Undetectable Plasma Viral Load Research Articles

Early Initiation Rather Than Prolonged Duration of Antiretroviral Therapy in HIV Infection Contributes to the Normalization of CD8 T-Cell Counts.

CD8 T-cell counts remain elevated in human immunodeficiency virus (HIV) infection even after long-term antiretroviral therapy (ART), which is associated with an increased risk of non-AIDS-related events. We assessed the impact of ART initiation in early versus chronic HIV infection on trajectories of CD8 cell counts over time. Of 280 individuals enrolled during primary HIV infection (PHI), 251 were followed up for 24 months; 84 started ART before 6 months of infection (eART), 49 started between 6 and 24 months, and 118 remained untreated. Plasma HIV viral load (VL), CD4 and CD8 cell counts were assessed at each study visit. CD8 counts were also examined in 182 age-matched HIV-infected individuals who started ART during chronic infection and maintained undetectable plasma VL for ≥5 years. At PHI baseline, higher CD8 cell counts were associated with more recent infection (P = .02), higher CD4 cell counts (P < .001), and higher VL (P < .001). The CD8 count in the eART group decreased from 797 to 588 cells/µL over 24 months (P < .001), to a level lower than that in untreated PHI (834 cells/µL; P = .004) or in long-term-treated patients with chronic HIV infection (743 cells/µL; P = .047). More prominent CD4 T-cell recovery was observed in the eART group than in the delayed ART group. ART initiated in early HIV infection is associated with improved resolution of CD8 T-cell elevation compared with long-term ART initiated in chronic infection. Early ART may help reduce the risk of non-AIDS-related events by alleviating this elevation.

Early Initiation of Antiretroviral Therapy Can Functionally Control Productive HIV-1 Infection in Humanized-BLT Mice.

Recent reports showed that functional control of HIV-1 infection for a prolonged time is possible by early antiretroviral therapy (ART); however, its underlying mechanism needs to be studied with a suitable animal model. Recently, humanized-BLT (bone marrow, liver, and thymus) mouse (hu-BLT) was shown to be an excellent model for studying HIV-1 infection. We thus tested the feasibility of studying functional control of HIV-1 infection using hu-BLT mice. Animals in 3 treatment groups (Rx-6h, Rx-24h, and Rx-48h) and untreated group were infected with HIV-1, followed by ART initiation at 6, 24, or 48 hours postinfection and continued daily for 2 weeks. Three weeks after stopping ART, CD8 T cells were depleted from all animals. Plasma viral load was monitored weekly using droplet digital polymerase chain reaction. Percentage of CD4 and CD8 T cells were measured by flow cytometry. In situ hybridization and droplet digital polymerase chain reaction were used to detect viral RNA (vRNA) and DNA. Although control animals had high viremia throughout the study, all Rx-6h animals had undetectable plasma viral load after ART cessation. After CD8 T-cell depletion, viremia increased and CD4 T cells decreased in all animals except the Rx-6h group. Viral DNA was detected in spleens of all animals and a few vRNA cells were detected by in situ hybridization in 1 of 3 Rx-6h animals. Early ART did not act as prophylaxes but, rather, can control HIV-1 productive infection and prevented CD4 T-cell depletion in hu-BLT mice. This mouse model can be used to elucidate the mechanism for functional control of HIV-1.

Cell-Associated HIV-1 DNA and RNA Decay Dynamics During Early Combination Antiretroviral Therapy in HIV-1-Infected Infants.

The decay of human immunodeficiency virus type 1 (HIV-1)-infected cells during early combination antiretroviral therapy (cART) in infected infants is not defined. HIV-1 DNA, including 2-long terminal repeat (2-LTR) circles, and multiply spliced (ms-) and unspliced (us-) HIV-1 RNA concentrations were measured at 0, 24, 48, and 96 weeks of cART in infants from the IMPAACT P1030 trial receiving lopinavir-ritonavir-based cART. The ratio of HIV-1 DNA concentrations to replication-competent genomes was also estimated. Linear mixed effects models with random intercept and linear splines were used to estimate patient-specific decay kinetics of HIV-1 DNA. The median HIV-1 DNA concentration before cART at a median age of 2 months was 3.2 log10 copies per million PBMC. With cART, the average estimated patient-specific change in HIV-1 DNA concentrations was -0.040 log10/week (95% confidence interval [CI], -.05, -.03) between 0 and 24 weeks and -0.017 log10/week between 24 and 48 weeks (95% CI, -.024, -.01). 2-LTR circles decreased with cART but remained detectable through 96 weeks. Pre-cART HIV-1 DNA concentration was correlated with time to undetectable plasma viral load and post-cART HIV-1 DNA at 96 weeks; although HIV-1 DNA concentrations exceeded replication-competent HIV-1 genomes by 148-fold. Almost all infants had ms- and usRNA detected pre-cART, with 75% having usRNA through 96 weeks of cART. By 2 months of age, a large pool of HIV-1-infected cells is established in perinatal infection, which influences time to undetectable viral load and reservoir size. This has implications for informing novel approaches aimed at early restriction of HIV-1 reservoirs to enable virologic remission and cure.

