ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Two hundred and forty-one prostitutes working in The Cambia 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),Candidaor pokeweed mitogen, and higher levels of neopterin and β2-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 <17 months. Coinfection with HTLV-I resulted in more severe immunological alterations than infection with HIV-2 alone.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Diagnosis of perinatal HIV-1 infection is complicated by the persistence of maternal antibodies and the conflicting reports on polymerase chain reaction (PCR) reactivity in children born to HIV-1-seropositive mothers. We have compared PCR with other diagnostic methods for perinatal HIV-1 infection and have attempted also to identify maternal markers which correlate with risk of transmission. PCR was the most sensitive method for early diagnosis of perinatal transmission of HIV-1, but the PCR-positive children (n = 11) developed at least one additional sign of infection. The PCR-negative children (n = 76) were clinically healthy, virus isolation negative, and their serum was HIV-1-antigen-negative. All children who had become seronegative (n = 36) were both PCR- and isolation-negative. Antigenaemia in the mothers correlated significantly with higher risk of perinatal transmission of HIV-1, while no other parameters (clinical stage, lymphocyte subsets, PCR and isolation) showed such a correlation. This indicates that the level of virus expression may be of key importance for the risk of vertical transmission of HIV-1 infection.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Recent reports have suggested that maternal antibodies to specific epitopes of the variable region 3 (V3 loop) of gp120 of HIV-1 might protect against perinatal transmission. In an attempt to confirm these findings, sera from 34 HIV-1-seropositive mothers, representing 13 episodes of mother-to-infant transmission and 23 episodes of non-transmission (two mothers had two pregnancies each during the study period), were tested for the presence of antibodies to various regions of the gp120 V3 loop. Synthetic peptides were generated from HIV-1MN. Of the four peptides tested by enzyme-linked immunosorbent assay (ELISA), only antibody to the C53 peptide (Env310–322, principal neutralizing determinant) was present in maternal sera. Antibody to the C53 sequence was present in 11 specimens from transmitting mothers and 21 from non-transmitting mothers (84.6 and 91.3%, respectively, P = 0.6). No reactivity was detected against the C51, C57, or C58 peptide sequences, located on the sides of the V3 loop. In an antigen-limited ELISA, only two specimens from transmitting mothers and two specimens from non-transmitting mothers had detectable ‘high-affinity’ antibodies to C53 at low antigen concentrations (15.4 and 8.7%, respectively; P = 0.6). Our results do not support previous reports that epitope-specific antibodies to the V3 loop peptides protect against perinatal transmission. Further research is required to determine whether any specific maternal humoral response might influence HIV-1 perinatal transmission.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Peripheral blood mononuclear cells (PBMC) from two haemophilia B patients, who presumably became infected with a putative HIV-1 biological clone following treatment with the same suspected batch of commercial factor, were used to clone and sequence the hypervariable V3 region of the HIV-1 envelope protein. In 10 of 12 clones the V3 region was identical and two (one from each patient) had a single non-synonymous point mutation. Viable reisolates (shown to be authentic by sequencing of V3) currently appear to be monocyte tropic. These results strongly indicate that the patients were infected from a common source with a very low number of infectious particles and indicate that variability under these conditions is limited.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Two hundred and twenty-eight blood samples from 154 HIV-seropositive subjects were investigated for the presence of HIV in peripheral blood mononuclear cells (PBMC) and plasma (without prior ultracentrifugation or filtration), using normal PBMC as the target for replication. HIV was recovered from PBMC and plasma in 80.5 and 19.5% of the patients, respectively. Plasma viraemia was significantly associated with clinical manifestations of HIV infection, indicating that HIV replication increased as disease progressed. This was confirmed by the statistically significant correlations between plasma viraemia and low CD4 cell counts (P<0.01) and low anti-p24 antibody titers (P<0.01). On patient follow-up, detection of HIV in plasma was transient. p24 antigenaemia was only detected in 13.6% of cases and was also associated with advanced clinical stages of the disease. When HIV RNA detection by polymerase chain reaction (PCR) was compared with plasma viraemia, HIV RNA was detected in plasma in all symptomatic cases and in 53.8% (seven out of 13) of asymptomatic patients [Centers for Disease Control (CDC) stages II and III], confirming that PCR was far more sensitive than plasma culture. These results indicate that cell-free virus production is associated with the clinical stage of HIV infection and may serve as a marker for disease progression. Detection of HIV RNA by PCR appears to be the most sensitive method to detect viraemia.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

