Current HIV Research - Volume 12, Issue 5, 2014

Introduction: There are more than 500 000 HIV-infected people on antiretroviral treatment (ART) in Zimbabwe with very limited laboratory monitoring. To ensure effective treatment and prevent transmission of drug resistance, affordable treatment monitoring is needed to guide individual treatment. Methods: 125 whole blood samples from patients on first-line ART were investigated for drug resistance mutations using an in-house genotypic testing method. Patients had been on HIV reverse transcriptase inhibitors only, with some having been on both HIV and TB treatment. DNA was extracted from whole blood; amplicons were generated by nested PCR and sequenced. Drug resistance mutations were determined using the Stanford HIV drug resistance database. Exact statistics were used to investigate relationships between drug resistance and predisposing factors. Results: From 125 samples, 108 were successfully analyzed for drug resistance mutations. 11 of the 108 sequences had drug resistance mutations; predominantly M184V and Y181C. For a 100-cell increase in CD4 count, the odds of being resistant were 61% lower than those with the baseline CD4 count (p=0.04, CI: 0.34-0.98). There was no association between concurrent HIV/TB treatment and drug resistance (p=0.41). Discussion and Conclusion: Although plasma samples are recommended for genotypic testing, the cost of analyzing plasma RNA makes it less feasible in resource limited settings. Lower cost DNA drug resistance testing from whole blood samples was assessed as a treatment-monitoring tool among patients followed by CD4 and clinical monitoring only. The infrequent detection of resistance and higher CD4 is consistent with effective first-line treatment. Further investigation of proviral DNA as a tool to identify drug resistance mutations is warranted.

Peripheral blood monocytes of HIV-infected individuals carry virus, constituting one potential reservoir. However, most studies of infection in tissue culture find monocytes refractory to HIV replication, suggesting that culture conditions limit the relative susceptibility of this target cell. We employed a tissue culture system optimized for maintenance of human monocytes without differentiation and compared HIV infection efficiency of monocytes and fully differentiated monocyte derived macrophages (MDM). We tested direct virus-cell fusion, expression of cell lineage markers, and productive HIV infection in fresh monocytes, monocytes after varying periods of supportive culture, and fully differentiated MDM comparing cells from individual donors. Fresh, uncultured monocytes allowed modest HIV fusion, however one week culture was sufficient to allow efficient fusion and an increase in expression of CD14, CD16, CD33, and CD105. Compared to freshly isolated monocytes, monocytes infected after a few days in culture produced p24 more quickly, but the peaks of production were similar. Fresh monocytes were highly susceptible to productive HIV infection in supportive culture, roughly equal to MDM from the same donor in expression of extracellular p24 up to five weeks after infection. Taken together our findings indicate that monocytes are biologically capable of supporting chronic, highly productive HIV infection, a capacity that may reflect their status in HIV-infected persons.

Out of the 15 discrete proteins encoding the total amount of genetic information in the chromosomes of human immunodeficiency virus type 1; three perform the vital enzymatic functions i.e. a reverse transcription, an integration, and proteolysis. The HIV integrase is the new validated drug target against AIDS amongst all essential enzymes due to the lack of the human homologue. In last few years quite, a few but potent inhibitors inhibiting HIV-1 integrase have been recognized and hence have gained a state-of-the-art for treating the infection caused by HIV-1. The greater understanding of HIV-integrase biological structure has further lead to continuous efforts for the proposal of novel inhibitors targeting diverse steps in the progression of integration with the primary goal to overcome resistance due to the rapid occurrence of integrase mutations in the treated patients. This review is focused on various aspects of the recently approved HIVintegrase inhibitor “dolutegravir”, its efficacy, safety profiles with the clinical data and molecular modeling studies highlighting its importance over the already approved HIV-integrase inhibitors.

Purpose: Switch to unboosted atazanavir (ATV) is an attractive option due to convenience and tolerability in HIV-positive patients. With limited available data we investigated the determinants of long-term efficacy and the consequences of virological failure of unboosted atazanavir-based regimens. Methods: Retrospective analysis in two Italian large outpatient clinics including demographic, immunovirological, resistance and pharmacokinetic data. Results: 249 patients receiving atazanavir (400 mg once-daily) plus 2 NRTIs were included; 163 were males (65.5%) and median age was 47 years (42-51.5). Median CD4+ T-cell count was 396/uL (261-583); 146 (58.6%) presented a viral load <50 copies/mL. Over a median follow up of 157 weeks (106-203) 193 patients (77.5%) were still on treatment with 10 (4%) and 2 (0.8%) stopping for virological failure or toxicity, respectively. Ten patients with virological failure presented newly selected resistance associated mutations (RAMs) for NRTIs (2/10) or ATV (4/10, one I50L). Total cholesterol and triglycerides showed significant decreases at 48 [-4 mg/dL and -41 mg/dL] and 96 weeks [-14 mg/dL and -54 mg/dL] as compared to baseline. At multivariate analysis a genotypic sensitivity score ≤1, atazanavir RAMs >1 and suboptimal adherence were independently associated with virological failure; in lamivudine/emtricitabine-treated patients the presence of M184V (without other NRTI RAMs) was not associated with virological failure. Conclusion: Unboosted-atazanavir containing regimens were efficacious (with uncommon virological failures) and welltolerated (with improvements in lipid profile over time) treatments in HIV-positive patients. Isolated M184V in lamivudine/emtricitabine recipients was not associated with higher failure rates supporting the use of functional ATVbased dual therapies as maintenance strategies.

