Incomplete restoration of Mycobacterium tuberculosis-specific-CD4 T cell responses despite antiretroviral therapy

OBJECTIVES

Despite antiretroviral therapy (ART), HIV-infected persons have increased risk of active tuberculosis (TB). PPD and combined ESAT-6 and CFP-10-specific-CD4 (EC-Sp-CD4) responses were examined over 96 weeks.

METHODS

HIV-infected, ART-naive Thai adults with CD4 T cell count ≤350 cells/μL starting ART were assessed at baseline, wk4, 8, 12, 24, 48 and 96. PPD and EC-Sp-CD4 T cells were detected by CD25/CD134 co-expression after stimulation with antigens.

RESULTS

Fifty subjects were enrolled, 39 were male, median age 32 yrs, median baseline CD4 T cell count 186 cells/μL and plasma HIV-viral-load 4.9log10 copies/mL. Seventeen were TB-sensitised. At baseline, 25 had positive PPD and 15 had positive EC-Sp-CD4 response. CD4 T cell count <100 cells/μL was less (P = 0.005) and TB-sensitisation was more likely (P = 0.013) to be associated with positive baseline PPD-Sp-CD4 response. At wk4, the number of subjects with positive PPD-Sp-CD4 response rose to 35 (P = 0.021). Mean PPD-Sp-CD4 T cells increased at wk4 (P = 0.017) in patients not classified as TB-sensitised. The number of subjects with positive EC-Sp-CD4 response did not change significantly post ART. In TB-sensitised patients, mean EC-Sp-CD4 T cells declined to below baseline from wk12 (P = 0.010) onwards. EC-Sp-CD4 responses were undetectable in 3 out of 17 TB-sensitised patients.

CONCLUSIONS

Restoration of responses to TB-antigens was incomplete and inconsistent under the employed experimental conditions and may account for persistent increased risk of TB despite ART.

Promoter Targeting shRNA Suppresses HIV-1 Infection In vivo Through Transcriptional Gene Silencing

Despite prolonged and intensive application, combined antiretroviral therapy cannot eradicate human immunodeficiency virus (HIV)-1 because it is harbored as a latent infection, surviving for long periods of time. Alternative approaches are required to overcome the limitations of current therapy. We have been developing a short interfering RNA (siRNA) gene silencing approach. Certain siRNAs targeting promoter regions of genes induce transcriptional gene silencing. We previously reported substantial transcriptional gene silencing of HIV-1 replication by an siRNA targeting the HIV-1 promoter in vitro. In this study, we show that this siRNA, expressed as a short hairpin RNA (shRNA) (shPromA-JRFL) delivered by lentiviral transduction of human peripheral blood mononuclear cells (PBMCs), which are then used to reconstitute NOJ mice, is able to inhibit HIV-1 replication in vivo, whereas a three-base mismatched variant (shPromA-M2) does not. In shPromA-JRFL–treated mice, HIV-1 RNA in serum is significantly reduced, and the ratio of CD4⁺/CD8⁺ T cells is significantly elevated. Expression levels of the antisense RNA strand inversely correlates with HIV-1 RNA in serum. The silenced HIV-1 can be reactivated by T-cell activation in ex vivo cultures. HIV-1 suppression is not due to offtarget effects of shPromA-JRFL. These data provide “proof-of principle” that an shRNA targeting the HIV-1 promoter is able to suppress HIV-1 replication in vivo.

Short communication: HIV blips while on antiretroviral therapy can indicate consistently detectable viral levels due to assay underreporting

Viral blips, where HIV RNA plasma viral load (pVL) intermittently increases above the lower limit of assay detection, are a cause for concern. We investigated a number of hypotheses for their cause. We assessed HIV RNA, and total and episomal HIV DNA from 16 individuals commencing antiretroviral therapy (ART) consisting of raltegravir and tenofovir/emtricitabine for 3 years, using two assays: a single-copy assay [SCA; lower limit of quantification (LLOQ), <1 copy/ml] and the Amplicor assay (LLOQ of 50 copies/ml). Two individuals exhibited viral blips. From week 20 onward, the period where ART had achieved its final suppressive levels, pVL ranged from <1 to 330 copies/ml, except for one individual at the final time. Both assays were 98% consistent (108/110) in assessing pVL <50 copies/ml, but the Amplicor assay registered 56% of samples (19/34) as below the LLOQ that were in the 50 to 1000 copy/ml range as quantified by SCA. pVL changes between successive time points did not correlate with changes in cellular infection as measured through either total or episomal HIV DNA. Changes in pVL were correlated (negatively) with changes in total CD4(+) T cell numbers (p=0.003), naive (CD45RO(-)CD62L(+)CD4(+)), natural regulatory (CD45RO(-)CD25(+)CD127(-)CD4(+)), activated effector (CD45RO(+)CD38(++)CCR5(+)CD8(+)), but not activated (CD38(+)HLA-DR(+)) CD4(+) T cells. Patients receiving stable, seemingly suppressive ART can have pVL near the 50 copy LLOQ at multiple time points. The high Amplicor assay error rate around this level implies that viral blips underrepresent pVL being more consistently above the LLOQ. Activation of latently infected cells is less likely to contribute to this phenomenon.

