Geoffrey Eisen

High Levels of Tumor Necrosis Factor—α and Interleukin-1β in Bacterial Vaginosis May Increase Susceptibility to Human Immunodeficiency Virus

Bacterial vaginosis (BV) was identified recently as a cofactor that promotes sexual transmission of human immunodeficiency virus (HIV). This study was done to determine if interleukin (IL)‐1b and tumor necrosis factor (TNF)‐a could be measured consistently in cervical secretions and if high levels of these cytokines were associated with BV. Secretions were obtained from 209 study subjects; most samples had detectable levels of TNF-a (84.2%) and IL-1b (79.8%). BV was detected in 53 (27.0%) of 196 women. High cytokine levels were significantly associated with BV (adjusted odds ratio [AOR], 4.17; 95% confidence interval [CI], 1.69‐10.30), oral contraceptive use (AOR, 2.78; 95% CI, 1.04‐7.48), and high leukocyte counts on vaginal smear (AOR, 1.18; 95% CI, 1.03‐1.36). Since these cytokines could up-regulate local HIV replication through activation of the long terminal repeat promoter region, the association of BV with high levels of IL-1b or TNF-a may partly explain the mechanism by which this risk factor enhances HIV transmission. Bacterial vaginosis (BV) is a common and recurrent disorder of the lower genital tract in women. It is characterized by the replacement of normal lactobacilli-predominant vaginal flora with Gardnerella vaginalis, anaerobic bacteria, and genital Mycoplasma organisms and/or is accompanied by increased vaginal pH [1, 2]. BV and abnormal vaginal flora have been found to be associated with human immunodeficiency virus (HIV) infection in various cross-sectional studies [3‐6]. More recently, in 2 separate longitudinal studies, BV and abnormal vaginal flora were associated with an increased risk of acquiring HIV [7, 8], which provides further argument for a causal relationship between disrupted vaginal flora and increased risk of HIV infection in women. However, the actual mechanism by which BV or the presence of abnormal vaginal flora could increase the susceptibility to HIV infection in women has not been defined clearly. Recently, a soluble activator of HIV transcription was found in genital secretions of women with vaginosis. The effect of this soluble factor was mediated through the activation of the NFkB enhancer in the long terminal repeat (LTR) promoter region of the virus [9‐11]. In addition, membrane components of BV

Immunologic Criteria Are Poor Predictors of Virologic Outcome: Implications for HIV Treatment Monitoring in Resource-Limited Settings

BACKGROUND Viral load (VL) quantification is considered essential for determining antiretroviral treatment (ART) success in resource-rich countries. However, it is not widely available in resource-limited settings where the burden of human immunodeficiency virus infection is greatest. In the absence of VL monitoring, switches to second-line ART are based on World Health Organization (WHO) clinical or immunologic failure criteria. METHODS We assessed the performance of CD4 cell criteria to predict virologic outcomes in a large ART program in Nigeria. Laboratory monitoring consists of CD4 cell count and VL at baseline, then every 6 months. Failure was defined as 2 consecutive VLs >1000 copies/mL after at least 6 months of ART. Virologic outcomes were compared with the 3 WHO-defined immunologic failure criteria. RESULTS A total of 9690 patients were included in the analysis (median follow-up, 33.2 months). A total of 1225 patients experienced failure by both immunologic and virologic criteria, 872 by virologic criteria only, and 1897 by immunologic criteria only. The sensitivity of CD4 cell criteria to detect viral failure was 58%, specificity was 75%, and the positive-predictive value was 39%. For patients with both virologic and immunologic failure, VL criteria identified failure significantly earlier than CD4 cell criteria (median, 10.4 vs 15.6 months; P < .0001). CONCLUSIONS Because of the low sensitivity of immunologic criteria, a substantial number of failures are missed, potentially resulting in accumulation of resistance mutations. In addition, specificity and predictive values are low, which may result in large numbers of unnecessary ART switches. Monitoring solely by immunologic criteria may result in increased costs because of excess switches to more expensive ART and development of drug-resistant virus.

Management of HIV-1 infection with a combination of nevirapine, stavudine, and lamivudine: a preliminary report on the Nigerian antiretroviral program.