The 2´3´-dialdehyde of ATP or oxidized ATP (oATP) is a compound known for specifically making covalent bonds with the nucleotide-binding site of several ATP-binding enzymes and receptors. We investigated the effects of oATP and other oxidized purines on HIV-1 infection and we found that this compound inhibits HIV-1 and SIV infection by blocking early steps of virus replication. oATP, oxidized ADP (oADP), and oxidized Adenosine (oADO) impact the natural activity of endogenous reverse transcriptase enzyme (RT) in cell free virus particles and are able to inhibit viral replication in different cell types when added to the cell cultures either before or after infection. We used UFLC-UV to show that both oADO and oATP can be detected in the cell after being added in the extracellular medium. oATP also suppresses RT activity and replication of the HIV-1 resistant variants M184V and T215Y. We conclude that oATP, oADP and oADO display anti HIV-1 activity that is at in least in part due to inhibitory activity on HIV-1 RT.

Objectives: This study aims to evaluate the effect of co-trimoxazole (CTX) prophylaxis on mortality reduction among HIV-infected patients receiving antiretroviral therapy (ART) in Henan Province, China. Design: We conducted a retrospective study. Methods: All individuals aged 15 years and older who initiated ART between 2008 and 2010 in Henan Province with completed CTX prophylaxis treatment information were included. The effect of CTX prophylaxis was estimated using Kaplan-Meier survival analysis and multivariate Cox proportional hazard modeling for mortality at 3-months and 12- months after ART initiation. Results: Overall mortality among patients receiving both ART and CTX was nearly double at 3-months after ART initiation compared with that at 12-months (12.4 per 100 PY vs 6.3 per 100 PY, p<0.01). After adjusting for gender, age, TB history, year of ART initiation and CD4 count at ART initiation, CTX was associated with a significant reduction in 12-month mortality (adjusted hazard ratio (AHR) = 0.65, 95% confidence interval (CI): 0.44 – 0.95; p = 0.027) compared with persons not receiving CTX. The protective effect was more pronounced in the first 3 months after ART initiation (AHR = 0.53, 95% CI: 0.32 – 0.89; p = 0.017). Conclusion: CTX prophylaxis together with ART reduced mortality of adult HIV patients during the first 12 months of ART in Henan Province, China. The effect was highest in the first 3 months of ART. CTX should be prescribed to all HIV-infected adults who initiate ART.

Background: Suboptimal adherence to antiretroviral therapy (ART) is a strong predictor of virologic failure (VF) among people with HIV. Various methods such as patient self-report, pill counts and pharmacy refills have been utilized to monitor adherence. However, there are limited data on the accuracy of combining methods to better predict VF in routine clinical settings. We examined various methods to assess adherence including pill count, medication possession ratio (MPR), and self-reported adherence in order to determine which was most highly associated with VF after > 6 months on ART. Methods: We conducted a secondary analysis of data from a case-control study. At enrollment, pharmacy refill data were collected retrospectively from the medical chart, pill counts were completed to derive a pill count adherence ratio (PCAR) and a self-report questionnaire was administered to all participants. Parametric smooth splines and receiver operator characteristic (ROC) analyses were carried out to assess the accuracy of the adherence methods. Results: 458 patients were enrolled from October 2010 to June 2012. Of these, 158 (34.50%) experienced VF (cases) and 300 (65.50%) were controls. The median (IQR) PCAR was 1.10 (0.99-1.14) for cases and 1.13 (1.08-1.18) for controls (p<0.0001). The median MPR was 1.00 (0.97-1.07) for cases and 1.03 (0.96-1.07) for controls (p=0.83). Combination of PCAR and self-reported questions was highly associated with VF. Conclusion: In this setting, a combination of pill count adherence and self-report adherence questions had the highest diagnostic accuracy for VF. Further validation of this simple, low-cost combination is warranted in large prospective studies.