Differentiation of exhausted CD8+ T cells after termination of chronic antigen stimulation stops short of achieving functional T cell memory.

T cell exhaustion is associated with failure to clear chronic infections and malignant cells. Defining the molecular mechanisms of T cell exhaustion and reinvigoration is essential to improving immunotherapeutic modalities. Here we confirmed pervasive phenotypic, functional and transcriptional differences between memory and exhausted antigen-specific CD8+ T cells in human hepatitis C virus (HCV) infection before and after treatment. After viral cure, phenotypic changes in clonally stable exhausted T cell populations suggested differentiation toward a memory-like profile. However, functionally, the cells showed little improvement, and critical transcriptional regulators remained in the exhaustion state. Notably, T cells from chronic HCV infection that were exposed to antigen for less time because of viral escape mutations were functionally and transcriptionally more similar to memory T cells from spontaneously resolved HCV infection. Thus, the duration of T cell stimulation impacts exhaustion recovery, with antigen removal after long-term exhaustion being insufficient for the development of functional T cell memory.

Early Transcriptional Divergence Marks Virus-Specific Primary Human CD8+ T Cells in Chronic versus Acute Infection.

Distinct molecular pathways govern the differentiation of CD8+ effector T cells into memory or exhausted T cells during acute and chronic viral infection, but these are not well studied in humans. Here, we employed an integrative systems immunology approach to identify transcriptional commonalities and differences between virus-specific CD8+ T cells from patients with persistent and spontaneously resolving hepatitis C virus (HCV) infection during the acute phase. We observed dysregulation of metabolic processes during early persistent infection that was linked to changes in expression of genes related to nucleosomal regulation of transcription, T cell differentiation, and the inflammatory response and correlated with subject age, sex, and the presence of HCV-specific CD4+ T cell populations. These early changes in HCV-specific CD8+ T cell transcription preceded the overt establishment of T cell exhaustion, making this signature a prime target in the search for the regulatory origins of T cell dysfunction in chronic viral infection.

HIV-1 p24 and CD4+ T cell count during boosted protease-inhibitor monotherapy in HIV-infected patients.

BACKGROUND: Plasma HIV p24 is considered a significant predictor of CD4+ T cell decline and progression to AIDS in HIV-infected patients. We evaluated the p24 levels in patients on triple therapy and after switching to ritonavir-boosted protease inhibitor monotherapy (mtPI/rtv), as well as the relationships with virological and immunological evolution. MATERIALS AND METHODS: Plasma samples from patients participating in two studies of simplification to mtPI/rtv were analysed for presence of p24, using a boosted enzyme-linked immunosorbent assay specific for mature p24. Only patients with available samples at baseline (on triple therapy) and during a follow-up of at least 12 months after switching to mtPI/rtv were included. RESULTS: A total of 233 samples from 51 patients were analysed. After switching to mtPI/rtv and a median follow-up of 24 months, 14 patients maintained continuous undetectable viraemia, and 37 patients experienced a total of 49 transient viraemic episodes. Unexpectedly, the evolutionary p24 patterns were uniform for most patients, both before and after switching to mtPI/rtv, independently of the virological behaviour, fitting into one of three categories: persistent undetectable p24 levels, positive p24, matching only with the viraemic episodes, and persistent detectable p24 levels. The last group showed lower CD4+ T cell counts and percentages, as well as lower CD4+/CD8+ T cell ratios after 12 and 24 months of follow up. CONCLUSION: Treatment simplification to mtPI/rtv does not influence the behaviour of p24 in plasma. Patients with continuous positive p24, despite undetectable viraemia, showed worse immunological evolution.

Telaprevir and ribavirin interaction: higher ribavirin levels are not only due to renal dysfunction during triple therapy.

