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Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sera from 622 individuals and culture supernatants from three HIV-1 viral isolates were assayed for HIV-1 p24 antigen to investigate the frequency of p24 antigenemia in African and North American populations using three commercial HIV-1 p24 antigen assays (Coulter, Du Pont, and Abbott). The prevalence of p24 antigenemia in 89 hospitalized Zairian AIDS patients was significantly lower than in 47 clinically comparable AIDS patients in the USA (17 versus 48%, P less than 0.0001). Prevalence of p24 antigenemia in sera from 200 asymptomatic HIV-1-infected individuals was also lower in individuals from Zaire compared with 83 individuals in the USA (3.5 versus 7%). In African individuals, antigenemia prevalence increased with advanced clinical status: 8% in ambulatory AIDS patients, 17% in hospitalized AIDS patients and 18% in postmortem AIDS patients. Acid hydrolysis treatment of sera from 63 Zairian AIDS patients initially negative for p24 antigen showed an 11% positivity rate confirmed by neutralization, suggesting that immune complexing of p24 antigen may play a role in the observed lower p24 antigenemia rates reported for African individuals.
AIDS 1991 Jan
PMID:Prevalence of HIV-1 p24 antigenemia in African and North American populations and correlation with clinical status. 190 53

Serum samples of 120 patients in different stages of chronic human immunodeficiency virus type 1 (HIV-1) infection, 11 patients with primary HIV-1 infection (PHI), and 49 HIV-1 seronegative homosexual men were analyzed for tumor necrosis factor-alpha (TNF-alpha), interferon-alpha (IFN-alpha), and HIV-1 p24 antigen. Increased levels of IFN-alpha and TNF-alpha were found in some, but not all, cases with PHI. During progressing disease IFN-alpha occurred in serum with increasing frequency and concentration. Raised levels of TNF-alpha were found in all stages of chronic infection, but were less common in patients with AIDS than were raised levels of IFN-alpha. The levels of the two substances were not correlated. There was a correlation between IFN-alpha, but not TNF-alpha, and the occurrence of HIV-1 p24 antigen in serum. These results suggest that IFN-alpha and TNF-alpha are induced by different agents during HIV-1 infection. The findings would be consistent with the hypothesis that IFN-alpha and TNF-alpha are counteracting forces that have important down- and upregulatory effects, respectively, on HIV-1 replication in vivo.
AIDS Res Hum Retroviruses 1991 Apr
PMID:Interferon-alpha and tumor necrosis factor-alpha in serum of patients in various stages of HIV-1 infection. 190 89

beta 2-microglobulin levels were determined in the serum of 18 initially asymptomatic HIV-1 p24 antigenaemic subjects who were treated with zidovudine (+/- acyclovir) and who were followed for 2 1/2 years. The median serum beta 2-microglobulin level at week 0 was 2.5 mg/l and decreased to 2.3 mg/l after 12 weeks of treatment (p = 0.001). A correlation was found between individual changes in serum beta 2-microglobulin levels and individual changes in serum p24 antigen levels during the first 48 weeks of treatment (p less than 0.05). Six out of 18 subjects progressed to AIDS after 60-126 weeks of treatment. In this group during a period of more than one year before disease progression median serum beta 2-microglobulin levels increased from 2.5 mg/l to 3.3 mg/l (p = 0.03) and median CD4+ cell counts decreased from 0.3 x 10(9)/l to 0.08 x 10(9)/l (p = 0.03), while in that period the pattern of serum p24 antigen levels was inconsistent. Although the variability in serum beta 2-microglobulin levels appeared to make this marker unsuitable for management decisions in individuals, a decline in beta 2-microglobulin levels was found to parallel a decline in p24 antigen levels during the early phase of zidovudine treatment. Moreover, after prolonged treatment, rising beta 2-microglobulin levels--in contrast to p24 antigen levels--were shown to have predictive value for disease progression.
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PMID:Serum beta 2-microglobulin levels in asymptomatic HIV-1-infected subjects during long-term zidovudine treatment. 190 25

