about the number of times they were tested for HIV, the type of agency at which testing occurred, and reasons for testing. RESULTS: The majority of participants reported being influenced to obtain testing by health care providers (53.1% of the HIV-infected group and 66.1% of the HIV-uninfected group, respectively). Female participants were somewhat more likely to have used a confidential or anonymous site for the most recent test, compared with male participants (73.5% and 67.5%, respectively). Among the HIV-infected group, feeling sick was the only factor associated with number of tests. Among the HIV-uninfected group, having more male partners, marijuana use in the past 3 months, white race, and having had same-gender partners in their lifetime (males only) were associated with number of tests. Multivariate analyses identified 2 significant models. Modeling the probability of having been tested 3 or more times, black participants were less likely to be tested than white participants (odds ratio [OR] = 0.4), and participants who felt sick were more likely to be tested than those who did not (OR = 1.7). Modeling the probability that the last test would be positive, black participants were more likely than white participants to test positive (OR = 2.3); those who were tested because they thought they might have gotten HIV from sex (OR = 3.0) or they felt sick (OR = 3.9) were more likely to test positive; participants who were tested because a health care professional recommended it were actually less likely (OR = 0.5) to test positive. CONCLUSIONS: Overall, these findings highlight the importance of making HIV testing more routinely available to sexually active adolescents. More work needs to be done to normalize HIV testing among adolescents, and more innovative approaches need to be implemented on a wide scale.

AIDS Serodiagnosis↗
PubMed1998

Quantification of CD8+ T lymphocytes responsive to human immunodeficiency virus (HIV) peptide antigens in HIV-infected patients and seronegative persons at high risk for recent HIV exposure.

The combination of a tumor necrosis factor (TNF)-alpha enzyme-linked immunospot (ELISPOT) assay and computer-assisted video image analysis was used to detect and quantitate in peripheral blood CD8+ T cells reactive with known human immunodeficiency virus type 1 (HIV-1) peptide antigens presented by HLA-A2 or HLA-A3. T lymphocyte responsiveness to at least one HIV peptide was found in 10 (83%) of 12 HIV-1-infected patients and in 5 (45%) of 11 persons who had no serologic and virologic signs of HIV infection but who were at high risk for recent sexual exposure to HIV-1. CD8+ T cells responding to HIV-1 peptides were observed in none of 11 HIV-seronegative donors without a history of HIV exposure. ELISPOT assays are relatively fast and easy to perform and appear to reliably detect T cell reactivity due to previous exposure to HIV. These findings support the use of the ELISPOT assay for monitoring T cell responsiveness to HIV peptides.

Antigen Presentation↗
PubMed2004

A nonneutralizing anti-HIV-1 antibody turns into a neutralizing antibody when expressed on the surface of HIV-1-susceptible cells: a new way to fight HIV.

During HIV-1 infection or vaccination, HIV-1 envelope spikes elicit Ab responses. Neutralizing Abs block viral entry by recognizing epitopes on spikes critical for their interaction with receptor, coreceptors or fusion. In contrast, nonneutralizing Abs fail to do so because they recognize epitopes either buried or exposed but not critical for viral entry. Previously, we produced a high-affinity human mAb against the cluster II determinant of gp41. This Ab or its recombinant Fab and single-chain Fv have been repeatedly shown to bind to HIV-1 gp160 or gp41, but fail to block viral entry. We report that, surprisingly, expression of this nonneutralizing anti-HIV-1 gp41 single-chain Fv on the surface of human CD4 T cells markedly inhibits HIV-1 replication and cell-cell fusion. The inhibition targets the HIV-1 envelope at the level of viral entry, regardless of HIV-1 tropism. Although this bona fide nonneutralizing Ab does not neutralize HIV-1 entry when produced as a soluble protein, it acts as a neutralizing Ab when expressed on the cell surface. Expressing Abs on the surface of HIV-1-susceptible cells can be a new way to fight HIV-1.

Antiviral Agents↗
PubMed1996

Assessment of HIV testing rates among HIV infected individuals using incidence data on HIV and AIDS diagnoses.

