Human immunodeficiency virus type 1 detected in all seropositive symptomatic and asymptomatic individuals.

Between February 1987 and October 1988, peripheral mononuclear blood cells (PBMC) from 409 adult individuals antibody positive by Western (immuno-)blot for human immunodeficiency virus type 1 (HIV-1) (56 acquired immunodeficiency syndrome [AIDS] patients, 88 patients with AIDS-related complex, and 265 asymptomatic individuals) were consecutively cultured for HIV-1 or tested for the presence of HIV-1 DNA sequences by a polymerase chain reaction assay (PCR). We isolated HIV-1 or detected HIV-1 DNA sequences from the PBMC of all 409 HIV-1 antibody-positive individuals. None of 131 healthy HIV-1 antibody-negative individuals were HIV-1 culture positive, nor were HIV-1 DNA sequences detected by PCR in the blood specimens of 43 seronegative individuals. In addition, HIV-1 PCR and HIV-1 culture were compared in testing the PBMC of 59 HIV-1 antibody-positive and 20 HIV-1 antibody-negative hemophiliacs. Both methods were found to have sensitivities and specificities of at least 97 and 100%, respectively. In contrast, the sensitivities of serum HIV-1 antigen testing in AIDS patients and asymptomatic seropositive patients were 42 and 17%, respectively. Our ability to directly demonstrate HIV-1 infection in all HIV-1 antibody-positive individuals provides definitive support that HIV-1 antibody positivity is associated with present HIV-1 infection. Moreover, the sensitivities and specificities of PCR and culture for the detection of HIV-1 appear to be equivalent, and both methods are superior to testing for HIV-1 antigen in serum for the direct detection of HIV-1.     

Rational peptide selection to detect human immunodeficiency virus type 1-specific T-cell responses under resource-limited conditions

Understanding human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T-lymphocyte responses is important for the development of vaccines and therapies. We describe a novel method for the rational selection of peptides that target stable regions of the HIV-1 genome, rich in epitopes specifically recognized by the study population. This method will be of particular use under resource/sample-limited conditions.     

The use of simple, rapid tests to detect antibodies to human immunodeficiency virus types 1 and 2 in pooled serum specimens.

BACKGROUND: The use of pooled specimens has been proposed as a means of expanding testing for human immunodeficiency virus (HIV) antibodies in population studies and in blood screening, while reducing laboratory costs. OBJECTIVES: To develop a strategic specimen pooling method to be used with rapid HIV antibody assays to detect positive specimens and to evaluate its performance in comparison with testing with commercial EIA and WB. STUDY DESIGN: Two lateral flow rapid HIV antibody assays, Seroz*Strip HIV-1/2(1) and Determine HIV-1/2, were evaluated for their ability to detect HIV-1 antibodies in serum and/or plasma specimens pooled in sizes ranging from two to 20 following the respective manufacturers' protocols. One thousand prospectively collected specimens and 55 seroconversion specimens were prepared in pools of five for evaluation by the two rapid HIV assays. RESULTS: Optimal detection and discrimination of HIV-1 antibody-positive and HIV-1 antibody-negative specimens was observed in pool sizes of five to ten for both assays. The ability of the two rapid assays to detect HIV-1 antibody-positive samples from commercial HIV-1 seroconversion panels contained in the pools was equivalent to that of commercial enzyme immunoassays (EIAs) and Western blot (WB) to detect HIV-1 antibody in the non-pooled samples. Application of the pooling method in prospectively collected specimens yielded excellent concordance with EIA/WB results in both sensitivity (98.88% for Seroz*Strip HIV-1/2, 100% for Determine HIV-1/2) and specificity (99.56% for Seroz*Strip HIV-1/2, 99.45% for Determine HIV-1/2). CONCLUSION: Use of a pooling strategy with either assay reduced the number of tests required by almost 50% and could provide substantial cost reductions for HIV screening in settings where HIV-1 prevalence is less than 10%.     

Comparison of indirect immunofluorescence and membrane fluorescence assays for the differentiation of antibodies to human immunodeficiency virus types 1 and 2.

