Median pVL Research Articles

Unveiling ecological/evolutionary insights in HIV viral load dynamics: Allowing random slopes to observe correlational changes to CpG-contents and other molecular and clinical predictors

In the context of infectious diseases, the dynamic interplay between ever-changing host populations and viral biology demands a more flexible modeling approach than common fixed correlations. Embracing random-effects regression models allows for a nuanced understanding of the intricate ecological and evolutionary dynamics underlying complex phenomena, offering valuable insights into disease progression and transmission patterns. In this article, we employed a random-effects regression to model an observed decreasing median plasma viral load (pVL) among individuals with HIV in Mexico City during 2019–2021. We identified how these functional slope changes (i.e. random slopes by year) improved predictions of the observed pVL median changes between 2019 and 2021, leading us to hypothesize underlying ecological and evolutionary factors. Our analysis involved a dataset of pVL values from 7325 ART-naïve individuals living with HIV, accompanied by their associated clinical and viral molecular predictors. A conventional fixed-effects linear model revealed significant correlations between pVL and predictors that evolved over time. However, this fixed-effects model could not fully explain the reduction in median pVL; thus, prompting us to adopt random-effects models. After applying a random effects regression model—with random slopes and intercepts by year—, we observed potential "functional changes" within the local HIV viral population, highlighting the importance of ecological and evolutionary considerations in HIV dynamics: A notably stronger negative correlation emerged between HIV pVL and the CpG content in the pol gene, suggesting a changing immune landscape influenced by CpG-induced innate immune responses that could impact viral load dynamics. Our study underscores the significance of random effects models in capturing dynamic correlations and the crucial role of molecular characteristics like CpG content. By enriching our understanding of changing host-virus interactions and HIV progression, our findings contribute to the broader relevance of such models in infectious disease research. They shed light on the changing interplay between host and pathogen, driving us closer to more effective strategies for managing infectious diseases. Significance of the studyThis study highlights a decreasing trend in median plasma viral loads among ART-naïve individuals living with HIV in Mexico City between 2019 and 2021. It uncovers various predictors significantly correlated with pVL, shedding light on the complex interplay between host-virus interactions and disease progression. By employing a random-slopes model, the researchers move beyond traditional fixed-effects models to better capture dynamic correlations and evolutionary changes in HIV dynamics. The discovery of a stronger negative correlation between pVL and CpG content in HIV-pol sequences suggests potential changes in the immune landscape and innate immune responses, opening avenues for further research into adaptive changes and responses to environmental shifts in the context of HIV infection. The study's emphasis on molecular characteristics as predictors of pVL adds valuable insights to epidemiological and evolutionary studies of viruses, providing new avenues for understanding and managing HIV infection at the population level.

Development and validation of a duplex real-time PCR for the rapid detection and quantitation of HTLV-1

BackgroundThe HTLV-1 prevalence in China varies geographically, while HTLV-2 infection has rarely been found so far. Proviral load is one of the determining factors of pathogenesis and progression of HTLV-1 related diseases. However, neither molecular assays nor commercial kits are available for HTLV-1 diagnosis in China. The objective of the present study was to develop and validate a TaqMan qPCR assay for HTLV-1 proviral load quantification.ResultsA plasmid containing both the HTLV-1 of interest and a fragment of the RNase P (RPPH1) gene was constructed and used to establish the standard curves. The assay has a wide dynamic range (2.5 × 108 copies/reaction ~ 25 copies/reaction) and sensitive to 1 copy for HTLV-1 and RPPH1. The limit of detection for Hut102 cell concentration was 0.0218% (95% confidence interval 0.0179–0.0298%). The assay gave coefficient of variation (CV) for both the HTLV-1 and RPPH1 Ct values. All of the HTLV-1 sero-negative samples and MOT cell line (infected with HTLV-2) amplified only the RPPH1 gene by our method, presenting 100% specificity. 85 Samples confirmed positive or indeterminate by LIA were performed by established qPCR assay and WB. 90.0% (27/30) of LIA-HTLV-1-positive, 33% (2/6) of LIA-untypeable and 2% (1/49) of LIA-indeterminate samples were defined as qPCR-positive. The median PVL of LIA-positive samples (n = 27, 1.780 copies/100 cells) was much higher than that of LIA-untypeable and (n = 2, 0.271 copies/100 cells) indeterminate samples (n = 1, 0.017 copies/ 100 cells). Additionally, compared to WB, the duplex qPCR verified more positive samples, demonstrating a better sensitivity.ConclusionThe duplex qPCR developed here with high sensitivity, good specificity and reproducibility could accurately and quantitatively detect the HTLV-1 PVLs, which can be used to confirm the initial reactive samples for an improved cost/benefit ratio as well as to monitor the clinical progression and efficacy of therapy in patients with HTLV-1 related disease.

