ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo reduce the number of HIV-1 Western blot (WB)-indeterminates requiring follow-up and the time taken to provide a clear positive or negative result.DesignIn the first of two stages, a testing and follow-up strategy was developed to resolve anti-HIV-1 status of WB-indeterminates. In the second stage, implementation of this strategy was assessed.MethodsAfter dividing indeterminates into four groups according to WB profile, samples were tested for anti-HIV-1, anti-HIV-2, anti-HTLV-1 antibodies, and HIV-1 antigen using the most sensitive assays available. When testing failed to clarify anti-HIV-1 status, follow-up samples were taken to monitor changes in antibody status.ResultsSamples in two out of the four indeterminate groups were negative for anti-HIV-1. The other two groups required additional testing and/or follow-up to distinguish reactivity caused by anti-HIV-1 from cross-reactivity.ConclusionGrouping HIV-1 WB-indeterminates according to profile allows a significant percentage to be reported as anti-HIV-1-negative, while additional testing may allow others to be reported as anti-HIV-1-positive. The remainder require a maximum of 3 months' follow-up to resolve anti-HIV-1 status.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine viral DNA load in peripheral blood mononuclear cells (PBMC) from HIV-1-infected individuals.DesignHIV-1 copy numbers were determined using a quantitative polymerase chain reaction (PCR), the PCR-aided template titration assay (PATTY). PATTY utilizes an internal plasmid control DNA, which is amplified within the same tube and using the same primers as the PBMC target DNA. HIV-1 copy numbers were confirmed by limiting-dilution PCR analysis.ResultsPBMC viral load of 19 long-term (>4 years) HIV-1-infected individuals ranged from 0.8 to 100 copies per 103PBMC. Significantly higher copy numbers were found among p24-antigen-positive than among p24-antigen-negative individuals. In addition, the PBMC viral load of two HIV-1-infected individuals was monitored during the first 3 months after acute infection. For both patients, the HIV-1 copy numbers were shown to peak at the time of HIV-1-antibody seroconversion and decline subsequently (range, 0.6–10 copies per 103PBMC).ConclusionsATTY is a useful method for assessing the HIV-1 copy numbers in PBMC DNA. Viral DNA load peaks shortly after infection and reaches an individual specific level that is probably stable within a few months of infection. Viral DNA load in PBMC varies widely among long-term HIV-1-infected individuals.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesCytotoxic T-lymphocytes (CTL) appear to be an important defense mechanism against HIV infection. This study proposes to examine the major histcompatibilty complex (MHC)-restricted HIV-1 Env-, Gag-and Pol-specific CTL activities in HIV-infected asymptomatic patients.DesignD4+ and CD8+ CTL were examined to establish whether the same HIV-1 protein (Env, Gag or Pol) was recognized by both CD4+ and CD8+ CTL with MHC antigen restriction.MethodsPeripheral blood mononuclear cells, CD4+ and CD8+ T-cells from 17 HIV-infected asymptomatic patients and 10 HIV-seronegative individuals were examined for HIV-1 Env-, Gag-and Pol-specific MHC-restricted cytotoxicity using autologous and heterologous B-lymphoblastoid cell lines infected with vaccinia recombinant expressing HIV-1 Env, Gag and Pol proteins as targets.ResultsCD4+ and CD8+ CTL specific for the HIV-1 Env, Gag and Pol were demonstrated in the peripheral blood. DR4 and DQw2 were possible sites of MHC class II restriction of CD4+ CTL. Possible MHC class I restriction sites of CD8+ CTL included A2 and B8 for Env, A1 and A2 for Gag, and A2 and B8 for Pol antigen.ConclusionsThese observations should help to define more precisely the nature and elements of protective immunity and to evaluate AIDS vaccine strategies.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine the relationship and occurrence of cell-free viraemia, free or immune-complexed p24-antigen and p24-antibody levels in blood from HIV-1-infected patients in Ethiopia.MethodsPeripheral blood was obtained from 66 Ethiopian and 137 Swedish HIV-1-seropositive patients. Blood samples were analysed for free or immune-complex bound p24 antigen by enzyme-linked immunosorbent assay before and after acid hydrolysis of immune complexes for infectious virus in plasma and peripheral blood mononuclear cells (PBMC), and for p24-antibody levels. We compared the kinetics of viral replication of Ethiopian with Swedish isolatesin vitro.ResultsInfectious virus was isolated from PBMC in 95% and from plasma in 81% of Ethiopian AIDS patients. In contrast, p24 antigen was detected in only 5% of AIDS patients from Ethiopia, compared with 76% of those from Sweden. p24-antibody levels were much higher and more persistent in Ethiopian than in Swedish subjects. The ratio between reverse transcriptase activity and p24 antigen was significantly higher in Ethiopian isolate culture than in those of the Swedish isolates.ConclusionsOur results show that relationships between viraemia, p24 antigenaemia and p24-antibody levels in HIV-1-infected Ethiopian patients differ from those found in comparable Swedish patients. This pattern may partly explain the differences seen in the natural course of HIV-1 infection in Ethiopia and Sweden.