Human Immunodeficiency Virus P24 Research Articles

Inhibition of X4-Tropic HIV Type 1 Replication by Knockdown of the Cellular Protein LEREPO4

Human immunodeficiency virus 1 (HIV-1) and host cell factors show important mutual interactions. We found that HIV-1 infection induced expression of a likely ortholog of mouse immediate early response erythropoietin 4 (LEREPO4) in vitro. When LEREPO4 expression was suppressed by siRNA in P4-CCR5 cells, HIV-1 replication showed significantly reduced HIV-1 transcript and p24 protein levels as measured by quantitative PCR and ELISA, respectively. The LEREPO4 knockdown also had an inhibitory effect on HIV-1-LTR-driven reporter plasmid expression of β-galactosidase. Furthermore, the inhibitory effect of LEREPO4 silencing on HIV-1 replication was confirmed in Jurkat T cells. The up-regulation of LEREPO4 by HIV-1 and the inhibition of HIV-1 replication mediated by knockdown of LEREPO4 may point to an important functional role of LEREPO4 as a novel HIV-1 dependency factor.

Estrogen receptor alpha inhibits the estrogen-mediated suppression of HIV transcription in astrocytes: implications for estrogen neuroprotection in HIV dementia.

Many human immunodeficiency virus (HIV) proteins including Tat are produced by HIV-infected astrocytes and secreted into the brain resulting in extensive neuronal damage that contributes to the pathogenesis of HIV dementia. The neuroprotective hormone 17beta-estradiol (E2) is known to negatively regulate the HIV transcriptional promoter in human fetal astrocytes (SVGA cell line) in a Tat-dependent manner. In the present study we extended our investigation in HIV-infected SVGA cells and found a reduction in HIV p24 levels following E2 treatment in comparison to control. Although many E2-mediated events occur through estrogen receptor alpha (ERalpha), we found low levels of ERalpha mRNA and failed to detect ERalpha protein in SVGA cells. Paradoxically, when ERalpha was overexpressed the E2-mediated decrease in Tat transactivation of the promotor was prevented. To determine whether ERalpha expression is altered in the human brain following HIV infection, postmortum hippocampal tissue was obtained from cognitively normal HIV- and HIV+ patients, patients diagnosed with either mild cognitive/motor disorder (MCMD) or HIV-associated dementia (HAD). Immunohistochemistry and quantitative real-time PCR (qRT-PCR) for ERalpha and glial fibrillary acidic protein (GFAP) showed that ERalpha mRNA levels were not significantly different between groups, while GFAP increased in the hippocampus in the HIV+ compared to the HIV- group and was decreased in the MCMD and HAD subgroups compared to HIV+ controls. Notably the ratio of ERalpha-positive reactive astrocytes to total reactive astrocytes increased and significantly correlated with the severity of cognitive impairment following HIV infection. The data suggest that E2 would have the most dramatic effect in reducing HIV transcription early in the disease process when the subpopulation of astrocytes expressing ERalpha is low.

Assessment of the Ability of a Fourth-Generation Immunoassay for Human Immunodeficiency Virus (HIV) Antibody and p24 Antigen To Detect both Acute and Recent HIV Infections in a High-Risk Setting

An immunoassay (IA) that simultaneously detects both antibody to human immunodeficiency virus (HIV) and HIV p24 antigen (Architect HIV Ag/Ab Combo) was evaluated for its ability to detect HIV infection by using a panel of specimens collected from individuals recently infected with HIV type 1 (HIV-1). This IA was found to be capable of detecting the majority (89%) of infections, including 80% of those considered acute infections based on the presence of HIV RNA and the lack of detectable antibody to HIV. Substantial improvements in detection of recent infections by the Architect HIV Ag/Ab Combo relative to previous generations of IAs as well as the capacity to detect acute infections have important implications for HIV prevention strategies.