Very high prevalence of infection with the human T cell leukaemia virus type 1c in remote Australian Aboriginal communities: Results of a large cross-sectional community survey.

Infection with the human T cell leukaemia virus type 1 (HTLV-1) subtype C is endemic among Aboriginal people in central Australia. To provide insights into the risk factors for transmission, we conducted the first large-scale, community-based prevalence study in seven remote Aboriginal communities. Residents >2 years old were invited to participate in the study between August 2014 and June 2018. HTLV-1 infection was defined as a positive western blot (WB) test or a positive HTLV-1 PCR. 720 community residents participated in the study (children <15 years, 142; adults, 578). Prevalences for children and adults were 3.5% (5/142) and 36.8% (213/578), respectively, reaching 49.3% (106/215) for those older than 45 years. A wide range of proviral loads were measured for both asymptomatic and symptomatic participants with no difference within groups according to age or gender; however, median PVL was 1.34 log10 higher for symptomatic participants. The adult prevalence of HTLV-1 infection in central Australia is the highest reported worldwide. Sexual contact is likely to be the predominant mode of transmission.

Impact of the frequency of plasma viral load monitoring on treatment outcomes among children with perinatally acquired HIV.

IntroductionRecommendations on the optimal frequency of plasma viral load (pVL) monitoring in children living with HIV (CLWH) who are stable on combination antiretroviral therapy (cART) are inconsistent. This study aimed to determine the impact of annual versus semi‐annual pVL monitoring on treatment outcomes in Asian CLWH.MethodsData on children with perinatally acquired HIV aged <18 years on first‐line, non‐nucleoside reverse transcriptase inhibitor‐based cART with viral suppression (two consecutive pVL <400 copies/mL over a six‐month period) were included from a regional cohort study; those exposed to prior mono‐ or dual antiretroviral treatment were excluded. Frequency of pVL monitoring was determined at the site‐level based on the median rate of pVL measurement: annual 0.75 to 1.5, and semi‐annual >1.5 tests/patient/year. Treatment failure was defined as virologic failure (two consecutive pVL >1000 copies/mL), change of antiretroviral drug class, or death. Baseline was the date of the second consecutive pVL <400 copies/mL. Competing risk regression models were used to identify predictors of treatment failure.ResultsDuring January 2008 to March 2015, there were 1220 eligible children from 10 sites that performed at least annual pVL monitoring, 1042 (85%) and 178 (15%) were from sites performing annual (n = 6) and semi‐annual pVL monitoring (n = 4) respectively. Pre‐cART, 675 children (55%) had World Health Organization clinical stage 3 or 4, the median nadir CD4 percentage was 9%, and the median pVL was 5.2 log10 copies/mL. At baseline, the median age was 9.2 years, 64% were on nevirapine‐based regimens, the median cART duration was 1.6 years, and the median CD4 percentage was 26%. Over the follow‐up period, 258 (25%) CLWH with annual and 40 (23%) with semi‐annual pVL monitoring developed treatment failure, corresponding to incidence rates of 5.4 (95% CI: 4.8 to 6.1) and 4.3 (95% CI: 3.1 to 5.8) per 100 patient‐years of follow‐up respectively (p = 0.27). In multivariable analyses, the frequency of pVL monitoring was not associated with treatment failure (adjusted hazard ratio: 1.12; 95% CI: 0.80 to 1.59).ConclusionsAnnual compared to semi‐annual pVL monitoring was not associated with an increased risk of treatment failure in our cohort of virally suppressed children with perinatally acquired HIV on first‐line NNRTI‐based cART.

Clinical features and human T-cell leukemia virus type-1 (HTLV-1) proviral load in HTLV-1-positive patients with rheumatoid arthritis: Baseline data in a single center cohort study

Objective: Recently, Human T-cell leukemia virus type-1 proviral load (HTLV-1 PVL) has been evaluated as an important predictor of adult T-cell leukemia/lymphoma (ATL) in HTLV-1 carriers. We aimed to evaluate whether HTLV-1 PVL is also important for the development of ATL among HTLV-1-positive patients with rheumatoid arthritis (RA).Methods: We established a cohort of 82 HTLV-1-positive RA patients between 2017 and 2018. Of those, 27 (32.9%) were treated with biological disease-modifying anti-rheumatic drugs (bDMARDs) with/without methotrexate. We measured HTLV-1 PVL in peripheral blood mononuclear cells (PBMCs) at study entry and compared the value by clinical status and treatment options.Results: The median PVL for all was 9.6 copies per 1000 PBMCs without sex difference (male 17.2 and female 8.6; p = .24). The median PVL was significantly higher for patient’s comorbid bronchiectasis, malignancies, and opportunistic infectious diseases, compared with patients without comorbidity. There were no significant differences in PVL levels among types of bDMARDs, although the level was tended to be higher for patients treated with JAK inhibitor.Conclusions: HTLV-1 seropositive RA patients comorbid for any diseases having higher HTLV-1 PVLs will be a higher risk for developing ATL. Careful follow-up of these patients is necessary to detect ATL development.