Monocyte--macrophages are important target cells and reservoirs for HIV. The existing methods for the quantification of infectious virus in HIV stocks are not totally satisfactory for use with macrophage cultures. We have developed an infectious focus assay for the direct quantification of virions infectious for human peripheral blood monocyte-derived macrophages adhering to plastic microtitre plates. The combination of an HIV-1 p24-antigen-specific monoclonal antibody and a beta-galactosidase-linked second antibody resulted in a sensitive and very specific assay. With 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside as substrate, the assay proved to be as sensitive as p24 antigen quantification in culture supernatants.
AIDS 1991 May
PMID:Direct quantification of HIV-1 infectivity for monocyte--macrophages using an infectious focus assay. 190 61

This study examines the impact of HIV-1 infection and AIDS on 500 of 563 consecutive deaths at University Hospital, Kinshasa, Zaire, in late 1987. HIV-1 seroprevalence was 31% for the entire population and 43% for the 247 adults. Forty-two (38%) of the 110 HIV-1-seropositive adult deaths occurred in those between the ages of 25 and 34 years. The mean age of death for seropositives was 36 years, 7.5 years less than seronegative deaths. AIDS and AIDS-associated diagnoses such as cryptococcal meningitis, chronic diarrhea and pneumonia accounted for 42% of all adult deaths and 74% of all HIV-1-seropositive adult deaths. Seventeen per cent of 50 sera initially negative by enzyme-linked immunosorbent assay (ELISA) were ultimately found to be HIV-1-seropositive by Western blot or p24 antigen testing. The data indicate that HIV-1 infection and AIDS contribute significantly to adult mortality in Kinshasa population and that sensitivity of ELISA tests decreases in terminal HIV-1 infection.
AIDS 1991 May
PMID:HIV-1 seropositivity and mortality at University Hospital, Kinshasa, Zaire, 1987. 190 62

Antibodies against human immunodeficiency virus, other infectious agents and neopterin levels were determined in 253 patients in a rural area of North-West Tanzania. Seroprevalence for HIV was 3.2%. In one case serology was positive for HIV-1 and HIV-2 antibodies and questions whether there was a real double infection or a cross reaction not only concerning core region proteins but also transmembrane protein. The specificity in the diagnosis of HIV-infection is markedly increased with newer serological methods using recombinant peptides but did not improve sensitivity on African sera. Neopterin was determined as a sensitive indirect marker for the activation of T-cells and is therefore correlated with the susceptibility of HIV infection and with progression of disease. High seroprevalence rates for various infectious agents were determined and may explain the high rate of elevated neopterin levels in 80% of the Africans. Neopterin levels were even higher in HIV patients. Viral p24 antigen was found only in two persons, one of whom had no antibodies detectable.
Int J STD AIDS
PMID:Evaluation on HIV serology and immune-stimulation on patients in Tanzania. 190 99

To define the natural variability of human immunodeficiency virus p24 antigen (HIV Ag) over time in untreated HIV-infected patients, we analyzed the percentage change of serum HIV Ag in 40 antigenemic ARC/AIDS subjects receiving placebo in a 24 week clinical trial. When grouped by month of observation, no differences in HIV Ag change were seen among all five 1 month observation periods (p greater than 0.4). After all 105 monthly changes (median of 3 per subject) were pooled, the mean monthly HIV Ag change was 0% change (standard deviation: 77% increase, 44% decrease). Furthermore, HIV Ag changes did not differ among all lengths of observation (from 1 to 5 months using all possible pairwise combinations of HIV Ag levels, p greater than 0.4). CD4 T-cell changes over the whole study did not correlate with HIV Ag changes over the same period. Knowledge of this broad HIV Ag variability should be useful in calculating sample size and in choosing categorical responses unlikely to occur spontaneously in clinical trials of antiviral agents where HIV Ag changes are used as surrogate markers of efficacy.
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PMID:HIV antigen variability in ARC/AIDS. 191 82