Impact of individual‐donation nucleic acid testing on risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus transmission by blood transfusion in South Africa

In 2005, the South African National Blood Service introduced individual-donation (ID) nucleic acid test (NAT) screening for human immunodeficiency virus (HIV) RNA, hepatitis C virus (HCV) RNA, and hepatitis B virus (HBV) DNA. At the same time the use of ethnic origin to prioritize the transfusion of blood according to a hierarchy of residual risk was discontinued. ID-NAT (Ultrio on Procleix Tigris, Chiron) and serology (PRISM, Abbott) repeat test and confirmation testing algorithms were designed to enable differentiation between false-positive and true-NAT and -serology yields. After 1 year, the NAT and serology yield rates in first-time, lapsed, and repeat donors were analyzed and used to estimate the residual risk of HIV, HBV, and HCV infections by blood transfusion. The HIV, HBV, and HCV ID-NAT window phase yield rates in 732,250 blood donations were 1:45,765, 1:11,810, and 1:732,200, respectively. Seven of 16 HIV window phase donations with viral loads above 16,000 copies/mL were HIV p24 antigen enzyme-linked immunosorbent assay positive. PRISM detected anti-HIV and hepatitis B surface antigen (HBsAg) in 89.4 and 73.9% of early infections in repeat donors. The Procleix assay detected viremia in 99.7 and 95.5% of anti-HIV- and HBsAg-positive first-time donors. In these donors, the occult HBV DNA carrier rate was 1:5200. The residual transmission risk of ID-NAT HIV, HBV, and HCV window phase donations was estimated at 1:479,000, 1:61,500, and 1:21,000,000 respectively. One-year ID-NAT screening of 732,250 donations interdicted 16 HIV, 20 HBV, and 1 HCV window phase donations and 42 anti-hepatitis B core antigen-reactive infections during an early recovery or a later stage of occult HBV infection.

Submandibular and sublingual glands involvement in advanced acquired immunodeficiency syndrome (AIDS): an autopsy-based study

To assess the histopathological, immunohistochemical (IHC), and in situ hybridization (ISH) features found in the submandibular (SM) and sublingual (SL) glands of 105 acquired immunodeficiency syndrome (AIDS) patients at autopsy. Gender, age, CD4 cell level, and clinical histories were obtained from clinical charts (SM: n = 103; SL: n = 92). Histologic analysis of hematoxylin and eosin, Gomori-Grocott, and Ziehl-Neelsen stained tissues, IHC to detect infectious agents and characterize inflammatory cells in sialadenitis, and ISH for EBER-1/2 were performed. The mean age of the patients and CD4 cell count were 36 years and 76 cells/microL, respectively. Fifty-eight cases (SM: n = 51 [49%]; SL: n = 54 [59%]) were considered to be microscopically normal. The most common infectious conditions were mycobacteriosis (SM: n = 11 [10%]; SL: n = 7 [7%]), followed by cytomegalovirus (CMV) (SM: n = 14 [13%]; SL: n = 2 [2%]), and cryptococcosis (SM: n = 3 [3%]; SL: n = 4 [4%]). Human immunodeficiency virus (HIV) p24 (SM: n = 2 [2%]; SL: n = 1 [1%]) and EBER-1/2 (SM: n = 9 [39%]; SL: n = 4 [20%]) were seen only in macrophages and lymphocytes, respectively. The most prevalent cells seen in chronic nonspecific sialadenitis (SM: n = 25; SL: n = 25) were CD8+ T lymphocytes, whereas CD68+ macrophages were predominant in the mycobacteriosis-associated granulomatous and nonspecific diffuse macrophagic sialadenitis. Concomitant infections occurred in 5 cases (SM: n = 4; SL: n = 1) and non-Hodgkin lymphoma in 1 case. Infectious diseases and chronic nonspecific sialadenitis were the main alterations found in the SM and SL glands. These alterations were greater in the SM than in the SL glands. CD8+ T lymphocytes and CD68+ macrophages might be relevant to the pathogenesis of the sialadenitis. Clinicians should consider these diseases when assessing the major salivary glands in advanced AIDS patients and follow biosafety procedures to avoid contamination by HIV, CMV, mycobacteriosis, and cryptococcosis.