8th IAS Conference on HIV Pathogenesis, Treatment & Prevention 19–22 July 2015, Vancouver, Canada

IntroductionSensitive assays are needed for detection of residual HIV in patients with undetectable plasma viral loads to determine if eradication strategies are effective. The gold standard quantitative viral outgrowth assay (QVOA) underestimates the magnitude of the viral reservoir, while sensitive PCR-based assays lack the ability to distinguish replication competent from defective virus. We sought to determine whether xenograft of leukocytes from HIV-1 infected patients with undetectable plasma viral loads into severely immunocompromised mice would result in viral amplification and measurable viral loads within the aberrant murine host.MethodsWe evaluated whether xenograft of 1) peripheral blood mononuclear cells (PBMCs) from five HIV-1+ patients on suppressive antiretroviral therapy (ART), 2) PBMCs or purified resting CD4+ T cells from 5 HIV-1+ elite suppressors (ES), or 3) PBMCs from a Simian Immunodeficiency Virus (SIV)+ pigtailed macaque on suppressive ART, all with undetectable plasma viral loads, into NOD. Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice resulted in viral amplification in the mouse. Successful xenograft of mice was confirmed by flow cytometry. Human CD8+ T cells were depleted in humanized mice with depleting antibody, and CD4+ T cells were activated in a subset of mice with activating anti-CD3. Plasma viral loads in xenografted mice were quantified using qRT-PCR, and compared to plasma viral load and QVOA results from the human or macaque donor.ResultsWith this murine viral outgrowth assay (MVOA), we amplified HIV-1 from all 10 HIV+ subjects with undetectable plasma viral load, including an ES from whom we were unable to recover virus by QVOA. We detected HIV in mice an average of 20 days after xenograft with PBMCs from patients on suppressive ART, and an average of 28 days after xenograft with PBMCs or resting CD4+ T cells from ES. For two of the mice xenografted with CD4+ T cells from ES, we detected HIV only after activation with anti-CD3. We similarly detected SIV in macaquized mice by seven days post-xenograft.ConclusionsThe MVOA has the potential to serve as a powerful tool to identify residual HIV-1 in patients with undetectable viral loads, such as those who have undergone promising cure therapies.

Elevated rates of mild cognitive impairment in HIV disease.

With the rising number of individuals in their 50s and 60s who are infected with HIV, concerns have emerged about possible increases in the rates of non-HIV-associated dementias. The current study examined the prevalence of mild cognitive impairment (MCI) in older HIV-infected adults, since MCI is an intermediate state between typical cognitive aging and dementia that emerges in this age range. Participants included 75 adults with HIV disease aged 50 years and older who were on combination antiretroviral therapy (cART) and had undetectable plasma viral loads and 80 demographically similar HIV-seronegative comparison subjects. Participants completed a research neuropsychological evaluation that was used to classify MCI according to the comprehensive diagnostic scheme described by Bondi et al. (J Alzheimers Dis 42:275-289, 2014). HIV-infected persons were over seven times more likely to have an MCI designation (16 %) than their seronegative counterparts (2.5 %). Within the HIV+ cohort, MCI had minimal overlap with diagnoses of asymptomatic neurocognitive impairment and was significantly associated with older age, lower Karnofsky Scale of Performance Scores, and mild difficulties performing instrumental activities of daily living (iADLs). HIV infection in older adults is associated with a notably elevated concurrent risk of MCI, which may increase the likelihood of developing non-HIV-associated dementias as this population ages further.