A higher incidence of anemia has been observed during the treatment of hepatitis C virus genotype 1 (HCV-1) infection with pegylated alpha interferon (pegIFN-α), ribavirin, and telaprevir. We assessed the impacts that concomitant administration of telaprevir and changes in the glomerular filtration rate have on ribavirin plasma levels. The minimum concentrations of ribavirin in plasma (ribavirin Cmin) determined during triple therapy including telaprevir were compared with those observed after telaprevir withdrawal and those observed in the same subjects and in a large cohort during a previous course of pegIFN-α plus ribavirin. Intensive pharmacokinetic sampling for ribavirin was performed at steady state during the triple-therapy phase. Ribavirin levels were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Twenty-seven HCV-1/HIV-coinfected patients were enrolled. The median ribavirin Cmin for triple therapy (4.08 µg/ml; range, 2.14 to 5.56 µg/ml) was higher than that observed after telaprevir withdrawal (1.96 µg/ml; range, 0.41 to 3.45 µg/ml) (P < 0.001) and that observed for 125 HCV-1/HIV-coinfected patients treated only with pegIFN-α plus ribavirin (1.65 µg/ml; range, 0.41 to 5.56 µg/ml) (P < 0.001). The estimated glomerular filtration rate (eGFR) decreased >20% from the baseline value in 11 of 27 patients and became normal after telaprevir removal in almost all cases. There was a negative correlation between eGFR and ribavirin clearance (r(2) = 0.257; P = 0.064) but not the ribavirin area under the concentration-time curve from 0 to 12 h (AUC0-12) (r(2) = 0.001; P = 0.455). Thus, there is a significant pharmacokinetic interaction between telaprevir and ribavirin that results in very high ribavirin levels, which explains the excess of toxicity observed with this drug combination. A blockade of the proximal tubular transporters might be implicated in both the increase in plasma creatinine and the high ribavirin levels. (This study has been registered at ClinicalTrials.gov under registration no. NCT01818856.).

Role of ritonavir in the drug interactions between telaprevir and ritonavir-boosted atazanavir.

BACKGROUND: Detrimental bidirectional pharmacokinetic interactions have been observed when telaprevir (TVR) and ritonavir (RTV)-boosted human immunodeficiency virus (HIV) protease inhibitors are coadministered in healthy volunteers. Our aim was to evaluate the role of RTV in the bidirectional TVR and atazanavir (ATV) interactions. METHOD: An open-label, sequential study was carried out in hepatitis C virus (HCV)/HIV-coinfected patients on a RTV-boosted ATV-based (ATVr) antiretroviral regimen (300/100 mg every 24 hours) and triple therapy for chronic C hepatitis genotype 1 (TVR, 1125 mg every 12 hours, pegylated interferon-alpha and ribavirin). Pharmacokinetic profiles were acquired before and after switching from ATVr to unboosted ATV (200 mg every 12 hours). The plasma levels of both drugs were determined by liquid chromatography coupled with mass spectrometry. Pharmacokinetic parameters were calculated by noncompartmental analysis and compared by geometric mean ratios and their 90% confidence intervals. RESULTS: Fourteen white HCV/HIV-coinfected males were enrolled in this study. After RTV was withdrawn, the TVR AUC(0-12) (area under the concentration-time curve), maximum concentration (C(max)), and minimum concentration (C(min)) values increased by 19% (7%-30%), 12% (0.9%-29%), and 18% (2%-34%), respectively, without any changes in the TVR terminal half-life. The ATV AUC(0-12), C(max), and C(min) values were 39% (13%-66%), 19% (8%-59%), and 48% (1%-96%) higher, respectively, with a significantly shorter terminal half-life (22.6 hours vs 10.4 hours). CONCLUSIONS: RTV is responsible for the adverse interactions that occur when TVR and ATVr are administered together, possibly by influencing either the absorption phase or first-pass metabolism of TVR. The boost effect of TVR on ATV exposure is higher than on RTV, despite its shorter terminal half-life. The coadministration of TVR and unboosted ATV results in increased exposure of both drugs compared with their coadministration with RTV. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov: NCT01818856. European Medicines Agency EudraCT no. 2012-002515-25.