Clinical and Molecular Features of Feline Foamy Virus and Feline Leukemia Virus Co-Infection in Naturally-Infected Cats.

Feline foamy virus (FFV) and feline leukemia virus (FeLV) belong to the Retroviridae family. While disease has not been reported for FFV infection, FeLV infection can cause anemia and immunosuppression (progressive infection). Co-infection with FFV/FeLV allows evaluation of the pathogenic potential and epidemiology of FFV infection in cats with FeLV pathology. Blood and buccal swab samples from 81 cats were collected in Rio de Janeiro. Plasma was serologically tested for FeLV. DNA extracted from peripheral blood mononuclear cells and buccal swabs was used to PCR detect FFV and FeLV. A qPCR was developed to detect and measure FFV proviral loads (pVLs) in cats. FeLV qPCR was performed using previous methods. The median log10 pVL of FFV mono-infected individuals was lower than found in FFV/FeLV co-infected cats in buccal swabs (p = 0.003). We found 78% of cats had detectable buccal FFV DNA in FFV mono-infected and FFV co-infected FeLV-progressive cats, while in FeLV-regressive cats (those without signs of disease) 22% of cats had detectable buccal FFV DNA (p = 0.004). Our results suggest that regressive FeLV infection may reduce FFV saliva transmission, the main mode of FV transmission. We did not find evidence of differences in pathogenicity in FFV mono- and -dually infected cats. In summary, we show that FVs may interact with FeLV within the same host. Our study supports the utility of cats naturally co-infected with retroviruses as a model to investigate the impact of FV on immunocompromised mammalian hosts.

Dual therapy (ritonavir boosted atazanavir + raltegravir) versus standard triple therapy (ritonavir boosted atazanavir + tenofovir/emtricitabine) in patients failing first line therapy: 48 week results from a randomized pilot study

Background: Dual therapy has emerged as a novel concept in treatment optimization in naive and supressed HIV patients. This study aimed at exploring virological response, safety and inflammation markers of a nucleoside-sparing dual regimen consisting of ATV/r + RAL (DT) vs standard therapy of ATV/r + TDF/FTC (TT) among patients failing first NNRTI-containing treatment. Methods & Materials: Randomized open label pilot study. Primary outcome measures were proportion of subjects with plasma HIV-1 RNA below the limit of detection (<50 copies/uL) and proportion of subjects discontinuing due to adverse events (AEs) during the first 48 weeks. ClinicalTrials.gov Identifier: NCT01829802. Results: Out of 57 patients screened, 34 were randomized to receive: DT (n: 18) or TT (n: 16). At baseline 80% males, 50% MSM, median age 38 years, CDC stage C:35%, Median pVL: 3.9 Log10, CD4: 289 cells/uL. At week 48, data from 32 participants (2 did not reach week 48 yet) showed virological response in 69% (n: 11/16) of participants receiving DT and 88% (n: 14/16) receiving TT by FDA snapshot analysis (p = NS) and 73% (DT) and 93% (TT) by per-protocol analysis (p = NS). CD4 cell count median change from baseline to week 48 was +119 and + 52 cell/uL in DT and TT, respectively. No deaths were recorded. Three SAEs occurred in 2 participants (pneumonia and stroke and, Belĺs paralysis), none related to study drugs. Eight Grade 2, probably drug-related AEs were observed: 1 in DT (gastrointestinal) and 7 in TT (5 gastrointestinal, 1 renal stone and 1 rash). Hyperbilirubinemia Grade 2/3 was seen in 77% in DT and 94% in TT, none requiring stopping ART. Two participants were discontinued due to loss of follow-up, one in each arm. Five participants had virological failure at W48, 4 in DT and 1 in TT, all with low pVL (52-589 copies/uL). One participant developed integrase resistance mutation and suppressed later on TT. Conclusion: ATV/r+RAL as second-line therapy showed a trend to more frequent virological failure, compared to TT, although the study was unpowered to prove this difference. No major differences were seen in tolerance or toxicity.

Human Immunodeficiency Virus Type 1 Group O Infection in France: Clinical Features and Immunovirological Response to Antiretrovirals.