This paper considers estimation of the rate HIV diagnosis in a population of HIV positive individuals. A number of previous papers have studied the situation where time of first positive HIV test is available for AIDS cases, and possibly for individuals who have not yet developed AIDS. In this context, AIDS diagnoses are linked to prior HIV diagnoses. The present paper focuses on the case where AIDS incidence data, and data on new HIV diagnoses, are unlinked. Although there is less information available when there is no linking AIDS diagnosis and HIV tests, it is shown that a useful assessment can be made of the pattern of HIV testing over time. The methodology makes use of back-projection estimates of HIV incidence and involves fitting a model for HIV diagnosis to the observed pattern of new positive HIV tests. Smooth non-parametric estimates are obtained by minimizing a penalized residual sum of squares. In analysis of data on HIV diagnoses among the homosexual/bisexual population in the state of Victoria, Australia, we find strong evidence of a significant decrease in testing rates during the latter part of the 1980s. Subsequent testing rate estimates are subject to greater uncertainty, but are of a comparable magnitude to estimates based on linked data in other countries.

AIDS Serodiagnosis↗
PubMed2006

The occurrence of vaginal infections among HIV-infected and high-risk HIV-uninfected women: longitudinal findings of the women's interagency HIV study.

OBJECTIVES: To evaluate changes over time in rates of bacterial vaginosis (BV), trichomoniasis (TV), and yeast vaginitis (YV) among HIV-infected and similar HIV-uninfected women. METHODS: Two thousand fifty-six HIV-infected women and 554 HIV-uninfected women were evaluated semiannually from 1994 until March 2003 in a prospective cohort study. BV was diagnosed by Gram stain, TV by wet mount, and YV by symptoms with microscopically visible hyphae or positive culture. Trends were assessed using Poisson models. RESULTS: At baseline, BV was present in 42.8% and 47.0% of HIV-infected and uninfected women (P = 0.21), TV in 6.1% and 7.8% (P = 0.17), and YV in 10.0% and 3.8% (P < 0.001). Over time, rates of BV and TV decreased significantly in both groups, whereas rates of YV declined only among HIV-infected women. Risk of BV was not associated with HIV status, whereas HIV-infected women had a lower risk of TV. Highly active antiretroviral therapy (HAART) use was associated with decreased risk of all 3 infections. CONCLUSIONS: : Declines in BV, TV, and YV represent decreased morbidity for HIV-infected women and, potentially, decreased risk of transmission of HIV, because each has been associated with increased genital detection of HIV.

Cohort Studies↗
PubMed2006

Trends in HIV testing, serial HIV prevalence and HIV incidence among people attending a Center for AIDS Prevention from 1988 to 2003.

AIM: To analyse trends in HIV testing, serial HIV prevalence and HIV incidence among people who underwent voluntary testing in a Center for AIDS Prevention in Valencia, Spain. METHODS: Open cohort study including all subjects who went to the Center for AIDS Prevention from 1988 to 2003. Information on sociodemographic variables and HIV test results was collected. Serial prevalence and incidence rates were calculated, and joinpoint regression was used to identify changes in trends over time. RESULTS: 21,241 subjects were analysed; 67% men, 27% injecting drug users (IDUs), 43% heterosexuals and 13% men who have sex with men (MSM). From 1988 to 1990, IDUs accounted for 57% of clinic attenders, decreasing to 14% by 1997-2003, accompanied by an increase in heterosexuals. Overall, HIV prevalence for the whole period was 15%, dropping from 35% to <10% after 1999 and to 3% by 2003, when HIV prevalence was 26% in IDUs, 6% in MSM and 2% in heterosexuals. Total HIV incidence was 2.5%. From 1988 to 1990, HIV incidence ranged from 6% to 8%, and a gradual and progressive decline observed from 1990 onwards. From 1995 onwards, HIV incidence was <2%. The highest incidence rate is seen in IDUs, 7-12% in the first period and 4-5% at the end. Among MSM, a change in the decreasing trend is seen by 1998, and increases in incidence are detected by 2002-3. CONCLUSIONS: Serial HIV prevalence has markedly decreased from 1988 in all transmission categories, although it is still high. With regard to HIV incidence, the drop has been marked too, although a worrying increase, that requires further follow-up, has been detected in MSM in the past 2 years.

Adolescent↗
PubMed1998

The use of a chimera HIV-1/HIV-2 envelope protein for immunodiagnosis of HIV infection: its expression and purification in E. coli by use of a translation initiation site within HIV-1 env gene.