Short communication: Aging not gender is associated with high atazanavir plasma concentrations in Asian HIV-infected patients

Physiological effects of aging make the older population more susceptible to adverse drug events and drug-drug interactions. We evaluated the impact of aging and gender on the pharmacokinetics (PK) of atazanavir/ritonavir (ATV/r) 300/100 mg once daily (qd) in 22 well-suppressed HIV-infected patients. This was a 24-h intensive PK study. Subjects were HIV-1-infected adults aged ≥18 years with HIV RNA <50 copies/ml and treated with ATV/r 300/100 mg once daily plus two nucleoside reverse transcriptase inhibitors (NRTIs) for at least 2 weeks. Atazanavir and ritonavir plasma concentrations were measured by validated high-performance liquid chromatography (HPLC). Plasma PK parameters were calculated using noncompartmental methods. Since 50% of the patients were older than 42 years, age 42 was selected as the cut-off point for the older (>42 years) group. Gender, weight, duration of ATV/r therapy, and proportion treated with tenofovir disoproxil fumarate (TDF)-containing regimens did not differ between both groups. Patients from the aging group had a reduced creatinine clearance (91 versus 76 ml/min). The older group had a higher atazanavir exposure with median AUC(0-24) 71.2 vs. 53.1 mg·h/liter, C(max) 8.5 vs. 5.5 mg/liter, and C(trough) 1.17 vs. 0.78 mg/liter, and slower apparent clearance (3.5 vs. 4.8 liter/h). Ten patients (91%) from the older group and 36% from the younger group had ATV C(trough) levels higher than the proposed upper limit for toxicity of 0.85 mg/liter. Females had a lower body weight (BW) (46 versus 63 kg) than the males, but atazanavir concentrations in females were greater. However, in multivariate analysis, older age was the only significant predictor for higher atazanavir concentrations. Parameter estimate for age and atazanavir AUC after adjusting for gender and BW was 2.17 (95% CI 1.01-3.33). That is, for every year increase in age, AUC increases by approximately 2 mg·h/liter. Age seems to be an important factor influencing atazanavir pharmacokinetics. Patients from the aging group appeared to have higher atazanavir exposure compared to the younger group. Further PK explorations of ATV in the extremely aged population are warranted.

HIV lipodystrophy in participants randomised to lopinavir/ritonavir (LPV/r) +2-3 nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTI) or LPV/r + raltegravir as second-line antiretroviral therapy

Objective

To compare changes over 48 weeks in body fat, lipids, Metabolic Syndrome and cardiovascular disease risk between patients randomised 1∶1 to lopinavir/ritonavir (r/LPV) plus raltegravir (RAL) compared to r/LPV plus 2–3 nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) as second-line therapy.

Methods

Participants were HIV-1 positive (>16 years) failing first-line treatment (2 consecutive HIV RNA >500 copies/mL) of NNRTI +2N(t)RTI. Whole body dual energy x-ray absorptiometry was performed at baseline and week 48. Data were obtained to calculate the Metabolic Syndrome and Framingham cardiovascular disease (CVD) risk score. Linear regression was used to compare mean differences between arms. Logistic regression compared incidence of metabolic syndrome. Associations between percent limb fat changes at 48 weeks with baseline variables were assessed by backward stepwise multivariate linear regression. Analyses were adjusted for gender, body mass index and smoking status.

Results

210 participants were randomised. The mean (95% CI) increase in limb fat over 48 weeks was 15.7% (5.3, 25.9) or 0.9 kg (0.2, 1.5) in the r/LPV+N(t)RTI arm and 21.1% (11.1, 31,1) or 1.3 kg (0.7, 1.9) in the r/LPV+RAL arm, with no significant difference between treatment arms (−5.4% [−0.4 kg], p>0.1). Increases in total body fat mass (kg) and trunk fat mass (kg) were also similar between groups. Total:HDL cholesterol ratio was significantly higher in the RAL arm (mean difference −0.4 (1.4); p = 0.03), there were no other differences in lipid parameters between treatment arms. There were no statistically significant differences in CVD risk or incidence of Metabolic Syndrome between the two treatment arms. The baseline predictors of increased limb fat were high viral load, high insulin and participant's not taking lipid lowering treatment.

Conclusion

In patients switching to second line therapy, r/LPV combined with RAL demonstrated similar improvements in limb fat as an N(t)RTI + r/LPV regimen, but a worse total:HDL cholesterol ratio over 48 weeks.

Trial Registration

This clinical trial is registered on Clinicaltrials.gov, registry number NCT00931463.

Restoration of CMV-specific-CD4 T cells with ART occurs early and is greater in those with more advanced immunodeficiency

Objectives

Restoration of Cytomegalovirus-specific-CD4 T cell (CMV-Sp-CD4) responses partly accounts for the reduction of CMV-disease with antiretroviral-therapy (ART), but CMV-Sp-CD4 may also drive immune activation and immunosenescence. This study characterized the dynamics of CMV-Sp-CD4 after ART initiation and explored associations with CD4 T cell recovery as well as frequency of naïve CD4 T cells at week 96.