To obtain reliable clinical data of human immunodeficiency virus type 1 group O (HIV-1/O) infection, and immunovirological responses to combination antiretroviral therapy (cART), in a large series of 101 patients. Piecewise linear models were used to estimate CD4 count before and after cART initiation. Kaplan-Meier survival curves were used to estimate time to reach clinical stage C before antiretroviral therapy (ART) and to analyze time to achieve a plasma viral load (pVL) <40 copies/mL following cART initiation. Immunovirological response was assessed at the most recent visit in patients on active follow-up. Data showed a 16.6% cumulative probability of reaching stage C within 5 years following diagnosis, and a mean CD4 decrease of -30.5 cells/μL/year. cART initiation in ART-naive patients led to a mean CD4 gain of 147 cells/μL after 12 months, and to a median pVL of <40 copies/mL after 3.8 months for 89.3%. Initiation with a nonrecommended nonnucleoside reverse transcriptase inhibitor-based vs a ritonavir-boosted protease inhibitor-based regimen resulted in a much smaller gain of around 100 CD4 cells/μL after 1 year. Patients on follow-up since 2007 had a median CD4 count of 498 cells/μL, and 87% had a pVL <40 copies/mL at the most recent follow-up visit. This work provides unique data on HIV-1/O infection, in favor of a milder natural evolution than HIV-1 group M (HIV-1/M) and of a highly efficient current management, based on HIV-1/M guidelines, despite genetic divergence. Studies of comparable HIV-1/M and HIV-1/O populations are needed to confirm these results.

The 10-year effectiveness of combination antiretroviral treatment in perinatally HIV-infected children participating in Thailand's National Access Program.

The National Access to Antiretroviral Program for People Living with HIV/AIDS was launched in Thailand in 2002. HIV-infected, antiretroviral-naive, severely immunosuppressed children were initiated on highly active combination antiretroviral treatment (cART). This study aimed to determine the long-term effectiveness of cART. Data were extracted from medical records. Primary end points were mortality rate, proportion of children who remained on first-line cART regimen and children with plasma HIV RNA level (pVL) <50 copies/ml at week 520. From August 2002 to July 2003, 107 children were enrolled. The baseline median age was 7.6 years (IQR 5.7-10.0), the median CD4(+) T-cell count was 60 cells/mm(3) (IQR 21-272) and the median pVL was 5.37 log10 copies/ml (IQR 5.01-5.76). The mortality rate during and after the first year was 3.7 and 0.006 deaths/100 person-years, respectively. At week 520, 90 (84%) continued to be actively followed. Their median age was 17.8 years (IQR 15.8-19.8). 73 (81% as-treated) remained on the first-line regimen, while 18 (20%) had switched to a second-line cART regimen, at the median time of 272 weeks (IQR 256-363) after the first-line cART initiation. 69 (77%) had pVL<50 copies/ml and the median CD4(+) T-cell count was 636 cells/mm(3) (IQR 466-804). 83 (92%) and 64 (71%) had CD4(+) T-cell counts ≥200 and >500 cells/mm(3), respectively. Long-term virological control, favourable immunological outcomes and healthy survival was achieved in severely immunosuppressed, perinatally HIV-infected children who started first-line NNRTI-based cART. Continuing surveillance for long-term complications is warranted.

High-intensity cannabis use associated with lower plasma human immunodeficiency virus-1 RNA viral load among recently infected people who use injection drugs.

Cannabis use is common among people who are living with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS). While there is growing pre-clinical evidence of the immunomodulatory and anti-viral effects of cannabinoids, their possible effects on HIV disease parameters in humans are largely unknown. Thus, we sought to investigate the possible effects of cannabis use on plasma HIV-1 RNA viral loads (pVLs) among recently seroconverted illicit drug users. We used data from two linked longitudinal observational cohorts of people who use injection drugs. Using multivariable linear mixed-effects modelling, we analysed the relationship between pVL and high-intensity cannabis use among participants who seroconverted following recruitment. Between May 1996 and March 2012, 88 individuals seroconverted after recruitment and were included in these analyses. Median pVL in the first 365 days among all seroconverters was 4.66 log10 c mL(-1) . In a multivariable model, at least daily cannabis use was associated with 0.51 log10 c mL(-1) lower pVL (β = -0.51, standard error = 0.170, P value = 0.003). Consistent with the findings from recent in vitro and in vivo studies, including one conducted among lentiviral-infected primates, we observed a strong association between cannabis use and lower pVL following seroconversion among illicit drug-using participants. Our findings support the further investigation of the immunomodulatory or antiviral effects of cannabinoids among individuals living with HIV/AIDS.