Rapid detection of HIV-1 p24 antigen using magnetic immuno-chromatography (MICT)

Detection of human immunodeficiency virus (HIV) infections has been enhanced by incorporating p24 antigen detection with current HIV antibody detection using enzyme immunoassays (EIAs). However, screening for HIV antibodies has increased through the use of rapid, lateral-flow HIV antibody detection assays that currently do not have the capability to detect HIV p24 antigen. In this report, a lateral-flow based assay using super-paramagnetic particles as the detection marker was developed for the detection of HIV-1 p24 antigen. This magnetic immuno-chromatographic test (MICT) uses an inexpensive, low-maintenance instrument that detects the magnetic moment of the super-paramagnetic particles in a magnetic field. MICT is simple to perform, provides a numerical output for easier determination of reactive results and can be completed in 40 min. The lower limit of detection for HIV-1 p24 spiked into assay sample buffer and 50% plasma was 30 pg/ml for both. Detection of HIV-1 p24 antigen at 50 pg/ml was reproducible in both inter-run and intra-run assays with coefficients of variation of <13%. Furthermore, the MICT p24 assay was able to detect intact virus spiked into 50% plasma (lower detection limit of ∼250,000 viral RNA copies/ml). MICT detection of increasing HIV-1 p24 levels in commercially available seroconversion panels by MICT was only slightly later than that detected by much more complex EIAs. MICT could provide a simple, low-cost, and portable method for rapid HIV-1 p24 detection in a variety of testing environments.

Human Immunodeficiency Virus (HIV) Antigens and RNA in HIV-Seronegative Women with Cervical Intraepithelial Neoplasia

While investigating whether proteins retrieved by cervicovaginal lavages (CVL) from women with cervical intraepithelial neoplasia (CIN) might correlate with risk of progression to invasive cervical cancer, we unexpectedly identified HIV gag and env glycoprotein in CVL from women with HIV-negative serology. HIV antigens were consistently identified by mass spectrometry (MS) in CVL from 4 women but were absent in CVL from the remaining 16 women. HIV serologies of all 20 patients were negative for both HIV-1 and HIV-2 antibodies. To validate the unexpected MS findings we performed Western blot (WB) and immunoaffinity chromatography (IC) analysis of CVL for HIV proteins, viral load assays of paired CVL and blood samples, and immunohistochemical HIV p24 expression in cervical biopsy specimens. WB analysis of CVL for prostate-specific antigen (PSA) was performed to exclude semen contamination as the source of HIV proteins. WB and IC results demonstrated the presence of HIV-1 gp41 and p24 antigens in four CVL that were identified by MS to have the HIV proteins. Despite negative serology, HIV RNA in CVL and HIV p24 in cervix biopsies were detected in patients with HIV antigen-positive CVL. HIV p24-positive CVL were PSA negative. All 20 subjects remained HIV seronegative throughout the study. Women with HIV proteins and RNA were comparatively older. Our findings suggest that CVL HIV proteins in women with CIN could be markers for unrecognized HIV exposure or subclinical infection. Proteomic screening of cervical secretions may be useful in identifying seronegative women exposed to HIV and/or at risk for AIDS.

Electrochemical Immunosensor for Human Immunodeficiency Virus p24 Antigen Based on Mercapto Succinic Acid Hydrazide Copper Monolayer Modified Gold Electrode

Abstract An immunosensor based on mercapto succinic acid hydrazide copper (II) (CuL) monolayer modified gold electrode (Au|CuL) was developed for the determination of human immunodeficiency virus p24 antigen in acquired immunodeficiency syndrome patients' serum. CuL displays reductive electrocatalyzation for H 2 O 2 and can be employed as electron transfer media between HRP and electrode. Based on a competition immunoreaction, a differential pulse voltammetric determination method for p24 antigen was established by the peak current increase of the immobilized CuL. The current increase results from the enhanced catalytic current of H 2 O 2 reduction with the help of HRP labeled immunocomplex. The free immunocomplex was produced by competitive binding to the limited amount of HRP labeled p24 antibody (HRP-anti p24) from the p24 in sample solution and immobilized on the bottom of the detective hole. The proposed method needs neither separation nor washing up step, which simplifies the immunoassay procedure and shortens the analytical time. The method provides a new promising platform for diagnosing the AIDs disease.