Prevalence of methicillin-resistant Staphylococcus aureus colonization in HIV-infected patients in Barcelona, Spain: a cross-sectional study

BackgroundColonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been found to be markedly more common in HIV-infected individuals in the USA. Studies evaluating the prevalence MRSA colonization in HIV-infected populations in Europe are scarce. The aim of this study was to investigate the prevalence of MRSA colonization in a cohort of HIV-infected patients in Barcelona, Spain.MethodsNasal and pharyngeal S. aureus carriage was assessed in a random sample of 190 patients from an outpatient HIV clinic. Nasal and pharyngeal swab specimens were obtained for staphylococcal culture from 190 and 110 patients respectively. All MRSA isolates were screened for Panton-Valentine leukocidin (PVL) genes by PCR. Molecular characterization of MRSA isolates was performed by multilocus sequence typing. Data related to HIV infection, healthcare exposure, and previously described risk factors for MRSA were collected from medical records and a questionnaire administered to each patient.ResultsThe patients’ characteristics were as follows: male, 83 %; median (IQR) age, 45 (39–49) years; intravenous drug users, 39 %; men who have sex with men, 32 %; heterosexual, 26 %; CD4 count, 528/μL (IQR 351–740); on antiretroviral therapy, 96 %; and undetectable plasma viral load, 80 %. Sixty-five patients (34 %) were colonized by S. aureus. MRSA colonization was found in 1 % and 2 % of nasal and pharyngeal samples respectively. No PVL positive MRSA strains were detected and all the MRSA isolates belonged to typical hospital-acquired clones.ConclusionsOur data suggest that CA-MRSA colonization is not currently a problem in HIV-infected individuals in our area.

Post-exposure treatment with neutralizing monoclonal antibodies prevents SHIV infection in infant rhesus macaques and limits establishment of latent viral reservoirs (VAC11P.1102)

Abstract We have developed a unique pre-clinical SHIV/macaque model with the potential to address translational implications of early intervention in mother-to-child-transmission (MTCT). Based on prior passive studies in this model, we hypothesized that very early therapeutic treatment with potent NmAbs would limit or ablate establishment of viral reservoirs in babies born to HIV-infected mothers. Fourteen one-month-old rhesus macaques were inoculated orally with SHIVSF162P3. Cocktails of NmAbs PGT121 and VRC07-523 were prepared for subcutaneous passive transfer. A control group of two animals did not receive NmAbs. Beginning at 24 hours (1 day) post SHIV exposure, NmAbs were delivered subcutaneously and repeated at days 4, 7, and 10. Blood samples monitored for plasma viral load (PVL) and transferred NmAb kinetics. Cell-associated viral loads (CAVL) were measured in PBMC and in tissues at necropsy. Animals were followed for 24 weeks to assess PVL, PBMC-based CAVL, and T and B cell responses. Controls were infected by three d.p.i. NmAb-treated infants had undetectable PVL with no evidence of CAVL in PBMC or tissue samples at necropsy. ICS was used to detect Gag and Vif T cell responses. No anti-SHIV T cell responses were detected in lymphocytes isolated from inguinal lymph nodes at week 20 or in necropsy tissue samples. Results indicate early therapeutic treatment with a cocktail of potent NmAbs can prevent infection and limit the establishment of latent viral reservoirs.

A Murine Viral Outgrowth Assay to Detect Residual HIV Type 1 in Patients With Undetectable Viral Loads.

Sensitive assays are needed for detection of residual human immunodeficiency virus (HIV) in patients with undetectable plasma viral loads to determine whether eradication strategies are effective. The gold standard quantitative viral outgrowth assay (QVOA) underestimates the magnitude of the viral reservoir. We sought to determine whether xenograft of leukocytes from HIV type 1 (HIV)-infected patients with undetectable plasma viral loads into immunocompromised mice would result in viral amplification. Peripheral blood mononuclear cells or purified CD4(+) T cells from HIV or simian immunodeficiency virus (SIV)-infected subjects with undetectable plasma viral loads were adoptively transferred into NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ (NSG) mice. The mice were monitored for viremia following depletion of human CD8(+) T cells to minimize antiviral activity. In some cases, humanized mice were also treated with activating anti-CD3 antibody. With this murine viral outgrowth assay (MVOA), we successfully amplified replication-competent HIV or SIV from all subjects tested, including 5 HIV-positive patients receiving suppressive antiretroviral therapy (ART) and 6 elite controllers or suppressors who were maintaining undetectable viral loads without ART, including an elite suppressor from whom we were unable to recover virus by QVOA. Our results suggest that the MVOA has the potential to serve as a powerful tool to identify residual HIV in patients with undetectable viral loads.