Risk of liver decompensation among HIV/hepatitis C virus-coinfected individuals with advanced fibrosis: implications for the timing of therapy.

BACKGROUND: Most human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-infected patients who are currently receiving boceprevir or telaprevir-based therapy against HCV show cirrhosis. However, the risk of liver decompensation (DC) among HIV/HCV-coinfected patients with stage 3 fibrosis in the short term could be high enough to not allow delays. We aimed at assessing the risk of DC among HIV/HCV-coinfected individuals with advanced fibrosis (F3-F4). METHODS: Eight hundred ninety-two HIV/HCV-coinfected patients, naive or without sustained virologic response to HCV therapy, were included in this cohort. Fibrosis was staged by biopsy in 317 patients and by liver stiffness measurement (LSM) in 575 individuals. Precirrhosis was defined as an LSM of 9.5-14.6 kilopascals (kPa), and cirrhosis as an LSM of ≥14.6 kPa. RESULTS: For patients with biopsy, the probability of remaining free of DC for F3 vs F4 was 99% (95% confidence interval [CI], 95%-100%) vs 96% (95% CI, 91%-98%) at 1 year, and 98% (95% CI, 94%-100%) vs 87% (95% CI, 81%-92%) at 3 years. The only factor independently associated with DC was fibrosis stage (F4 vs F3, subhazard ratio [SHR], 2.1; 95% CI, 1.07-4.1; P = .032). For patients with LSM, the probability of remaining free of DC for precirrhosis vs cirrhosis was 99% (95% CI, 96%-100%) vs 93% (95% CI, 89%-96%) at 1 year, and 97% (95% CI, 94%-99%) vs 83% (95% CI, 77%-87%) at 3 years. Factors independently associated with DC were platelet count (<100 × 10(3) vs ≥100 × 10(3): SHR, 1.86; 95% CI, 1.01-3.42; P = .046) and LSM (cirrhosis vs precirrhosis: SHR, 5.67; 95% CI, 2.27-14.1; P < .0001). CONCLUSIONS: As in patients with cirrhosis, immediate therapy against HCV is warranted for patients with precirrhosis and HIV coinfection, as they are at risk of DC soon after the diagnosis of advanced fibrosis.

Benefits from sustained virologic response to pegylated interferon plus ribavirin in HIV/hepatitis C virus-coinfected patients with compensated cirrhosis.

BACKGROUND: The objective of this study was to determine the impact of sustained virologic response (SVR) to pegylated interferon (peg-IFN) plus ribavirin (RBV) on the incidence of liver-related complications and overall mortality in human immunodeficiency virus (HIV)-infected patients with compensated hepatitis C virus (HCV)-related cirrhosis. METHODS: We included in this prospective cohort study 166 coinfected patients with compensated cirrhosis, who received peg-IFN plus RBV, to assess the time from the starting date of HCV therapy to the first hepatic decompensation and death due to any cause. RESULTS: SVR was observed in 43 (25%) individuals. Two (4.6%) patients with SVR developed liver decompensation vs 33 (26.8%) individuals without SVR (P = .002). The incidence of liver-related complications was 0.89 cases per 100 person-years (95% confidence interval [CI], .11-3.1) in SVR patients and 6.4 cases per 100 person-years (95% CI, 4.5-8.9) in non-SVR patients. Factors independently associated with liver decompensation were non-SVR (hazard ratio [HR], 8.1; 95% CI, 1.08-61.5; P = .042) and MELD score ≥9 at baseline (HR, 2.9; 95% CI, 1.2-7.2; P = .016). Two (4.6%) patients with SVR died due to any cause compared with 22 (17.9%) individuals without SVR (P = .02). MELD score ≥9 (HR, 3.1; 95% CI, 1.3-7.7; P = .011) and non-SVR (HR, 8.0; 95% CI, 1.07-61; P = .043) were independently associated with overall mortality. CONCLUSIONS: The achievement of SVR following peg-IFN plus RBV markedly reduces the incidence of liver-related decompensation and the overall mortality in HIV/HCV-coinfected patients with compensated cirrhosis.