In Vivo Biosafety Model to Assess the Risk of Adverse Events From Retroviral and Lentiviral Vectors

Serious adverse events in some human gene therapy clinical trials have raised safety concerns when retroviral or lentiviral vectors are used for gene transfer. We evaluated the potential for generating replication-competent retrovirus (RCR) and assessed the risk of occurrence of adverse events in an in vivo system. Human hematopoietic stem and progenitor cells (HSCs) and mesenchymal stem cells (MSCs) transduced with two different Moloney murine leukemia virus (MoMuLV)-based vectors were cotransplanted into a total of 481 immune-deficient mice (that are unable to reject cells that become transformed), and the animals were monitored for 18 months. Animals with any signs of illness were immediately killed, autopsied, and subjected to a range of biosafety studies. There was no detectable evidence of insertional mutagenesis leading to human leukemias or solid tumors in the 18 months during which the animals were studied. In 117 serum samples analyzed by vector rescue assay there was no detectable RCR. An additional 149 mice received HSCs transduced with lentiviral vectors, and were followed for 2-6 months. No vector-associated adverse events were observed, and none of the mice had detectable human immunodeficiency virus (HIV) p24 antigen in their sera. Our in vivo system, therefore, helps to provide an assessment of the risks involved when retroviral or lentiviral vectors are considered for use in clinical gene therapy applications.

Antigen‐antibody combination assays for blood donor screening: weighing the advantages and costs

Antigen‐antibody combination assays for blood donor screening: weighing the advantages and costs

Performance evaluation of the new fully automated human immunodeficiency virus antigen‐antibody combination assay designed for blood screening

Before the introduction of human immunodeficiency virus (HIV) combination assays, serologic diagnosis of HIV infection was performed with assays that detected either antibodies or p24 antigen. Owing to the capability to detect the early appearance of p24 antigen, combination assays that are designed for simultaneous detection of antibodies and antigen can significantly reduce the diagnostic window. Specificity and sensitivity of a commercially available HIV antigen-antibody combination assay (Abbott PRISM; assay is not licensed by the FDA for use in the United States) were evaluated in a multicenter study by testing volunteer blood donors, hospitalized patients, seroconversion panels, and p24 antigen and HIV antibody subtype panels. Performance data were compared to a commercially available HIV combination assay and the PRISM HIV O Plus assay. Apparent specificity of 99.95 percent was observed in the donor population for the PRISM HIV antigen-antibody combination assay, and better seroconversion sensitivity was demonstrated compared with another combination assay and the PRISM HIV O Plus assay. Analytical HIV antigen detection sensitivity averaged 33 pg per mL on the Agence Française de Sécurité Sanitaire des Produits de Santé (AFSSAPS) panel. Furthermore, comparable antigen sensitivity was demonstrated for 32 HIV-1 group M subtype and group O panels. The PRISM HIV combination assay detected all HIV-1 group M and O and HIV-2 antibody-positive specimens evaluated. The PRISM HIV antigen-antibody combination assay demonstrated a significant reduction of the window period for diagnosis of HIV infection. The assay demonstrated enhanced specificity and sensitivity along with broad subtype detection. The assay performance represents the "state-of-the art" technology for serologic blood screening of HIV infection.

The Trap

The Centers for Disease Control and Prevention, national public health agencies, and an expert committee of the European Commission have recently published updated guidelines on postexposure prophylaxis (PEP) of occupational human immunodeficiency virus (HIV) exposure. 1,2 Management of occupational HIV exposure relies heavily on HIV antibody testing of the source patient. However, patients with acute HIV infection may be antibody negative yet particularly contagious because of high viremia. We report 2 cases involving health care workers who were exposed to patients with acute primary HIV infection (PHI). The patients were in the window period of seroconversion, during which detection of HIV p24 antigen provided the definitive indication for PEP. We also review the literature on the topic.

