ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective:To determine the value of (combinations of) synthetic peptides representing immunodominant sites on HIV-1/HIV-2 transmembrane proteins for the detection and discrimination between HIV-1 and HIV-2 infection in various populations.Design and methods:Two 24-mer synthetic peptides derived from immunodominant sites on the HIV-1 and HIV-2 transmembrane proteins were used separately, in combination (env 1/2), and in combination with recombinant p24 (p24/env) in enzyme-linked immunosorbent assays.Results:Positive reactions with env-1 were found in 150 out of 150 (100%) samples from Dutch AIDS patients, 60 out of 60 (100%) samples from Dutch homosexual men obtained 1 year after HIV-1-antibody seroconversion, 29 out of 30 (96.7%) samples from these men obtained at the time of HIV-1-antibody seroconversion, 40 out of 41 (97.6%) samples from East Africans with AIDS-related symptoms, and three out of 29 (10.3%) samples from West Africans with HIV-2 infection (including a sample from an individual infected with both HIV-1 and HIV-2). Positive reactions with env-2 in these study populations were 11 out of 150 (7.3%), nine out of 60 (15%), none out of 30 (0%), 25 out of 41 (60.9%) and 29 out of 29 (100%), respectively, in the samples with dual reactivity, true versus cross-reactivity could generally be differentiated on the basis of large differences in optical density values in the respective assays. All samples reacted positively with p24/env; 308 out of 310 (99.3%) were positive in the env 1/2 assay. Four East African samples that had negative or only weakly positive reactions with env-1 showed a noticeably stronger reaction with variant peptides derived from Central African isolate sequences. In all samples from HIV-1-infected Dutch homosexual men, the strongest signal was detected using the env-1 peptide sequence, which is derived from European and American isolates.Conclusions: Small peptide antigens may permit the detection of strain-specific antibodies, allowing serological characterization of HIV isolates.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective: To compare variation in the HIV-1 V3 neutralization domain in Tanzania and The Netherlands.Methods: For serologic analysis, the specificity of anti-V3 antibodies (immunoglobulin G) for a panel of V3 peptides was determined in sera from 55 symptomatic HIV-1-infected Tanzanians and 51 Dutch AIDS patients. For genetic analysis, viral RNA was isolated from 15 of the Tanzanian sera and six of the Dutch sera. The V3 encoding region was reverse-transcribed, polymerase chain reaction-amplified and bacterially cloned, and sequences were determined over a stretch of at least 207 nucleotides.Results: Thirty-five per cent of the Tanzanian sera, versus 2% of the Dutch sera, showed the highest reactivity to a V3 sequence of Zairian origin (RKSIHVGPGQAFYATG). Twenty-nine per cent of the Tanzanian sera, versus 82% of the Dutch sera, showed the highest reactivity to V3 sequences of US/European origin (RKSIXIGPGRAFYTTG; X = H, P or N). The Tanzanian RNA sequences showed greater diversity (mean distance, 19%) than the Dutch RNA sequences (10%). The measured anti-V3 specificities of the Tanzanian sera did not match accurately with the V3 sequences recovered from these sera. However, reactivity to the Zairian V3 peptide was associated with the sequence GPGQ, found in the centre of the V3 in 50% of the Tanzanian sequences. Sera from both countries that showed similar reactivities to the peptide panel contained RNA sequences that were relatively distant.Conclusions: The diversity of the HIV-1 population in Tanzania is much greater than that in The Netherlands. An indication of the HIV-1 V3 variation in a particular geographic region can be obtained by serological methods, but sequence analysis should not be omitted.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective: To characterize the recombinant env peptides, 566 (HIV-1) and 996 (HIV-2), for their ability to serodiagnose HIV-1 and HIV-2 infection. To develop a cost-effective dot-blot format for these peptides, and to evaluate its performance in a developing country laboratory.Design: The recombinant env peptides were evaluated using a select panel of sera (n = 327) with known serostatus from geographically diverse areas. A dot-blot assay was developed and tested on a second set of immunoblotted sera (n = 331) and further evaluated in the field on a third set of sera (n = 2718) from study populations.Methods: All sera were evaluated by immunoblot with both HIV-1 and HIV-2 viral lysates. The recombinant env peptides were characterized in immunoblot assay before development of the dot-blot assay.Results: The 566 (HIV-1) peptide showed 100% sensitivity and specificity. The 996 (HIV-2) peptide performed similarly, but showed the presence of HIV-1 cross-reactive epitopes. When the two env peptides were used together, there was high specificity and sensitivity for detecting HIV-positive sera in both immunoblot and dot-blot formats. The dot-blot assay performed in the field showed slightly lower specificity and sensitivity for HIV diagnosis. The relative cost of this assay combined with non-commercial immunoblot confirmation was 10-fold lower than conventional commercial assays.Conclusions: The 566 and 996 env peptides are appropriate antigens for HIV serotype diagnosis. A dot-blot assay using these peptides may be a useful cost-effective method for HIV diagnosis applicable in developing country laboratories.