Methods

Fifty HIV-infected, ART-naïve Thai adults with CD4 T cell count ≤350cells/µL and starting ART were evaluated over 96 weeks (ClinicalTrials.gov identifier NCT01296373). CMV-Sp-CD4 was detected by co-expression of CD25/CD134 by flow cytometry after CMV-antigen stimulation.

Results

All subjects were CMV sero-positive, 4 had quantifiable CMV-DNA (range 2.3-3.9 log₁₀ copies/mL) at baseline but none had clinically apparent CMV-disease. Baseline CMV-Sp-CD4 response was positive in 40 subjects. Those with CD4 T cell count <100cells/µL were less likely to have positive baseline CMV-Sp-CD4 response (P=0.003). Positive baseline CMV-Sp-CD4 response was associated with reduced odds of quantifiable CMV-DNA (P=0.022). Mean CD4 T cell increase at week 96 was 213 cells/µL. This was associated positively with baseline HIV-VL (P=0.001) and negatively with age (P=0.003). The frequency of CMV-Sp-CD4 increased at week 4 (P=0.008), then declined. Those with lower baseline CMV-Sp-CD4 (P=0.009) or CDC category C (P<0.001) had greater increases in CMV-Sp-CD4 at week 4. At week 96, CD4 T cell count was positively (P<0.001) and the frequency of CMV-Sp-CD4 was negatively (P=0.001) associated with the percentage of naïve CD4 T cells.

Conclusions

Increases in CMV-Sp-CD4 with ART occurred early and were greater in those with more advanced immunodeficiency. The frequency of CMV-Sp-CD4 was associated with reduced naïve CD4 T cells, a marker associated with immunosenescence.

The majority of HIV type 1 DNA in circulating CD4+ T lymphocytes is present in non-gut-homing resting memory CD4+ T cells

Memory CD4(+) T lymphocytes in peripheral blood that express integrins α4ß7 preferentially recirculate through gut-associated lymphoid tissue (GALT), a proposed site of significant HIV-1 replication. Tregs and activated CD4(+) T cells in GALT could also be particularly susceptible to infection. We therefore hypothesized that infection of these subsets of memory CD4(+) T cells may contribute disproportionately to the HIV-1 reservoir. A cross-sectional study of CD4(+) T cell subsets of memory CD45RO(+) cells in peripheral blood mononuclear cells (PBMCs) was conducted using leukapheresis from eight subjects with untreated chronic HIV-1 infection. Real-time polymerase chain reaction (PCR) was used to quantify total and integrated HIV-1 DNA levels from memory CD4(+) T cells sorted into integrin β7(+) vs. β7(-), CD25(+)CD127(low) Treg vs. CD127(high), and activated CD38(+) vs. CD38(-). More than 80% of total HIV-1 DNA was found to reside in the integrin β7-negative non-gut-homing subset of CD45RO(+) memory CD4(+) T cells. Less than 10% was found in highly purified Tregs or CD38(+) activated memory cells. Similarly, integrated HIV-1 DNA copies were found to be more abundant in resting non-gut-homing memory CD4(+) T cells (76%) than in their activated counterparts (23%). Our investigations showed that the majority of both total and integrated HIV-1 DNA was found within non-gut-homing resting CD4(+) T cells.

Bone mineral density in HIV participants randomized to raltegravir and lopinavir/ritonavir compared with standard second line therapy

OBJECTIVE

To compare changes over 48 weeks in bone mineral density (BMD) between participants randomized to lopinavir/ritonavir (LPV/r) + raltegravir (RAL) or LPV/r + 2-3 nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) as second line therapy.

DESIGN

48-week open-label sub-study of the Second Line trial conducted in South Africa, India, Thailand, Malaysia and Argentina.

METHODS

Dual energy X-ray absorptiometry scans of proximal femur and lumbar spine were performed at baseline and week 48. Linear regression was used to compare means of differences between arms. McNemars test compared osteopenia and osteoporosis. Associations between percentage BMD changes and baseline variables were assessed by multivariate linear regression.

RESULTS

Two hundred and ten participants were randomized. Analyses were adjusted for sex, BMI and smoking status. Mean (95% CI) proximal femur BMD% reduced over 48 weeks by -5.2% (-6.7 to -3.8%) in the LPV/r+2-3N(t)RTIs arm and by -2.9% (-4.3 to -1.5%) in the LPV/r+RAL arm (P = 0.0001). Lumbar spine BMD reduced by -4.2% (-5.7 to -2.7%) in the LPV/r+2-3N(t)RTIs arm and by -2.0% (-3.5 to -0.6%) in the LPV/r+RAL arm (P = 0.0006). The incidence of osteopenia (7.6%) and osteoporosis (2.0%) assessed over 48 weeks were similar between arms. Reduced BMD over 48 weeks was significantly associated with longer duration of tenofovir on study [% change (SE) -1.58 (0.38) femur, -1.65 (0.38) spine, P = 0.0001] and low baseline BMI [% change (SE) 0.5 (0.13) femur, 0.17 (0.07) spine; P < 0.01].