Resolution of de novo HIV production and trafficking in immature dendritic cells

The challenge in observing de novo virus production in human immunodeficiency virus (HIV)-infected dendritic cells (DCs) is the lack of resolution between cytosolic immature and endocytic mature HIV gag protein. To track HIV production, we developed an infectious HIV construct bearing a diothiol-resistant tetracysteine motif (dTCM) at the C terminus of HIV p17 matrix within the HIV gag protein. Using this construct in combination with biarsenical dyes, we observed restricted staining of the dTCM to de novo-synthesized uncleaved gag in the DC cytosol. Co-staining with HIV gag antibodies, reactive to either p17 matrix or p24 capsid, preferentially stained mature virions and thus allowed us to track the virus at distinct stages of its life cycle within DCs and upon transfer to neighboring DCs or T cells. Thus, in staining HIV gag with biarsenical dye system in situ, we characterized a replication-competent virus capable of being tracked preferentially within infected leukocytes and observed in detail the dynamic nature of the HIV production and transfer in primary DCs.

Anti-HIV-1 activities of 4 Telomerase Restrictors

MTT Cell Proliferation Assay was used to optimize the concentration of Telomerase Restrictors(TRs) with minimum toxicity to the selected cells. FACSort flow cytometer and Innotest P24 HIV(Human immunodeficiency Virus) antigen mAb ELISA Kit were used to investigate the anti-HIV-1 activities of TRs. The results showed that TRs had low cytotoxicity to the PBMC (Peripheral Blood mononuclear cells) and CEM/GFP if the concentration of TRs was at 50 μmol/L or below, and the supernatant from PBMC pretreated with SHIV and TR1-001 /TR1-002 could not infect the PBMC, while can infect the C8166 with reduced infectivity, which suggested that the TRs may be one of the novel resources for screening anti-HIV-1 agents.

SAMMA, a mandelic acid condensation polymer, inhibits dendritic cell-mediated HIV transmission

SAMMA, a mandelic acid condensation polymer, exhibits a broad antimicrobial activity against several sexually transmitted pathogens including human immunodeficiency virus (HIV). Here we demonstrated that SAMMA suppressed HIV transmission by dendritic cells (DCs), one of the first target cells for primary infection. The greatest inhibitory effect was achieved when SAMMA was present during the co-culture with target cells. The inhibitory effect of SAMMA on DC-mediated HIV transmission was not due to cytotoxicity. Analysis of the level of DC-associated HIV p24 antigen revealed that SAMMA prevented HIV internalization by DCs when the virus was pre-incubated with the compound. In contrast, pre-incubation of DCs with SAMMA followed by wash-off did not affect the amount of cell-associated HIV p24 antigen. In addition, SAMMA blocked HIV glycoprotein-mediated cell–cell fusion. This study suggests that SAMMA prevents HIV infection through multiple mechanisms.

Interaction between HIV-1 Rev and Integrase Proteins

Human immunodeficiency virus 1 (HIV-1) Rev and integrase (IN) proteins are required within the nuclei of infected cells in the late and early phases of the viral replication cycle, respectively. Here we show using various biochemical methods, that these two proteins interact with each other in vitro and in vivo. Peptide mapping and fluorescence anisotropy showed that IN binds residues 1-30 and 49-74 of Rev. Following this observation, we identified two short Rev-derived peptides that inhibit the 3'-end processing and strand-transfer enzymatic activities of IN in vitro. The peptides bound IN in vitro, penetrated into cultured cells, and significantly inhibited HIV-1 in multinuclear activation of a galactosidase indicator (MAGI) and lymphoid cultured cells. Real time PCR analysis revealed that the inhibition of HIV-1 multiplication is due to inhibition of the catalytic activity of the viral IN. The present work describes novel anti-HIV-1 lead peptides that inhibit viral replication in cultured cells by blocking DNA integration in vivo.

Human immunodeficiency virus infection inhibits granulocyte-macrophage colony-stimulating factor–induced microglial proliferation

