Higher set point plasma viral load and more-severe acute HIV type 1 (HIV-1) illness predict mortality among high-risk HIV-1-infected African women

Interleukin-6 and D-dimer levels at seroconversion as predictors of HIV-1 disease progression

OBJECTIVE

Inflammation and coagulation biomarkers interleukin (IL)-6 and D-dimer are predictive of all-cause mortality in chronic HIV-1 infection; however, their predictive value in individuals with recent infection has not been described.

METHODS

SPARTAC was a randomized controlled trial comparing three strategies of intervention in primary HIV-1 infection [no therapy, 12-week or 48-week antiretroviral therapy (ART)]. Plasma IL-6 and D-dimer were measured in 200 participants from sites in Australia, Brazil, UK and Italy. We evaluated age, sex/HIV risk group, time since HIV-1 seroconversion, baseline HIV-RNA, CD4 cell count and BMI as possible predictors of IL-6 and D-dimer levels at seroconversion using multivariable linear regression. For participants remaining ART-naive, we evaluated whether baseline IL-6 and D-dimer levels independently predicted time to reaching CD4 cell count less than 350 cells/μl or initiating ART using multivariable Cox proportional hazards models.

RESULTS

Median (interquartile range, IQR) baseline IL-6 and D-dimer levels were 1.45 (0.88-2.41) pg/ml and 0.34 (0.20-0.50) μg/l, respectively. Higher levels were associated with older age (P=0.008 and 0.004, respectively). Higher D-dimer levels were associated with higher HIV-RNA (P<0.001). For the 73 participants not initiating ART (median follow-up 225 weeks), of whom 48 reached the primary endpoint, higher baseline IL-6, but not D-dimer, was independently associated with a shorter time to primary endpoint [hazard ratio=1.38 per additional pg/ml, 95% confidence interval (CI) 1.09-1.75; P=0.007]. Other baseline predictors were older age (P=0.030), higher RNA (P=0.033) and lower CD4 cell count (P<0.001).

CONCLUSION

IL-6 levels at time of HIV-1 seroconversion independently predict HIV-1 disease progression in patients with primary HIV-1 infection.

The Significance of Interferon-γ in HIV-1 Pathogenesis, Therapy, and Prophylaxis

Interferon-γ (IFNγ) plays various roles in the pathogenesis of HIV/AIDS. In an HIV-1 infected individual, the production of IFNγ is detected as early as the acute phase and continually detected throughout the course of infection. Initially produced to clear the primary infection, IFNγ together with other inflammatory cytokines are involved in establishing a chronic immune activation that exacerbates clinical diseases associated with AIDS. Unlike Type 1 IFNs, IFNγ has no direct antiviral activity against HIV-1 in primary cultures, as supported by the in vivo findings of IFNγ therapy in infected subjects. Results from both in vitro and ex vivo studies show that IFNγ can instead enhance HIV-1 replication and its associated diseases, and therapies aimed at decreasing its production are under consideration. On the other hand, IFNγ has been shown to enhance cytotoxic T lymphocytes and NK cell activities against HIV-1 infected cells. These activities are important in controlling HIV-1 replication in an individual and will most likely play a role in the prophylaxis of an effective vaccine against HIV-1. Additionally, IFNγ has been used in combination with HIV-1 vaccine to augment antiviral immunity. Technological advancements have focused on using IFNγ as a biological marker to analyze the type(s) of immunity generated by candidate HIV vaccines and the levels of immunity restored by anti-retroviral drug therapies or novel immunotherapies. Hence, in addition to its valuable ancillary role as a biological marker for the development of effective HIV-1 prophylactic and therapeutic strategies, IFNγ has a vital role in promoting the pathogenesis of HIV.

Symptomatic illness and low CD4 cell count at HIV seroconversion as markers of severe primary HIV infection

BACKGROUND

The risk/benefit of initiating ART in primary HIV infection (PHI) is unclear. The benefits are more likely to outweigh the risks in patients with severe PHI. An accepted definition of severe PHI is, however, lacking.

METHODS

CASCADE patients with HIV test interval <6 months were classified as severe and non-severe PHI based on whether the following traits were recorded in the first 6 months following seroconversion: severe specific pre-defined symptoms, central nervous system-implicated illness, and ≥1, ≥2 CD4<350 (and <500) cells/mm(3). For each definition, we used Kaplan-Meier curves and Cox survival models to compare time to AIDS/death, censoring at the earlier of last clinic visit or 1/1/1997, when combination antiretroviral therapy (cART) became available.

RESULTS

Among 1108 included patients mostly males (85%) infected through sex between men (71%), 366 were diagnosed with AIDS/died. The risk of AIDS/death was significantly higher for individuals with severe symptoms, those with ≥1 CD4<350 cells/mm(3) or ≥2 CD4 <500 cells/mm(3) in the first 6 months [aHR (95% confidence interval) 2.1 (1.4,3.2), 2.0 (1.5,2.7), and 2.3, (1.5-3.5) respectively]. Median [interquantile range] survival for patients with ≥2, ≥1 and no CD4<350 cells/mm(3) within 6 months of seroconversion was 3.9 [2.7,6.5], 5.4 [4.5,8.4] and 8.1 [4.3,10.3] years, respectively. The diagnosis of CNS-implicated symptoms was rare and did not appear to be prognostic.

CONCLUSION

One CD4 count <350 or two <500 cells/mm(3) within 6 months of seroconversion and/or severe illness in PHI may be useful early indicators of individuals at high risk of disease progression.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

Virus-induced target cell activation reconciles set-point viral load heritability and within-host evolution

The asymptomatic phase of HIV-1 infections is characterised by a stable set-point viral load (SPVL) within patients. The SPVL is a strong predictor of disease progression and shows considerable variation of multiple orders of magnitude between patients. Recent studies have found that the SPVL in donor and recipient pairs is strongly correlated indicating that the virus genotype strongly influences viral load. Viral genetic factors that increase both viral load and the replicative capacity of the virus would result in rapid within-host evolution to higher viral loads. Reconciling a stable SPVL over time with high SPVL heritability requires viral genetic factors that strongly influence SPVL but only weakly influence the competitive ability of the virus within hosts. We propose a virus trait that affects the activation of target cells, and therefore viral load, but does not confer a competitive advantage to the virus. We incorporate this virus-induced target cell activation into within- and between-host models and determine its effect on the competitive ability of virus strains and on the variation in SPVL in the host population. On the within-host level, our results show that higher rates of virus-induced target cell activation increase the SPVL and confer no selective advantage to the virus. This leads to a build up of diversity in target cell activation rates in the virus population during within-host evolution. On the between-host level, higher rates of target cell activation and therefore higher SPVL affect the transmission potential of the virus. Random selection of a new founder strain from the diverse virus population within a donor results in a standing variation in SPVL in the host population. Therefore, virus-induced target cell activation can explain the heritability of SPVL, the absence of evolution to higher viral loads during infection and a large standing variation in SPVL between hosts.

Endothelial activation biomarkers increase after HIV-1 acquisition: plasma vascular cell adhesion molecule-1 predicts disease progression

OBJECTIVE

We aimed to determine whether endothelial activation biomarkers increase after HIV-1 acquisition, and whether biomarker levels measured in chronic infection would predict disease progression and death in HIV-1 seroconverters.

DESIGN

HIV-1-seronegative Kenyan women were monitored monthly for seroconversion, and followed prospectively after HIV-1 acquisition.

METHODS

Plasma levels of angiopoietin-1 and angiopoietin-2 (ANG-1, ANG-2) and soluble vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin were tested in stored samples from pre-infection, acute infection, and two chronic infection time points. We used nonparametric tests to compare biomarkers before and after HIV-1 acquisition, and Cox proportional-hazards regression to analyze associations with disease progression (CD4 < 200 cells/μl, stage IV disease, or antiretroviral therapy initiation) or death.

RESULTS

Soluble ICAM-1 and VCAM-1 were elevated relative to baseline in all postinfection periods assessed (P < 0.0001). Soluble E-selectin and the ANG-2:ANG-1 ratio increased in acute infection (P = 0.0001), and ANG-1 decreased in chronic infection (P = 0.0004). Among 228 participants followed over 1028 person-years, 115 experienced disease progression or death. Plasma VCAM-1 levels measured during chronic infection were independently associated with time to HIV progression or death (adjusted hazard ratio 5.36, 95% confidence interval 1.99-14.44 per log10 increase), after adjustment for set point plasma viral load, age at infection, and soluble ICAM-1 levels.