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveSeven French laboratories tested the specificity and sensitivity of the polymerase chain reaction (PCR) for the detection of HIV-1 DNA.MethodsFollowing its own PCR protocols, each laboratory independently tested blind two panels of 20 coded peripheral blood mononuclear cell samples collected from HIV-1-seropositive individuals and from HIV-1-seronegative individuals at high or low risk of HIV infection. For the first panel, laboratories were free to select type and number of primers; for the second, all were required to use the two primer pairs Pol 3/4 and MMy 9/10' (Nef 1).ResultsFalse-positive and false-negative results were observed in all laboratories (concordance with serology ranged from 40 to 100%). In addition, the number of positive PCR results did not differ significantly between high-and low-risk seronegatives. The use of crude cell lysates in DNA preparation produced the same PCR results as phenol-extracted DNA. Discrepancies between laboratories indicated that factors other than primer pairs contributed strongly to laboratory variability.ConclusionsOur results emphasize the importance of both positive and negative controls in PCR and demonstrate the value of multicentre PCR quality control.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine the kinetics of decline of CD4+ lymphocytes in HIV-1-infected asymptomatic homosexual men.MethodsCD4 + lymphocytes were enumerated in a cohort of 187 HIV-1-infected initially asymptomatic homosexual men seen at 3-month intervals over 5 years. During follow-up, 45 men progressed to AIDS (excluding cases presenting with Kaposi's sarcoma). Correlation between rate of CD4+ cell decline and presence of a particular HIV-1 biological phenotype was analysed in 43 participants.ResultsCD4+ cell counts declined slowly and continuously in HIV-1-seropositive men who remained asymptomatic during follow-up. A biphasic CD4+ cell count decline was observed in the group who developed AIDS: the decline was slow and steady (5.6 × 106/1 per month, similar to that observed in the asymptomatic group) until 18 months before AIDS diagnosis, but became three to five times faster thereafter. Rapid CD4+ cell decline was significantly related to syncytium-inducing, fast-replicating HIV-1 isolates; during the period of slow and steady CD4+ cell count decline, non-syncytium-inducing isolates were predominant.ConclusionsAt an average of 18 months preceding AIDS diagnosis, a three to fivefold increase in the rate of loss of CD4+ lymphocytes occurs, and may be related to the appearance of a more virulent HIV-1 phenotype.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo describe the natural history of advanced HIV disease in patients treated with zidovudine.DesignLongitudinal, observational study.SettingTwelve academic and community-based sites.Patients, participantsEight hundred and sixty-three patients with AIDS or AIDS-related complex (ARC) with a CD4+ lymphocyte count <250 × 106/1, who first received zidovudine between 15 April 1987 and 14 April 1988.Main outcome measuresSurvival, progression to AIDS and first development of specific opportunistic illness.ResultsMedian survival after initiation of zidovudine therapy ranged from >900 days in patients with a baseline CD4+ lymphocyte count ≥150 × 106/1 to 560 days in patients with a CD4+ lymphocyte count < 50 × 106/1. Other factors associated significantly with poorer survival were diagnosis of AIDS (versus ARC), baseline age ≥40 years, hematocrit < 35%, and diminished functional status. In patients with ARC at enrollment, median time of progression to AIDS ranged from 810 days in patients with a CD4+ lymphocyte count ≥150 × 106/1 to 310 days in patients with a CD4 + lymphocyte count < 50 × 106/1. Rates of development of specific opportunistic infections or neoplasms and HIV encephalopathy were determined for different baseline CD4 + lymphocyte count ranges. Myelosuppression was significantly more common in patients with CD4+ lymphocyte counts ≥100 × 106/1. Sixty-five per cent of patients with a CD4 + lymphocyte count ≥100 × 106/1 and 51% with a CD4+ lymphocyte count < 100 × 106/1 continued to receive zidovudine 2 years after starting therapy.ConclusionsWe describe the natural history of a cohort of patients treated with zidovudine for advanced HIV disease. These CD4+ lymphocyte count-stratified estimates of disease progression should provide prognostic information useful in the clinical management of advanced disease and the design of future studies.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveInvestigation of the prevalence and pathogenic role of parvovirus B19 infection in Italian and Rumanian children with AIDS, compared with age-matched HIV-negative children (controls) with various recurrent infections of unknown aetiology.DesignDetection of B19-specific immunoglobulin (Ig) M and IgG antibodies as the most indicative markers of past or current B19 infection.MethodsB19 antibodies were detected by two enzyme immunoassays using synthetic peptide or recombinant protein, which corresponded to different B19 epitopes, as coating antigens.ResultsB19 IgM and IgG were seen in 10 out of 20 (50%) Italian and in 20 out of 51 (39.2%) Rumanian children with AIDS, in contrast to none out of 17 Italian and one out of 22 Rumanian controls (P< 0.001). In addition, two Italian controls (11.8%), two Rumanian children with AIDS (3.9%), and two Rumanian controls (9.1%) had B19 IgM alone. Specific IgG alone was detected in eight (40%) Italian and 14 (27.5%) Rumanian children with AIDS, and in seven (41.2%) Italian and four (10.2%) Rumanian controls.ConclusionsWhile it is possible to attribute some B19 infections in Rumanian children to blood transfusion, the source was unknown for Italian children. However, in three of the Italian children who had B19 IgM and IgC persistently for 15–22 months, and in a 2-month-old Italian infant with B19 IgM and IgC, HIV might have activated a congenital or perinatally-acquired B19 infection.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID