False-positive sera do not react with human immunodeficiency virus (HIV) gag-encoded recombinant antigen

Ten sera from healthy blood donors positive by enzyme-linked immunoadsorbent assay (ELISA) were studied by immunoblot assay using natural and recombinant proteins. They interacted only with p17 or p24 proteins but were nonreactive with a recombinant protein (RP 50), which carries antigenic determinants to p17 and p24. Reactions were not blocked by preincubation of sera with genetically engineered p17 and p24 or purified viral p24, indicating that some new epitopes were formed during the Western blot procedure. Recombinant gag-encoded protein is required for confirmation of human immunodeficiency virus (HIV) seropositivity.     

Haematological abnormalities in human immunodeficiency virus (HIV) disease.

Peripheral blood and bone marrow changes are commonly seen in disease associated with human immunodeficiency virus (HIV). This annotation aims to summarise these changes and to suggest possible factors entailed in their occurrence.     

Comparison of six serological assays for human immunodeficiency virus antibody detection in developing countries.

Three commercially available assays for the detection of human immunodeficiency virus (HIV) antibodies-Vironostika enzyme immunoassay (EIA), Wellcozyme competitive EIA, and JLC Allaman indirect immunofluorescence assay--were tested on 300 serum samples from African subjects with and without HIV-related conditions. Two experimental assays both rapid and simple to perform (Biotech dip stick and Cambridge Bioscience latex agglutination) were also evaluated on the same serum samples. The results were compared with those of a commercial Western blot (WB) (immunoblot) assay from Biotech, used as the reference technique. All assays were tested in the laboratory of the AIDS Project in Kigali, Rwanda. Calculated specificity ranged from 90.8% (dip stick) to 98.6% (Vironostika EIA, Wellcozyme competitive EIA, and Cambridge Bioscience latex agglutination). Sensitivity ranged from 95.2% (Cambridge Bioscience latex agglutination) to 98.0% (Vironstika EIA) and JLC indirect immunofluorescence assay). However, the sensitivity of the latex agglutination test improved to 98.6% after the prozone effect was controlled for by serial twofold dilution of latex agglutination-negative, WB-positive samples. In situations with a high prevalence of HIV infection, any one of these tests can be regarded as an alternative to the more expensive, time-consuming, and difficult WB assay.     

A sensitive radioimmunoprecipitation assay for human immunodeficiency virus (HIV)

A sensitive and efficient radioimmunoprecipitation procedure is described which provides an alternative to Western blotting assays for characterizing antibodies directed against human immunodeficiency viruses (HIV-1). Reaction of solubilized preparations of HTLV-III with 125I-labeled Bolton-Hunter reagent leads to the efficient labeling of all of the major virus-specific proteins, including gp120, gp41, RT (p66/p51), p24, and p17. These labeled proteins are readily immunoprecipitated by immune human sera, by specific sera derived from hyperimmunized animals, and by monoclonal antibodies. This procedure, referred to as BH-RIP, provides a simple assay for characterizing and titering antibodies against HIV which is equivalent in specificity, and more sensitive and efficient than the Western blotting method. In addition, viral proteins labeled in this way are suitable for biochemical studies. In one such application, the number of high-mannose and complex oligosaccharide side chains of gp120 and gp41 were determined by examining the sensitivities of the two viral glycoproteins labeled by this procedure to the glycosidases Endo H and PNGase F.     

Allergic manifestations of human immunodeficiency virus (HIV) infection

Drug allergy is the most common and significant allergic manifestation of HIV³ infection. Initially described in patients treated with SMX-TMP for PCP, allergy is now known to involve a multitude of drugs. The pathogenesis of, and risk factors for, allergy in HIV infection are poorly understood, although there is evidence suggesting that allergy is more common with advancing immunodeficiency. HIV-negative subjects with sulfonamide allergy may have drug-specific antibodies and drug metabolite-induced lymphocyte cytotoxicity, abnormalities that could partly explain the allergic mechanisms and which may have future diagnostic potential; these abnormalities have not been described in HIV-infected subjects. Therapy includes avoidance, suppressive agents such as corticosteroids, and desensitization, although the appropriate role for each is not entirely clear. Serum IgE levels have been shown to rise with progressive disease; those patients with higher levels may have a worse prognosis. The mechanisms of this rise are multifactorial, probably a combination of altered T-lymphocyte regulation of IgE synthesis and of production of specific IgE directed against microbial antigens.     