CONCLUSION

HIV-1 acquisition was associated with endothelial activation, with sustained elevations of soluble ICAM-1 and VCAM-1 postinfection. Soluble VCAM-1 may be an informative biomarker for predicting the risk of HIV-1 disease progression, morbidity, and mortality.

The detection and management of early HIV infection: a clinical and public health emergency

This review considers the detection and management of early HIV infection (EHI), defined here as the first 6 months of infection. This phase is clinically important because a reservoir of infected cells formed in the individual renders HIV incurable, and the magnitude of viremia at the end of this period predicts the natural history of disease. Epidemiologically, it is critical because the very high viral load that typically accompanies early infection also makes infected individuals maximally contagious to their sexual partners. Future efforts to prevent HIV transmission with expanded testing and treatment may be compromised by elevated transmission risk earlier in the course of HIV infection, although the extent of this impact is yet unknown. Treatment as prevention efforts will nevertheless need to develop strategies to address testing, linkage to care, and treatment of EHI. Cost-effective and efficient identification of more persons with early HIV will depend on advancements in diagnostic technology and strengthened symptom-based screening strategies. Treatment for persons with EHI must balance individual health benefits and reduction of the risk of onward viral transmission. An increasing body of evidence supports the use of immediate antiretroviral therapy to treat EHI to maintain CD4 count and functionality, limit the size of the HIV reservoir, and reduce the risk of onward viral transmission. Although we can anticipate considerable challenges in identifying and linking to care persons in the earliest phases of HIV infection, there are many reasons to pursue this strategy.

Challenges of diagnosing acute HIV-1 subtype C infection in African women: performance of a clinical algorithm and the need for point-of-care nucleic-acid based testing

Background

Prompt diagnosis of acute HIV infection (AHI) benefits the individual and provides opportunities for public health intervention. The aim of this study was to describe most common signs and symptoms of AHI, correlate these with early disease progression and develop a clinical algorithm to identify acute HIV cases in resource limited setting.

Methods

245 South African women at high-risk of HIV-1 were assessed for AHI and received monthly HIV-1 antibody and RNA testing. Signs and symptoms at first HIV-positive visit were compared to HIV-negative visits. Logistic regression identified clinical predictors of AHI. A model-based score was assigned to each predictor to create a risk score for every woman.

Results

Twenty-eight women seroconverted after a total of 390 person-years of follow-up with an HIV incidence of 7.2/100 person-years (95%CI 4.5–9.8). Fifty-seven percent reported ≥1 sign or symptom at the AHI visit. Factors predictive of AHI included age <25 years (OR = 3.2; 1.4–7.1), rash (OR = 6.1; 2.4–15.4), sore throat (OR = 2.7; 1.0–7.6), weight loss (OR = 4.4; 1.5–13.4), genital ulcers (OR = 8.0; 1.6–39.5) and vaginal discharge (OR = 5.4; 1.6–18.4). A risk score of 2 correctly predicted AHI in 50.0% of cases. The number of signs and symptoms correlated with higher HIV-1 RNA at diagnosis (r = 0.63; p<0.001).

Conclusions

Accurate recognition of signs and symptoms of AHI is critical for early diagnosis of HIV infection. Our algorithm may assist in risk-stratifying individuals for AHI, especially in resource-limited settings where there is no routine testing for AHI. Independent validation of the algorithm on another cohort is needed to assess its utility further. Point-of-care antigen or viral load technology is required, however, to detect asymptomatic, antibody negative cases enabling early interventions and prevention of transmission.

Effect of concurrent use of anti-retroviral therapy and levonorgestrel sub-dermal implant for contraception on CD4 counts: a prospective cohort study in Kenya

INTRODUCTION

Simultaneous use of contraceptive hormones and anti-retroviral therapy (ART) may theoretically lessen the effectiveness of both. Women on ART need assurance that hormonal contraception is safe and effective. The sub-dermal implant is an ideal product to study: low and steady progestin release and no adherence uncertainties. We sought to determine if the medications' effectiveness is compromised.

METHODS

We conducted a prospective cohort study among women on first line ART (stavudine or zidovudine and lamivudine+nevirapine). We recruited new implant users and matched them to women not using hormonal contraception, based on age and baseline CD4. Participants were followed prospectively for up to two years, recording serial CD4 measures and medical histories. We used generalized growth curve models and Wald chi-square tests to compare changes in CD4 counts across study groups. Prospective CD4 measures were censored (excluded) if any of the following events occurred: change in ART, implant removal or use of any hormonal contraception among controls. We examined incidence of opportunistic infection and pregnancy.

RESULTS

We matched 48 implant users to 33 non-hormonal controls. Over time, CD4 counts for both groups rose slightly but did not deviate significantly from each other (p=0.44). Opportunistic infection rates did not differ between the groups. None of the implant users and one of the non-hormonal controls became pregnant during follow-up.

CONCLUSIONS

This small study found concurrent use of contraceptive implants and ART to be safe and effective. Although other hormonal contraceptive products and ART regimens may interact in unknown ways, the results of this study are reassuring.

A model of HIV drug resistance driven by heterogeneities in host immunity and adherence patterns

Background

Population transmission models of antiretroviral therapy (ART) and pre-exposure prophylaxis (PrEP) use simplistic assumptions – typically constant, homogeneous rates – to represent the short-term risk and long-term effects of drug resistance. In contrast, within-host models of drug resistance allow for more detailed dynamics of host immunity, latent reservoirs of virus, and drug PK/PD. Bridging these two levels of modeling detail requires an understanding of the “levers” – model parameters or combinations thereof – that change only one independent observable at a time. Using the example of accidental tenofovir-based pre-exposure prophyaxis (PrEP) use during HIV infection, we will explore methods of implementing host heterogeneities and their long-term effects on drug resistance.

Results

We combined and extended existing models of virus dynamics by incorporating pharmacokinetics, pharmacodynamics, and adherence behavior. We identified two “levers” associated with the host immune pressure against the virus, which can be used to independently modify the setpoint viral load and the shape of the acute phase viral load peak. We propose parameter relationships that can explain differences in acute and setpoint viral load among hosts, and demonstrate their influence on the rates of emergence and reversion of drug resistance. The importance of these dynamics is illustrated by modeling long-lived latent reservoirs of virus, through which past intervals of drug resistance can lead to failure of suppressive drug regimens. Finally, we analyze assumptions about temporal patterns of drug adherence and their impact on resistance dynamics, finding that with the same overall level of adherence, the dwell times in drug-adherent versus not-adherent states can alter the levels of drug-resistant virus incorporated into latent reservoirs.

Conclusions

We have shown how a diverse range of observable viral load trajectories can be produced from a basic model of virus dynamics using immunity-related “levers”. Immune pressure, in turn, influences the dynamics of drug resistance, with increased immune activity delaying drug resistance and driving more rapid return to dominance of drug-susceptible virus after drug cessation. Both immune pressure and patterns of drug adherence influence the long-term risk of drug resistance. In the case of accidental PrEP use during infection, rapid transitions between adherence states and/or weak immunity fortifies the “memory” of previous PrEP exposure, increasing the risk of future drug resistance. This model framework provides a means for analyzing individual-level risks of drug resistance and implementing heterogeneities among hosts, thereby achieving a crucial prerequisite for improving population-level models of drug resistance.

Precise determination of time to reach viral load set point after acute HIV-1 infection

OBJECTIVE

The HIV viral load set point has long been used as a prognostic marker of disease progression and more recently as an end-point parameter in HIV vaccine clinical trials. The definition of set point, however, is variable. Moreover, the earliest time at which the set point is reached after the onset of infection has never been clearly defined.

METHODS

In this study, we obtained sequential plasma viral load data from 60 acutely HIV-infected Chinese patients among a cohort of men who have sex with men, mathematically determined viral load set point levels, and estimated time to attain set point after infection. We also compared the results derived from our models and that obtained from an empirical method.

RESULTS

With novel uncomplicated mathematic model, we discovered that set points may vary from 21 to 119 days dependent on the patients' initial viral load trajectory. The viral load set points were 4.28 ± 0.86 and 4.25 ± 0.87 log10 copies per milliliter (P = 0.08), respectively, as determined by our model and an empirical method, suggesting an excellent agreement between the old and new methods.