It is well known that infection by the human immunodeficiency virus (HIV) dysregulates cell physiology, but little information is available on the consequences of HIV infection in primary macrophages and microglia. The authors examined the relationship between cell proliferation and HIV infection in primary cultures of microglia and in human central nervous system (CNS). In cultures infected with HIV (ADA and BaL), granulocyte-macrophage colony-stimulating factor (GM-CSF)-mediated cell proliferation was reduced in productively infected (p24+) cells as compared to p24- cells. The reduction was observed with both Ki67 and BrdU labeling, suggesting a G1/S block. The reduction was insignificant when microglia were infected with a Vpr- mutant virus. In human CNS, proliferating (Ki67+) cells were rare but were increased in the HIV+ and HIV encephalitis (HIVE) groups compared to the HIV- group. A positive correlation between GM-CSF immunoreactivity and Ki67 counts, implicating GM-CSF as a growth factor in human CNS was found. The relationship between total macrophage (CD68+) proliferation and infected macrophage (p24+) proliferation was assessed in HIVE by double labeling. Whereas 1.2% of total CD68+ cells were Ki67+, only 0.5% of HIV p24+ cells were Ki67+ (P < .05). Furthermore, staining for CD45RB (as opposed to CD68) facilitated the identification of Ki67+ microglia, indicating that CD68 could underestimate proliferating microglia. The authors conclude that although there is increased expression of GM-CSF and increased cell proliferation in the CNS of HIV-seropositive individuals, cell proliferation in the productively infected population is actually suppressed. These data suggest that there might be a viral gain in the suppressed host cell proliferation.

Simultaneous Activation of Viral Antigen-specific Memory CD4+ and CD8+ T-cells Using mRNA-electroporated CD40-activated Autologous B-cells

Recently, it has become obvious that not only CD8 T-cells, but also CD4 T-helper cells are required for the induction of an effective, long-lasting cellular immune response. In view of the clinical importance of cytomegalovirus (CMV) and human immunodeficiency virus (HIV) infection, we developed 2 strategies to simultaneously reactivate viral antigen-specific memory CD4 and CD8 T-cells of CMV-seropositive and HIV-seropositive subjects using mRNA-electroporated autologous CD40-activated B cells. In the setting of HIV, we provide evidence that CD40-activated B cells can be cultured from HAART-naive HIV-1 seropositive patients. These cells not only express and secrete the HIV p24 antigen after electroporation with codon-optimized HIV-1 gag mRNA, but can also be used to in vitro reactivate Gag antigen-specific interferon-gamma-producing CD4 and CD8 autologous T-cells. For the CMV-specific approach, we applied mRNA coding for the pp65 protein coupled to the lysosomal-associated membrane protein-1 to transfect CD40-activated B cells to induce CMV antigen-specific CD4 and CD8 T-cells. More detailed analysis of the activated interferon-gamma-producing CMV pp65 tetramer positive CD8 T-cells revealed an effector memory phenotype with the capacity to produce interleukin-2. Our findings clearly show that the concomitant activation of both CD4 and CD8 (memory) T-cells using mRNA-electroporated CD40-B cells is feasible in CMV and HIV-1-seropositive persons, which indicates the potential value of this approach for application in cellular immunotherapy of infectious diseases.

Primo-infection par le VIH révélée par une symptomatologie psychiatrique

Any atypical psychiatric disorder, especially if associated with somatic manifestations and when any psychiatric antecedents are missing, should lead to search for an organic pathology, and notably a Human Immunodeficiency Virus (HIV) infection. In the case of Primary Human Immunodeficiency Virus Infection (PHI), which is often symptomatic, the diagnosis is seldom made, probably because of atypical or non specific manifestations. Therefore, it is essential to consider such a diagnosis, because it may have important clinical and public health consequences (stopping the contamination chain). We present the case of a 38 year-old homosexual man from West Indies, in whom the diagnosis of PHI had been made on the basis of psychiatric symptoms evoking a Major Depressive Episode with a doubt on the presence of psychotic symptoms. To our knowledge, this is the first report of psychiatric PHI found in scientific literature. Clinical presentation was atypical: the patient had no psychiatric history (except probably a schizotypical personality, according to his family), symptoms were atypical (sudden onset and fast improvement) associated with somatic symptoms (fever, headache, sound intolerance), the latter possibly due to a meningo-encephalitis, which had been underestimated and attributed to dehydration in a period when France was faced with an important and unexpected heatwave. Blood samples were performed on admission and revealed a thrombopenia and presence of HIV P24 antigen, testifying a contamination by HIV 2 to 4 weeks earlier, this possibility having been confirmed by the patient. Further analyses found a Western-Blot partially positive test and an HIV viral load of 315 711 Eq copies/mL. The main question about this report is the primary or secondary nature of psychiatric symptoms towards HIV infection, given that in this patient mood alteration could have possibly occurred, before HIV contamination, due to particularities of his personal and professional life. We can also question whether the neurological manifestations of PHI might be changed by a schizotypical personality. Further reports are required to answer these questions.