Lopinavir plasma concentrations and virological outcome with lopinavir-ritonavir monotherapy in HIV-1-infected patients.

There is significant intra- and intersubject variability in lopinavir (LPV) plasma concentrations after standard dosing; thus, this prospective study was conducted to determine whether low plasma LPV concentrations could be associated with virological outcome throughout lopinavir-ritonavir maintenance monotherapy (mtLPVr) in the clinical practice setting. If this hypothesis would be confirmed, LPV drug monitoring could improve the efficacy of mtLPVr regimens. Patients with previous virological failure (VF) on protease inhibitor-based regimens were also included if the genotypic resistance tests showed no major resistance mutation associated with reduced susceptibility to lopinavir-ritonavir. VF was defined as 2 consecutive determinations of HIV RNA levels of >200 copies/ml. Efficacy was analyzed by per-protocol analysis. Plasma LPV trough concentrations were measured by high-performance liquid chromatography using a UV detector. A total of 127 patients were included (22% with previous failure on protease inhibitors). After 96 weeks, the efficacy rate was 82.3% (95% confidence interval [CI(95)], 75.3 to 89.3%). Virological efficacy was independent of LPV plasma concentrations even when LPVr was given once daily. An adherence of <90% (HR, 4.4 [CI(95), 1.78 to 10.8; P = 0.001]) and the presence of blips in the preceding 12 months (HR, 3.06 [CI(95), 1.17 to 8.01; P = 0.022]) were the only variables independently associated with time to VF. These findings suggest that the LPV concentrations achieved with the standard doses of LPVr are sufficient to maintain virological control during monotherapy and that measurement of LPV concentrations is not useful for predicting virological outcome. Tight control of viral replication in the previous months and strict adherence throughout the mtLPVr regimen could improve the virological efficacy of this maintenance regimen.

Prediction of response to pegylated interferon plus ribavirin in HIV/hepatitis C virus (HCV)-coinfected patients using HCV genotype, IL28B variations, and HCV-RNA load.

BACKGROUND & AIMS: This study aimed at developing a predictive algorithm based on interleukin 28B (IL28B) genotype, hepatitis C virus (HCV) genotype, and plasma HCV-RNA load, which could accurately allow us to define the probability of response to pegylated interferon (Peg-IFN) plus ribavirin (RBV) therapy in HIV/HCV-coinfected patients. METHODS: Five hundred and twenty-one treatment-naive HIV-infected patients, who initiated HCV therapy with Peg-IFN/RBV, were analysed in an on-treatment basis. Patients were categorized as unlikely responders, uncertain responders, and anticipated responders (<20%, 20-60%, and >60% probability to achieve SVR, respectively). RESULTS: HCV genotype, baseline HCV-RNA load, and IL28B genotype were confirmed as independent predictors of SVR in a logistic regression analysis. A stepwise algorithm based on these three variables was created based on 321 patients and evaluated in the remaining 200 patients. Unlikely responders included patients with genotype 1 or 4, HCV-RNA load ≥600,000IU/ml, and rs12979860 non-CC (rate of SVR: 17.3%). Anticipated responders were those with HCV genotype 2-3, patients harboring HCV genotype 4 and IL28B CC, as well as those who simultaneously bore HCV genotype 1, HCV-RNA load <600,000IU/ml, and IL28B CC (rate of SVR 74.1%, 77.8%, and 64.4%, respectively). The area under the receiver operating characteristic curve of the model was 0.77 (0.733-0.814). CONCLUSIONS: The combined use of IL28B genotype, HCV genotype, and HCV-RNA load enables to easily identify patients with a high and very low likelihood of SVR. HCV therapy could be deferred in the latter patients, until more effective options are available, at least if they do not show advanced liver fibrosis.