CONCLUSIONS

We provide a novel method to estimate viral load set point at the very early stage of HIV infection. Application of this model can accurately and reliably determine the set point, thus providing a new tool for physicians to better monitor early intervention strategies in acutely infected patients and scientists to rationally design preventative vaccine studies.

Plasma viral loads during early HIV-1 infection are similar in subtype C- and non-subtype C-infected African seroconverters

Recent data suggest that infection with human immunodeficiency virus type 1 (HIV-1) subtype C results in prolonged high-level viremia (>5 log10 copies/mL) during early infection. We examined the relationship between HIV-1 subtype and plasma viremia among 153 African seroconverters. Mean setpoint viral loads were similar for C and non-C subtypes: 4.36 vs 4.42 log10 copies/mL (P = .61). The proportion of subtype C-infected participants with viral loads >5 log10 copies/mL was not greater than the proportion for those with non-C infection. Our data do not support the hypothesis that higher early viral load accounts for the rapid spread of HIV-1 subtype C in southern Africa.

Partner characteristics predicting HIV-1 set point in sexually acquired HIV-1 among African seroconverters

Plasma HIV-1 RNA set point is an important predictor of HIV-1 disease progression. We hypothesized that inoculum size and HIV-1 exposure prior to HIV-1 transmission may modulate set point. We evaluated predictors of set point among 141 African HIV-1 seroconverters and their HIV-1-infected study partners. We compared characteristics of seroconverters and their HIV-1-infected partners and HIV-1 set point. Data were from a clinical trial of genital HSV-2 suppression with acyclovir to reduce HIV-1 transmission in HIV-1 serodiscordant couples with HIV-1 transmission linkage assigned through virus sequencing. Our analysis includes data from all transmissions including those with transmission linkage to the HIV-1-infected "source partner" and those that were not linked to their HIV-1-infected study partner. In multivariable analysis, higher plasma HIV-1 in source partners was associated with higher seroconverter set point ( + 0.44 log10 copies/ml per log(10) source partner plasma HIV-1, p < 0.001). In addition, bacterial vaginosis (BV) among female source partners near the time of infection was associated with higher set point in their male seroconverters ( + 0.49 log(10), p = 0.04). Source partner characteristics associated with lower set point included male circumcision ( - 0.63 log(10), p = 0.03) and assignment to acyclovir ( - 0.44 log10, p = 0.02). The proportion of variation in set point explained by plasma HIV-1 RNA of the source partner, after controlling for other factors, was 0.06. Source partner plasma HIV-1 level is the most significant predictor of seroconverter set point, possibly reflecting characteristics of the transmitted virus. Acyclovir use, BV among women source partners, and circumcision among male source partners may alter the set point by affecting transmitted virus inoculum in the source partners' genital compartment.

Differences in the Nonuse of any Contraception and Use of Specific Contraceptive Methods in HIV Positive and HIV Negative Rwandan Women

Contraception can reduce the dual burden of high fertility and high HIV prevalence in sub-Sahara Africa, but significant barriers remain regarding access and use. We describe factors associated with nonuse of contraception and with use of specific contraceptive methods in HIV positive and HIV negative Rwandan women. Data from 395 HIV-positive and 76 HIV-negative women who desired no pregnancy in the previous 6 months were analyzed using univariate and multivariate logistic regression models to identify clinical and demographic characteristics that predict contraceptive use. Differences in contraceptive methods used were dependent on marital/partner status, partner's knowledge of a woman's HIV status, and age. Overall, condoms, abstinence, and hormonal methods were the most used, though differences existed by HIV status. Less than 10% of women both HIV+ and HIV− used no contraception. Important differences exist between HIV-positive and HIV-negative women with regard to contraceptive method use that should be addressed by interventions seeking to improve contraceptive prevalence.

Implications of HIV diversity for the HIV-1 pandemic

HIV-1 genetic variability within individuals and populations plays a central role in the HIV pandemic. Multiple zoonotic transmissions of SIV to humans have resulted in distinct HIV lineages in humans which have further diversified within the population over time. High rates of mutation and recombination during HIV reverse transcription create a genetic diversity in the host which is subject to selection pressures by the immune response and antiretroviral treatment. The global distribution of HIV genetic variants and the impact of HIV diversity on pathogenesis, transmission and clinical management are reviewed. Finally, the key role of escape mutations in the immune response to HIV is discussed as well as the major challenge which HIV-1 diversity poses to HIV vaccine development.

HIV-1 dynamics: a reappraisal of host and viral factors, as well as methodological issues

The dynamics of HIV-1 viremia is a complex and evolving landscape with clinical and epidemiological (public health) implications. Most studies have relied on the use of set-point viral load (VL) as a readily available proxy of viral dynamics to assess host and viral correlates. This review highlights recent findings from population-based studies of set-point VL, focusing primarily on robust data related to host genetics. A comprehensive understanding of viral dynamics will clearly need to consider both host and viral characteristics, with close attention to (i) the timing of VL measurements, (ii) the biology of viral evolution, (iii) compartments of active viral replication, (iv) the transmission source partner as the immediate past microenvironment, and (v) proper application of statistical models.

Quantifying ongoing HIV-1 exposure in HIV-1-serodiscordant couples to identify individuals with potential host resistance to HIV-1

BACKGROUND

Immunogenetic correlates of resistance to HIV-1 in HIV-1-exposed seronegative (HESN) individuals with consistently high exposure may inform HIV-1 prevention strategies. We developed a novel approach for quantifying HIV-1 exposure to identify individuals remaining HIV-1 uninfected despite persistent high exposure.

METHODS

We used longitudinal predictors of HIV-1 transmission in HIV-1 serodiscordant couples to score HIV-1 exposure and define HESN clusters with persistently high, low, and decreasing risk trajectories. The model was validated in an independent cohort of serodiscordant couples. We describe a statistical tool that can be applied to other HESN cohorts to identify individuals with high exposure to HIV-1.

RESULTS

HIV-1 exposure was best quantified by frequency of unprotected sex with, plasma HIV-1 RNA levels among, and presence of genital ulcer disease among HIV-1-infected partners and by age, pregnancy status, herpes simplex virus 2 serostatus, and male circumcision status among HESN participants. Overall, 14% of HESN individuals persistently had high HIV-1 exposure and exhibited a declining incidence of HIV-1 infection over time.

CONCLUSIONS

A minority of HESN individuals from HIV-1-discordant couples had persistent high HIV-1 exposure over time. Decreasing incidence of infection in this group suggests these individuals were selected for resistance to HIV-1 and may be most appropriate for identifying biological correlates of natural host resistance to HIV-1 infection.

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.

HIV-1 superinfection in women broadens and strengthens the neutralizing antibody response

Identifying naturally-occurring neutralizing antibodies (NAb) that are cross-reactive against all global subtypes of HIV-1 is an important step toward the development of a vaccine. Establishing the host and viral determinants for eliciting such broadly NAbs is also critical for immunogen design. NAb breadth has previously been shown to be positively associated with viral diversity. Therefore, we hypothesized that superinfected individuals develop a broad NAb response as a result of increased antigenic stimulation by two distinct viruses. To test this hypothesis, plasma samples from 12 superinfected women each assigned to three singly infected women were tested against a panel of eight viruses representing four different HIV-1 subtypes at matched time points post-superinfection (~5 years post-initial infection). Here we show superinfected individuals develop significantly broader NAb responses post-superinfection when compared to singly infected individuals (RR = 1.68, CI: 1.23-2.30, p = 0.001). This was true even after controlling for NAb breadth developed prior to superinfection, contemporaneous CD4+ T cell count and viral load. Similarly, both unadjusted and adjusted analyses showed significantly greater potency in superinfected cases compared to controls. Notably, two superinfected individuals were able to neutralize variants from four different subtypes at plasma dilutions >1∶300, suggesting that their NAbs exhibit elite activity. Cross-subtype breadth was detected within a year of superinfection in both of these individuals, which was within 1.5 years of their initial infection. These data suggest that sequential infections lead to augmentation of the NAb response, a process that may provide insight into potential mechanisms that contribute to the development of antibody breadth. Therefore, a successful vaccination strategy that mimics superinfection may lead to the development of broad NAbs in immunized individuals.