Objective:To evaluate treatment outcome in the first 12 months among HIV-positive patients managed with a combination of nevirapine + stavudine + lamivudine under the current national antiretroviral (ARV) program in Nigeria. Design:This was a prospective observational, cohort study on 50 ARV-naive patients who met the inclusion criteria for the program and had given informed consent. All patients were in stage 2 or stage 3 periods of infection based on World Health Organization clinical classification. The patients were treated with the generic brands of ARVs and treatment consisted of oral nevirapine (Nevimal, Cipla, Mumbai, India), 200 mg daily, lamivudine (Lamivir, Cipla), 150 mg twice daily, and stavudine (Stavir, Cipla), 40 mg twice daily. Prior to initiation of treatment, the clinical history and baseline data for each patient were documented. The levels of plasma HIV-1 RNA, CD4+ cell counts, frequency of opportunistic infections, and estimated body mass index were recorded at baseline and subsequently at intervals during treatment. Data obtained at the various sampling times for each parameter were compared against their baseline values. Results:Data on the plasma HIV-1 RNA levels indicated that between baseline and week 24, the median viral load of the patients decreased by 1.79 log10 copies/mL. Equally between baseline and week 48 the median CD4+ cell counts increased by 186 × 106 cells/L, the frequency of opportunistic infections decreased by 82%, the median body mass index increased by 4.8 kg/m2, and 36% experienced side effects, which were minor and transient. The most prevalent side effect recorded was skin rash associated with nevirapine. Good adherence to this triple regimen was recorded in >85% of the patients. Conclusions:The overall results within the 12-month treatment period indicated an effective suppression of viral replication, the reconstitution of the immune system, and improvement of the physical well-being of the study population. Though there may be differences in global distribution of the infecting HIV-1 subtypes, the clinical and biologic results of this study compared favorably to those documented in cohorts treated with branded and generic ARV drugs in some developed and developing countries. The cumulative data in this study further confirmed that the correct use of generic brands of ARVs is a feasible option in HIV care and support programs in resource-poor countries.

Drug-induced alterations in gene expression of the asexual blood forms of Plasmodium falciparum

The complete genome sequence of the malarial parasite, Plasmodium falciparum[Gardner, M.J., Hall, N., Fung, E., White, O., Berriman, M., and Hyman, R.W. (2002) Nature 419: 498–510; Hyman, R.W., Fung, E., Conway, A., Kurdi, O., Mao, J., Miranda, M. et al. (2002) Nature 419: 534–537], has provided researchers with the informational base for establishing genomic [Volkman, S.K., Hartl, D.L., Wirth, D.F., Nielsen, K.M., Choi, M., Batalov, S., et al. (2002) Science 298: 216–218], proteomic [Florens, L., Washburn, M.P.J.D.R., Anthony, R.M., Grainger, M., Haynes, J.D., et al. (2002) Nature 419: 520–526; Lasonder, E., Ishihama, Y., Anderson, J.S., Vermunt, A.M.W., Pain, A., Sauerwein, R.W., et al. (2002) Nature 419: 537–542] and genome‐wide RNA expression [Ben Mamoun, C., Gluzman, I.Y., Hott, C., MacMillan, S.K., Amarakone, A.S., Anderson, D.L., et al. (2001) Mol Microbiol 39: 26–36; Hayward, R.E., Derisi, J.L., Alfadhli, S., Kaslow, D.C., Brown, P.O., and Rathod, P.K. (2000) Mol Microbiol 35: 6–14] analyses in this system. In fact, we have previously utilized SAGE (serial analysis of gene expression) to identify abundant loci that probably constitute part of the active metabolome [Patankar, S., Munasinghe, A., Shoaibi, A., Cummings, L.M., and Wirth, D.F. (2001) Mol Biol Cell 12: 3114–3125], as well as to characterize antisense transcription on a global scale in Plasmodium. In the present study, the comprehensive annotation of SAGE libraries derived from an asexual stage population exposed to drug and its matched control was used to assess the modulation of gene expression by chloroquine. Here, we observed a constellation of changes, with the differential regulation of over 100 transcripts, and have confirmed the data by alternate methods. A few responsive loci, including PfMDR1, have previously been implicated in the mechanism of chloroquine action/resistance. Several others, however, were derived from unexpected categories, including a large number of unknown open reading frames (ORFs), whose induction after drug exposure may provide first hints to their possible function.