Evidence for a Euro-American origin of human immunodeficiency virus (HIV)

Recent reports of the nonspecificity of the enzyme-linked immunosorbent assay (ELISA) test in African populations, significant genomic differences between simian T-cell lymphotropic virus and human immunodeficiency virus (HIV), and the early appearance of clinical acquired immunodeficiency syndroME (AIDS) in the US and Europe are powerful arguments against the assumption that AIDS originated in Africa. The authors postulate that HIV infection has been endemic in the Euro-American population at least since the beginning of the 20th century and that sociocultural changes led to the introduction of the virus into Africa. A search of the literature reveals 28 cases of disseminated Kaposi's sarcoma in the pre-epidemic 1902-66 period. In none of these cases are notations made on intravenous drug abuse, homosexuality, or other risk factors for AIDS. The majority of cases involved men, however. It is pointed out that, in a population where the incidence of a virus such as HIV is low, the number of sexual partners is limited, and intravenous drug abuse is nonexistent, an infection with as long a latency period as HIV may not only be expressed sporadically, but would probably not be recognized as a transmissible infection. On the other hand, the significant changes in these social factors that occurred as a result of the sexual revolution of the late 1960s and early 1970s would be expected to increase the spread of infection and clinical disease so that recognition would be achieved. During the past decade, there have been marked increases in the number of sexually transmitted infections in the homosexual male population. The efficiency of anal intercourse as a mode of transmission probably accounts for the fact that HIV infection first expressed itself in this population.     

Tuberculous lymphadenitis associated with human immunodeficiency virus (HIV) in Uganda.

Sixteen adults presented with lymphadenopathy which was tuberculous on biopsy; they were all seropositive for human immunodeficiency virus (HIV-1), but none had the clinical criteria of the acquired immunodeficiency syndrome (AIDS). The biopsy specimen showed caseating tuberculosis, with scanty or no visible acid fast bacilli in seven cases; the remaining nine had a poor cellular reactivity with numerous bacilli. Antituberculous chemotherapy for two months reduced the lymphadenopathy. Two patients subsequently developed AIDS. Mycobacterial cultures were not performed, but the infection was almost certainly Mycobacterium tuberculosis. The space-time clustering of tuberculous lymphadenitis now seen in Kampala, and the unusual non-reactive histopathology, are typical of the impairment of cellular immunity induced by HIV infection.     

Cytokine regulation of the human immunodeficiency virus (HIV)

The remarkable ability of HIV to insinuate itself into the working of the immune system is the key of its success as an infectious agent. Given that the cytokine network regulates the immune responses, it is not surprising that cytokines can modulate HIV infection. GM-CSF, IL6 and TNF-α enhance HIV, but TGF-β and HIF inhibits the virus. However, the anti-HIV activity of TGF-β is restricted to myeloid cells, while HIF inhibits HIV in myeloid cells and in T-lymphocytes. HIF is produced by CEM cells after induction by an extract from pine cones. It is not an interferon and is likely a novel cytokine. It is pepsin-sensitive but trypsin-resistant and has an apparent molecular weight of 7–12 KDa. Apart from having anti-HIV activity, crude preparations of HIF also inhibit HTLV-1 virus but not HSV virus replication.     

Serological survey of human immunodeficiency virus (HIV) in Ethiopia

The presence of anti-human immunodeficiency virus 1 antibodies was tested in 5,565 serum samples from Ethiopia of which 5,265 were collected from military recruits in the framework of a hepatitis B (HBV) seroepidemiological study performed on a national scale in 1985-1986; the remaining were 300 sera from a population of outpatients belonging to the Arsi region. Of the 5,565 sera, 121 (2.1%) were found to be repeatedly reactive by enzyme-linked immunosorbent assay (ELISA) test for HIV-1 antibodies, but these reactivities were confirmed by Western Blot (WB) assay in only four cases (0.07%) and by ENVACOR (confirmatory competitive ELISA) in three samples. Twenty-three sera were positive by WB to one or two bands related to core proteins but were all negative by ENVACOR. However, according to accepted criteria for positivity, these sera must be regarded as indeterminant reactors. A sample of 409 sera, both reactive and nonreactive by HIV-1 ELISA, were further tested for antibodies to HIV-2 by ELISA. Reactive sera were analysed by WB and by radioimmunoprecipitation assay (RIPA) using 35S-cysteine metabolically labelled SIVmac (HTLV-IV) infected cell lysates. Only 11 sera were found to be slightly reactive in ELISA, but this was not confirmed by WB or RIPA. Data indicate that HIV infection was not widespread in the general population of Ethiopia up to 1986.     

Immunoprecipitation of human immunodeficiency virus type 2 glycoproteins by sera positive for human immunodeficiency virus type 1.

