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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently there have been increasing reports of HIV infection acquired through transfusion of HIV seronegative blood in Thailand due to high incidence of HIV new infection in blood donors. Blood or blood components (BC) prepared from HIV seronegative blood donation pose significant hazards to recipients because of the risk of viremia during the "window period" of HIV infection. This paper presents the HIV seroprevalence in hematologic patients other than hemophiliacs who received multiple blood transfusion at Ramathibodi Hospital. The retrospective analysis was done on 167 patients: 132 thalassemia, 19 leukemia, 5 aplastic anemia, 5 ITP, 2 pure red cell aplasia, 2 congenital non spherocytic hemolytic anemia, 1 hereditary spherocytosis and 1 autoimmune hemolytic anemia patients, who received blood transfusion during January 1, 1987 till February 29, 1992 at the Department of Pediatrics, Ramathibodi Hospital. The number of blood or BC transfused in each patient was 1-154 units with the average of 23 units per patient per 5 years with a total 4,000 units. All were HIV sero-negative. Anti-HIV screening was performed periodically in these patients about 1-2 times per year or as necessary. The results were HIV seronegative in all cases. The reason for negative results cannot be explained clearly. It should be noted that our thalassemic patients receive leukocyte poor blood and avoid a hypertransfusion program. Patients with other blood diseases received both whole blood and BC. The HIV contaminated blood in the window period was estimated to be 1:10,000 in Thailand which showed HIV antigen positive but antibody negative. These patients may be fortunately received HIV non contaminated blood.
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PMID:HIV seroprevalence in hematologic patients other than hemophiliacs at Ramathibodi Hospital. 788 70

Studies have shown that cytolytic T lymphocyte (CTL) responses may be critical to the clearance of the early viremia in acute HIV-1 infection. It is likely that these cells play an important role in prolonging the asymptomatic phase of the infection. Although HIV-1-specific CTL activity can be detected in direct assays of freshly isolated peripheral blood lymphocytes (PBL) from some infected individuals, this method fails to detect CTL that are present at low frequency and resting, memory CTL. For these reasons, direct CTL assays on PBL from seropositive individuals may underestimate the level of CTL immunity. As part of ongoing investigations of CTL activity in HIV-1-infected individuals, we developed a novel strategy for the detection and ex vivo expansion of HIV-1-specific CTL. This technique involves selective stimulation of PBL from seropositive individuals with autologous Epstein-Barr virus (EBV)-transformed, B-lymphoblastoid cell lines (B-LCL) infected with vaccinia vectors expressing various HIV-1 genes. Prior to their use for in vitro stimulation, B-LCL are treated with psoralen and UV light to inactivate vaccinia virus. After 1 week of stimulation, CTL activity in stimulated cultures is measured in a standard 51Cr release assay. This ex vivo expansion method can selectively increase the bulk culture CTL activity against env, gag and nef, even in some seropositive individuals with low CD4 counts and little evidence of HIV-1-specific CTL in assays of freshly isolated PBL. These expanded CTL are predominantly of the CD8+ phenotype.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A novel method for detection and ex vivo expansion of HIV type 1-specific cytolytic T lymphocytes. 788 97

Quantitation of human immunodeficiency virus type 1 (HIV-1) in plasma is frequently used to monitor virus load and assess the effect of antiviral agents, but information regarding the stability of the virus is limited. Plasma from patients with CD4 cell counts of < 300/microL was tested by quantitative cultures 1, 4, and 24 h after phlebotomy and after storage at -75 degrees C. Viremia was detected in 18 (69%) of 26 patients. Of 16 samples, 2 (13%) at 4 h and 6 (38%) at 24 h had a significantly lower titer than the sample cultured at 1 h. No culture result after the freezing step was significantly different from the 1-h reference value. The decrease in virus titer over time was observed primarily in patients with CD4 cell counts of > 100/microL. Plasma should not be stored for > 2-4 h at room temperature for HIV-1 culture. If immediate processing is not an option, plasma can be frozen shortly after phlebotomy for later testing without a significant loss of infectious virus.
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PMID:Loss of infectivity ex vivo in plasma of human immunodeficiency virus-infected patients correlates with a high CD4 cell count. 790 Dec 90

Quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in the plasma of seropositive individuals was performed by using an external control assay with techniques to standardize and control each measurement. Rigorous study of the variability of the assay showed that the median intraassay reproducibility was log10 0.15 RNA copies per ml of plasma, while the median interassay reproducibility on replicate plasma samples was log10 0.25 copies perml. Specimen stability studies showed reproducible recovery of RNA from plasma stored at -70 degrees C for up to 12 months. In clinically stable patients who were either untreated or taking zidovudine, the average week-to-week variation in plasma RNA levels, measured in real time, was log10 0.30 RNA copies per ml. In contrast, patients either initiating or changing antiretroviral therapy showed a fall of log10 0.8 to log10 2.0 copies per ml in plasma RNA levels. Overall, 105 of 110 (96%) HIV-1-seropositive individuals with CD4 counts of 36 to 868 cells per mm3 had quantifiable HIV-1 RNA over a range of log10 2.70 to log10 6.23 RNA copies per ml, including 81% (13 of 16) of the individuals with greater than 500 CD4 cells per mm3. Accurate and reproducible quantitation of plasma viremia in real time by reverse transcriptase polymerase chain reaction, particularly in asymptomatic HIV-1-infected individuals with high CD4 counts, provides a basis for the use of this virologic measure to monitor the short- and long-term effects of early intervention therapeutic strategies on viral burden.
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PMID:Biological variation and quality control of plasma human immunodeficiency virus type 1 RNA quantitation by reverse transcriptase polymerase chain reaction. 790 17

Human retroviral infections result in significant neoplastic disease. Human T cell lymphotropic virus I (HTLV-I), the first human retrovirus to be discovered, is associated with the development of acute T cell leukemia with characteristic hypercalcemia and skin lesions after many years of chronic infection of CD4+ cells. HTLV-I also produces myelopathy. A minor T cell immunodeficiency occurs in HTLV-I acute T cell leukemia with associated strongyloidiasis and Pneumocystis carinii pneumonia. Human T cell lymphotropic virus II (HTLV-II) is found to be endemic in Amerindians and intravenous drug users (IVDUs) and has been linked to some cases of hairy-cell leukemia. HTLV-II infects the CD8+ population, with significant cell-associated viremia. Clinical neurological disease is rare, with one patient with myelopathy having been described. Immunodeficiency does not seem to occur. Human immunodeficiency virus 1 (HIV-1) produces aggressive large cell and Burkitt's lymphoma in as many as 10% of HIV-1-infected patients. More than 20% of homosexual men infected with HIV-1 develop Kaposi's sarcoma (KS). The pathogenesis of KS is better understood through studying KS-like cell lines that induce angiogenic factors. In some patients HIV-1 and HTLV-I or HTLV-II infections occur concomitantly. HIV-1 accelerates the tumorigenesis of HTLV-I and produces unusual skin diseases when combined with HTLV-II. Immunodeficiency occurs in all HIV-1-infected patients.
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PMID:Human retroviruses and neoplastic disease. 790 70

Six procedures for quantifying plasma human immunodeficiency virus type 1 (HIV-1) RNA were evaluated by nine laboratories. The procedures differed in their sample volume and preparation of samples and methods of amplification and detection. Coded samples in a 10-fold dilution series of HIV-1-spiked plasma were correctly ranked by all six procedures. Subsequently, coded duplicate plasma samples from 16 HIV-1-infected patients were tested using a common set of standards. Several HIV-1 RNA procedures were sufficiently reproducible so that an empiric 4-fold change could be viewed as significant. HIV-1 RNA levels in the patients (up to 370,000 RNA copies/mL) correlated with proviral HIV-1 DNA and were inversely correlated with CD4 cell counts; HIV-1 RNA assays were more sensitive than plasma viremia, standard p24 antigen, or immune complex-dissociated p24 antigen assays. This study demonstrated that several HIV-1 RNA quantitative assays are ready for use in clinical trials.
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PMID:Multicenter evaluation of quantification methods for plasma human immunodeficiency virus type 1 RNA. 791 48