A chimera HIV-1/HIV-2 envelope sequence composed of multiple conserved immunodominant epitopes of HIV-1 envelope protein (HIV-1 IIIB: env482-518 + env548-675) and the HIV-2 gp36 immunodominant epitope (env592-603), was constructed and directly over-expressed in E. coli by using a prokaryotic translation initiation sequence contained within the gene of HIV-1 envelope. The recombinant product was purified and applied in antibody-screening assay. The purified chimera antigen reacted with all the thirty-eight HIV-1 positive serum samples, the two HIV-2 serum samples, and had no cross-reaction with all the eighty-eight normal healthy serum sample. The results indicated that this recombinant chimera HIV-1/HIV-2 envelope protein could be useful for diagnostic purposes of HIV infection.

AIDS Serodiagnosis↗
PubMed1998

Amplicor HIV monitor, NASBA HIV-1 RNA QT and quantiplex HIV RNA version 2.0 viral load assays: a Canadian evaluation.

BACKGROUND: HIV-1 viral load quantitation is now recognized as a useful tool to monitor the efficiency of antiviral treatment and a powerful predictor of disease outcome. Three HIV-1 viral load quantitation methods have been currently available as commercial kits in Canada since 1996. OBJECTIVE: To evaluate the ability to quantify HIV-1 RNA in plasma of the Amplicor HIV Monitor Test, the NASBA HIV-1 RNA QT Assay and the Quantiplex HIV RNA Assay, version 2.0, at comparable lower detection limits. STUDY DESIGN: Blood was collected from 50 HIV-1-infected patients at various stages of infection and therapy. CD4+ cell count were estimated by flow cytometry. Plasma was isolated and tested in duplicate on four occasions using viral load kits from a single lot. HIV RNA data, performance, sensitivity and intra- and inter-assay variability were compared. RESULTS: RNA could be quantified in 33 patients by each technique. An inverse correlation was observed between viral load level and CD4+ cell counts in patients with counts below 200. Monitor could detect RNA in 94% of patients, but it showed the greatest variability and failure rate. Quantiplex 2.0 could detect HIV-1 RNA in 78%, and NASBA in 88% of the patients at theoretically equivalent lower detection limits, suggesting that the detection limit of Quantiplex 2.0 may be higher than 500 HIV-1 RNA copies per ml. NASBA had the fewest invalid tests and good reproducibility, comparable to that of Quantiplex 2.0. The mean values from NASBA and Monitor were the most similar but the best correlation was observed between Monitor and Quantiplex 2.0 results. CONCLUSIONS: Monitor, NASBA and Quantiplex results were comparable, although those obtained by Quantiplex were significantly lower. Performing this study at comparable detection limits showed that the detection limit of Quantiplex 2.0 may be higher than stated by the manufacturer.

Adolescent↗
PubMed1997

HIV-specific mucosal and cellular immunity in HIV-seronegative partners of HIV-seropositive individuals.

HIV-specific mucosal and cellular immunity was analyzed in heterosexual couples discordant for HIV status in serum and in HIV-unexposed controls. HIV-specific IgA but not IgG was present in urine and vaginal wash samples from HIV-exposed seronegative individuals (ESN), whereas both IgA and IgG were observed in their HIV-seropositive partners; antibodies were not detected in low-risk controls. Envelope protein (Env) peptide-stimulated interleukin-2 (IL-2) production by peripheral blood mononuclear cells (PBMCs) was detected in 9 out of 16 ESNs, 5 out of 16 HIV-infected patients and 1 out of 50 controls. Env peptide-stimulated PBMCs of ESNs produced more IL-2 and less IL-10 compared with those of HIV-infected individuals; no differences were observed in chemokine production or in CCR5 expression. These data demonstrate that a compartmentalized immune response to pathogens is possible in humans and raise the possibility of protective roles for cell-mediated immunity and mucosal IgA in HIV-seronegative individuals exposed to HIV.

Adult↗
PubMed1991

HIV-2-induced immunosuppression among asymptomatic West African prostitutes: evidence that HIV-2 is pathogenic, but less so than HIV-1.