CONCLUSION

An N(t)RTI-sparing antiretroviral regimen of LPV/r and raltegravir as second line therapy is associated with less bone loss than a LPV/r regimen containing N(t)RTIs.

Anal cytological abnormalities are poor predictors of high-grade intraepithelial neoplasia amongst HIV-positive men who have sex with men

BACKGROUND

Although anal squamous cell carcinomas (ASCC) are rare in the general community, rates of ASCC among HIV-positive men who have sex with men (MSM) approach those of major cancers in the general community, such as colorectal and lung cancers. Anal cytology and high-resolution anoscopy (HRA) have been proposed as methods for the diagnosis of high-grade anal intraepithelial neoplasia (HGAIN), the precursor of ASCC. To determine the prevalence of anal disease among HIV-positive MSM, we investigated anal cytological and histological findings in men from a large HIV clinic in Sydney, Australia.

METHODS

This was a single-centre study conducted between October 2008 and January 2010. Participants self-collected cytology specimens, and those yielding abnormal cytology results of atypical cells of undetermined significance, atypical cells of undetermined significance - possibly high-grade (ASC-H) and high-grade squamous intraepithelial lesions (HSIL) were offered HRA. In addition, of those yielding low-grade squamous intraepithelial lesions results, a systematically selected group (25%) were offered HRA.

RESULTS

Of the 1339 HIV-positive MSM who attended the clinic during the study period, 291 (31.8%) were finally included in the study, 262 yielded technically satisfactory cytological results and 101 (36.7%) participants underwent HRA. HGAIN was identified in 55 (54.5%) of the 101 men undergoing HRA. HGAIN was diagnosed in 28 (52.7%) without cytological ASC-H or HSIL results.

CONCLUSIONS

Despite the poor correlation between anal cytological and histological findings, high levels of HGAIN were identified in HIV-positive MSM attending this clinical service.

Ritonavir-boosted lopinavir plus nucleoside or nucleotide reverse transcriptase inhibitors versus ritonavir-boosted lopinavir plus raltegravir for treatment of HIV-1 infection in adults with virological failure of a standard first-line ART regimen (SECOND-LINE): a randomised, open-label, non-inferiority study

BACKGROUND

Uncertainty exists about the best treatment for people with HIV-1 who have virological failure with first-line combination antiretroviral therapy of a non-nucleoside analogue (NNRTI) plus two nucleoside or nucleotide analogue reverse transcriptase inhibitors (NtRTI). We compared a second-line regimen combining two new classes of drug with a WHO-recommended regimen.

METHODS

We did this 96-week, phase 3b/4, randomised, open-label non-inferiority trial at 37 sites worldwide. Adults with HIV-1 who had confirmed virological failure (plasma viral load >500 copies per mL) after 24 weeks or more of first-line treatment were randomly assigned (1:1) to receive ritonavir-boosted lopinavir plus two or three NtRTIs (control group) or ritonavir-boosted lopinavir plus raltegravir (raltegravir group). The randomisation sequence was computer generated with block randomisation (block size four). Neither participants nor investigators were masked to allocation. The primary endpoint was the proportion of participants with plasma viral load less than 200 copies per mL at 48 weeks in the modified intention-to-treat population, with a non-inferiority margin of 12%. This study is registered with ClinicalTrials.gov, number NCT00931463.

FINDINGS

We enrolled 558 patients, of whom 541 (271 in the control group, 270 in the raltegravir group) were included in the primary analysis. At 48 weeks, 219 (81%) patients in the control group compared with 223 (83%) in the raltegravir group met the primary endpoint (difference 1·8%, 95% CI -4·7 to 8·3), fulfilling the criterion for non-inferiority. 993 adverse events occurred in 271 participants in the control group versus 895 in 270 participants in the raltegravir group, the most common being gastrointestinal.

INTERPRETATION

The raltegravir regimen was no less efficacious than the standard of care and was safe and well tolerated. This simple NtRTI-free treatment strategy might extend the successful public health approach to management of HIV by providing simple, easy to administer, effective, safe, and tolerable second-line combination antiretroviral therapy.

FUNDING

University of New South Wales, Merck, AbbVie, the Foundation for AIDS Research.

The 2010 Royal Australasian College of Physicians' policy statement 'Circumcision of infant males' is not evidence based

Infant male circumcision (MC) is an important issue guided by Royal Australasian College of Physicians (RACP) policy. Here we analytically review the RACP's 2010 policy statement 'Circumcision of infant males'. Comprehensive evaluation in the context of published research was used. We find that the Statement is not a fair and balanced representation of the literature on MC. It ignores, downplays, obfuscates or misrepresents the considerable evidence attesting to the strong protection MC affords against childhood urinary tract infections, sexually transmitted infections (human immunodeficiency virus, human papilloma virus, herpes simplex virus type 2, trichomonas and genital ulcer disease), thrush, inferior penile hygiene, phimosis, balanoposthitis and penile cancer, and in women protection against human papilloma virus, herpes simplex virus type 2, bacterial vaginosis and cervical cancer. The Statement exaggerates the complication rate. Assertions that 'the foreskin has a functional role' and 'is a primary sensory part of the penis' are not supported by research, including randomised controlled trials. Instead of citing these and meta-analyses, the Statement selectively cites poor quality studies. Its claim, without support from a literature-based risk-benefit analysis, that the currently available evidence does 'not warrant routine infant circumcision in Australia and New Zealand' is misleading. The Statement fails to explain that performing MC in the neonatal period using local anaesthesia maximises benefits, safety, convenience and cost savings. Because the RACP's policy statement is not a fair and balanced representation of the current literature, it should not be used to guide policy. In the interests of public health and individual well-being, an extensive, comprehensive, balanced review of the scientific literature and a risk-benefit analysis should be conducted to formulate policy.