Analysis by radioimmunoprecipitation of serum samples from 27 different human immunodeficiency virus type 1 (HIV-1)-infected individuals residing in Chile showed that the sera of 26% of these individuals also react with glycoprotein gp125 of HIV type 2 (HIV-2). This cross-reaction seems to reflect a qualitative difference among infected individuals, because the titer of antibodies against gp120 of HIV-1 in the cross-reacting samples did not differ significantly from that in the non-cross-reacting samples. Most of the HIV-1-seropositive sera, including many that did not react with gp125 of HIV-2, reacted with gp140, the precursor of HIV-2 glycoproteins. The observed cross-reactions allowed us to distinguish three groups of HIV-1-infected individuals: (i) those whose sera react with both gp140 and gp125, (ii) those whose sera react with gp140, and (iii) those whose sera react with neither of these glycoproteins. The possible cause and significance of these differences is under study.     

Serum IgE and human immunodeficiency virus (HIV) infection

Human immunodeficiency virus infection is characterized by a progressive depletion of helper T-lymphocytes and, like allergic diseases, is associated with altered T cell regulation. Total serum IgE was measured in 67 infected male subjects, 27 uninfected heterosexual male subjects, and 18 uninfected homosexual male subjects. The mean IgE level (132 IU/ml) of infected subjects with a helper T-lymphocyte number less than or equal to 200/mm3 was significantly greater than mean IgE levels of the uninfected heterosexual (38 IU/ml) and homosexual (35 IU/ml) groups. IgE levels were inversely related to both helper T cell and suppressor/cytotoxic T cell numbers but not to IgG or IgA levels. The increase in IgE was not a reflection of an increased prevalence of atopic disease (allergic asthma, allergic rhinitis, or atopic dermatitis) in the infected subjects. The elevation of IgE may be related to a difference among the groups in T cell production of IgE regulatory lymphokines.     

Neutralization profiles of sera from human immunodeficiency virus (HIV)-infected individuals: relationship to HIV viral load and CD4 cell count

The relationship of the neutralizing activity (NA) profile of sera from human immunodeficiency virus (HIV)-infected individuals to the HIV viral load and the absolute CD4 count was examined. The NA of 24 serum samples against autologous isolates (AI) and HIV type 1 strain MN was examined. Three NA patterns were recognized. Nine sera neutralized both AI and MN (+/+), six sera neutralized MN but not AI (-/+), and nine sera failed to neutralize both AI and MN (-/-). The identification of the three neutralization patterns (+/+, -/+, and -/-) indicated that resistance to neutralization was progressive. A reciprocal relationship between the viral burden of the patients and the NA profiles was observed. The nine subjects with a -/- NA profile had a plasma viral load of > or =5 x 10(4) copies/ml and a cellular viral burden of > or =1,122 infectious units per million viable cells, which were significantly different from those of the other groups (P < 0.02). These patterns were independent of the phenotypic characteristics of the virus. Longitudinally, subjects with a -/- profile at baseline gained their HIV-specific NA by 24 weeks of antiretroviral therapy when this was associated with a >/=1-log(10) decline in the plasma HIV viral load. The sera from week 24 from some patients were able to neutralize both the 24-week and the baseline dominant virus isolates. A change in CD4 cell count of 50 or more in either direction predicted a -/- or +/+ profile. The verification of the autologous NA profile might be important in selecting patients who may benefit from immune-based therapies involving neutralizing monoclonal antibodies.     

Endocrine consequences of infection by human immunodeficiency virus (HIV)

The acquired immunodeficiency syndrome (SIDA) is a severe multivisceral affection that is sometimes composed of a clinical expression compatible with an endocrine insufficiency. The post-mortem verifications confirmed the high frequency of the suprarenal, pituitary and testicular lesions. The hormonal functional exploration confirmed the possibility of a decrease in the cortical suprarenal function that contrasts with a moderate hypercortisolemia and an hypogonadism without elevation of the gonadotrophins. The clinical expression of the deficits is unusual. Nevertheless a few cases of obvious suprarenal or antepituitary insufficiency bond to a secondary inflammatory necrosis, an infection by CMV, or a toxoplasmosis have been reported. More often, these hormonal alterations are moderate. There mechanisms are still imprecise. The non-specific response to the stress led by the disease doesn't give an explanation to the observed abnormalities. The described existence of antihormone antibodies in AIDS or the secretory potentialities of the activated lymphocytes might contribute to the physiopathology of the endocrine modifications outside of any infections or endocrine metastatical localisation.     

Simplified testing for antibodies to human immunodeficiency virus.

Test strips for the detection of antibodies to human immunodeficiency virus type 1 were investigated using specimens from risk groups in Thailand (141 reactive; 445 nonreactive) in a local Thai laboratory. The diagnostic sensitivity and specificity were both 100%. Using a set of seroconversion panels, the sensitivity of the test strips was within the range of sensitivities obtained with enzyme immunoassays. The test was developed for performance at decentralized settings under nonlaboratory conditions.