Two hundred and forty-one prostitutes working in The Gambia were tested for retroviral infections and their immune system evaluated. Sixty-three were seropositive for HIV-2 only, five for HIV-1 only and six for both HIV-1 and HIV-2 (26.1, 2.1 and 2.5%, respectively). When compared to seronegative individuals, the 63 women infected with HIV-2 clearly had an abnormal immune system, with significantly lower CD4+ and higher CD8+ lymphocyte counts and percentages, lower CD4+:CD8+ ratios, lower CD25+ (activated) lymphocyte counts, and lower lymphocyte proliferation responses after stimulation with phytohaemagglutinin, purified protein derivative (PPD), Candida or pokeweed mitogen, and higher levels of neopterin and beta 2-microglobulin. However, when the HIV-2-seropositive prostitutes were compared with the five women infected with HIV-1, the former were less abnormal, with significantly higher CD4+ percentages and CD4+:CD8+ ratios and lower CD8+ percentages and counts. Immunological anomalies were seen in five women known to have been infected with HIV-2 for less than 17 months. Coinfection with HTLV-1 resulted in more severe immunological alterations than infection with HIV-2 alone.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Evaluation of performance across the dynamic range of the Abbott RealTime HIV-1 assay as compared to VERSANT HIV-1 RNA 3.0 and AMPLICOR HIV-1 MONITOR v1.5 using serial dilutions of 39 group M and O viruses.

Performance of the Abbott m2000 instrument system and the Abbott RealTime HIV-1 assay was evaluated using a panel of 37 group M (subtypes A-D, F, G, CRF01_AE, CRF02_AG and unique recombinant forms) and 2 group O virus isolates. Testing was performed on 273 sample dilutions and compared to VERSANT HIV-1 RNA 3.0 (bDNA) and AMPLICOR HIV-1 MONITOR v1.5 (Monitor v1.5) test results. RealTime HIV-1, bDNA, and Monitor v1.5 tests quantified 87%, 78%, and 81% of samples, respectively. RealTime HIV-1 detected an additional 31 samples at < 40 copies/mL. For group M, RealTime HIV-1 dilution profiles and viral loads were highly correlated with bDNA and Monitor v1.5 values; 87% and 89% of values were within 0.5 log(10) copies/mL. In contrast, the group O viruses were not detected by Monitor v1.5 and were substantially underquantified by approximately 2 log(10) copies/mL in bDNA relative to the RealTime HIV-1 assay. Sequence analysis revealed that RealTime HIV-1 primer/probe binding sites are highly conserved and exhibit fewer nucleotide mismatches relative to Monitor v1.5. The automated m2000 system and RealTime HIV-1 assay offer the advantages of efficient sample processing and throughput with reduced "hands-on" time while providing improved sensitivity, expanded dynamic range and reliable quantification of genetically diverse HIV-1 strains.

Automation↗
PubMed1998

Distribution of HIV type 1 (HIV-1) in blood components: detection and significance of high levels of HIV-1 associated with platelets.

BACKGROUND: Although inactivation of enveloped viruses transmitted by plasma derivatives has been successful, no methods for virus inactivation or removal have been established for platelet concentrates or red cell (RBC) components. Relatively little is known regarding the extent or significance of virus interactions with the cellular constituents in these components. STUDY DESIGN AND METHODS: Units of whole blood were collected from six HIV type 1 (HIV-1)-positive, asymptomatic individuals and separated into peripheral blood mononuclear cells (PBMNCs), cell-free plasma, white cell-reduced platelet concentrate, and white cell-reduced RBCs. DNA and RNA polymerase chain reaction and virus culture methods were used to study the compartmentalization of HIV-1 immediately after component preparation and after storage. RESULTS: As expected, HIV DNA and infectious virus were detected in fresh blood and in PBMNCs, and virion-associated RNA was detected in fresh plasma from all six donors. The levels of viral nucleic acids in these preparations remained relatively stable with 4 degrees C storage, whereas infectivity of PBMNCs was rapidly lost. Washed RBCs tested negative for HIV in all assays at all time points. Platelets retained high levels of HIV RNA (but not infectivity) after extensive washing, as well as after storage at 4 and 22 degrees C. High-level platelet-associated HIV-1 was also demonstrated in samples collected during early seroconversion. Periseroconversion and postseroconversion levels of platelet-associated HIV-1 correlated with the level of plasma viremia and with the rate of progression to AIDS. Cell-free virus from donor plasma and tissue culture fluid rapidly and firmly attached to platelets from noninfected donors. Infectivity of tissue culture virus bound to platelets was demonstrated in vitro. CONCLUSION: Significant levels of HIV-1 are associated with platelets during all stages of infection. Platelet-associated HIV could either mediate virus clearance or facilitate virus dissemination and expanded tropism. Finally, virus inactivation research must address virus associations with platelets.

Blood Platelets↗