Serum samples from 20 human immunodeficiency virus type 1 (HIV-1)- and 30 HIV-2-infected and 7 dually infected individuals were reacted by using the indirect immunofluorescence assay (IFA) and membrane fluorescence assay in order to determine whether these methods were useful for typing HIV-1 and HIV-2 antibodies. Although 41 of 50 (82%) of the HIV-1- and HIV-2-positive specimens cross-reacted to some extent with the heterologous antigen in the IFA, the antigen with the higher titer correlated completely with the infecting type. The IFA could not distinguish single from dual infections, however. In contrast, only 4 of the 50 (8%) serum samples cross-reacted in the membrane fluorescence test. All seven of the specimens from patients with mixed infections reacted with both antigens. The membrane fluorescence test appears to be reliable for serodifferentiation of HIV-1 and HIV-2 infections and may be useful for laboratories with low-volume typing requirements.     

T-helper reactivity to simian immunodeficiency virus gag synthetic peptides in human immunodeficiency virus type 2 infected individuals

West African populations are infected with divergent strains of human immunodeficiency virus type 2 (HIV21, some of which are closely related to simian immunodeficiency virus (SIV) and it has been postulated that the HIV2 epidemic might have arisen by cross-species spread of SIV into the human population in West Africa. To gain some insight into the possible basis for cross protection between these two closely related viruses, the T-helper responses to 15 synthetic peptides from SIV gag synthetic peptides were investigated in seven HIV2-infected subjects and in seven healthy controls. Significant reactivity to at least one of the synthetic peptides tested was found in all patients and a statistically significant correlation between CD4+ lymphocyte absolute numbers and the number of reacting peptides was observed. A marginal lymphocyte reactivity was found in two of the healthy controls studied. In conclusion, this preliminary evidence that HIV2-infected patients exhibit T-cell responses to SIV gag peptides suggests that both viruses share t-helper epitopes in the gag viral region and raises the possibility of cross protection between SIV and HIV2 which may be relevant for HIV2 vaccine research based on closely related retroviruses. © 1995 WiIey-Liss, Inc.     

Performance of a quantitative human immunodeficiency virus type 1 p24 antigen assay on various HIV-1 subtypes for the follow-up of human immunodeficiency type 1 seropositive individuals

The heat-denatured signal-amplified p24 antigen assay is a low-cost test allowing the determination of plasma levels of HIV-1 p24 antigen in infected patients. This assay may be appropriate for monitoring disease progression in HIV seropositive patients in developing countries. Only a few data on the clinical validation of the test are available for HIV-1 non-subtypes B viruses that represent the vast majority of virus circulating in Africa. The present study was undertaken to evaluate and compare the performance of a heat-denatured signal-amplified p24 assay for the determination of p24 viral load in the plasma of individuals infected with different subtypes of HIV-1 and using the RT-PCR-based RNA viral load test as the gold standard. A total of 120 plasma samples from individuals infected with HIV-1 strains belonging to group M (subtypes A-->H) and group O, as well as recombinant strains, were tested in parallel with the heat-denatured signal-amplified p24 assay and the RNA viral load. Plasma p24 levels appeared to be correlated significantly with the plasma RNA viral loads (R=0.751, P<0.0001). The heat-denatured p24 antigen assay was capable of measuring the plasma level of p24 derived from all the HIV-1 subtypes and recombinants selected for this study, in contrast to the RNA viral load test which lacked sensitivity towards HIV-1 group O. The heat-denatured signal-amplified p24 assay is a reliable, sensitive and a more affordable tool that can be used for the follow-up of patients infected with B and non-B subtypes as well as recombinant forms of HIV-1 in developing countries.     

Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive women in Zaire

To examine perinatal transmission of the human immunodeficiency virus type 1 (HIV-1) in Zaire, we screened 8108 women who gave birth at one of two Kinshasa hospitals that serve populations of markedly different socioeconomic status. For up to one year, we followed the 475 infants of the 466 seropositive women (5.8 percent of those screened) and the 616 infants of 606 seronegative women matched for age, parity, and hospital. On the basis of clinical criteria, 85 of the seropositive women (18 percent) had the acquired immunodeficiency syndrome (AIDS). The infants of seropositive mothers, as compared with those of seronegative mothers, were more frequently premature, had lower birth weights, and had a higher death rate in the first 28 days (6.2 vs. 1.2 percent; P less than 0.0001). The patterns were similar at the two hospitals. Twenty-one percent of the cultures for HIV-1 of 92 randomly selected cord-blood samples from infants of seropositive women were positive. T4-cell counts were performed in 37 seropositive women, and cord blood from their infants was cultured. The cultures were positive in the infants of 6 of the 18 women with antepartum T4 counts of 400 or fewer cells per cubic millimeter, as compared with none of the infants of the 19 women with more than 400 T4 cells per cubic millimeter (P = 0.02). One year later, 21 percent of the infants of the seropositive mothers had died as compared with 3.8 percent of the control infants (P less than 0.001), and 7.9 percent of their surviving infants had AIDS. We conclude that the mortality rates among children of seropositive mothers are high regardless of socioeconomic status, and that perinatal transmission of HIV-1 has a major adverse effect on infant survival in Kinshasa.     

Enteric prevalence of adenovirus in human immunodeficiency virus seropositive patients

To evaluate the prevalence of adenovirus strains in human immunodeficiency virus (HlV)-positive patients and to investigate their possible role in the onset of diarrhea, a total of 103 stools from HIV-seropositive patients at various stages of infection and 200 stools from sex and age cross-matched control subjects were examined. Adenovirus prevalence was measured by ELISA as well as conventional and rapid cell culture techniques. Results were compared between patients suffering from diarrhea and those without diarrhea. Adenovirus prevalence was statistically greater in HIV-seropositive cases than controls (8.7%, 2.5%, respectively). No significant difference was found between HIV-positive patients with diarrhea and those without gastrointestinal complications (P > 0.05). However, a significant difference in adenovirus prevalence was found between HIV-positive patients with diarrhea and control subjects with diarrhea (P = 0.02). Although viral prevalence varied with the different stages of HIV infection, differences were not statistically significant. In conclusion, although current opinion considers adenovi-ruses to be no more than opportunistic pathogens, the results of this large-scale study do not exclude a potential reactivation of latent adenovirus in HIV infection and suggest that further effort should be directed to elucidating such a mechanism if it exists as well as investigating the specific role of certain adenovirus serotypes in provoking diarrhea during later stages of HIV infection. © 1995 Wiley-Liss, Inc.     

Calicivirus infection in human immunodeficiency virus seropositive children and adults.

BACKGROUND: The importance of enteric viral infections in HIV-related diarrhea is uncertain. Human caliciviruses have emerged as a leading cause of acute diarrhea worldwide. OBJECTIVES: To evaluate the importance of calicivirus infections in HIV-related diarrhea. Study design 151 fecal samples collected from children and adults infected with HIV, with and without diarrhea, were examined. In addition, 89 fecal samples from non HIV-infected children and adults were also tested. Samples were analyzed by RT-PCR using primer sets specific to Norovirus genogroup I or genogroup II as well as primers designed to react with both Noroviruses and Sapovirus genus. RESULTS: Viruses were detected with equal frequencies in stools from HIV infected and non-infected adults (12%). However, specimens from HIV infected children were more likely than those of HIV-negative children to have caliciviruses (51% versus 24%, P<0.05). Viral infections were not significantly associated with diarrhea neither in children nor in adults, regardless of HIV status. Viruses genetically related to the common Lordsdale virus (Norovirus genogroup II) and London/92 virus (Sapovirus) clusters were detected circulating among children. CONCLUSIONS: These results suggest that caliciviruses may be an important opportunistic pathogen in children infected with HIV.     

Synthetic peptide-based immunoassays for distinguishing between human T-cell lymphotropic virus type I and type II infections in seropositive individuals