Intracellular and plasma pharmacokinetics of 400 mg of etravirine once daily versus 200 mg of etravirine twice daily in HIV-infected patients.

OBJECTIVES: To compare intracellular and plasma etravirine concentrations when etravirine was given at 200 mg/12 h versus 400 mg/24 h and to evaluate whether the results would support once-daily dosing. METHODS: This was an open-label sequential study in which eight patients on protease inhibitor (PI)-sparing regimens containing etravirine were included. Full pharmacokinetic profiles were performed while on 200 mg of etravirine/12 h and after switching to 400 mg of etravirine/24 h. Intracellular and plasma levels were determined by liquid chromatography coupled with mass spectrometry. Pharmacokinetic parameters were calculated by non-compartmental analysis and compared by geometric mean ratios (GMRs) using 200 mg of etravirine/12 h as the reference group. TRIAL REGISTRATION: ClinicalTrials.gov NCT01121809. RESULTS: The geometric mean (GM) for etravirine AUC(0-τ) (5602 versus 5076 ng · h/mL, GMR 0.91), C(max) (403 versus 495 ng/mL, GMR 1.23) and C(min) (139 versus 102 ng/mL, GMR 0.74) were similar with both dosing schedules at the intracellular level. In plasma, the GMRs for AUC(0-τ), C(max) and C(min) were 1.31, 1.76 and 0.99, respectively. The mean intracellular penetration, evaluated as intracellular and plasma AUC(0-τ) ratios, was 81% when etravirine was dosed twice daily and 56% with once-daily dosing. CONCLUSIONS: Our results show that intracellular etravirine levels were similar with both dosing regimens in patients with PI-sparing regimens, while etravirine plasma AUC(0-τ) and C(max) were 30% and 76% higher with the once-daily regimen, respectively. Thus, a once-daily dosing regimen is supported not only by plasma etravirine pharmacokinetic profiles but also by intracellular levels.

Liver toxicity associated with antiretroviral therapy including efavirenz or ritonavir-boosted protease inhibitors in a cohort of HIV/hepatitis C virus co-infected patients.

OBJECTIVES: To compare the frequency of grade 3 or 4 transaminase elevations (TEs) in HIV/hepatitis C virus (HCV) co-infected patients who started a three-antiretroviral drug regimen including efavirenz or a ritonavir-boosted protease inhibitor (PI/r) and the influence of pre-existing significant hepatic fibrosis or cirrhosis. PATIENTS AND METHODS: All pre-treated or treatment-naive HIV/HCV co-infected patients who started an antiretroviral regimen including two nucleos(t)ide reverse transcriptase inhibitors along with efavirenz or a PI/r in seven Spanish centres from January 2007 to December 2009 were included in this prospective study. RESULTS: Of 262 patients included in this study, 76 (29%) individuals began antiretroviral therapy (ART) including efavirenz and 186 (71%) a PI/r-based combination. The median (interquartile) follow-up was 14.0 (6.2-23.7) months. A total of 20 (7.6%) patients presented grade 3-4 TEs. Four (1.5%) subjects discontinued ART due to this adverse event. Grade 3-4 TEs were observed in 5 (6.6%) subjects receiving efavirenz and 15 (8.1%) treated with PI/r (P = 0.681). Three (6.5%) patients in the efavirenz group with significant fibrosis developed grade 3-4 TEs versus 2 (8.7%) without pre-existing significant fibrosis (P = 0.743). In the PI/r group, the corresponding figures were 10 (8.8%) and 5 (9.3%), respectively (P = 0.931). CONCLUSIONS: The frequency of grade 3-4 TEs associated with efavirenz-based ART combinations under clinical practice conditions is low and similar to that found in patients receiving PI/r currently used in HIV/HCV co-infected patients. The baseline fibrosis stage does not have an impact on the development of TEs caused by these antiretroviral drugs in this population.

