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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study analyzes the degree of immune activation and characterizes apoptosis in lymphocytes from healthy West African donors or patients infected with human immunodeficiency virus (HIV)-1 or -2. The lower decline of CD4 T cells in HIV-2- compared with HIV-1-infected donors is associated with lower levels of immune activation, evaluated by HLA-DR expression on lymphocytes and sera concentrations of IgG and beta2 microglobulin (beta2m). Ex vivo apoptosis was found in both infections in all lymphocyte subsets, including CD4 and CD8 T cells, as well as B cells, but was lower in HIV-2 than in HIV-1 infection. Interestingly, high correlations were found in HIV-2- and HIV-1-infected donors between the level of CD4 T cell apoptosis and beta2m concentration and progression of the disease. These observations support the hypothesis that long-term activation of the immune system, weaker in HIV-2 infection, significantly contributes to T cell deletion and disease evolution.
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PMID:Reduced immune activation and T cell apoptosis in human immunodeficiency virus type 2 compared with type 1: correlation of T cell apoptosis with beta2 microglobulin concentration and disease evolution. 1060 52

Levels of virus in the plasma are closely related to the pathogenicity of human immunodeficiency virus type 1 (HIV-1). HIV-2 is much less pathogenic than HIV-1, and infection with HIV-2 leads to significantly lower plasma viral load. To identify the source of this difference, we measured both viral RNA and proviral DNA in matched samples from 34 HIV-2-infected individuals. Nearly half had undetectable viral RNA loads (<100 copies/ml), but levels of proviral DNA were relatively high and confirmed that quantities of provirus in HIV-1 and HIV-2 infection were similar. Overall, HIV-2 proviral DNA load did not correlate with viral RNA load, and higher viral RNA load was associated with increased production of plasma virus from the proviral template. These results suggest that low viral load in HIV-2 infection is due to decreased rates of viral production, rather than differences in target cell infectivity.
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PMID:Low plasma human immunodeficiency virus type 2 viral load is independent of proviral load: low virus production in vivo. 1062 69

The FUT2 gene encodes the enzyme alpha (1,2) fucosyltransferase, which determines expression of blood-group antigens on mucosal epithelial cell surfaces and in secretions. Homozygotes for a specific stop mutation in FUT2 (nonsecretors) cannot produce this enzyme and thus are unable to express blood group antigens. Nonsecretor status is associated with a decreased risk of several respiratory viral infections. By use of molecular genotyping, 2 populations of Senegalese women were examined for polymorphisms of the FUT2 gene. Among Senegalese commercial sex workers, absence of FUT2 (nonsecretor genotype) was associated with reduced risk of human immunodeficiency virus (HIV) type 1 infection (odds ratio [OR] adjusted for cervical and vaginal infection, 0.18; 95% confidence interval [CI], 0.04-0.90) and HIV-2 infection (adjusted OR, 0.43; 95% CI, 0.13-1.39), although the latter was not statistically significant. Modification of cell surface carbohydrates at mucosal surfaces determined by the FUT2 gene may underlie the protective association against heterosexual HIV infection.
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PMID:Secretor polymorphism and human immunodeficiency virus infection in Senegalese women. 1066 66

The prevalence of human immunodeficiency virus types 1 and 2 in rural areas of Nigeria was estimated using 1089 sera collected in 18 locations from 1992 to early 1994. The sera were tested with Enzyme linked Immunosorbent Assay (ELISA) and confirmed by Western Immunoblotting technique. Overall, 13 (1.2%) of the 1089 sera were positive for antibodies to HIV-1 and HIV-2. Prevalence of 0.6% and 0.8% were obtained for HIV-1 and HIV-2 respectively. The highest prevalence of HIV-1 and HIV-2 (50.0%) were found in Zuhlrrua and Umubuzu. A seroprevalence of 1.2% was obtained for both male and female groups tested. The highest prevalence of HIV was found among individuals 30-39 years age group. An overall increase in prevalence of HIV-1 and HIV-2 infection was obtained over the three years during which samples were collected for this study (0.7% in 1992, 1.0% in 1992 and 3.4% in 1994). In addition, two sera were positive for both HIV-1 and HIV-2. The detection of antibodies to HIV-1 and HIV-2 in the rural areas where blood samples were collected for this study shows that both viruses are widespread in the rural communities of Nigeria.
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PMID:Human immunodeficiency virus types 1 and 2 infection in some rural areas of Nigeria. 1089 30