Efficient use of longitudinal CD4 counts and viral load measures in survival analysis

CD4 counts and viral loads are dynamic quantities that change with time in HIV-infected persons. Commonly used single summary measures, such as viral load set point or early CD4 count, do not explicitly account for changes in viral load or CD4 counts or other features of the overall time course of these measures. However, the efficient use of all repeated measurements within each subject is often a challenge made more difficult by sparse and irregular sampling over time. Here, we illustrate how functional principal component (FPC) analysis provides an effective statistical approach for exploiting the patterns in CD4 count and viral load data over time. We demonstrate the method by using data from Kenyan women who acquired HIV-1 during follow-up in a cohort that practices high-risk activities and were subsequently followed up prospectively from early infection. The FPC scores for each woman obtained using this method served as informative summary statistics for the CD4 count and viral load trajectories. Similar to baseline CD4 count or viral set point, the first FPC score can be interpreted as a single-value summary measure of an individual's overall CD4 count or viral load. However, unlike most single-value summaries of CD4 count or viral load trajectories, the first FPC score summarizes the dynamics of these quantities and is seen to reveal specific features of the trajectories associated with mortality in this cohort. Moreover, the FPC scores are shown to be a more powerful prognostic factor than other common summaries when used in survival analysis.

Recent HIV-1 infection: identification of individuals with high viral load setpoint in a voluntary counselling and testing centre in rural Mozambique

Background

Identification of recent HIV-infections is important for describing the HIV epidemic and compiling HIV-RNA-setpoint data for future HIV intervention trials. We conducted a study to characterize recent infections, and HIV-RNA-setpoint within the adult population presenting at a voluntary counselling and testing centre (VCT) in southern Mozambique.

Methods

All adults attending the Manhiça District-Hospital VCT between April and October 2009 were recruited if they had at least one positive rapid HIV-serology test. Patients were screened for recent HIV-1 infection by BED-CEIA HIV-incidence test. Clinical examination, assessment of HIV-RNA and CD4 cell counts were performed at enrollment, 4 and 10 months.

Results

Of the 492 participants included in this study, the prevalence of recent infections as defined by BED-CEIA test, CD4 counts >200 cells/µl and HIV-RNA >400 copies/mL, was 11.58% (57/492; 95% CI 8.89–14.74). Due to heterogeneity in HIV-RNA levels in recently infected patients, individuals were categorized as having “high” HIV-RNA load if their HIV-RNA level was above the median (4.98 log₁₀ copies/mL) at diagnosis. The “high” HIV-RNA group sustained a significantly higher HIV-viral load at all visits with a median HIV-RNA setpoint of 5.22 log₁₀ copies/mL (IQR 5.18–5.47) as compared to the median of 4.15 log₁₀ copies/ml (IQR 3.37–4.43) for the other patients (p = 0.0001).

Conclusion

The low proportion of recent HIV-infections among HIV-seropositive VCT clients suggests that most of this population attends the VCT at later stages of HIV/AIDS. Characterization of HIV-RNA-setpoint may serve to identify recently infected individuals maintaining HIV viral load>5 log10 copies/mL as candidates for antiretroviral treatment as prevention interventions.

Mortality trends in the US Perinatal AIDS Collaborative Transmission Study (1986-2004)

BACKGROUND

Highly active antiretroviral therapy (HAART) has improved human immunodeficiency virus (HIV)-associated morbidity and mortality. The bimodal mortality distribution in HIV-infected children makes it important to evaluate temporal effects of HAART among a birth cohort with long-term, prospective follow-up.

METHODS

Perinatal AIDS Collaborative Transmission Study (PACTS)/PACTS-HIV Follow-up of Perinatally Exposed Children (HOPE) study was a Centers for Disease Control and Prevention-sponsored multicenter, prospective birth cohort study of HIV-exposed uninfected and infected infants from 1985 until 2004. Mortality was evaluated for the no/monotherapy, mono-/dual-therapy, and HAART eras, that is, 1 January 1986 through 31 December 1990, from 1 January 1991 through 31 December 1996, and 1 January 1997 through 31 December 2004.

RESULTS

Among 364 HIV-infected children, 56% were female and 69% black non-Hispanic. Of 98 deaths, 79 (81%) and 61 (62%) occurred in children ≤3 and ≤2 years old, respectively. The median age at death increased significantly across the eras (P < .0001). The average annual mortality rates were 18 (95% confidence interval [CI], 11.6-26.8), 6.9 (95% CI, 5.4-8.8), and 0.8 (95% CI, 0.4-1.5) events per 100 person-years for the no/monotherapy, mono-/dual-therapy and HAART eras, respectively. The corresponding 6-year survival rates for children born in these eras were 57%, 76%, and 91%, respectively (P < .0001). Among children who received HAART in the first 6 months of age, the probability of 6-year survival was 94%. Ten-year survival rates for HAART and non-HAART recipients were 94% and 45% (P < .05). HAART-associated reductions in mortality remained significant after adjustment for confounders (hazard ratio, 0.3; 95% CI, .08-.76). Opportunistic infections (OIs) caused 31.8%, 16.9%, and 9.1% of deaths across the respective eras (P = .051).

CONCLUSIONS

A significant decrease in annual mortality and a prolongation in survival were seen in this US perinatal cohort of HIV-infected children. Temporal decreases in OI-associated mortality resulted in relative proportional increases of non-OI-associated deaths.

Prevalence of seroconversion symptoms and relationship to set-point viral load: findings from a subtype C epidemic, 1995-2009

OBJECTIVE

To describe symptoms, physical examination findings, and set-point viral load associated with acute HIV seroconversion in a heterosexual cohort of HIV-discordant couples in Zambia.

DESIGN

We followed HIV serodiscordant couples in Lusaka, Zambia from 1995 to 2009 with HIV testing of negative partners and symptom inventories 3 monthly, and physical examinations annually.

METHODS

We compared prevalence of self-reported or treated symptoms (malaria syndrome, chronic diarrhea, asthenia, night sweats, and oral candidiasis) and annual physical examination findings (unilateral or bilateral neck, axillary, or inguinal adenopathy; and dermatosis) in seroconverting vs. HIV-negative or HIV-positive intervals, controlling for repeated observations, age, and sex. A composite score comprised of significant symptoms and physical examination findings predictive of seroconversion vs. HIV-negative intervals was constructed. We modeled the relationship between number of symptoms and physical examination findings at seroconversion and log set-point viral load using linear regression.

RESULTS

Two thousand, three hundred and eighty-eight HIV-negative partners were followed for a median of 18 months; 429 seroconversions occurred. Neither symptoms nor physical examination findings were reported for most seroconverters. Seroconversion was significantly associated with malaria syndrome among nondiarrheic patients [adjusted odds ratio (aOR) = 4.0], night sweats (aOR = 1.4), and bilateral axillary (aOR = 1.6), inguinal (aOR = 2.2), and neck (aOR = 2.2) adenopathy relative to HIV-negative intervals. Median number of symptoms and findings was positively associated with set-point viral load (P < 0.001).

CONCLUSION

Although most acute and early infections were asymptomatic, malaria syndrome was more common and more severe during seroconversion. When present, symptoms and physical examination findings were nonspecific and associated with higher set-point viremia.

The setpoint study (ACTG A5217): effect of immediate versus deferred antiretroviral therapy on virologic set point in recently HIV-1-infected individuals

BACKGROUND

The benefits of antiretroviral therapy during early human immunodeficiency virus type 1 (HIV-1) infection remain unproved.

METHODS

A5217 study team randomized patients within 6 months of HIV-1 seroconversion to receive either 36 weeks of antiretrovirals (immediate treatment [IT]) or no treatment (deferred treatment [DT]). Patients were to start or restart antiretroviral therapy if they met predefined criteria. The primary end point was a composite of requiring treatment or retreatment and the log(10) HIV-1 RNA level at week 72 (both groups) and 36 (DT group).

RESULTS

At the June 2009 Data Safety Monitoring Board (DSMB) review, 130 of 150 targeted participants had enrolled. Efficacy analysis included 79 individuals randomized ≥72 weeks previously. For the primary end point, the IT group at week 72 had a better outcome than the DT group at week 72 (P = .005) and the DT group at week 36 (P = .002). The differences were primarily due to the higher rate of progression to needing treatment in the DT group (50%) versus the IT (10%) group. The DSMB recommended stopping the study because further follow-up was unlikely to change these findings.