Until now, serologic tests that distinguish the closely related human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) infections have not been available. Synthetic peptide assays, employing peptides derived from the core and envelope proteins of HTLV-I and HTLV-II (SynthEIA and Select-HTLV tests), were evaluated for the ability to serologically discriminate HTLV-I and HTLV-II infections. Of 32 HTLV-I- and 57 HTLV-II-positive serum specimens from individuals whose infections were confirmed by polymerase chain reaction, the SynthEIA test categorized 29 (91%) as HTLV-I and 50 (88%) as HTLV-II, and 10 (11%) were nontypeable. In contrast, the Select-HTLV test categorized 32 (100%) as HTLV-I and 55 (96%) as HTLV-II, and 2 (2%) were nontypeable. The specificity of both the assays in seropositive serum specimens was 100% in that none of the specimens were incorrectly classified. Additional serum specimens obtained from clinically diseased patients from the United States (n = 8) and asymptomatic carriers and patients from Japan (an endemic population for HTLV-I; n = 40) were categorized as HTLV-I by at least one of the assays, while serum specimens from Guaymi Indians from Panama (an endemic population for HTLV-II; n = 13) were categorized as HTLV-II. Thus, peptide enzyme immunoassays appear to represent a simple technique employing chemically synthesized antigens for discrimination between antibodies of HTLV-I and HTLV-II.     

The detection and quantitative determination of antigens to the human immunodeficiency virus types 1 and 2]

Three modifications of ELISA test system for HIV antigen detection are described. They are based on IgG from HIV-1 and HIV-2-infected human sera and monoclonal antibodies against HIV-1 p24 used as immunosorbents. The peroxidase/anti-HIV-IgG conjugate was used in all the test systems. A possibility of quantitative detection of viral antigen in native culture fluids, lysates, and purified virus preparations was demonstrated. The test system for HIV-1 antigen detection cannot be used for HIV-2 antigen detection and vice versa. The diagnostic value of HIV-1 p24 antigen detection consists in the possibility of earlier AIDS identification and monitoring of the disease at various stages. The sensitivity of "p24" assay is 0.5 ng/ml.     

Serum antibody pattern, antigenemia, and virus isolation in infants born to mothers seropositive for human immunodeficiency virus type 1

Forty children born to mothers seropositive for the human immunodeficiency virus type 1 (HIV-1) followed-up to 15 months after birth were studied by means of serum antibody patterns to individual viral polypeptides, by the presence of detectable levels of viral core antigen (p24) and virus in serum and peripheral blood lymphocytes, and by total lymphocyte counts and T4/T8 lymphocyte ratios. The results obtained indicate that a persistent antigenemia is significantly associated with positive virus isolation from peripheral blood lymphocytes and with changes in the intensity of antibody reaction to core (p24, p17) and pol (p31) antigens. Six children (15%) presented unequivocal signs of HIV-1 infection and five also had signs of immune system involvement.     

Laboratory abnormalities in former blood donors seropositive for human T-lymphotropic virus types 1 and 2: a prospective analysis

CONTEXT: The human T-lymphotropic viruses types 1 and 2 (HTLV-1 and HTLV-2) are highly prevalent among injection drug users in the United States. However, the clinical course of infection has not been well characterized. OBJECTIVE: To understand HTLV-1-and HTLV-2-associated laboratory abnormalities, which may provide insights into their underlying pathophysiology. DESIGN: Cohort study. SETTING: Five US blood centers. PARTICIPANTS: A total of 133 HTLV-1-and 332 HTLV-2-seropositive former blood donors and 717 HTLV-seronegative donors followed up prospectively since 1991. MAIN OUTCOME MEASURES: Selected serum chemistry tests and complete blood cell counts were analyzed at enrollment and approximately 2 years later in participants. Repeated-measures analyses were conducted to evaluate the effect of HTLV infection on laboratory measures. RESULTS: Compared with seronegative subjects, HTLV-1-seropositive subjects had 13% higher creatine kinase (P =.02) and slightly elevated lactate dehydrogenase (P =.03) levels at follow-up. The HTLV-2-seropositive participants had 11% higher absolute lymphocyte counts than seronegative subjects (P =.0001). Infection with HTLV-2 also appeared to be associated with slightly higher hemoglobin levels (P =.03) and hematocrit (P =.03) and with lower albumin levels (P =.01). CONCLUSIONS: These results further our understanding of the biological mechanisms underlying HTLV and suggest that HTLV-associated laboratory changes are unlikely to alter clinical evaluation or counseling of otherwise healthy HTLV-infected subjects.     

Nonorgan-specific autoantibodies in individuals infected with type 1 human immunodeficiency virus.