Although human immunodeficiency viruses 1 and 2 (HIV-1 and HIV-2) share mode of transmission, their epidemiologic characteristics differ and international spread of HIV-2 has been limited. To investigate the extent of HIV-2 infection in South Korea and to clarify the characteristic of HIV-2 isolates, we describe epidemiological, serological and genetic analyses of five HIV-2 isolates from South Korea. Five of 964 HIV antibody-positive serum specimens showed positive reactivity by HIV1/2 enzyme immunoassay (EIA), HIV-2 Western blot analysis, HIV-2 particle agglutination (PA) test and line immunoassay (LIA) but negative or indeterminate one by HIV-1 PA test and HIV-1 Western blot analysis. To confirm HIV-2 infection by genetic analysis, reverse transcription-polymerase chain reaction (RT-PCR) was performed on five HIV-2 seropositive samples. PCR products from gag (197 bp) and env gene regions (137 bp) were obtained with three of the five samples with HIV-2 specific gag primers and with all the five samples with env primers. To obtain larger sequences for a more comprehensive phylogenetic analysis, we performed PCR for a 1191 bp env region of HIV-2 but only two such products were obtained. For the phylogenetic analysis, three 197 bp gag and two 1191 bp env PCR products were cloned and sequenced. Based on the gag and env sequences alignments, three isolates (KR4063, KR7051 and KR8091) were clustered phylogenetically within HIV-2 subtype A. In conclusion, HIV-2 virus is present in South Korea and was detected in five subjects. Furthermore, the prevalence of HIV-2 infection should be monitored continuously in South Korea to assess the spread of this virus and to assist in the diagnosis of HIV infection.
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PMID:Introduction of human immunodeficiency virus 2 infection into South Korea. 1098 87

Human immunodeficiency virus 2 (HIV-2) is endemic in West Africa and is a causative agent of the acquired immunodeficiency syndrome. Only a small number of HIV-2-infected patients have been described in detail. Non-Hodgkin's lymphoma (NHL) is the second most common neoplasm occurring in HIV-1-infected patients, but its incidence seems to be lower in HIV-2-infected individuals. We report an HIV-2-infected patient from Cape Verde (West Africa) with separate and distinct systemic and primary central nervous system large B-cell lymphomas and review the findings of cases of HIV-2-associated lymphomas reported in the literature. Different clonal rearrangements of the immunoglobulin heavy chain gene could be detected in the two lymphomas of our patient by polymerase chain reaction and sequence analysis. These data indicate the presence of two clonally unrelated large B-cell lymphomas in the same patient, which is an unusual finding. Neither Epstein-Barr virus nor human herpesvirus 8 could be detected in the tumor tissues or the cerebrospinal fluid. HIV-2 infection should be considered in patients with NHL, especially in those from West Africa.
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PMID:Clinicopathological characterization of an HIV-2-infected individual with two clonally unrelated primary lymphomas. 1107 59

Between 1993-96, blood donated by 12,235 replacement blood donors was screened by various Enzyme Linked Immunosorbent Assays for detecting antibodies to Human Immunodeficiency Viruses types 1 and 2 according to the guidelines specified by Indian--Food and Drug Administration. 222 replacement blood donors (1.81%) were found to be seropositive for antibodies to Human Immunodeficiency Virus types 1 and 2. Furthermore, the ImmunoComb II HIV 1 & 2 BiSpot rapid sandwich ELISA in a comb format was used for differentially identifying HIV-1 and/or HIV-2 infection among these blood donors in Mumbai. Our data indicates that there is a low seroprevalence of HIV-1-2 infection among replacement blood donors in Mumbai (Bombay). Among them, while HIV-1 is still the predominant virus, dual HIV-1-2 and HIV-2 only infections are steadily increasing.
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PMID:Human immunodeficiency viruses types 1 and 2 infection among replacement blood donors in Mumbai (Bombay). 1127 23