A simple and rapid assay for the quantification of infectious HIV-1 in plasma was developed using short-term culture and DNA PCR. This method, called culture PCR, allows detection and quantification of infectious HIV-1 viraemia within 48 hours, and measures the number of infectious cell-free HIV-1 particles, expressed as culture PCR infectious doses (CPID/ml). 42 HIV infected subjects were assessed by this method. The titres obtained by CPID closely correlated with CD4+ count and clinical status. CPID titres had significant correlation with infectious virus titre determined by conventional limiting dilution tissue-culture methods. This culture-PCR technique permits rapid assessment of infectious plasma viraemia, and is comparable to longer culture based assay methods.
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PMID:Development of a rapid quantitative assay for HIV-1 plasma infectious viraemia-culture-PCR (CPID). 791 32

Studies with the simian immunodeficiency virus have shown that nef deletion results in a low level of viremia and a lack of disease progression in monkeys. Given the similarity of this clinical profile to that observed in long-term survivors of human immunodeficiency virus type 1 (HIV-1) infection, we sought to examine the nef gene in 10 patients who are clinically healthy and immunologically normal despite 12 to 15 years of infection. PCR and DNA sequencing were used to determine nef sequences in peripheral blood mononuclear cells obtained from long-term survivors. We found that there is no gross deletion within nef in the cases studied; most nef sequences (91.1%) obtained from 10 subjects contained a full-length and intact open reading frame. In addition, at the protein level, there were no discernible differences between the Nef consensus sequences derived from long-term survivors and those from patients with AIDS. We therefore conclude that deletion of or gross sequence abnormality within nef is not likely to be a common explanation for the well-being of long-term survivors of HIV-1 infection. Moreover, phylogenetic analysis of nef sequences suggests that HIV-1 strains found in our study subjects do not have a common origin.
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PMID:Characterization of nef sequences in long-term survivors of human immunodeficiency virus type 1 infection. 798 71

Acute HIV infection is accompanied by a sharp rise in virus titres that soon fall, but the role of humoral and cellular immunity is not clear in the control of initial virus replication. We have found seven HIV-1 infected subjects who had CD8 T-cell non-cytolytic anti-HIV activity in plasma many months before neutralising antibodies can be detected. We observed an inverse relation between the extent of this CD8 cell response and the level of plasma viraemia in some subjects. These results suggest that a cellular immune response controls viral replication soon after HIV infection.
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PMID:Non-cytolytic CD8 T-cell anti-HIV responses in primary HIV-1 infection. 799 61

The hepatitis viruses A through D are prevalent among patients at risk for human immunodeficiency virus (HIV) infection. The courses of hepatitis B, C, and D are modified by HIV infection. With hepatitis B, increased carriage rates, increased viral replication, and milder liver injury are seen. The degree of HIV-induced immunosuppression does not correlate well with liver injury or amount of hepatitis B viral replication. With progression to AIDS, surface antibody titers can decline, resulting in reactivation of latent hepatitis B virus or reinfection with another subtype. hepatitis B virus may enhance progression to AIDS. Preliminary data suggest that HIV infection can prolong or increase hepatitis C or D viremia and decrease the accuracy of tests for hepatitis C. Interferon may have efficacy against hepatitis C but rarely against hepatitis B in patients who are coinfected with HIV. Zidovudine, ganciclovir, and foscarnet also may be active against these hepatotropic viruses.
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PMID:Clinical aspects of the interactions between human immunodeficiency virus and the hepatotropic viruses. 801 13


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