It has been reported that the period of latency between HIV-1 infection and the production of antibodies against the virus is sometimes prolonged for >6 months. However, the data supporting this are still controversial and it is not known whether these individuals are actually infectious, especially through body fluids. We have performed a prospective study of 65 high-risk HIV-1-antibody-negative individuals who were followed-up for a period of at least 1 year. Twelve of these individuals were shown by polymerase chain reaction (PCR) to be carriers of HIV-1 proviral sequences. The virus was isolated from lymphocytes in five out of 10 PCR-positive subjects and from cell-free plasma in two. Our data indicate that in some cases delayed seroconversions may be associated with productive infection, suggesting that mechanism(s) other than viral latency may be responsible for the absence of antibody responses to HIV-1 proteins.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Evidence of frequent HIV-1 infections in antibody-negative, high-risk individuals (so-called ‘silent’ infections) remains controversial. To evaluate whether these discrepant results may be the consequence of intermittent detection of rare infected cells (low viral load) preceding seroconversion, we developed a modification of the polymerase chain reaction (PCR) technique which enabled analysis of 10-fold greater amounts of cellular DNA per reaction than standard PCR (2 × 106rather than 0.2 × 106input cells). This technique allowed consistent detection of HIV-1 provirus in two seropositive individuals who had repeatedly tested negative by standard-input PCR. However, results were negative when high-input PCR was applied to 51 specimens from 39 selected high-risk seronegative individuals. These results suggest that variations in viral load preceding or in the absence of seroconversion probably do not explain discrepant evidence regarding silent HIV-1 infection.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Early intervention guidelines in HIV infection require knowledge of CD4+ lymphocyte count; however, CD4 + determinations require special laboratory procedures and may not be readily available in all situations. Using data from 207 HIV-seropositive homosexual men without AIDS, we evaluated the association of difference clinical conditions or serologic tests with CD4+ count. Men with conditions including seborrheic dermatitis, hairy leukoplakia, oral candidiasis and chronic diarrhea, and men with beta2-microglobulin levels ≥4.0mg/l had significantly lower CD4 + counts. However, the probability that a subject with such parameters had <200 × 106/I CD4+ cells was limited (25–63%). Although the probability that a subject with such parameters had <500 × 106/I CD4+ cells was better (76–88%), the probability that a person without these parameters had ≥500 × 106/I CD4 + cells was only 45–50%. Clinical and serologic parameters may provide important prognostic information, but cannot be used to reliably determine the level of CD4+ cells.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

A cohort of 111 HIV-infected haemophiliacs has been followed for up to 11 years, during which time 33 patients have been diagnosed with AIDS. Twenty-seven of the cohort developed detectable p24 antigenaemia while remaining free of AIDS. These patients experienced an increased risk of progression to AIDS compared with those patients who were persistently p24-negative (relative risk 7.24; P < 0.0001, Cox proportional hazards model). The relative risk was reduced to 5.42 (P < 0.0001) after adjustment for age and cytomegalovirus seropositivity. After adjustment for the patients' declining CD4 lymphocyte count during follow-up, the relative risk fell dramatically to 1.97 and became non-significant (P = 0.2). p24-antigenaemic patients tended to develop AIDS at levels of similar CD4 lymphocyte counts to those who were persistently p24-antigen-negative (median CD4 lymphocyte counts, 70 and 50 × 106/I, respectively). These results suggests that the association between p24 antigenaemia and the rate of progression to AIDS can be explained largely by a more rapid decline in CD4 lymphocyte count among patients with p24 antigenaemia than in those without. The major pathological effects of increased plasma viral load, as detected by the presence or absence of p24 antigenaemia, appear to act via progressive CD4 lymphocyte depletion.

ISSN:0269-9370    

出版商:OVID    

年代:1991

数据来源: OVID