To evaluate serologic testing algorithms for human immunodeficiency virus (HIV) based on a combination of rapid assays among persons with HIV-1 (non-B subtypes) infection, HIV-2 infection, and HIV-1-HIV-2 dual infections in Abidjan, Ivory Coast, a total of 1,216 sera with known HIV serologic status were used to evaluate the sensitivity and specificity of four rapid assays: Determine HIV-1/2, Capillus HIV-1/HIV-2, HIV-SPOT, and Genie II HIV-1/HIV-2. Two serum panels obtained from patients recently infected with HIV-1 subtypes B and non-B were also included. Based on sensitivity and specificity, three of the four rapid assays were evaluated prospectively in parallel (serum samples tested by two simultaneous rapid assays) and serial (serum samples tested by two consecutive rapid assays) testing algorithms. All assays were 100% sensitive, and specificities ranged from 99.4 to 100%. In the prospective evaluation, both the parallel and serial algorithms were 100% sensitive and specific. Our results suggest that rapid assays have high sensitivity and specificity and, when used in parallel or serial testing algorithms, yield results similar to those of enzyme-linked immunosorbent assay-based testing strategies. HIV serodiagnosis based on rapid assays may be a valuable alternative in implementing HIV prevention and surveillance programs in areas where sophisticated laboratories are difficult to establish.
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PMID:Sensitivity and specificity of human immunodeficiency virus rapid serologic assays and testing algorithms in an antenatal clinic in Abidjan, Ivory Coast. 1132 95

The serodiagnosis of human immunodeficiency virus (HIV) infection has widely been established by the screening test and the confirmatory test. At present, Western blot (WB) assay is mostly used as the confirmatory test. However, this method has the problem in that the sensitivity and the specificity are not enough. A new confirmatory test "CHIRON RIBA HIV-1/HIV-2 SIA" developed by Chiron Corporation uses an immunoblot enzyme immunoassay technique for detection of anti HIV-1 and/or HIV-2 antibodies. This assay employs four recombinant viral antigens (gp120, gp41, p24/p26 and p31) and a synthetic viral antigen (HIV-2 envelope peptide). The characteristic of this method is that the HIV-1 infection and the HIV-2 infection can be differentiated from each other. We therefore compared this SIA method with the WB1 assay for detection of anti HIV-1 antibodies and with the WB2 assay for detection of anti HIV-2 antibodies. Eighty samples from normal adults without HIV infection and known to be negative by three HIV screening tests, respectively, were tested by SIA, WB1 and WB2 assays. The negative rates (specificities) were 97.5%, 80.0% and 87.5% by the SIA, WB1 assay and WB2 assay, respectively. With forty samples from patients without HIV infection but known to be positive by at least one HIV screening test, the negative rates (specificities) were 97.5%, 72.5% and 85.5% by the SIA, WB1 assay and WB2 assay, respectively. The results indicated that the SIA method was more specific than two WB assays. Forty samples from patients with HIV-1 infection and known to be positive by three HIV screening tests, were tested by the SIA and WB1 assay. The positive rates (sensitivities) were 97.5% and 75.0% by the SIA and WB1 assay, respectively. With thirteen samples from patients with HIV-2 infection and known to be positive by three HIV screening test, the positive rates (sensitivities) were 100% and 92.3% by the SIA and WB1 assay, respectively. The results indicated that the SIA method was more sensitive than the WB1 assay. Three sets of sera, which were collected during seroconversion for HIV-1 antibody, were used to compare the positive readings by the SIA and WB1 assay. The SIA method indicated the positive readings earlier than the WB1 assay. The present findings indicated that the SIA method was more specific and sensitive than the WB assay, and would be useful as a confirmatory test.
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PMID:[Strip immunoblot assay (SIA) with recombinant antigens and synthetic peptide for detection of anti HIV-1 and HIV-2 antibodies]. 1142 86

V3 enzyme immunoassays have been shown to discriminate effectively between human immunodeficiency virus type 1 (HIV-1) subtypes. The aim of this study was to investigate the feasibility of V3 serotyping for HIV-2 infection. We serotyped 29 sera with three peptides, corresponding to the V3 loop of subtypes A, B, and D of HIV-2. Sera were collected from HIV-2-infected patients, whose infecting strains were sequenced and subjected to phylogenetic analysis. Our results indicate that HIV-2 serotyping using V3 peptides is not relevant. V3 serotyping data were not consistent with genotyping results. The V3-A and V3-D peptides displayed poor discrimination, and the V3-B peptide was not representative of circulating viruses. Comparison of amino acid sequences and serotype reactivities demonstrated the importance of positions 309 and 314, located on either side of the tip of the V3 loop, in antibody binding.
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PMID:V3 serological subtyping of human immunodeficiency virus type 2 infection is not relevant. 1157 25


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