Antiviral activity and CSF concentrations of 600/100 mg of darunavir/ritonavir once daily in HIV-1 patients with plasma viral suppression.

The objective of this study was to assess whether a lower dose than the currently used one of darunavir/ritonavir might achieve good CSF concentrations and contribute to inhibition of CNS viral replication. This was a substudy of a randomized, open, multicentre study (eudraCT 2011-006272-39), comparing the efficacy and safety of 800/100 mg of darunavir/ritonavir (darunavir 800) versus 600/100 mg of darunavir/ritonavir (darunavir 600) once daily plus tenofovir/emtricitabine or abacavir/lamivudine in 100 virologically suppressed patients. Paired blood and CSF samples were obtained. Total plasma darunavir concentrations were determined by HPLC, and CSF concentrations by liquid chromatography-tandem MS. Viral load (VL) was determined in plasma and CSF (limit of detection = 40 copies/mL) by PCR. Sixteen patients were enrolled. The median (range) of darunavir CSF concentrations in darunavir 600 (n = 8) and darunavir 800 (n = 8) patients was 17.08 (5.79-30.19) and 13.23 (3.47-32.98) ng/mL, respectively (P = 0.916). The median (range) darunavir CSF:plasma ratio was 0.010 (0.005-0.022) in darunavir 600 patients and 0.008 (0.004-0.017) in the darunavir 800 arm (P = 0.370). All 16 patients had a VL < 40 copies/mL in plasma and 14 had a VL < 40 copies/mL in CSF. Of the two patients with detectable CSF VL (280 copies/mL and 159 copies/mL), one was receiving darunavir 600 and the other darunavir 800 plus tenofovir/emtricitabine. Of note, these patients had the lowest CSF darunavir concentrations in their respective groups: 5.79 ng/mL (802 ng/mL in plasma) and 3.47 ng/mL (958 ng/mL in plasma). Darunavir CSF and plasma concentrations were comparable between the two arms. However, one patient from each group (with the lowest CSF darunavir concentrations in their respective groups) had detectable CSF VL despite undetectable plasma VL.

Healthy HIV-1-infected individuals on highly active antiretroviral therapy harbor HIV-1 in their alveolar macrophages.

In a prospective cross-sectional study we quantified HIV viral load within the alveolar macrophage in a cohort of healthy HIV-infected subjects who did not have medical comorbidities or smoke cigarettes to determine if alveolar macrophage proviral DNA was associated with alveolar macrophage phagocytic immune dysfunction. We enrolled 23 subjects who underwent bronchoscopy and bronchoalveolar lavage. Alveolar macrophages were isolated and HIV-1 RNA was quantified in the cells using the Abbott RealTime HIV-1 Assay. Proviral DNA was qualitatively measured using a modified version of the HIV-1 RNA assay. Phagocytosis measured by incubating alveolar macrophages with FITC-labeled Staphylococcus aureus and determining fluorescence with a Zeiss inverted microscope. Phagocytic index was calculated as (% positive cells × mean channel fluorescence)/100. Sixteen subjects had (+) proviral DNA and seven had (-) proviral DNA in their alveolar macrophages. Of all subjects 100% in both groups were on highly active antiretroviral therapy (HAART). The median plasma viral load was 0 in both groups. HIV-1-infected subjects with (+) proviral DNA in their alveolar macrophages had a significantly lower median alveolar macrophage phagocytic index compared to those with (-) proviral DNA in their alveolar macrophages [11.8 (IQR 4.8-39.0) vs. 64.9 (IQR 14.0-166.0), p = 0.05]. Alveolar macrophages harbor HIV even in otherwise healthy subjects with undetectable plasma viral loads, representing a potential reservoir for the virus. In addition, HIV viral replication within the macrophage may impair phagocytosis and other immune functions in the lung, leading to an increased risk for lung infection.

Thymic HIV-2 infection uncovers posttranscriptional control of viral replication in human thymocytes.