Trends in Plasma HIV-RNA Suppression and Antiretroviral Resistance in British Columbia, 1997–2010

To examine temporal trends in plasma viral load (pVL) suppression and antiretroviral resistance from 1997 to 2010 in British Columbia (BC), Canada, and determine characteristics, pVL ranges, and resistance profiles of HIV-positive individuals with unsuppressed pVL in 2010. HIV-positive individuals ≥19 years old in the provincial database at the BC Centre for Excellence in HIV/AIDS were included. Virological suppression was defined as 2 consecutive pVL <500 copies per milliliter within each calendar year. Temporal trends were evaluated using the Cochran-Armitage test. Persons with suppressed vs. unsuppressed pVL in 2010 were compared using the Pearson χ² or Fisher exact test (categorical variables) and the Wilcoxon rank-sum test (quantitative variables), including unsuppressed individuals only if they were on antiretroviral therapy (ART) in 2010 or their baseline CD4 count was <350 cells per cubic millimeter or <500 cells per cubic millimeter, in separate analyses. The proportion of individuals with suppressed pVL increased from 24% to 80% (P < 0.001). In comparative analyses, individuals with unsuppressed pVL (877 of 6142) were more likely to be female (30% vs. 16%), younger (median, 43 vs. 48 years), have injection drug use history (38% vs. 30%), report Aboriginal ancestry (30% vs. 16%), and have hepatitis C coinfection (57% vs. 34%) (all P < 0.001). Similar patterns were observed using the <500 cells per cubic millimeter CD4 cutoff. The median pVL of all unsuppressed individuals in 2010 was 12,896 copies per milliliter (interquartile range, 1495-47,763). The proportion of individuals achieving pVL suppression in BC has increased markedly since 1997; however, further efforts are needed to maximize the individual and societal benefits of modern antiretroviral therapy.

Lack of correlation between the size of HIV proviral DNA reservoir and the level of immune activation in HIV-infected patients with a sustained undetectable HIV viral load for 10 years

BackgroundThe persistence of HIV residual replication in patients with an undetectable plasma viral load (pVL) may limit immune recovery and facilitate inflammation-induced comorbidities. ObjectiveThe objective was to evaluate any correlation between immune restoration and intracellular [IC] HIV-DNA in cART-treated patients with a sustained undetectable pVL. Study designThis retrospective cross sectional study included 62 patients with a median duration of undetectable pVL of 10.3 years. IC HIV DNA in peripheral mononuclear blood cells (PBMCs) and T cell subsets were measured at the last visit. pVL, CD4+ and CD8+ T cell counts were retrospectively collected from the onset of long-term inhibition by antiretroviral treatment. The patients were separated into two groups: 27 non-blippers (sustained pVL<threshold value during all the visits) and 35 blippers (≥1 episodes of pVL>threshold but <1000 copies/ml). The median pVL in blippers was 115 copies/ml. ResultsThe median IC HIV DNA rate was 34 copies/106 PBMCs (71% ≥20 copies/106 PBMCs) with no significant difference between the groups. The proportion of CD8+CD38+ and CD8+DR+ T cells was higher in blipper patients, but the difference was only significant for the CD8+DR+ marker (p=0.036). No correlation was found between markers of immune activation on CD4+ and CD8+ T cells and the IC HIV-DNA level. ConclusionNo relation was found between the size of HIV reservoirs and immune activation in patients with sustained undetectable pVL. Mechanisms of immune activation have to be better understood in order to define specific therapeutic interventions.

Effectiveness of first‐line antiretroviral therapy based on NNRTIs vs ritonavir‐boosted PIs in HIV‐1 infected patients with high plasma viral load

Purpose of the studyFew clinical trials have compared non‐nucleoside reverse transcriptase inhibitors (NNRTI) and ritonavir‐boosted protease inhibitors (PI/r) as initial combined antiretroviral therapy (cART) for HIV‐1‐infected patients with high plasma viral load (pVL), and non‐conclusive results have been reported. We compared the effectiveness between NNRTI and PI/r as first‐line cART for HIV‐1‐infected patients with high pVL.MethodsObservational retrospective study of 664 consecutive treatment‐naïve HIV‐1‐infected patients with pVL (HIV‐1 RNA) &gt;100,000 copies/mL who initiated NNRTI or PI/r‐based cART between 2000–2010 in three University hospitals. Only currently preferred or alternative regimens in clinical guidelines were included. Primary endpoint: percentage of therapeutic failures at week 48. Virologic failure was defined as: a) lack of virologic response (&lt;1 log RNA HIV‐1 decrease in first 3 months); b) RNA HIV‐1 &gt;50 c/mL at week 48; c) confirmed rebound &gt;50 c/ml after a previous value &lt;50 c/mL. Intent‐to‐treat (ITT noncompleter=failure) and on‐treatment (OT) analyses were performed.Results62% of patients initiated NNRTI‐regimens (83% efavirenz) and 38% PI/r‐regimens (62% lopinavir/). Baseline characteristics: male 83%; median age 39 yrs; median CD4 count: 212/µL (NNRTI 232 vs PI/r 177, p=0.028); pVL 5.83 log10 c/mL (NNRTI 5.43 vs PI/r 5.55, p=0.007); AIDS 24% (NNRTI 21% vs PI/r 29%, p=0.015). NRTI backbones were tenofovir plus 3TC or FTC in 72%. The percentage of therapeutic failure was higher in the PI/r group (ITT NC=F 26% vs 18%, p=0.012) with no differences in virologic failures (PI/r 5%, NNRTI 6%, p=0.688). The rate of treatment changes due to toxicity and/or voluntary discontinuations was higher in the PI/r group (15% vs 8%, p=0.008). A multivariate analysis adjusted for age, gender, CD4 count, VL and AIDS showed NNRTI vs PI/r as the only variable associated with treatment response (OR 0.61, 95% CI 0.41–0.88). Median pVL and rate of resistance at virologic failure were higher in patients receiving NNRTI (3.97 vs 2.49 log copies/mL, p&lt;0.001 and 62% vs 12%, p=0.004, respectively).ConclusionsInitial NNRTI‐regimens showed higher effectiveness compared with PI/r‐regimens in HIV‐1‐infected patients with high pVL, although virologic failure rates were low and comparable. Resistance emergence was more frequent and pVL higher in patients failing NNRTI. However, more patients initiating PI/r‐based regimens changed or discontinued therapy.