The immune response to the p24 core antigen of human immunodeficiency virus type 1 (HIV-1) was studied in serial samples collected prospectively from 52 homosexual males in two separate cohorts from Amsterdam and San Francisco. p24 antibody levels were quantified with an antigen sandwich immunoassay using p24 recombinant antigen as capture and probe. Titers and slopes of dilution curves reflecting antibody affinity were analyzed. Only 45 of 52 men developed a measurable primary immune response to p24. In 17 (33%) patients there was a low response with maximum antibody titer below 66, shallow (low affinity) dilution curve, and 10 of the 17 became HIV antigen positive over a 2 year period. In 24 (46%) of the 52 patients titers ranged from 100-4000, steeper dilution curves were noted, and none became HIV antigen positive. Four (8%) men developed a strong immune response with high titers (greater than 12,000) and high affinity type dilution curve. Over time, after the peak immune response, antibody titer declined in some individuals related in part to the formation of immune complexes between HIV-1 p24 antigen and antibody which were dissociable. In vitro, the addition of increasing amounts of purified p24 antigen corresponded to decreasing antibody titer and a shallower dilution curve suggesting a preferential consumption of high affinity antibodies for complex formation. The magnitude of immune response to HIV-1 p24 antigen varies widely in infected homosexual men. Both the intrinsic ability to mount an immune response and immune complex formation contribute to the measurable antibody level.
AIDS Res Hum Retroviruses 1991 Aug
PMID:Immune response to HIV p24 core protein during the early phases of human immunodeficiency virus infection. 193 Dec 33

We evaluated three cellular and five serologic markers that are affected by infection with the human immunodeficiency virus type 1 (HIV-1) for their ability to predict the progression to clinical acquired immunodeficiency syndrome (AIDS). The cellular markers were the number of CD4+ T cells, the number of CD8+ T cells, and the ratio of CD4+ T cells to CD8+ T cells. The serologic markers were the serum levels of neopterin (a product of stimulated macrophages), beta 2-microglobulin, soluble interleukin-2 receptors, IgA, and HIV p24 antigen. We evaluated the usefulness of these measures as markers of the progression to AIDS prospectively, over four years, in a cohort of 395 HIV-seropositive homosexual men who were initially free of AIDS. CD4+ T cells (expressed as an absolute number, a percentage of lymphocytes, or a ratio of CD4+ to CD8+ T cells) were the best single predictor of the progression to AIDS, but the serum neopterin and beta 2-microglobulin levels each had nearly as much predictive power. The neopterin level appeared to be a slightly better predictor than the beta 2-microglobulin level. The levels of IgA, interleukin-2 receptors, and p24 antigen had less predictive value. A stepwise multivariate analysis indicated that the best predictors, in descending order, were CD4+ T cells (the percentage of lymphocytes or the CD4+: CD8+ ratio), the serum level of neopterin or beta 2-microglobulin, the level of IgA, that of interleukin-2 receptors, and that of p24 antigen. The last three markers had little additional predictive power beyond that of the first two. We conclude that of the eight markers studied, progression to AIDS was predicted most accurately by the level of CD4+ T cells in combination with the serum level of either neopterin or beta 2-microglobulin. At least one of these two serum markers, which reflect immune activation, should be used along with measurement of CD4+ T cells in disease-classification schemes and in the evaluation of responses to therapy.
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PMID:The prognostic value of cellular and serologic markers in infection with human immunodeficiency virus type 1. 197 15

HIV-1 neutralizing activity was demonstrated in serum and 200-fold concentrated urine from individuals who were HIV-1 antibody positive in both their serum and urine, including AIDS-KS, AIDS-OI, ARC, and asymptomatic patients. Virus neutralization activity was detected in 23 of 56 (41.1%) of the serum samples and in 19 of 56 (33.9%) of the urine samples tested, with titers ranging from 1:8 to 1:256 and 1:1 to 1:4, respectively. The highest frequency of HIV-1 neutralizing activity (87.5%) and the highest mean neutralization titers (1:65) were found in the ARC patients. A high prevalence of p24 antigen in serum and low numbers of T4-lymphocytes correlated with a low frequency of neutralizing activity in either serum or urine in the infected individuals. HIV-1 neutralizing activity in the urine was shown to be due to immunoglobulins using a Sephadex G-100 filtration gel. All 19 urine samples with neutralizing activity contained antibodies reactive with envelope glycoproteins gp160, gp120, and gp41 by Western blot, similar to that seen with serum. The frequency of HIV-1 neutralizing activity in the urine concentrates was generally associated with high titers of neutralizing antibody in the corresponding serum. These findings suggest that HIV-1 neutralizing antibodies are lost in the urine by an as yet unknown mechanism.
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PMID:HIV-1 neutralizing antibodies in urine from seropositive individuals. 196 94


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