A unique HIV-host equilibrium exists in untreated HIV-2-infected individuals. This equilibrium is characterized by low to undetectable levels of viremia throughout the disease course, despite the establishment of disseminated HIV-2 reservoirs at levels comparable to those observed in untreated HIV-1 infection. Although the clinical spectrum is similar in the two infections, HIV-2 infection is associated with a much lower rate of CD4 T-cell decline and has a limited impact on the mortality of infected adults. Here we investigated HIV-2 infection of the human thymus, the primary organ for T-cell production. Human thymic tissue and suspensions of total or purified CD4 single-positive thymocytes were infected with HIV-2 or HIV-1 primary isolates using either CCR5 or CXCR4 coreceptors. We found that HIV-2 infected both thymic organ cultures and thymocyte suspensions, as attested to by the total HIV DNA and cell-associated viral mRNA levels. Nevertheless, thymocytes featured reduced levels of intracellular Gag viral protein, irrespective of HIV-2 coreceptor tropism and cell differentiation stage, in agreement with the low viral load in culture supernatants. Our data show that HIV-2 is able to infect the human thymus, but the HIV-2 replication cycle in thymocytes is impaired, providing a new model to identify therapeutic targets for viral replication control. HIV-1 infects the thymus, leading to a decrease in CD4 T-cell production that contributes to the characteristic CD4 T-cell loss. HIV-2 infection is associated with a very low rate of progression to AIDS and is therefore considered a unique naturally occurring model of attenuated HIV disease. HIV-2-infected individuals feature low to undetectable plasma viral loads, in spite of the numbers of circulating infected T cells being similar to those found in patients infected with HIV-1. We assessed, for the first time, the direct impact of HIV-2 infection on the human thymus. We show that HIV-2 is able to infect the thymus but that the HIV-2 replication cycle in thymocytes is impaired. We propose that this system will be important to devise immunotherapies that target viral production, aiding the design of future therapeutic strategies for HIV control.

Validation of an ultrasensitive digital droplet PCR assay for HIV-2 plasma RNA quantification.

IntroductionLow or undetectable plasma viral load (VL) using current qPCR assays is common for HIV-2 patients. Digital PCR is an emerging technology enabling more precision and reproducibility than qPCR at low DNA/RNA copy numbers. Available data related to digital droplet PCR (ddPCR, Bio-Rad) underscore issues linked to the threshold definition of positivity, coupled to the specificity of low copy results [1].Materials and MethodsA RT-PCR protocol was set up using the One-Step RT-ddPCR Kit for Probes on the QX200 platform (Bio-Rad, Hercules, CA) in an accredited environment (ISO15189:2012 norm). Parameters tested were in line with the digital MIQE guidelines [2]. Inter-run coefficient of variation (CV) was established using synthetic RNA controls diluted in HIV-negative plasma. The ddPCR assay was compared to a qRT-PCR previously used in routine (LOQ 50 cop/mL [3]) using 46 clinical samples and the NIBSC international HIV-2 RNA standard.ResultsThe optimal PCR efficiency and the best separation between positive and negative droplets were obtained with a mixture containing 0.5 mM manganese acetate, 700 nM primers and 250 nM of the 5'FAM-probe. Using a manual threshold to define positivity, 7.74% of negative controls (n=168) were scored as positive due to one positive droplet. The presence of two positive droplets or more was not observed for negative controls. Serial dilutions of a positive control showed excellent linearity (R2=0.999) and enabled us to define a limit of quantification of two positives droplets, which corresponds to 0.14 copies/μL in the reaction mixture and to seven copies per mL of plasma. The inter-run coefficient of variation was 3.37% at a mean value of 4,468 cop/mL, 19.59% at 416 cop/mL and 32.28% at 8 cop/mL. The NIBSC standard of 1,000 IU was quantified 1,400 copies by ddPCR and close to 5,000 copies by qPCR (delta log superior to 0.5). Among 46 clinical samples, 22 were undetectable with both qPCR and ddPCR, 12 were detected with both methods (respective means of 10,612 and 2,224 cop/mL, delta log=0.68) and 12 others were quantified by ddPCR only below 50 cop/mL (mean=16 cop/mL).ConclusionsWe validated a ddPCR HIV-2 VL assay that is more sensitive and more reproducible than the qPCR assay used as comparator, with a limit of quantification of 7 cop/mL of plasma. A careful definition of the limit of blank allows the management of false positive droplets, but the variable user-defined positive threshold may be an issue for compliance to the quality norms.