Blood Safety—At What Cost?

BLOOD IS AN INTRINSIC PART OF HUMAN LIFE. IT IS SOMEthing others need and it is each person’s to give. Blood can be sold or given voluntarily out of a feeling of social obligation. The characteristics that make donated blood an expression of human altruism also make it a threat to human health. Blood products can be life saving but can also transmit life-threatening viral, bacterial, and parasitic infections from donors to recipients. The provision of safe and adequate blood supply is an important component of national health requiring government commitment and support to ensure that blood and blood products are safe, accessible, and adequate to meet transfusion requirements. The cornerstone of a safe and adequate supply of blood products is the recruitment, selection, and retention of voluntary nonremunerated blood donors from low-risk populations. To identify these low-risk populations, reliable epidemiologic data on both prevalence and incidence of infectious diseases in the general population are required. There are large inequalities in the distribution of safe blood; 80% of the world’s population has access to only 20% of the world’s safe blood supply. A lack of safe blood results in considerable mortality, with the major impact sustained by women with complications of pregnancy, trauma patients, and children with life-threatening anemia as a result of malaria. It is estimated that up to 150 000 pregnancy-related deaths could be avoided each year with greater access to safe blood. Presently fewer than 30% of countries have nationwide blood transfusion services and approximately 50% of donations are from family or paid donors—recognized sources of unsafe blood. Most developing countries do not screen donated blood for even the most common blood-borne infections. Unsafe blood accounts for 8 million to 16 million hepatitis B infections, 2.3 to 4.7 million hepatitis C infections, and 80 000 to 160 000 human immunodeficiency virus (HIV) infections each year. In this issue of JAMA, Heyns and colleagues describe policy changes instituted in 1999 to safeguard the blood supply of South Africa, a middle-income developing country. The disparities of access to health care between the rich and poor in South Africa mirror the global disparities between industrialized and resource-poor countries. South Africa has a liberal human rights oriented constitution, which outlaws discrimination on the basis of race, ethnic or social origin, sex, age, or sexual orientation. Prior to 1999, the South African National Blood Service relied on a pool of voluntary nonremunerated, predominantly repeat donors, along with universal serological testing for HIV-1 and 2, hepatitis C, and syphilis combined with HIV p24 and hepatitis B surface antigen testing. In 1999 public sector antenatal HIV seroprevalence was higher than 20% and the HIV prevalence reached 0.26% in the blood donor pool, with an estimated 26 HIVinfected units entering the blood supply in that year. A policy was instituted that involved closing donor clinics where HIV seroprevalence was high, providing educational materials to encourage self-exclusion of those with high-risk behaviors, and triaging donated blood by population profiling based on ethnicity, sex, and donation frequency. As Heyns et al point out, following introduction of this policy, HIV prevalence in donated blood decreased from 0.26% in 1999 to 0.04% in 2003. However, racial profiling was not universally used by all South African blood transfusion services during this period. For example, the Western Province Blood Transfusion Service, which supplies approximately 150 000 units of blood per annum in a province with an antenatal HIV seroprevalence of 13%, used a combination of other interventions, and the HIV-positive rate in donated blood decreased to 0.03% in 2004. As early as 1977, it was recognized that there was a need to redress the cultural and socioeconomic distortions of the regular blood donor pool to maintain the long-term sustainability of South African blood supply. The policy of racial profiling was highlighted in late 2004 when a nurse working for the South African National Blood Service was dismissed following her refusal to sign her employment contract because she did not agree with racial profiling as a means of determining high-risk blood. After it became public knowledge that President Mbeki’s blood donation had been discarded as a result of the existing policy, a meeting between the Minister of Health and the National Blood Service was held on February 17, 2005, at which time it was determined to change the existing policy. The structured blood safety policy outlined by Heyns et al was associated with a significant decline in HIV prevalence in the volunteer donors at the Inland Region of the South African National Blood Service during a period of in-