CONCLUSIONS

Progression to meeting criteria for antiretroviral initiation in the DT group occurred more frequently than anticipated, limiting the ability to evaluate virologic set point. Antiretrovirals during early HIV-1 infection modestly delayed the need for subsequent treatment.

CLINICAL TRIALS REGISTRATION

NCT00090779.

Central nervous system immune activation characterizes primary human immunodeficiency virus 1 infection even in participants with minimal cerebrospinal fluid viral burden

BACKGROUND

Central nervous system (CNS) human immunodeficiency virus (HIV) infection and immune activation lead to brain injury and neurological impairment. Although HIV enters the nervous system soon after transmission, the magnitude of infection and immunoactivation within the CNS during primary HIV infection (PHI) has not been characterized.

METHODS

This cross-sectional study analyzed cerebrospinal fluid (CSF) and blood from 96 participants with PHI and compared them with samples from neuroasymptomatic participants with chronic infection and ≥ 200 or < 200 blood CD4 T cells/μL, and with samples from HIV-seronegative participants with respect to CSF and plasma HIV RNA, CSF to serum albumin ratio, and CSF white blood cell counts (WBC), neopterin levels, and concentrations of chemokines CXCL10 and CCL2.

RESULTS

The PHI participants (median 77 days post transmission) had CSF HIV RNA, WBC, neopterin, and CXCL10 concentrations similar to the chronic infection participants but uniquely high albumin ratios. 18 participants had ≤ 100 copies/mL CSF HIV RNA, which was associated with low CSF to plasma HIV ratios and levels of CSF inflammation lower than in other PHI participants but higher than in HIV-seronegative controls.

CONCLUSIONS

Prominent CNS infection and immune activation is evident during the first months after HIV transmission, though a proportion of PHI patients demonstrate relatively reduced CSF HIV RNA and inflammation during this early period.

High-dose valacyclovir HSV-2 suppression results in greater reduction in plasma HIV-1 levels compared with standard dose acyclovir among HIV-1/HSV-2 coinfected persons: a randomized, crossover trial

BACKGROUND

Standard-dose HSV-2 suppressive therapy (acyclovir 400 mg twice daily) reduces plasma HIV-1 levels by 0.25-0.50 log(10) copies/mL. It is not known if higher doses might further suppress HIV-1 levels.

METHODS

We enrolled 32 HIV-1/HSV-2 dually infected Kenyan individuals who were not on antiretroviral therapy (ART) into a randomized, crossover trial of 2 dosing regimens of HSV-2 suppression: valacyclovir 1.5 g vs acyclovir 400 mg, both twice daily for 12 weeks, then a 2-week washout, and then the alternative for 12 weeks. Weekly plasma HIV-1 RNA quantity was measured (ClinicalTrials.gov number NCT01026454).

RESULTS

Mean plasma HIV-1 levels were significantly lower on valacyclovir compared with acyclovir: 2.94 vs 3.56 log(10) copies/mL, an average difference of 0.62 log(10) copies/mL (95% confidence interval [CI]: -0.68, -0.55; P < .001), a 76% decrease. Valacyclovir resulted in a 1.23 log(10) copies/mL decrease compared with baseline HIV-1 levels without HSV-2 suppression. Adherence was similar (99.4% of dispensed study tablets taken), and high-dose valacyclovir was well tolerated.

CONCLUSIONS

High-dose valacyclovir reduced plasma HIV-1 viral levels by 0.62 log(10) copies/mL compared with standard-dose acyclovir. The potential for higher-dose HSV-2 suppressive therapy to slow HIV-1 disease progression and reduce HIV-1 infectiousness among HIV-1/HSV-2 coinfected persons not yet eligible for ART warrants further evaluation.

Acute retroviral syndrome and high baseline viral load are predictors of rapid HIV progression among untreated Argentinean seroconverters

Background

Diagnosis of primary HIV infection (PHI) has important clinical and public health implications. HAART initiation at this stage remains controversial.

Methods

Our objective was to identify predictors of disease progression among Argentinean seroconverters during the first year of infection, within a multicentre registry of PHI-patients diagnosed between 1997 and 2008. Cox regression was used to analyze predictors of progression (LT-CD4 < 350 cells/mm³, B, C events or death) at 12 months among untreated patients.

Results

Among 134 subjects, 74% presented with acute retroviral syndrome (ARS). Seven opportunistic infections (one death), nine B events, and 10 non-AIDS defining serious events were observed. Among the 92 untreated patients, 24 (26%) progressed at 12 months versus three (7%) in the treated group (p = 0.01). The 12-month progression rate among untreated patients with ARS was 34% (95% CI 22.5-46.3) versus 13% (95% CI 1.1-24.7) in asymptomatic patients (p = 0.04). In univariate analysis, ARS, baseline LT-CD4 < 350 cells/mm³, and baseline and six-month viral load (VL) > 100,000 copies/mL were associated with progression. In multivariate analysis, only ARS and baseline VL > 100,000 copies/mL remained independently associated; HR: 8.44 (95% CI 0.97-73.42) and 9.44 (95% CI 1.38-64.68), respectively.

Conclusions

In Argentina, PHI is associated with significant morbidity. HAART should be considered in PHI patients with ARS and high baseline VL to prevent disease progression.

Most adults seek urgent healthcare when acquiring HIV-1 and are frequently treated for malaria in coastal Kenya

BACKGROUND

Acute HIV-1 infection (AHI) may present with symptoms for which urgent healthcare is sought. However, little is known about healthcare seeking around the time of HIV-1 seroconversion in sub-Saharan Africa.

METHODS

Review of clinical, counselling, treatment and laboratory records of previously HIV-1 seronegative at-risk adults, followed at monthly or 3-monthly visits, who seroconverted and enrolled in an AHI cohort. All HIV-seronegative plasma samples were tested for p24 antigen (p24) and stored preseroconversion samples for HIV-1 RNA (RNA). Factors associated with malaria treatment while acquiring HIV-1 were evaluated in multiple logistic regression.

RESULTS

Sixty men and 12 women (95% of 75 seroconverters) were evaluated, including 43 (60%) with either p24-positive or RNA-positive or HIV-1 discordant rapid antibodies prior to seroconversion. Prior to diagnosis, 54 patients (75%) reported fever and 50 (69%) sought urgent care for symptomatic illness, including 23 (32%) who sought care in a nonresearch setting. Twenty-nine patients (40%) received presumptive malaria treatment. Only 24% of febrile patients were tested for malaria parasites. All documented smear results were negative. Malaria treatment was strongly associated with fever [adjusted odds ratio (aOR): 46, 95% confidence interval (CI): 3-725] and nonresearch setting (aOR: 5, 95% CI: 3-64). AHI was suspected in six (12%) patients who presented for urgent care during research evaluation.

CONCLUSIONS

The majority of adults with AHI seek urgent healthcare. These individuals are often presumptively treated for malaria. Improved recognition of AHI in adults presenting for care may offer opportunities for optimizing HIV prevention strategies.

Clinical symptoms and courses of primary HIV-1 infection in recent years in Japan

BACKGROUND

The natural course of HIV-1 infection includes 10 years of an asymptomatic period before the development of AIDS. However, in Japan, the disease progression process seems faster in recent years.

METHODS

The study subjects were 108 new patients with primary HIV-1 infection during the period from 1997 through 2007. We evaluated their clinical symptoms and laboratory data, and then analyzed disease progression in 82 eligible patients. Disease progression was defined as a fall in CD4 count below 350/µL and/or initiation of antiretroviral therapy.

RESULTS

Ninety percent of the patients were infected via homosexual intercourse. All patients had at least one clinical symptom (mean; 4.75±1.99) related to primary HIV-1 infection, with a mean duration of 23.2 days (±14.8) and 53.3% of them had to be hospitalized due to severe symptoms. The mean CD4 count and viral load at first visit were 390/µL (±220.1) and 4.81 log10/mL (±0.78), respectively. None developed AIDS during the study period. Estimates of risk of disease progression were 61.0% at 48 weeks and 82.2% at 144 weeks. In patients who required antiretroviral therapy, the median CD4 count was 215/µL (range, 52-858) at initiation of such therapy. Among the patients with a CD4 count of <350/µL at first visit, 53% never showed recovery of CD4 count (>350/µL) without antiretroviral therapy.