Executive summary of the GeSIDA/National AIDS Plan consensus document on antiretroviral therapy in adults infected by the human immunodeficiency virus (updated January 2014)

In this update, antiretroviral therapy (ART) is recommended for all patients infected by type 1 human immunodeficiency virus (HIV-1). The strength and grade of the recommendation varies with clinical circumstances, number of CD4 cells, comorbid conditions and prevention of transmission of HIV. The objective of ART is to achieve an undetectable plasma viral load. Initial ART should always comprise a combination of 3 drugs, including 2 nucleoside reverse transcriptase inhibitors and a third drug from a different family (non-nucleoside reverse transcriptase inhibitor, protease inhibitor, or integrase inhibitor). This update presents the causes and criteria for switching ART in patients with undetectable plasma viral load and in cases of virological failure. An update is also provided for the specific criteria for ART in special situations (acute infection, HIV-2 infection, and pregnancy) and with comorbid conditions (tuberculosis or other opportunistic infections, kidney disease, liver disease, and cancer).

Documento de consenso de GeSIDA/Plan Nacional sobre el Sida respecto al tratamiento antirretroviral en adultos infectados por el virus de la inmunodeficiencia humana (Actualización enero 2014)

ObjectiveThis consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients. MethodsTo formulate these recommendations a panel composed of members of the Grupo de Estudio de Sida and the 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. Recommendations strength and the evidence in which they are supported are based on modified criteria of the Infectious Diseases Society of America. ResultsIn this update, antiretroviral therapy (ART) is recommended for all patients infected by type 1 human immunodeficiency virus (HIV-1). The strength and grade of the recommendation varies with the clinical circumstances: CDC stage B or C disease (A-I), asymptomatic patients (depending on the CD4+ T-lymphocyte count: <350cells/μL, A-I; 350-500 cells/μL, A-II, and >500 cells/μL, B-III), comorbid conditions (HIV nephropathy, chronic hepatitis caused by HBV or HCV, age >55years, high cardiovascular risk, neurocognitive disorders, and cancer, A-II), and prevention of transmission of HIV (mother-to-child or heterosexual, A-I; men who have sex with men, A-III). The objective of ART is to achieve an undetectable plasma viral load. Initial ART should always comprise a combination of 3 drugs, including 2 nucleoside reverse transcriptase inhibitors and a third drug from a different family (non-nucleoside reverse transcriptase inhibitor, protease inhibitor, or integrase inhibitor). Some of the possible initial regimens have been considered alternatives. This update presents the causes and criteria for switching ART in patients with undetectable plasma viral load and in cases of virological failure where rescue ART should comprise 2 or 3 drugs that are fully active against the virus. An update is also provided for the specific criteria for ART in special situations (acute infection, HIV-2 infection, and pregnancy) and with comorbid conditions (tuberculosis or other opportunistic infections, kidney disease, liver disease, and cancer). ConclusionsThese new guidelines updates previous recommendations related to cART (when to begin and what drugs should be used), how to monitor and what to do in case of viral failure or drug adverse reactions. cART specific criteria in comorbid patients and special situations are equally updated.

Rate, Predictors, and Consequences of Late Antenatal Booking in a National Cohort Study of Pregnant Women With HIV in Italy

Objective: To evaluate the prevalence and consequences of late antenatal booking (13 or more weeks gestation) in a national observational study of pregnant women with HIV. Methods: The clinical and demographic characteristics associated with late booking were evaluated in univariate analyses using the Mann-Whitney U test for quantitative data and the chi-square test for categorical data. The associations that were found were re-evaluated in multivariable logistic regression models. Main outcomes were preterm delivery, low birthweight, nonelective cesarean section, birth defects, undetectable (<50 copies/mL) HIV plasma viral load at third trimester, delivery complications, and gender-adjusted and gestational age-adjusted Z scores for birthweight. Results: Rate of late booking among 1,643 pregnancies was 32.9%. This condition was associated with younger age, African provenance, diagnosis of HIV during pregnancy, and less antiretroviral exposure. Undetectable HIV RNA at third trimester and preterm delivery were significantly more prevalent with earlier booking (67.1% vs 46.3%, P < .001, and 23.2% vs 17.6, P = .010, respectively), whereas complications of delivery were more common with late booking (8.2% vs 5.0%, P = .013). Multivariable analyses confirmed an independent role of late booking in predicting detectable HIV RNA at third trimester (adjusted odds ratio [AOR], 1.7; 95% CI, 1.3-2.3; P < .001) and delivery complications (AOR, 1.8; 95% CI, 1.2-2.8; P = .005). Conclusions: Late antenatal booking was associated with detectable HIV RNA in late pregnancy and with complications of delivery. Measures should be taken to ensure an earlier entry into antenatal care, particularly for African women, and to facilitate access to counselling and antenatal services. These measures can significantly improve pregnancy management and reduce morbidity and complications in pregnant women with HIV.