Efficacy and safety of raltegravir for treatment of HIV for 5 years in the BENCHMRK studies: final results of two randomised, placebo-controlled trials

BACKGROUND

Two randomised, placebo-controlled trials-BENCHMRK-1 and BENCHMRK-2-investigated the efficacy and safety of raltegravir, an HIV-1 integrase strand-transfer inhibitor. We report final results of BENCHMRK-1 and BENCHMRK-2 combined at 3 years (the end of the double-blind phase) and 5 years (the end of the study).

METHODS

Integrase-inhibitor-naive patients with HIV resistant to three classes of drug and who were failing antiretroviral therapy were enrolled. Patients were randomly assigned (2:1) to raltegravir 400 mg twice daily or placebo, both with optimised background treatment. Patients and investigators were masked to treatment allocation until week 156, after which all patients were offered open-label raltegravir until week 240. The primary endpoint was previously assessed at 16 weeks. We assessed long-term efficacy with endpoints of the proportion of patients with an HIV viral load of less than 50 copies per mL and less than 400 copies per mL, and mean change in CD4 cell count, at weeks 156 and 240.

FINDINGS

1012 patients were screened for inclusion. 462 were treated with raltegravir and 237 with placebo. At week 156, 51% in the raltegravir group versus 22% in the placebo group (non-completer classed as failure) had viral loads of less than 50 copies per mL, and 54% versus 23% had viral loads of less than 400 copies per mL. Mean CD4 cell count increase (analysed by an observed failure approach) was 164 cells per μL versus 63 cells per μL. After week 156, 251 patients (54%) from the raltegravir group and 47 (20%) from the placebo group entered the open-label raltergravir phase; 221 (47%) versus 44 (19%) completed the entire study. At week 240, viral load was less than 50 copies per mL in 193 (42%) of all patients initially assigned to raltegravir and less than 400 copies per mL in 210 (45%); mean CD4 cell count increased by 183 cells per μL. Virological failure occurred in 166 raltegravir recipients (36%) during the double-blind phase and in 17 of all patients (6%) during the open-label phase. The most common drug-related adverse events at 5 years in both groups were nausea, headache, and diarrhoea, and occurred in similar proportions in each group. Laboratory test results were similar in both treatment groups and showed little change after year 2.

INTERPRETATION

Raltegravir has a favourable long-term efficacy and safety profile in integrase-inhibitor-naive patients with triple-class resistant HIV in whom antiretroviral therapy is failing. Raltegravir is an alternative for treatment-experienced patients, particularly those with few treatment options.

FUNDING

Merck Sharp & Dohme.

Explaining the determinants of first phase HIV decay dynamics through the effects of stage-dependent drug action

A recent investigation of the effect of different antiretroviral drug classes on first phase dynamics of HIV RNA plasma virus levels has indicated that drugs acting at stages closer to viral production, such as the integrase inhibitor raltegravir, can produce a steeper first phase decay slope that may not be due to drug efficacy. Moreover it was found that for most drug classes the first phase transitions from a faster (phase IA) to a slightly slower decay region (phase IB) before the start of the usual second phase. Neither of these effects has been explained to date. We use a mathematical model that incorporates the different stages of the HIV viral life cycle in CD4+ T cells: viral entry, reverse transcription, integration, and viral production, to investigate the intracellular HIV mechanisms responsible for these complex plasma virus decay dynamics. We find differences in the phase IA slope across drug classes arise from a higher death rate of cells when they enter the productively infected stage post-integration, with a half-life of approximately 8 hours in this stage, whereas cells in earlier stages of the infection cycle have half-lives similar to uninfected cells. This implies any immune clearance is predominantly limited to the productive infection stage. We also show that the slowing of phase IA to phase IB at day 2 to 4 of monotherapy, depending on drug class, is a result of new rounds of infection. The level at which this slowing occurs is a better indicator of drug efficacy than the slope of the initial decay.

The infection of a cell by HIV proceeds through a series of stages and each stage can now be inhibited by an available antiretroviral drug class. It is known that different drug classes can result in different decay curves of plasma viral levels that are not well explained by current mathematical models of HIV dynamics. Here we develop a mathematical model that incorporates these stages of infection and show how it successfully reproduces plasma decay curves for the five classes of currently available antiretroviral drugs. Our modeling indicates that the efficacy of antiretroviral drugs is not solely described by the rate of decay of plasma viral levels as currently thought. Drugs such as the integrase inhibitor raltegravir will result in a faster initial decline of plasma viral levels compared to a drug that acts further from viral integration and production such as the CCR5 inhibitor maraviroc, even though they may have the same efficacy. Moreover, we find that infected cells only die at rates above the background level when they are in the productive phase, indicating that immune clearance is mostly absent from the early stages of HIV cellular infection. This is of particular concern given that most infected cells are in these early stages of infection.