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective:The testing of neonatal blood specimens dried on filter paper for maternal HIV antibodies, using an enzyme immunoassay (EIA) with confirmation of repeatedly reactive specimens by immunoblot (IB), was first described in 1987. It has been used to conduct large, unlinked, anonymous HIV seroprevalence surveys for surveillance of HIV in child-bearing women in several countries. We directly assessed the sensitivity and specificity of this combination of tests to detect maternal HIV antibodies.Setting: Serum samples obtained from mothers delivering at a major hospital in Kinshasa, Zaire were screened for HIV antibody using the rapid assay HIVCHEK.Design: Plasma from HIVCHEK-positive women and age-matched negative controls were tested by enzyme-linked immunosorbent assay (ELISA); repeatedly reactive specimens were confirmed by Western blot (WB). Two days after delivery, whole blood was obtained from each newborn by heel-stick, dried on filter paper, and tested by EIA. Repeatedly reactive specimens were confirmed by IB.Main outcome measure: The serologic status of neonatal filter-paper specimens was compared with that of corresponding maternal plasma.Results: The testing of neonatal filter-paper specimens using EIA, with confirmatory testing of repeatedly reactive specimens using IB, was 100.0% sensitive [of the 192 ELISA-positive and WB-positive maternal plasma specimens, 192 of the corresponding newborn filter-paper specimens were EIA-positive and IB-positive; 95% confidence interval (CD, 98.1–100]. The detection of maternal HIV antibodies was 99.6% specific using this combination of tests (of the 281 ELISA-negative or ELISA-positive but WB-negative maternal plasma samples, 280 of the corresponding newborn filter-paper specimens were EIA-negative or EIA-positive but IB-negative; 95% Cl, 98.0–100).Conclusions: Maternal HIV antibodies can be detected accurately by testing neonatal blood dried on filter paper, using EIA with confirmation of repeatedly reactive specimens by IB. This approach can facilitate the determination of HIV seroprevalence in child-bearing women in countries with neonatal screening programs, or where serum or plasma is difficult to obtain.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective: To further characterize cell surface proteins binding to recombinant soluble (rs) forms of the transmembrane glycoproteins gp41 of HIV-1 (rsgp41) and gp36 of HIV-2 (rsgp36).Methods: Various human and murine cell lines of different lineages were surface-labelled with 125I. rsgp41 and rsgp36 were bound to CnBr-Sepharose and used as an affinity matrix for the surface-labelled cell lysates. The bound cell surface proteins were separated on sodium dodecyl sulphate polyacrylamide gel electrophoresis under reducing conditions. A rabbit serum was produced against one of the cell surface proteins and flow cytometry used to compare the results with those obtained from affinity chromatography.Results: We have confirmed and extended the results obtained by Qureshi et al. [1]. In addition to the 44 kD protein, we identified cell surface proteins with molecular weights of 98 and 106 kD binding with high affinity to both rsgp41 and rsgp36. We have demonstrated differences between human and murine cell lines in the expression of the cell surface proteins that interact with rsgp41 and rsgp36. Furthermore, a correlation between the level of rsgp41 and rsgp36 binding proteins, detected either by affinity chromatography or by reactivity with an antiserum directed against one of the cell surface binding components was shown.Conclusions: Three cell surface proteins, with molecular weights of 44, 98 and 106 kD, bind with high affinity to rs forms of gp41 and gp36. Their expression decreases from a T-lymphoid cell line, to a monoblastoid cell line, to a cell line representing mature monocytes. Human T-cell lymphotropic virus-infected cell lines show a predominance of the 44 kD protein. There are species-specific differences, in that murine cell lines lack the 44 kD protein.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective: To evaluate whether HLA-B35 influences progression to AIDS in HIV-seropositive subjects with haemophilia.Design: Retrospective (before 1985) and prospective (after 1985) follow-up of a group of French haemophiliacs.Methods: We studied 144 seropositive patients with moderate or severe haemophilia A or B or von Willebrand's disease. Enzyme-linked immunosorbent assay was used to screen patient sera for total HIV antigen and core p24 antigen antibodies. All patients were typed for HLA A, B and C antigens in the same laboratory. Time of seroconversion was estimated to be the mid-point between the last seronegative test and the first seropositive test. AIDS-free survival curves were constructed using the Kaplan—Meier estimate and differences in survival analysed using the Mantel—Cox test. The Cox proportional hazards model was used to adjust for confounding variables.Results: Median follow-up after seroconversion was 8.7 years (range, 3.5–10.7 years). By the end of the study, six HLA-B35-positive patients and 12 HLA-B35-negative patients had progressed to AIDS. Individuals with HLA-B35 showed a significantly faster rate of progression to AIDS over the follow-up period than HLA-B35-negative individuals (hazard ratio, 2.72;P= 0.037). After adjusting for type and severity of haemophilia, CD4 cell count at first seropositive test, age at seroconversion, and zidovudine treatment before AIDS, the hazard ratio was 2.74 (P= 0.045).Conclusion: HLA-B35 is a risk factor for more rapid progression to AIDS in subjects with haemophilia.