Efficacy of initial antiretroviral therapy for HIV-1 infection in adults: a systematic review and meta-analysis of 114 studies with up to 144 weeks' follow-up.

BackgroundA comprehensive assessment of initial HIV-1 treatment success may inform study design and treatment guidelines.MethodsGroup-based, systematic review and meta-analysis of initial antiretroviral therapy studies, in adults, of ≥48 weeks duration, reported through December 31, 2012. Size-weighted, intention-to-treat efficacy was calculated. Parameters of study design/eligibility, participant and treatment characteristics were abstracted. Multivariable, random effects, linear regression models with backwards, stepwise selection were then used to identify variables associated with efficacy.Outcome MeasuresAntiviral efficacy (undetectable plasma viral load) and premature cessation of therapy.Results114 studies were included (216 treatment groups; 40,124 participants; mean CD4 count 248 cells/µL [SD 81]; mean HIV-1 plasma viral load log10 4.9 [SD 0.2]). Mean efficacy across all groups was 60% (SD 16) over a mean 82 weeks' follow-up (SD 38). Efficacy declined over time: 66% (SD 16) at 48 weeks, 60% (SD 16) at 96 weeks, 52% (SD 18) at 144 weeks. The most common reason for treatment cessation was participant decision (11%, SD 6.6). Efficacy was higher with ‘Preferred’ than ‘Alternative’ regimens (as defined by 2013 United States antiretroviral guidelines): 75% vs. 65%, respectively, difference 10%; 95%CI 7.6 to 15.4; p<0.001. In 98 groups (45%) reporting efficacy stratified by pre-treatment viral load (< or ≥100,000 copies/mL), efficacy was greater for the lower stratum (70% vs. 62%, respectively, difference 8.4%; 95%CI 6.0 to 10.9; p<0.001). This difference persisted within ‘Preferred’ regimens. Greatest efficacy was associated with use of tenofovir-emtricitabine (vs. other nucleoside analogue backbones) and integrase strand transfer inhibitors (vs. other third drug classes).ConclusionInitial antiretroviral treatments for HIV-1 to date appear to have suboptimal long-term efficacy, but are more effective when commenced at plasma viral loads <100,000 copies/mL. Rising viral load should be considered an indication for starting treatment. Integrase inhibitors offer a treatment advantage (vs. other third drug classes).

Therapeutic drug monitoring of atazanavir/ritonavir in pregnancy.

Pregnant women experience physiological changes during pregnancy that can have a significant impact on antiretroviral pharmacokinetics. Ensuring optimal plasma concentrations of antiretrovirals is essential for maternal health and to minimize the risk of vertical transmission. Here we describe atazanavir/ritonavir (ATV/r) plasma concentrations in a cohort of pregnant women undergoing routine therapeutic drug monitoring (TDM). Pregnant HIV-positive women received ATV/r as part of their routine pre-natal care. Demographic and clinical data were collected. ATV plasma concentrations ([ATV]) were determined in the first (T1), second (T2) and third (T3) trimesters and at postpartum (PP) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). From January 2007, 44 women (37 black African) were enrolled in the study. All received ATV/r at a dose of 300/100 mg once a day. Twenty-four had received antiretroviral therapy (ART) prior to pregnancy, and 20 initiated ATV/r in pregnancy. At the time nearest to delivery, 36 patients had undetectable plasma viral loads. [ATV] values were determined in 11 (T1), 25 (T2), 34 (T3) and 28 (PP) patients. [ATV] at 24 hours post-dose (C24) values significantly lower at T2/T3 relative to PP. This study was carried out in one of the larger cohorts of women undergoing TDM for ATV in pregnancy. Lower [ATV] values were seen in T2/T3 compared with T1/PP. However, [ATV] were not associated with a lack of virologic suppression at delivery. Nonetheless, careful monitoring of women in pregnancy is required, and dose adjustment of ATV to 400 mg may be an option.