CONCLUSION

Despite possible bias in patient population, disease progression seemed faster in symptomatic Japanese patients with recently acquired primary HIV-1 infection than the previously defined natural course of the disease.

Clinical management of acute HIV infection: best practice remains unknown

Best practice for the clinical management of acute human immunodeficiency virus (HIV) infection remains unknown. Although some data suggest possible immunologic, virologic, or clinical benefit of early treatment, other studies show no difference in these outcomes over time, after early treatment is discontinued. The literature on acute HIV infection is predominantly small nonrandomized studies, which further limits interpretation. As a result, the physician is left to grapple with these uncertainties while making clinical decisions for patients with acute HIV infection. Here we review the literature, focusing on the potential advantages and disadvantages of treating acute HIV infection outlined in treatment guidelines, and summarize the presentations on clinical management of acute HIV infection from the 2009 Acute HIV Infection Meeting in Boston, Massachusetts.

Transmission of single HIV-1 genomes and dynamics of early immune escape revealed by ultra-deep sequencing

We used ultra-deep sequencing to obtain tens of thousands of HIV-1 sequences from regions targeted by CD8+ T lymphocytes from longitudinal samples from three acutely infected subjects, and modeled viral evolution during the critical first weeks of infection. Previous studies suggested that a single virus established productive infection, but these conclusions were tempered because of limited sampling; now, we have greatly increased our confidence in this observation through modeling the observed earliest sample diversity based on vastly more extensive sampling. Conventional sequencing of HIV-1 from acute/early infection has shown different patterns of escape at different epitopes; we investigated the earliest escapes in exquisite detail. Over 3–6 weeks, ultradeep sequencing revealed that the virus explored an extraordinary array of potential escape routes in the process of evading the earliest CD8 T-lymphocyte responses – using 454 sequencing, we identified over 50 variant forms of each targeted epitope during early immune escape, while only 2–7 variants were detected in the same samples via conventional sequencing. In contrast to the diversity seen within epitopes, non-epitope regions, including the Envelope V3 region, which was sequenced as a control in each subject, displayed very low levels of variation. In early infection, in the regions sequenced, the consensus forms did not have a fitness advantage large enough to trigger reversion to consensus amino acids in the absence of immune pressure. In one subject, a genetic bottleneck was observed, with extensive diversity at the second time point narrowing to two dominant escape forms by the third time point, all within two months of infection. Traces of immune escape were observed in the earliest samples, suggesting that immune pressure is present and effective earlier than previously reported; quantifying the loss rate of the founder virus suggests a direct role for CD8 T-lymphocyte responses in viral containment after peak viremia. Dramatic shifts in the frequencies of epitope variants during the first weeks of infection revealed a complex interplay between viral fitness and immune escape.

Quantifying how MHC polymorphism prevents pathogens from adapting to the antigen presentation pathway

The classical antigen presentation pathway consists of two monomorphic (proteasome and TAP) and one polymorphic components (MHC Class I). Viruses can escape CTL responses by mutating an epitope so that it is no longer correctly processed by the pathway. Whereas escape mutations that affect MHC binding are typically no longer under selection pressure in the next host of the virus (as hosts differ in their MHC alleles), escape mutations that affect the antigen processing of epitope precursors prevent the use of those epitope precursors by any of the MHC alleles in a host population. Viruses might therefore be under selection pressure to adapt to the monomorphic proteasome and TAP. We designed an agent-based model of a host population, in which an HIV-1 like virus adapts to the antigen presentation pathway of individual hosts, as the virus spreads through the population. We studied how the polymorphism of the MHC and the monomorphism of the proteasome and TAP affected the level of adaptation to the host population that the virus could reach. We found that due to the polymorphism and high specificity of the MHC class I molecules, the CTL epitopes that are targeted by the CTL responses of different hosts do not share many epitope precursors. Therefore, escape mutations in epitope precursors are frequently released from immune selection pressure, and can revert back to the virus wildtype sequence. As a result, the selection pressure on the virus to adapt to the proteasome and TAP is relatively small, which explains the low level of adaptation of the virus to the monomorphic steps in the antigen presentation pathway.

[AIDS Study Group/Spanish AIDS Plan consensus document on antiretroviral therapy in adults with human immunodeficiency virus infection (updated January 2010)]

OBJECTIVE

This consensus document is an update of antiretroviral therapy recommendations for adult patients with human immunodeficiency virus infection.

METHODS

To formulate these recommendations a panel made up of members of the Grupo de Estudio de Sida (Gesida, AIDS Study Group) and the Plan Nacional sobre el Sida (PNS, Spanish AIDS Plan) reviewed the advances in the current understanding of the pathophysiology of human immunodeficiency virus (HIV) infection, the efficacy and safety of clinical trials, and cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings. Three levels of evidence were defined according to the data source: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not to recommend ART was established in each situation.

RESULTS

Currently, the treatment of choice for chronic HIV infection is the combination of three drugs of two different classes, including 2 nucleosides or nucleotide analogs (NRTI) plus 1 non-nucleoside (NNRTI) or 1 boosted protease inhibitor (PI/r), but other combinations are possible. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts below 350 cells/microl; 2) When CD4 counts are between 350 and 500 cells/microl, therapy should be started in case of cirrhosis, chronic hepatitis C, high cardiovascular risk, HIV nephropathy, HIV viral load above 100,000 copies/ml, proportion of CD4 cells under 14%, and in people aged over 55; 3) Therapy should be deferred when CD4 are above 500 cells/microl, but could be considered if any of previous considerations concurs. Treatment should be initiated in case of hepatitis B requiring treatment and should be considered for reduce sexual transmission. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures but undetectable viral loads maybe possible with the new drugs even in highly drug experienced patients. Genotype studies are useful in these situations. Drug toxicity of ART therapy is losing importance as benefits exceed adverse effects. Criteria for antiretroviral treatment in acute infection, pregnancy and post-exposure prophylaxis are mentioned as well as the management of HIV co-infection with hepatitis B or C.

CONCLUSIONS

CD4 cells counts, viral load and patient co-morbidities are the most important reference factors to consider when initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the ability to determine viral resistance is leading to a more individualized therapy approach in order to achieve undetectable viral load under any circumstances.

HIV RNA level in early infection is predicted by viral load in the transmission source

OBJECTIVE

HIV-1 viral load in early infection predicts the risk of subsequent disease progression but the factors responsible for the differences between individuals in viral load during this period have not been fully identified. We sought to determine the relationship between HIV-1 RNA levels in the source partner and recently infected recipient partners within transmission pairs.

METHODS

We recruited donor partners of persons who presented with acute or recent (<6 months) HIV infection. Transmission was confirmed by phylogenetic comparison of virus sequence in the donor and recipient partners. We compared viral load in the donor partner and the recipient in the first 6 months of HIV infection.

RESULTS

We identified 24 transmission pairs. The median estimated time from infection to evaluation in acutely/recently infected recipient individuals was 72 days. The viral load in the donor was closely associated with viral load at presentation in the recipient case (r = 0.55, P = 0.006).

CONCLUSION

The strong correlation between HIV-1 RNA levels within HIV transmission pairs indicates that virus characteristics are an important determinant of viral load in early HIV infection.

Daily acyclovir for HIV-1 disease progression in people dually infected with HIV-1 and herpes simplex virus type 2: a randomised placebo-controlled trial

BACKGROUND

Most people infected with HIV-1 are dually infected with herpes simplex virus type 2. Daily suppression of this herpes virus reduces plasma HIV-1 concentrations, but whether it delays HIV-1 disease progression is unknown. We investigated the effect of acyclovir on HIV-1 progression.

METHODS

In a trial with 14 sites in southern Africa and east Africa, 3381 heterosexual people who were dually infected with herpes simplex virus type 2 and HIV-1 were randomly assigned in a 1:1 ratio to acyclovir 400 mg orally twice daily or placebo, and were followed up for up to 24 months. Eligible participants had CD4 cell counts of 250 cells per mL or higher and were not taking antiretroviral therapy. We used block randomisation, and patients and investigators were masked to treatment allocation. Effect of acyclovir on HIV-1 disease progression was defined by a primary composite endpoint of first occurrence of CD4 cell counts of fewer than 200 cells per microL, antiretroviral therapy initiation, or non-trauma related death. As an exploratory analysis, we assessed the endpoint of CD4 falling to <350 cells per microL. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00194519.