Highly Active Antiretroviral Therapy and Viral Response in HIV Type 2 Infection

Human immunodeficiency virus type 2 (HIV-2), the second human retrovirus known to cause AIDS, is endemic to West Africa but is infrequently found outside this region. We present a case series of 10 HIV-2--infected individuals treated in the United States. Physicians applied the principles of highly active antiretroviral therapy (HAART), normally used in treating HIV type 1, with modifications considered appropriate for treating HIV-2. CD4+ cell count, HIV-2 virus load, and clinical status were found to correlate well, providing evidence that HIV-2 virus load is useful in managing treatment of patients with HIV-2 who are receiving therapy. However, HAART regimens with predicted efficacy for treatment of HIV type 1 infection are not as efficacious for treatment of HIV-2. Controlled clinical trials of HIV-2-infected patients receiving various HAART regimens are needed to provide therapeutic guidance to the medical community.

Intrapatient Diversity and Its Correlation with Viral Setpoint in Human Immunodeficiency Virus Type 1 CRF02_A/G-IbNG Infection

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) viral setpoint during the disease-free interval has been strongly associated with future risk of disease progression. An awareness of the correlation between viral setpoint and HIV-1 genetic evolution over time is important in the understanding of viral dynamics and infection. We examined genetic diversity in HIV-1 CRF02_A/G-IbNG-infected seroincident women in Dakar, Senegal; determined whether a viral setpoint kinetic pattern existed for CRF02_A/G-IbNG during the disease-free interval; and correlated viral load level and diversity. Samples were drawn during the disease-free interval from consenting CRF02_A/G-IbNG-infected, antiretroviral therapy-naïve female commercial sex workers in Dakar, Senegal. Based on sequential plasma RNA values, low and high viral setpoint groups were established. Intrapatient diversity and divergence over time was determined from earlier and later time point DNA samples from each person. Most individuals followed the viral setpoint paradigm. For each 1|−|log10 copy/ml of plasma increase in viral load, intrapatient diversity increased by 1.4% (P = 0.028). A greater diversification rate was observed in the high viral setpoint group than in the low viral setpoint group (P = 0.01). Greater nucleotide (P = 0.015) and amino acid (P = 0.048) divergences and a greater nucleotide divergence rate (P = 0.03) were found in the high viral setpoint group. There was no difference between the groups in the ratio of the number of nonsynonymous substitutions per nonsynonymous site to the number of synonymous substitutions per synonymous site. The greater intrapatient diversity, divergence, and diversification rates observed in the high viral setpoint group supports the notion that diversity is driven by cycles of viral replication resulting in accumulated mutations. Recognizing diversity potential based on viral load levels in individuals may inform the design of vaccines and therapies.

Impact of HIV type 1 subtype on drug resistance mutations in Nigerian patients failing first-line therapy.

A diverse array of non-subtype B HIV-1 viruses circulates in Africa and dominates the global pandemic. It is important to understand how drug resistance mutations in non-B subtypes may develop differently from the patterns described in subtype B. HIV-1 reverse transcriptase and protease sequences from 338 patients with treatment failure to first-line ART regimens were evaluated. Multivariate logistic regression was used to examine the effect of subtype on each mutation controlling for regimen, time on therapy, and total mutations. The distribution of HIV-1 subtypes included CRF02_AG (45.0%), G (37.9%), CRF06_cpx (4.4%), A (3.6%), and other subtypes or recombinant sequences (9.2%). The most common NRTI mutations were M184V (89.1%) and thymidine analog mutations (TAMs). The most common NNRTI mutations were Y181C (49.7%), K103N (36.4%), G190A (26.3%), and A98G (19.5%). Multivariate analysis showed that CRF02_AG was less likely to have the M41L mutation compared to other subtypes [adjusted odds ratio (AOR) = 0.35; p = 0.022]. Subtype A patients showed a 42.5-fold increased risk (AOR = 42.5, p = 0.001) for the L210W mutation. Among NNRTI mutations, subtype G patients had an increased risk for A98G (AOR = 2.40, p = 0.036) and V106I (AOR = 6.15, p = 0.010), whereas subtype CRF02_AG patients had an increased risk for V90I (AOR = 3.16; p = 0.003) and a decreased risk for A98G (AOR = 0.48, p = 0.019). Five RT mutations were found to vary significantly between different non-B West African subtypes. Further study to understand the clinical impact of subtype-specific diversity on drug resistance will be critically important to the continued success of ART scale-up in resource-limited settings.