No Advantage of Quadruple- or Triple-Class Antiretroviral Therapy as Initial Treatment in Patients with Very High Viraemia

We assessed whether quadruple or triple-class therapy for the initial treatment of HIV-1 infection provides a virological benefit over standard triple therapy in patients with very high plasma viraemia. The assessment was made based on a national observational HIV cohort in the Netherlands. Inclusion criteria were age ≥18 years, treatment-naive, plasma viral load (pVL) ≥500,000 copies/ml and initiation of quadruple or triple therapy between 2001 and 2011. Time to viral suppression, defined as pVL<50 copies/ml, was compared between the two groups using Kaplan-Meier plots and multivariate Cox regression analysis. A total of 675 patients were included: 125 (19%) initiated quadruple and 550 (81%) triple therapy. Median pVL was 5.9 (IQR 5.8-6.1) log(10) copies/ml in both groups (P=0.49). 22 (18%) patients on quadruple and 63 (12%) on triple therapy interrupted the treatment regimen because of drug-related toxicity (P=0.06). Median time to viral suppression was 5.8 (IQR 4.6-7.9) and 6.0 (4.0-9.4) months in the patients on quadruple and triple therapy, respectively (log-rank, P=0.42). In the adjusted Cox analysis, quadruple therapy was not associated with time to viral suppression (HR 1.07 [95% CI 0.86, 1.33], P=0.53). Similar results were seen when comparing triple- versus dual-class therapy (n=72 versus n=601, respectively). Initial quadruple- or triple-class therapy was equally effective as standard triple therapy in the suppression of HIV-1 in treatment-naive patients with very high viraemia and did not result in faster pVL decreases, but did expose patients to additional toxicity.

High frequency of genotypic resistance in HIV‐1‐infected patients on highly active antiretroviral therapy with persistent low level viremia

BackgroundResistance is a major cause of virologic failure in HIV‐1‐infected patients; genotypic analyses optimize salvage therapy but technical constraints limit testing in plasma viral load (pVL) below 1000 copies/ml. Nevertheless a great amount of patients are failing therapy with a persistent low viral load, it is possible to obtain genotypic information at lower viremias although slight modifications are required during genotype standard procedures.ObjectiveTo assess genotypic resistance in HIV‐1‐infected patients with persistent low level viremia and virologic response after switching to genotype‐guided salvage therapy. To evaluate viral selection of mutation when previous genotypic information were available.Study designCohort prospective study in which eligible patients were at least 18 years old, provided informed consent, were on HAART for at least 12 months with two consecutive pVL between 200–999 copies/ml after achieving and maintaining viral suppression (two pVL &lt;50 copies/ml). Modifications in genotype standard procedures included a larger volume of starting plasma, concentrating the sample by centrifugation and higher viral RNA input. Resistance was defined as the detection of any NRTI, NNRTI or PR major resistance mutations. Virologic response was assessed 12 weeks after salvage therapy.ResultsEighteen patients, 50% male, median age 52, median CD4 405 cells/mm3, median pVL 596 copies/ml, median of number of previous regimens 5, 17 (94%) with successful genotype. Resistance mutations were detected in 14 patients (77%). All patients had NRTI mutations, four patients had NNRTI mutations and ten patients had PR mutations, most common mutations were M41L, D67N, M184V, K103N, M46I, I47V, I54V and L90M. Of these fourteen patients, nine started a genotype‐guided salvage regimen and presented a pVL &lt; 50 copies/ml after 12 weeks of follow up. For two patients there was previous genotypic information highlighting the selection and accumulation of resistance mutation during persistent low level viremia.ConclusionIn this group of heavily pretreated patients with persistent low viremia, a high frequency of genotypic resistance was observed; obtaining genotypic information may prevent further accumulation of resistance mutation and preserve future therapeutic options.