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective: To compare the efficacy and safety of two intermittent regimens for the simultaneous primary prevention ofPneumocystis cariniipneumonia (PCP) and toxoplasmosis in HIV-infected patients.Design: Prospective randomized open trial.Setting: HIV outpatient clinic of an Infectious Disease Service and a 1000-bed university teaching hospital.Patients: A total of 166 HIV-infected patients with a CD4 cell count < 200 x 106/I or a CD4 percentage < 20%, without previous PCP or toxoplasmosis.Intervention: Patients were randomized to oral (1) cotrimoxazole [160 mg trimethoprim (TMP) and 800 mg sulphamethoxazole (SMX)] twice a day on Mondays, Wednesdays and Fridays (n = 81), or (2) dapsone (100 mg) plus pyrimethamine (25 mg) (DP) once a week (n = 85).Main outcome measures: Clinical and biological evaluation was performed every 30–60 days. End-points were PCP, toxoplasmosis and death. Adverse reactions were considered as defined in the protocol.Results: After a mean follow-up of 380 days, intention-to-treat analysis revealed that DP patients had a higher rate of PCP [13 out of 85 (15.2%) versus three out of 81 (3.7%);P= 0.01]. The cumulative rates of PCP at 12 and 24 months were 5 and 42% for DP patients and 3 and 10% for TMP-SMX patients, respectively (Mantel-Cox,P= 0.0007). Of the 29 patients who died during follow-up, 14 were in the TMP-SMX group and 15 in the DP group (not significant). Two patients in the TMP-SMX group and three in the DP group developed toxoplasmosis (not significant). Adverse reactions were common (66.7% of TMP-SMX patients and 42.4% of DP patients;P= 0.001). However, only 12.3% of TMP-SMX patients and 2.3% of DP patients (P= 0.01) had to discontinue therapy because of toxicity.Conclusions: At the given doses, DP was inferior to TMP—SMX in preventing first episodes of PCP. Although more patients and a longer follow-up are required, the regimens appeared to prevent toxoplasmosis equally well.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective: To describe the incidence of, and risk factors for, Mycobacterium avium intracellulare complex (MAC) infection in HIV-infected children.Setting: University-affiliated children's hospital.Design and methods: The medical records of 70 HIV-infected infants and children were reviewed retrospectively.Results: Seven children (10% of the HIV-infected patients; 18% of those with AIDS) developed disseminated MAC (dMAC). An additional seven children had gastrointestinal colonization with MAC. Risk of dMAC was associated with increasing age, decreasing CD4 cell count, and (possibly) long-term steroid therapy.Conclusions: HIV-infected children are at risk of developing dMAC. Children older than 60 months and those with a CD4 cell count < 100 x 106/I are most at risk.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Objective: To examine the relationship between rate of loss of CD4+ T lymphocytes and risk of AIDS in HIV-infected intravenous drug users (IVDU) enrolled in a methadone program in the Bronx, New York.Design: Serial CD4 percentages (CD4%) among lymphocytes before AIDS diagnosis were recorded at approximately 6-month intervals for 190 HIV-antibody-positive subjects.Methods: A nested case-control study was performed, in which all subjects who developed AIDS were compared with those who remained AIDS-free. The relationship between CD4% decline and AIDS risk was evaluated using proportional-hazards regression.Results: Analyses that used a single baseline CD4% measurement to adjust for CD4 + lymphocyte count suggested that both low (1–5 CD4% per semester) and high (≥ 5 CD4% per semester) rates of decline might be related to AIDS risk: relative risks were 1.83 and 1.44, although the 95% confidence intervals (CI) included 1.0 in each case. Adjustment for current level of CD4% eliminated the association between low rates of CD4% decline and AIDS risk, but not that between high rates of decline and AIDS risk (adjusted relative risk, 1.80; 95% CI, 0.57–5.70). Serial observations showed that a rate of decline of CD4% ≥ 5 per semester was a significant predictor of AIDS risk after controlling for level of CD4% achieved (adjusted relative risk, 3.58; 95% CI, 1.07–11.95).Conclusions: IVDU who develop AIDS have a greater rate of CD4 cell loss than subjects who remain AIDS-free. A low rate of CD4+ lymphocyte depletion is not an important predictor of the immediate onset of AIDS in HIV-infected IVDU, compared with CD4 + lymphocyte level, but a high rate of CD4+ decline can be.

ISSN:0269-9370    

出版商:OVID    

年代:1993

数据来源: OVID