Specific antibody-dependent cellular cytotoxicity responses associated with slow progression of HIV infection

Antibody-dependent cellular cytotoxicity (ADCC) is potentially an effective adaptive immune response to HIV infection. However, little is understood about the role of ADCC in controlling chronic infection in the small number of long-term slow-progressors (LTSP) who maintain a relatively normal immunological state for prolonged periods of time. We analysed HIV-specific ADCC responses in sera from 139 HIV(+) subjects not on antiretroviral therapy. Sixty-five subjects were LTSP, who maintained a CD4 T-cell count > 500/μl for over 8 years after infection without antiretroviral therapy and 74 were non-LTSP individuals. The ADCC responses were measured using an natural killer cell activation assay to overlapping HIV peptides that allowed us to map ADCC epitopes. We found that although the magnitude of ADCC responses in the LTSP cohort were not higher and did not correlate with CD4 T-cell depletion rates, the LTSP cohort had significantly broader ADCC responses compared with the non-LTSP cohort. Specifically, regulatory/accessory HIV-1 proteins were targeted more frequently by LTSP. Indeed, three particular ADCC epitopes within the Vpu protein of HIV were recognized only by LTSP individuals. Our study provides evidence that broader ADCC responses may play a role in long-term control of HIV progression and suggests novel vaccine targets.

Efficacy and safety of lersivirine (UK-453,061) versus efavirenz in antiretroviral treatment-naive HIV-1-infected patients: week 48 primary analysis results from an ongoing, multicenter, randomized, double-blind, phase IIb trial

OBJECTIVE

A 96-week clinical study was planned to estimate the antiviral activity and safety of lersivirine in treatment-naive HIV-1-infected patients.

METHODS

This ongoing international, multicenter, double-blind, randomized, Phase IIb exploratory study evaluates the efficacy and safety of 2 doses of lersivirine or 1 of efavirenz, each combined with tenofovir disoproxil fumarate/emtricitabine. Patients were randomized 1:1:1 to receive lersivirine (500 or 750 mg once daily) or efavirenz (600 mg once daily), each administered with tenofovir disoproxil fumarate/emtricitabine (300 mg/200 mg, once daily). The primary endpoint is the proportion of patients with HIV-1 RNA <50 copies per milliliter (missing/discontinuation = failure) at week 48.

RESULTS

For the 193 patients in the study, baseline mean plasma HIV-1 RNA was 4.7 log10 copies per milliliter, and median CD4 cell count was 312 cells per cubic millimeter. At week 48, the percentage of patients with HIV-1 RNA <50 copies per milliliter was 78.5% (51/65), 78.5% (51/65), and 85.7% (54/63) in the lersivirine 500 mg, 750 mg, and efavirenz groups, respectively. CD4 cell count changes from baseline were similar across groups. Virologic failure occurred in 7 patients (11%) in each of the lersivirine groups and 3 patients (5%) in the efavirenz group. The pattern of lersivirine resistance was distinct from other nonnucleoside reverse transcriptase inhibitors. Overall incidences of all-causality treatment-related or grade 3/4 adverse events (AEs) or AE-related discontinuations were lower with lersivirine than with efavirenz, and serious AEs occurred at similar rates across treatment groups.

CONCLUSIONS

Both lersivirine doses showed broadly comparable efficacy to efavirenz over 48 weeks in treatment-naive patients, with different AE profiles from efavirenz.

The search for an HIV cure: tackling latent infection

Strategies to eliminate infectious HIV that persists despite present treatments and with the potential to cure HIV infection are of great interest. One patient seems to have been cured of HIV infection after receiving a bone marrow transplant with cells resistant to the virus, although this strategy is not viable for large numbers of infected people. Several clinical trials are underway in which drugs are being used to activate cells that harbour latent HIV. In a recent study, investigators showed that activation of latent HIV infection in patients on antiretroviral therapy could be achieved with a single dose of vorinostat, a licensed anticancer drug that inhibits histone deacetylase. Although far from a cure, such studies provide some guidance towards the logical next steps for research. Clinical studies that use a longer duration of drug dosing, alternative agents, combination approaches, gene therapy, and immune-modulation approaches are all underway.

The potential cost and benefits of raltegravir in simplified second-line therapy among HIV infected patients in Nigeria and South Africa

BACKGROUND

There is an urgent need to improve the evidence base for provision of second-line antiretroviral therapy (ART) following first-line virological failure. This is particularly the case in Sub-Saharan Africa where 70% of all people living with HIV/AIDS (PHA) reside. The aim of this study was to simulate the potential risks and benefits of treatment simplification in second-line therapy compared to the current standard of care (SOC) in a lower-middle income and an upper-middle income country in Sub-Saharan Africa.