Factors predictive of successful darunavir/ritonavir-based therapy in highly antiretroviral-experienced HIV-1-infected patients (the DARWEST study)

Background Darunavir (DRV) is the latest protease inhibitor (PI) to be approved for antiretroviral-naive and -experienced HIV-infected patients. Objectives We examined virologic and immunologic outcomes of highly antiretroviral-experienced patients with triple-class drug resistance receiving DRV/r-based regimens, and attempted to identify factors predictive of virologic success. Study design We studied patients beginning a ritonavir-boosted DRV (DRV/r 600/100 mg twice daily)-containing regimen. Virologic success was defined as plasma viral load (pVL) < 50 copies/ml at week 36. Results We studied 62 patients with very severe immunodeficiency (CDC stage C in 69% of cases; median CD4 cell nadir 12/mm 3). They had previously received a median of four PI and had extensive PI resistance, with a median of three major PI and two DRV resistance mutations. The baseline median pVL and CD4 cell count values were 4.6 log 10 and 150/mm 3. At week 36, pVL had fallen by 2.6 log 10 and the CD4 cell count had risen by 123 cells/mm 3. The virologic success rate was 55% overall, and was improved by concomitant first use of enfuvirtide (67%), raltegravir (69%) or etravirine (75%). Virologic success was independently associated with fewer major PI mutations, previous tipranavir exposure, and concomitant first use of enfuvirtide or raltegravir. Conclusions In these highly antiretroviral-experienced patients with triple-class drug resistance, virologic success of DRV-containing regimens was mainly associated with the use of new drug classes and/or fully active drugs. Interestingly, previous tipranavir failure did not undermine the efficacy of DRV, confirming the low level of cross-resistance and, probably, distinct resistance profiles between DRV and tipranavir.

HIV-1-infected patients from the French National Observatory experiencing virological failure while receiving enfuvirtide

We studied gp41 mutations associated with failing enfuvirtide salvage therapy. This multicentre study involved patients with HIV-1 plasma viral load (pVL) > 5000 copies/mL after at least 3 months of uninterrupted enfuvirtide therapy and with plasma samples available at inclusion (T0), at initial enfuvirtide failure (T1) and at last follow-up visit during continued failing enfuvirtide therapy (T2). The HR-1 and HR-2 domains of the gp41 gene were sequenced at T0, T1 and T2. Ninety-nine patients were enrolled. At baseline, the median pVL and CD4 cell count were 5.1 log copies/mL and 72 cells/mm(3), respectively. Based on the ANRS Resistance Group algorithm, the proportion of patients harbouring viruses with enfuvirtide resistance mutations increased significantly between T0 and T1. In the HR-1 domain, the V38A/M, Q40H, N42T, N43D and L45M mutations wereselected (P < 0.02). In the HR-2 domain, no mutations were significantly selected during the follow-up. None of the mutations was associated with a CD4 cell count increment. Mutations selected during failing enfuvirtide salvage therapy are mainly located in the HR-1 domain of the gp41 gene, between codons 38 and 45. No mutations were associated with an increase in the CD4 cell count.

Dual Nucleoside Reverse Transcriptase Inhibitor Therapy in the Combination Antiretroviral Therapy Era and Predictors of Discontinuation or Switch to Combination Antiretroviral Therapy

Contrary to current HIV/AIDS management guidelines, and despite the arrival of potent combination antiretroviral therapy (cART) many years ago, some patients are still treated with dual nucleoside reverse transcriptase inhibitor (NRTI) regimens. We selected 5222 patients who received dual NRTI therapy for at least 6 months during 1998 to 2002, representing 9.9% of the 52,981 ARV-treated patients recorded in the French Hospital Database on HIV. Factors associated with switching to cART or with ARV discontinuation were identified by using Cox models. The 3-year probabilities of switching to cART and of antiretroviral (ARV) drug discontinuation were 55.2% (95% confidence interval [CI]: 53.8 to 56.7) and 10.9% (95% CI: 10.1 to 11.8), respectively, whereas 1591 patients (30.5%) kept the dual NRTI therapy during all the study period. Place of birth and region of care did not influence the choice of treatment strategy. After adjustment, the likelihood of switching to cART was lower among women, intravenous drug users, and patients with an undetectable plasma viral load (pVL) on at least 1 occasion during follow-up; in contrast, it was higher among patients with AIDS and those with a low CD4 cell count at enrollment or at the last follow-up visit. The likelihood of ARV discontinuation was higher among women and intravenous drug users and lower among patients with a low CD4 cell count at inclusion or at the last follow-up visit and among patients with an undetectable pVL on at least 1 occasion during follow-up. The likelihood of switching to cART or discontinuing ARV drugs was higher among patients receiving zidovudine/zalcitabine or didanosine/stavudine than among those receiving zidovudine/lamivudine. In France, until recent years, some patients (mainly women and intravenous drug users) were still receiving dual NRTI therapy despite free access to care and to highly effective ARV regimens. Dual NRTI therapy is gradually being replaced by cART, although some patients with satisfactory immunovirologic status are discontinuing all ARV drugs.