FINDINGS

At enrollment, the median CD4 cell count was 462 cells per microL and median HIV-1 plasma RNA was 4.1 log(10) copies per microL. Acyclovir reduced risk of HIV-1 disease progression by 16%; 284 participants assigned acyclovir versus 324 assigned placebo reached the primary endpoint (hazard ratio [HR] 0.84, 95% CI 0.71-0.98, p=0.03). In those with CD4 counts >or=350 cells per microL, aciclovir delayed risk of CD4 cell counts falling to <350 cells per microL by 19% (0.81, 0.71-0.93, p=0.002)

INTERPRETATION

The role of suppression of herpes simplex virus type 2 in reduction of HIV-1 disease progression before initiation of antiretroviral therapy warrants consideration.

FUNDING

Bill & Melinda Gates Foundation.

Sex steroid hormones, hormonal contraception, and the immunobiology of human immunodeficiency virus-1 infection

Worldwide, an increasing number of women use oral or injectable hormonal contraceptives. However, inadequate information is available to aid women and health care professionals in weighing the potential risks of hormonal contraceptive use in individuals living with HIV-1 or at high risk of infection. Numerous epidemiological studies and challenge studies in a rhesus macaque model suggest that progesterone-based contraceptives increase the risk of HIV-1 infection in humans and simian immunodeficiency virus (SIV) infection in macaques, accelerate disease progression, and increase viral shedding in the genital tract. However, because several other studies in humans have not observed any effect of exogenously administered progesterone on HIV-1 acquisition and disease progression, the issue continues to be a topic of intense research and ongoing discussion. In contrast to progesterone, systemic or intravaginal treatment with estrogen efficiently protects female rhesus macaques against the transmission of SIV, likely by enhancing the natural protective properties of the lower genital tract mucosal tissue. Although the molecular and cellular mechanisms underlying the effect of sex steroid hormones on HIV-1 and SIV acquisition and disease progression are not well understood, progesterone and estrogen are known to regulate a number of immune mechanisms that may exert an effect on retroviral infection. This review summarizes current knowledge of the effects of various types of sex steroid hormones on immune processes involved in the biology of HIV-1 infection.

Host factors associated with outcome from primary human immunodeficiency virus-1 infection

PURPOSE OF REVIEW

The early events in human immunodeficiency virus-1 infection are increasingly recognized as critical for the overall evolution of the disease. Viral and host factors interact to establish a point of equilibrium defined by the viral set point. This review highlights new opportunities in the understanding of the genetic and genomic determinants of those early events.

RECENT FINDINGS

The field of human immunodeficiency virus host genetics is shifting from the measure of long-term consequences of infection to the analysis of quantitative biological endpoints of viral control, with particular attention on the earliest events as study phenotypes. The field has also been enriched by a better understanding of the determinant and complex role of human leukocyte antigen and killer cell immunoglobulin-like-receptor variation, and by the completion of the first genome-wide study of determinants of human immunodeficiency virus-1 replication. The genome analysis highlights the central influence of acquired immunity in viral control, and provides an extensive catalogue of novel gene candidates.

SUMMARY

Host genetics and genomic analyses of precise quantitative study phenotypes offer an unprecedented opportunity to dissect critical steps in human immunodeficiency virus-1 pathogenesis.

Clinical presentation and diagnosis of primary HIV-1 infection

PURPOSE OF REVIEW

To describe current findings concerning the clinical manifestations and diagnosis of primary HIV-1 infection.

RECENT FINDINGS

HIV-1 seroconversion can occur with a variety of clinical manifestations or without symptoms. More severe and numerous symptoms during primary HIV-1 infection predict a higher plasma HIV-1 RNA set-point and faster disease progression. While detection of primary HIV-1 infection is potentially very important for HIV-1 prevention and may offer clinical benefits, the diagnosis is often missed. Diagnosis of symptomatic individuals with antibody-negative HIV-1 infection requires recognition of the diverse signs and symptoms of this syndrome. Diagnostic tests for primary HIV-1 infection include assays for HIV-1 RNA, p24 antigen, and third generation enzyme immunoassay antibody tests capable of detecting IgM antibodies. Targeting these tests using clinical presentation alone will probably miss the diagnosis in many individuals. Consequently, increasing effort has gone into developing strategies to incorporate the use of these assays into routine HIV-1 testing algorithms.

SUMMARY

More numerous and severe primary HIV-1 infection symptoms predict more rapid disease progression. Pooled HIV-1 RNA screening and fourth generation HIV-1 enzyme immunoassay antibody tests with sensitive p24 antigen detection are beginning to be implemented in routine HIV-1 testing algorithms, but further research is needed to define optimal strategies for increasing detection of primary HIV-1 infection.

Adaptive changes in HIV-1 subtype C proteins during early infection are driven by changes in HLA-associated immune pressure

It is unresolved whether recently transmitted human immunodeficiency viruses (HIV) have genetic features that specifically favour their transmissibility. To identify potential "transmission signatures", we compared 20 full-length HIV-1 subtype C genomes from primary infections, with 66 sampled from ethnically and geographically matched individuals with chronic infections. Controlling for recombination and phylogenetic relatedness, we identified 39 sites at which amino acid frequency spectra differed significantly between groups. These sites were predominantly located within Env, Pol and Gag (14/39, 9/39 and 6/39 respectively) and were significantly clustered (33/39) within known immunoreactive peptides. Within 6 months of infection, we detected reversion-to-consensus mutations at 14 sites and potential CTL escape mutations at seven. Here we provide evidence that frequent reversion mutations probably allows the virus to recover replicative fitness which, together with immune escape driven by the HLA alleles of the new hosts, differentiate sequences from chronic infections from those sampled shortly after transmission.

Hormonal contraception and HIV disease progression: a multicountry cohort analysis of the MTCT-Plus Initiative

OBJECTIVE

HIV-infected women need access to safe and effective contraception. Recent animal and human data suggest that hormonal contraception may accelerate HIV disease progression.

METHODS

We compared the incidence of HIV disease progression among antiretroviral therapy-naive women with and without exposure to hormonal contraception at 13 sites in Africa and Asia. Disease progression was defined as becoming eligible for antiretroviral therapy or death.

RESULTS

Between 1 August 2002 and 31 December 2007, the MTCT-Plus programs enrolled 7846 women. In total, 4109 (52%) women met eligibility criteria for this analysis and contributed 5911 person-years of follow-up (median follow-up, 379 days; interquartile range, 121-833). At baseline, 3064 (75%) women reported using either no contraception or a nonhormonal method, whereas 823 (20%) reported using implants/injectables and 222 (5%) reported using oral contraceptive pills. The disease progression outcome was met by 944 (29%) women (rate, 18.3/100 woman-years). Neither implants/injectables (adjusted hazard ratio 1.0, 95% confidence interval 0.8-1.1) nor oral contraceptive pills (adjusted hazard ratio 0.8, 95% confidence interval 0.6-1.1) were associated with disease progression. Treating contraceptive method as a time-varying exposure did not change this negative finding.

CONCLUSION

This multicountry cohort analysis provides some reassurance that hormonal contraception is not associated with HIV disease progression. Further research is needed to address the contraceptive needs of HIV-infected women.

Breadth of neutralizing antibody response to human immunodeficiency virus type 1 is affected by factors early in infection but does not influence disease progression

The determinants of a broad neutralizing antibody (NAb) response and its effect on human immunodeficiency virus type 1 (HIV-1) disease progression are not well defined, partly because most prior studies of a broad NAb response were cross-sectional. We examined correlates of NAb response breadth among 70 HIV-infected, antiretroviral-naïve Kenyan women from a longitudinal seroincident cohort. NAb response breadth was measured 5 years after infection against five subtype A viruses and one subtype B virus. Greater NAb response breadth was associated with a higher viral load set point and greater HIV-1 env diversity early in infection. However, greater NAb response breadth was not associated with a delayed time to a CD4(+) T-cell count of <200, antiretroviral therapy, or death. Thus, a broad NAb response results from a high level of antigenic stimulation early in infection, which likely accounts for prior observations that greater NAb response breadth is associated with a higher viral load later in infection.