METHODS

We developed a microsimulation model to compare outcomes associated with reducing treatment discontinuations between current SOC for second-line therapy in South Africa and Nigeria and an alternative regimen: ritonavir-boosted lopinavir (LPV/r) combined with raltegravir (RAL). We used published studies and collaborating sites to estimate efficacy, adverse effect and cost. Model outcomes were reported as incremental cost effectiveness ratios (ICERs) in 2011 USD per quality adjusted life year ($/QALY) gained.

RESULTS

Reducing treatment discontinuations with LPV/r+RAL resulted in an additional 0.4 discounted QALYs and increased the undiscounted life expectancy by 0.8 years per person compared to the current SOC. The average incremental cost was $6,525 per treated patient in Nigeria and $4,409 per treated patient in South Africa. The cost-effectiveness ratios were $16,302/QALY gained and $11,085/QALY gained for Nigeria and South Africa, respectively. Our results were sensitive to the probability of ART discontinuation and the unit cost for RAL.

CONCLUSIONS

The combination of raltegravir and ritonavir-boosted lopinavir was projected to be cost-effective in South Africa. However, at its current price, it is unlikely to be cost-effective in Nigeria.

Inhibition of telomerase activity by human immunodeficiency virus (HIV) nucleos(t)ide reverse transcriptase inhibitors: a potential factor contributing to HIV-associated accelerated aging

BACKGROUND

Human immunodeficiency virus (HIV)-infected patients on combination active antiretroviral therapy (cART) are at increased risk of age-related complications. We hypothesized that nucleos(t)ide reverse transcriptase inhibitors (NRTI) may contribute to accelerated aging in HIV-infected individuals on cART via inhibition of telomerase activity.

METHODS

Telomerase activity and telomere length (TL) were measured by quantitative polymerase chain reaction in vitro in activated peripheral blood mononuclear cells (PBMCs) cultured with NRTI and ex vivo in PBMCs from uninfected patients exposed to NRTI and from HIV-infected patients on NRTI-containing cART.

RESULTS

Lamivudine, abacavir, zidovudine, emtricitabine, and tenofovir significantly inhibited telomerase activity in activated PBMCs in vitro. Tenofovir was the most potent inhibitor of telomerase activity and caused greatest shortening of TL in vitro at the therapeutic concentration of 0.3 μM. PBMCs from HIV-infected patients receiving NRTI-containing cART (n = 39) had significantly lower telomerase activity than HIV-uninfected patients (n = 47; P = .011) and HIV-infected patients receiving non-NRTI-containing cART (n = 11; P < .001). TL was significantly inversely associated with age (P = .009) and the total duration on any NRTI (P = .01).

CONCLUSIONS

NRTIs and, specifically tenofovir at therapeutic concentrations, inhibit telomerase activity leading to accelerated shortening of TL in activated PBMCs. The relationship between NRTI, reduced telomerase activity, and accelerated aging requires further investigation in HIV-infected individuals on cART.

Prevalence of anemia and underlying iron status in naive antiretroviral therapy HIV-infected children with moderate immune suppression

Anemia is common in HIV-infected children and iron deficiency is thought to be a common cause. This study investigates the prevalence of anemia, thalassemia, and underlying iron status in Thai and Cambodian children without advanced HIV disease to determine the necessity of routine iron supplementation. Antiretroviral (ARV)-naive HIV-infected Asian children aged 1-12 years, with CD4 15-24%, CDC A or B, and hemoglobin (Hb) ≥7.5 g/dl were eligible for the study. Iron studies, serum ferritin, Hb typing, and C-reactive protein were assessed. Anemia was defined as Hb <11.0 g/dl in children <5 years of age or <11.5 g/dl in children 5-12 years. We enrolled 299 children; 57.9% were female and the mean (SD) age was 6.3 (2.9) years. The mean (SD) CD4% and HIV-RNA were 20% (4.6) and 4.6 (0.6) log(10) copies/ml, respectively. The mean (SD) Hb and serum ferritin were 11.2 (1.1) g/dl and 78.3 (76.4) μg/liter, respectively. The overall iron deficiency anemia (IDA) prevalence was 2.7%. One hundred and forty-eight (50%) children had anemia, mostly of a mild degree. Of these, 69 (46.6%) had the thalassemia trait, 62 (41.8%) had anemia of chronic disease (ACD), 9 (6.1%) had thalassemia diseases, 3 (2.0%) had iron deficiency anemia, and 5 (3.4%) had IDA and the thalassemia trait. The thalassemia trait was not associated with increased serum ferritin levels. Mild anemia is common in ARV-naïve Thai and Cambodian children without advanced HIV. However, IDA prevalence is low; with the majority of cases caused by ACD. A routine prescription of iron supplement in anemic HIV-infected children without laboratory confirmation of IDA should be discouraged, especially in regions with a high prevalence of thalassemia and low prevalence of IDA.