Feasibility of testing and detection of HIV-1 drug resistance in proviral DNA

In recent years antiretroviral availability and access has become more prevalent in resource poor settings, whilst the availability of access to HIV-1 drug resistance testing remains limited and patients are often started on therapy or switched when failing without a resistance test. Proviral DNA has been proposed as a source of archived resistance mutations. We investigated the feasibility of using proviral DNA to detect previously documented plasma resistance mutations. Amplification and sequencing of pol from proviral DNA derived from buffy coat (BCL), buffy coat dried on filter paper (BCS) or dried blood spots (DBS) was performed using an in-house assay. Only 2/20 samples were amplified from long term stored buffy coat (>1 year) compared to at least one prospective sample from 10/20 patients. Six patients had a plasma viral load (PVL) <40 cp/ml at time of sampling, though 4/6 only become undetectable on the most recent sample, 2/4 had been undetectable for 149 and 819 days respectively. The remaining 6 patients had detectable PVL (median 3.1 log10 cp/ml, range: 1.7–6.2 log10 cp/ml). In contrast, 21/28 (75%) of samples which failed to amplify were <40 cp/ml, 2 had become undetectable in the most recent sample and 19 had been undetectable for a median of 577 days (range: 32–2481 days). 6/10 BCL samples showed none of the previously documented resistance for those patients, 3/10 showed some of the previously known mutations and only 1/10 showed all historic resistance, though this patient had only one documented mutation (K103N). For the BCS samples 3/4 showed none of the documented resistance, 1/4 harboured the previously known mutations (M184V, K103N). 3/6 of the DBS had none of the previously documented resistance, 2/6 showed some of the known mutations and 1/6 showed both known resistance mutations (M41L, T215S). In patients where multiple specimen types were amplified, 3/5 showed differences in mutations detected between sample types, with 2/5 correlating but having no mutations detected in any specimens. In patients with undetectable PVL, particularly those undetectable for long periods, it was difficult to sequence archived DNA. Concordance between different specimen types was variable as was concordance with previously documented mutations. Historic resistance reports remain important in the clinical management of patients on antiretroviral therapy, though proviral DNA testing may be useful in patients where historic reports are not available.

Timing of Intermittent Seminal HIV-1 RNA Shedding in Patients with Undetectable Plasma Viral Load under Combination Antiretroviral Therapy

It was demonstrated that combination antiretroviral therapy (cART) reduces the HIV-1 viral load (VL) in the blood and the seminal compartment. Some studies have reported that the seminal HIV-1 VL is undetectable in individuals with an undetectable blood plasma viral load (bpVL) under cART. However, some recent studies have demonstrated that seminal HIV-1 RNA may still be detected, and potentially infectious, even in the case of an undetectable bpVL. The aim of this retrospective study was to determine the detection rate of a seminal VL and whether shedding could be intermittent over a very short time.From January 2006 to December 2011, 88 HIV-1 infected men, enrolled in an Assisted Reproduction program, provided 306 semen samples, corresponding to 177 frozen sperm samples (two samples delivered at a one-hour interval (n = 129) or one sample (n = 48)). All enrolled men were under cART, with an undetectable bpVL for more than 6 months. HIV-1 RNA was quantified in seminal plasma using a Roche COBAS Ampliprep COBAS TaqMan HIV-1 test.Seminal HIV-1 RNA was detected in 23 samples (7.5%) from 17 patients (19.3%). This detection rate was stable over years. With regards to the freezing of two samples delivered at a one-hour interval, the proportion of discordance between the first and second samples was 9.3% (12/129).Our results confirm the intermittent shedding of HIV-1 in semen. While this finding has been shown by studies examining longer time intervals, to our knowledge, this has never been demonstrated over such a short time interval.

The First Report of HIV-1 Group O Infection in Canada

We report here the first case of HIV-1 group O infection in Canada. The patient presented with a progressive decline in CD4+ T lymphocyte count despite an undetectable plasma viral load, due to an inability to detect group O infection by standard techniques. This in turn resulted in a delay in initiation of treatment.