Intravenous Immunoglobulin (IVIG) Treatment for Modulation of Immune Activation in Human Immunodeficiency Virus Type 1 Infected Therapy-Naive Individuals

We evaluated the ability of intravenous immunoglobulin (IVIG) to diminish immune hyperactivation, which is considered a major cause of CD4+ T cell loss during chronic HIV-1 infection and whether this affected CD4+ T cell counts and plasma HIV-1 RNA (pVL). Therefore, we treated six chronically HIV-1-infected, antiretroviral-therapy-naive patients with IVIG (0.4 g/kg) at weeks 0 and 4, with a follow-up of 12 weeks after the second dosage during which pVL, T cell numbers, and T cell activation were measured. At baseline median CD4+ T cell counts were 300 (range 200-460) x 10(6)/liter and median pVL was 5.0 (range 3.2-5.2) log10 copies/ml. IgG plasma levels peaked during the first days after administration. We observed a decrease in the percentage of activated (CD38+ HLA-DR+) CD4+ and CD8+ T cells [3.5% (range 1-7%) and 5% (1-10%), respectively (p = 0.027)], but no effect on the fraction of proliferating CD4+ or CD8+ T cells as measured by Ki67 expression. CD4+ T cell counts were significantly increased on day 4 (median +55 cells, range 0-150, p = 0.043). pVL was significantly increased on day 1 after IVIG infusion (median +0.13 log10, range 0.01-0.55, p = 0.028). All these parameters returned to baseline levels within 1 week after infusion. In conclusion, administration of IVIG caused a temporary decrease in T cell activation and an increase in CD4+ T cell counts, despite an increase in pVL. Our results support the hypothesis that T cell activation, rather than direct HIV-1 infection, mediates the loss of CD4+ T cells and suggest that immunomodulating therapy in HIV-1 infection could indeed be effective.

Implementation of an Antiretroviral Access Program for HIV-1-Infected Individuals in Resource-Limited Settings

We assessed the effectiveness and safety of highly active antiretroviral therapy (HAART) in HIV-1-infected patients in resource-limited African countries. HIV-1 screening, therapy, counseling, monitoring, training, and education were provided free of charge. In an open-label cohort program, 206 antiretroviral-naive HIV-1-infected patients who could not afford HAART were recruited in 4 urban clinics in Senegal, Côte d'Ivoire, Uganda, and Kenya and were treated with saquinavir boosted with ritonavir (1600/100 mg once daily), lamivudine (150 mg twice daily), and zidovudine (300 mg twice daily). The primary outcome was a plasma viral load (pVL) of <400 copies/mL after 96 weeks of treatment. Secondary analyses included CD4 cell count changes and the occurrence of treatment-emergent adverse events. The median age of the patient group was 36 years, 38% were male, 35% of the patients had AIDS, the median CD4 count was 119 cells/microL, and the median pVL was 304,210 copies/mL. Overall, 65%/52% (on treatment [OT]/intent to treat [ITT]) of the patients had a pVL <400 copies/mL after 96 weeks of follow-up. This proportion varied significantly between sites, however; although in Nairobi and Dakar, 51%/40% and 56%/46% (OT/ITT) were found, respectively, Abidjan and Kampala showed proportions of 69%/54% and 83%/69% (OT/ITT), respectively. The median increase in the CD4 count was 198 cells/microL (interquartile range: 86-319 cells/microL), ranging from 191 to 292 cells/microL between the sites. Fourteen patients (6.8%) died between 8 and 96 weeks of follow-up, whereas 18 (9%) developed an AIDS-defining event between 8 and 96 weeks of follow-up. Non-HIV-related serious adverse events occurred in 55 patients (26.7%), of whom 13 were diagnosed with severe anemia. Thirty-five patients (17%) changed treatment for toxicity reasons. Although a statistically significant difference was observed between sites with respect to virologic success, overall virologic and immunologic responses to HAART in resource-limited African settings can be as good as in Western settings. There were some difficulties (eg, laboratory, logistics, proper training) during the early phase of the program. Therefore, provision of adequate medical care, counseling, proper instruction, and education of patients and medical staff during the entire study is warranted in such programs, with special care in the early phase.