Viral Dynamics of Primary HIV-1 Infection in Senegal, West Africa

BACKGROUND Few studies have addressed primary human immunodeficiency virus (HIV) type 1 infection in sub-Saharan Africa, where the epidemic is of a predominantly heterosexual character and is caused by different subtypes. The present study examines the dynamics of viral replication in subjects infected with various HIV-1 subtypes. METHODS Seven hundred fifty-two HIV-negative Senegalese women at high risk for infection were monitored every 3 months for acute/early HIV infection; 26 infections were identified (23 HIV-1 and 3 HIV-2), with an HIV-1 incidence rate of 3.23 cases/person-years observation. Multiple viral-load measurements were taken for all seroconverters. RESULTS The mean+/-standard deviation viral load for all subjects during the early stage of infection was 4.13+/-0.66 log10 copies/mL, with an overall decrease of 0.22 log10 copies/mL after the early stage; the viral set point was reached after 12 months of infection. Most subjects had relatively low viral loads during the early stage of infection. HIV-1 CRF02_AG-infected women had a significantly higher mean viral load during the early stage of infection (mean +/- SD, 4.45+/-0.60 log(10) copies/mL) than did non-HIV-1 CRF02_AG-infected women (mean+/-SD, 3.78+/-0.46 log(10) copies/mL) (P=.008). None of the subjects reported symptoms consistent with primary HIV-1 infection. CONCLUSION Our findings in Senegalese women differ from what have been described for primary HIV-1 infection. Further investigations of primary infections with non-B subtypes are warranted, to better characterize their differences with primary infections with subtype B.

Molecular Epidemiology of Human Immunodeficiency Virus Type 1 Sub-Subtype A3 in Senegal from 1988 to 2001

ABSTRACT The global human immunodeficiency virus (HIV)epidemic is characterized by significant genetic diversity in circulating viruses. We have recently characterized a group of viruses that form a distinct sub-subtype within the subtype A radiation, which we have designated HIV type 1 (HIV-1) sub-subtype A, circulating in West Africa. A prospective study of a cohort of female sex workers (FSW) in Dakar, Senegal over an 18-year period indicated that an A3-specific sequence in the C2-V3 region of the env gene was found in 46 HIV-1-infected women. HIV-1 sub-subtype A3 appeared in the FSW population as early as 1988 and continued to be transmitted as of 2001. We also found that HIV-1 A3 is not confined to the FSW cohort in Senegal but is also circulating in the general population in Dakar. Furthermore, analyses of viral sequences from a few other West and Central African countries also demonstrated evidence of HIV-1 A3 sequence in isolates from HIV-1-infected people in Ivory Coast, Nigeria, Niger, Guinea Bissau, Benin, and Equatorial Guinea. Overall, because of the evidence of sub-subtype A3 in the general population in Senegal, as well as in a few neighboring West and Central African countries, along with the increasing incidence of infection with A3-containing viruses in the Dakar high-risk FSW population, we feel that HIV-1 sub-subtype A3 viruses are important to distinguish and monitor.

CCR5 Receptor Expression Is Down-Regulated in HIV Type 2 Infection: Implication for Viral Control and Protection

HIV-2 is known to display an attenuated phenotype in vivo with prolonged time to disease and decreased rate of transmission. Observational studies in Senegal have demonstrated protection from HIV-1 infection, although the putative mechanism for immunoprotection remains undefined. We evaluated HIV-2-seropositive women from a cohort of commercial sex workers in Dakar, Senegal and identified individuals with very low surface CCR5 receptor expression on CD4+ T cells. In vitro up-regulation of the CCR5 receptor was readily achieved. Down-regulation of the CCR5 was not correlated with activation markers (HLA-DR), beta-chemokine levels, or plasma viral loads. A correlation was observed with HIV-2-specific CD8+ T cell activity as measured by intracellular cytokine production. We postulate that down-regulation of the CCR5 receptor in HIV-2 infection contributes to slower disease course and to the protective mechanism against HIV-1 superinfection, mediated in part by HIV-2-specific cellular immune responses.