Fifty-six human immunodeficiency virus-1-positive asymptomatic carriers were tested for the presence of a variety of nonorgan-specific autoantibodies. Antinuclear antibodies were detected in 34 sera, of which 27 were directed to the mitotic spindle apparatus and all were of the IgG isotype. Anti-Golgi complex, anti-centriole, and anti-vimentin antibodies were also present in 20.4, and 4 sera, respectively. Ten patients had less than 500 CD4-carrying T lymphocytes per cubic millimeter. Nine of them had more than one autoantibody. No correlation could be demonstrated between the number of autoantibodies and the level of serum immunoglobulins.     

Prevalence of enteric viruses in human immunodeficiency virus seropositive patients in Venezuela

The prevalence of enteric viruses associated with gastroenteritis was determined in 125 stool samples from patients infected with the human immunodeficiency virus (HIV), with or without diarrhea. Diagnostic assays included enzyme immunoassays for the identification of rotavirus, adenovirus, and Norwalk virus; polyacrylamide gel electrophoresis for atypical rotaviruses and picobirnaviruses and polymerase chain reaction for astrovirus. Enteric viruses were detected in 6.4% (8 of 125) of the stools collected: five (4.0%) samples positive for adenoviruses, and three (2.3%) samples positive for picobirnaviruses were detected. No rotavirus, astrovirus, or Norwalk virus were observed. Only one of the viruses identified (adenovirus) was found in a sample from a patient with diarrhea. Viruses were detected in 10% of the patients with AIDS, 14% of the symptomatic patients, and none of the asymptomatic persons. These results do not support a major role for enteric viruses in the diarrhea suffered by HIV-infected patients. J. Med. Virol. 55:288–292, 1998. © 1998 Wiley-Liss, Inc.     

Characterization of human immunodeficiency virus type-1 from HIV-1 seropositive cases with undetectable viremia.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) viral load has become a standard of care among HIV-1-infected patients; however, a small number of patients have undetectable viral load even though they have never been treated. METHODS: By using RT-PCR and DNA-PCR, and followed by sequencing and phylogenetic analyses, a detailed molecular characterization was carried out from five HIV-1-seropositive patients who had undetectable viral load by commercially available ultrasensitive viral load assays. RESULTS: Of the four patients whose plasmas were available, viral RNAs were detected in three of them by using an in-house RT-PCR in at least one of the three regions (integrase, protease or envgp41). The fourth patient had positive RT-PCR signals in these regions only when RNA isolated from the supernatant of cocultivated patient PBLs with PHA-stimulated HIV-1 negative donor PBLs was used. Further analysis of DNA extracted from the PBMCs revealed that four of the five patients had detectable proviral sequences in at least two of the three regions. The fifth patient had only positive PCR results in all three regions when DNA isolated from PHA-stimulated patient's PBLs was used. Phylogenetic analysis of protease and envgp41 regions revealed that three patients were infected with subtype B viruses while the remaining two patients were infected with subtype C and CRF02_AG viruses. These subtypes coincided with geographic origin and known molecular epidemiology of HIV-1 infection. CONCLUSION: These data provide evidence that both subtype B and non-B HIV-1 infection can result in undetectable viral load in HIV-1-infected patients and that efforts should continue to further characterize these viruses.     

Immunoblotting analysis of IgA and IgM antibody to human immunodeficiency virus type 1 (HIV-1) polypeptides in seropositive infants

Seventy infants born to human immunodeficiency virus type 1 (HIV-1) seropositive mothers were studied for specific antibody (IgA, IgM and IgG) production and the presence of active infection (detectable level of virus in peripheral blood lymphocytes). Among these children, followed for up to 15–40 months after birth, 11 presented unequivocal signs of HIV-1 infection (persistent p24 antigenemia and/or positive virus isolation). Analysis of sera by immunoblotting showed that IgA antibody to HIV-1 p24 core protein, alone or associated with envelope glycoproteins (gp120, gp41), was present in the majority of infected babies (7 of 11), while IgM was found in a lower percentage of cases (4 of 11). No IgA and or IgM antibody to HIV-1 was ever found in babies, born to seropositive mothers, who seroreverted after birth or in the control group enrolled in this study. Our results indicate that immunoblotting analysis of IgA antibody to HIV-1 polypeptides may represent a useful complementary prognostic marker in children born to HIV-1 seropositive mothers.