Cross-subtype neutralization sensitivity despite monoclonal antibody resistance among early subtype A, C, and D envelope variants of human immunodeficiency virus type 1

The human immunodeficiency virus type 1 (HIV-1) variants that are transmitted to newly infected individuals are the primary targets of interventions, such as vaccines and microbicides, aimed at preventing new infections. Newly acquired subtype A, B, and C variants have been the focus of neutralization studies, although many of these viruses, particularly of subtypes A and B, represent viruses circulating more than a decade ago. In order to better represent the global diversity of transmitted HIV-1 variants, an additional 31 sexually transmitted Kenyan HIV-1 env genes, representing several recent infections with subtype A, as well as subtypes A/D, C, and D, were cloned, and their neutralization profiles were characterized. Most env variants were resistant to neutralization by the monoclonal antibodies (MAbs) b12, 4E10, 2F5, and 2G12, suggesting that targeting the epitopes of these MAbs may not be effective against variants that are spreading in areas of endemicity. However, significant cross-subtype neutralization by plasma was observed, indicating that there may be other epitopes, not yet defined by the limited available MAbs, which could be recognized more broadly.

Analysis of the percentage of human immunodeficiency virus type 1 sequences that are hypermutated and markers of disease progression in a longitudinal cohort, including one individual with a partially defective Vif

Hypermutation, the introduction of excessive G-to-A substitutions by host proteins in the APOBEC family, can impair replication of the human immunodeficiency virus (HIV). Because hypermutation represents a potential antiviral strategy, it is important to determine whether greater hypermutation is associated with slower disease progression in natural infection. We examined the level of HIV-1 hypermutation among 28 antiretroviral-naive Kenyan women at two times during infection. By examining single-copy gag sequences from proviral DNA, hypermutation was detected in 16 of 28 individuals. Among individuals with any hypermutation, a median of 15% of gag sequences were hypermutated (range, 5 to 43%). However, there was no association between the level of gag hypermutation and the viral load or CD4 count. Thus, we observed no overall relationship between hypermutation and markers of disease progression among individuals with low to moderate levels of hypermutation. In addition, one individual sustained a typical viral load despite having a high level of hypermutation. This individual had 43% of gag sequences hypermutated and harbored a partially defective Vif, which was found to permit hypermutation in a peripheral blood mononuclear cell culture. Overall, our results suggest that a potential antiviral therapy based on hypermutation may need to achieve a substantially higher level of hypermutation than is naturally seen in most individuals to impair virus replication and subsequent disease progression.

HIV disease progression by hormonal contraceptive method: secondary analysis of a randomized trial

BACKGROUND

HIV-infected women need access to safe contraception. We hypothesized that women using depomedroxyprogesterone acetate (DMPA) contraception would have faster HIV disease progression than women using oral contraceptive pills (OCPs) and nonhormonal methods.

METHODS

In a previously reported trial, we randomized 599 HIV-infected women to the intrauterine device (IUD) or hormonal contraception. Women randomized to hormonal contraception chose between OCPs and DMPA. This analysis investigates the relationship between exposure to hormonal contraception and HIV disease progression [defined as death, becoming eligible for antiretroviral therapy (ART), or both].

RESULTS

Of the 595 women not on ART at the time of randomization, 302 were allocated to hormonal contraception, of whom 190 (63%) initiated DMPA and 112 (37%) initiated OCPs. Women starting IUD, OCPs, or DMPA were similar at baseline. Compared with women using the IUD, the adjusted hazard of death was not significantly increased among women using OCPs [1.24; 95% confidence interval (CI) 0.42-3.63] or DMPA (1.83; 95% CI 0.82-4.08). However, women using OCPs (adjusted hazard ratio (AHR) 1.69; 95% CI 1.09-2.64) or DMPA (AHR 1.56; 95% CI 1.08-2.26) trended toward an increased likelihood of becoming eligible for ART. Women exposed to OCPs (AHR 1.67; 95% CI 1.10-2.51) and DMPA (AHR 1.62; 95% CI 1.16-2.28) also had an increased hazard of meeting our composite disease progression outcome (death or becoming ART eligible) than women using the IUD.

CONCLUSION

In this secondary analysis, exposure to OCPs or DMPA was associated with HIV disease progression among women not yet on ART. This finding, if confirmed elsewhere, would have global implications and requires urgent further investigation.

Clinical prognostic value of RNA viral load and CD4 cell counts during untreated HIV-1 infection--a quantitative review

Background

The prognostic value of CD4 counts and RNA viral load for identifying treatment need in HIV-infected individuals depends on (a) variation within and among individuals, and (b) relative risks of clinical progression per unit CD4 or RNA difference.

Methodology/Principal Findings

We reviewed these measurements across (a) 30 studies, and (b) 16 cohorts of untreated seropositive adults. Median within-population interquartile ranges were 74,000 copies/mL for RNA with no significant change during the course of infection; and 330 cells/µL for CD4, with a slight proportional increase over infection. Applying measurement and physiological fluctuations observed on chronically infected patients, we estimate that 45% of population-level variation in RNA, and 25% of variation in CD4, were due to within-patient fluctuations. Comparing a patient with RNA at upper 75^th centile with a patient at median RNA, 5-year relative risks were 1.4 (95% CI 1.2–1.7) for AIDS and 1.5 (1.3–1.9) for death, without change over the course of infection. In contrast, for a patient with CD4 count at the lower 75^th centile, relative risks increased from 1.0 at seroconversion to maxima of 6.3 (4.4–8.9) for AIDS and 5.5 (2.7–10.1) for death by year 6, when the population median had fallen to 300 cells/µL. Below 300 cells/µL, prognostic power did not increase, due to a narrower CD4 range.

Conclusions

Findings support the current WHO recommendation (used with clinical criteria) to start antiretroviral treatment in low-income settings at CD4 thresholds of 200–350 cells/µL, without pre-treatment RNA monitoring – while not precluding earlier treatment based on clinical, socio-demographic or public health criteria.

Fourteen million women with limited options: HIV/AIDS and highly effective reversible contraception in sub-Saharan Africa

An estimated 14 million women in sub-Saharan Africa are HIV infected and these women deserve access to evidence-based family planning services. Increasing contraceptive use in HIV-infected women can reduce the numbers of unintended pregnancies and thus reduce maternal death and vertical transmission of HIV. A delicate balance exists between risks associated with pregnancy and any theoretical risks of acquiring, transmitting or worsening HIV attributable to using a contraceptive. This commentary reviews interactions between hormonal, intrauterine and barrier contraception in HIV-infected women, with a focus on sub-Saharan Africa. Unfortunately, the evidence on these interactions to guide family planning providers is limited and more research in this area is urgently needed.

HIV-1 evolution in gag and env is highly correlated but exhibits different relationships with viral load and the immune response

OBJECTIVE

To evaluate relationships between HIV-1 evolution, including immune evasion, and markers of disease progression during chronic infection.

DESIGN

HIV-1 evolution and disease progression markers were evaluated over approximately 5 years of infection among 37 Kenyan women from a prospective, seroincident cohort. Evolution was measured in two genes, gag and env, which are primary targets of cellular and humoral immune responses, respectively.

METHODS

Proviral HIV-1 gag and env sequences were obtained from early and chronic infection when plasma viral load and CD4 cell counts were available. Human leukocyte antigen types were obtained to identify changes in gag cytotoxic T-lymphocyte epitopes. The breadth of the neutralizing antibody response was measured for each woman's plasma against a panel of six viruses. Tests of association were performed between virus evolution (diversity, divergence, and ratio of nonsynonymous to synonymous divergence), markers of disease progression (viral load and CD4 cell count), and immune parameters (gag cytotoxic T lymphocyte epitope mutation and neutralizing antibody breadth).

RESULTS

HIV-1 gag and env diversity and divergence were highly correlated in early and late infection. Divergence in gag was strongly correlated with viral load, largely because of the accumulation of synonymous changes. Mutation in gag cytotoxic T-lymphocyte epitopes was associated with higher viral load. There was evidence for adaptive evolution in env, but the extent of env evolution was only weakly associated with neutralizing antibody breadth.

CONCLUSION

Our results indicate that HIV-1 evolution in gag and env is highly correlated but exhibits gene-specific differences. The different immune pressures on these genes may partly explain differences in evolution and consequences for HIV-1 disease progression.