Optimisation of HIV care and service delivery: doing more with less

The unprecedented, successful collaborative international effort to provide universal access to HIV care, including effective antiretroviral therapy, has reached a crucial point. Global economic downturn, changing donor priorities, and competing priorities in the health sector threaten the target of provision of 15 million people with HIV/AIDS with treatment by 2015, as agreed by the UN General Assembly. This aspiration has received added impetus from the finding that treatment prevents transmission by reduction of infectiousness of patients. In this report we critically review success thus far and examine efforts to optimise delivery of HIV care including antiretroviral therapy in low-income and middle-income countries for four main domains: treatment strategy, drug dosing, monitoring, and service delivery.

Changes in metabolic, inflammatory and coagulation biomarkers after HIV seroconversion--the Health in Men (HIM) Biomarker Substudy

BACKGROUND

Biomarkers of inflammation, coagulation, lipids and vitamin D have been associated with cardiovascular and mortality risk in HIV-infected individuals. Scarce data exist on changes in these markers from pre- to post-HIV seroconversion.

METHODS

The study participants were drawn from the Health in Men Study, which recruited HIV-negative homosexual men. Participants with incident HIV infection (n=26) were compared with HIV-negative controls (n=52) matched on age at enrolment, date of visit and reported intravenous drug use. Levels of metabolic (lipids and vitamin D), inflammatory (C-reactive protein and interleukin-6) and coagulation (D-dimer and fibrinogen) biomarkers were measured at pre- and post-HIV seroconversion visits and corresponding visits for controls. Random-effect models were used to compare changes in markers between cases and controls.

RESULTS

The median gap between pre- and post-seroconversion or matched first and second visits in controls was 12 months. HIV seroconversion was associated with decline in high density lipoprotein (HDL-C; difference in mean change between cases and controls -0.14 mmol/l; 95% CI -0.22, -0.01; P=0.035). There were no significant differences in changes in other lipids, markers of inflammation, coagulation or vitamin D.

CONCLUSIONS

Decline in HDL-C seems to be the main proatherogenic change within 1-1.5 years after HIV seroconversion. HIV seroconversion was not associated with profound changes in other lipids, or markers of inflammation, coagulation and vitamin D. Longitudinal assessment of these markers in comparable population needs further assessment.

Early versus deferred antiretroviral therapy for children older than 1 year infected with HIV (PREDICT): a multicentre, randomised, open-label trial

BACKGROUND

The optimum time to start antiretroviral therapy for children diagnosed with HIV infection after 1 year of age is unknown. We assessed whether antiretroviral therapy could be deferred until CD4 percentages declined to less than 15% without affecting AIDS-free survival.

METHODS

In our multicentre, randomised, open-label trial at nine research sites in Thailand and Cambodia, we enrolled children aged 1-12 years who were infected with HIV and had CD4 percentages of 15-24%. Participants were randomly assigned (1:1) by a minimisation scheme to start antiretroviral therapy at study entry (early treatment group) or antiretroviral therapy to start when CD4 percentages declined to less than 15% (deferred treatment group). The primary endpoint was AIDS-free survival (based on US Centers for Disease Control and Prevention category C events) at week 144, assessed with the Kaplan-Meier analysis and the log-rank approach. This study is registered with ClinicalTrials.gov, number NCT00234091.

FINDINGS

Between March 28, 2006, and Sept 10, 2008, we enrolled 300 Thai and Cambodian children infected with HIV, with a median age of 6·4 years (IQR 3·9-8·4). 150 children were randomly allocated early antiretroviral therapy (one participant was excluded from analyses after withdrawing before week 0) and 150 children were randomly allocated deferred antiretroviral therapy. Median baseline CD4 percentage was 19% (16-22%). 69 children (46%) in the deferred treatment group started antiretroviral therapy during the study. AIDS-free survival at week 144 in the deferred treatment group was 98·7% (95% CI 94·7-99·7; 148 of 150 patients) compared with 97·9% (93·7-99·3; 146 of 149 patients) in the early treatment group (p=0·6).

INTERPRETATION

AIDS-free survival in both treatment groups was high. This low event rate meant that our study was underpowered to detect differences between treatment start times and thus additional follow-up of study participants or future studies are needed to answer this clinical question.

Assessing adherence in Thai patients taking combination antiretroviral therapy

In settings where medications and viral load (VL) monitoring are limited by cost, clinicians need reliable ways to assess patient adherence to therapy. We assessed sensitivity and specificity of two self-reported adherence tools (a visual analogue scale [VAS] and the CASE [Center for Adherence Support Evaluation] adherence index), against a standard of detectable VL, with 288 patients from three sites in Thailand. We also assessed predictors of non-adherence. The sensitivity and specificity of the VAS <95% and CASE adherence index ≤11 against a VL >50 copies/mL were 26% and 90%, 19% and 95%, respectively. Against a VL ≥1000 copies/mL sensitivities increased to 55% and 36%, respectively, and specificities were unchanged. Attending a clinic not staffed by HIV specialists (odds ratio [OR] 3.14; 95% confidence interval [CI] 1.19-8.34) and being educated to primary school level or less (OR 2.24; 95% CI 1.01-4.94) were associated with self-reported adherence <95% on the VAS in multivariate analysis. Adherence assessed by the VAS was a more accurate predictor of detectable VL. Policy-makers in resource-limited settings should ensure that treatment centres are staffed with well-trained personnel aware of the importance of good patient adherence.