CD4+ T cell restoration and control of hepatitis C virus replication after childbirth.

Chronic hepatitis C virus (HCV) infection is characterized by persistent high-level viremia and defective cellular immunity, including a lack of functional HCV-specific CD4+ T cells. We previously described an exceptional period of viral control that occurs in some chronically infected women after childbirth. Here, we investigated whether reduced HCV replication after pregnancy is associated with recovery of CD4+ T cell immunity. Class II tetramer analysis revealed significantly greater frequencies of circulating HCV-specific CD4+ T cells at 3 months postpartum in women with concurrent declines in viremia compared with those with stable viremia. These HCV-specific CD4+ T cells had an effector-memory phenotype. Inhibitory coreceptor expression on these cells corresponded to the degree of viral control. Circulating CD4+ T cells produced IL-2 and IFN-γ after HCV antigen stimulation, demonstrating Th1 functionality. These data provide direct evidence that the profound loss of HCV-specific CD4+ T cell help that results in chronic infection is reversible following pregnancy, and this recovery of CD4+ T cells is associated with at least transient control of persistent viral replication.

Evolution of the innate and adaptive immune response in women with acute Zika virus infection.

Zika virus (ZIKV) is a flavivirus that is closely related to other human pathogens, such as dengue virus (DENV)1. Primary transmission usually involves Aedes aegypti, which has expanded its distribution range considerably2, although rarer infection routes, including mother-to-fetus transmission, sexual contact and blood transfusion, have also been observed3-7. Primary ZIKV infection is usually asymptomatic or mild in adults, with quickly resolved blood viraemia, but ZIKV might persist for months in saliva, urine, semen, breast milk and the central nervous system8-12. During a recent ZIKV outbreak in South America, substantial numbers of neurological complications, such as Guillain-Barré syndrome, were reported13,14 together with cases of microcephaly and associated developmental problems in infants born to women infected with ZIKV during pregnancy15-20, highlighting the clinical importance of this infection. Analyses of the human immune response to ZIKV are lacking21-28, but the recent outbreak has provided an opportunity to assess ZIKV immunity using current immunological methods. Here, we comprehensively assess the acute innate and adaptive immune response to ZIKV infection in ten women who were recruited during early infection and followed through reconvalescence. We define a cascade of events that lead to immunological control of ZIKV, with previous exposure to DENV impacting some, but not all, mediators of antiviral immunity.

Hurdles to the Development of Effective HBV Immunotherapies and HCV Vaccines.

Chronic infections with HBV and HCV continue to be major public health problems, with hundreds of millions of people infected worldwide; this is despite the availability of both an effective prophylactic HBV vaccine for more than 3 decades and potent direct antivirals for HBV and, more recently, HCV infection. Consequently, development of HBV immunotherapies and prophylactic HCV vaccines remains extremely urgent, but limited funding and significant gaps in our understanding of the correlates of immune protection pose serious hurdles for the development of novel immune-based interventions. Here we discuss immunological questions related to HBV and HCV, some shared and some pertinent to only 1 of the viruses, that should be addressed for the rational design of HBV immunotherapies and HCV vaccines.

Higher Activation in CD4(+) T Cells But Similar Viral Control Among HIV/Hepatitis C Virus-Coinfected Patients on a Simplification Monotherapy.

The aim of this study was to assess whether hepatitis C virus (HCV) coinfection would affect the clinical and immunological outcome of HIV-infected patients following a simplification strategy. A prospective cohort of HIV-infected patients starting a ritonavir boosted darunavir monotherapy (mtDRV/rtv) was followed for 24 months. HCV infection was evaluated by HCV viremia and hepatic fibrosis. Immune activation was studied as HLA-DR CD38 coexpression on CD4(+) and CD8(+) T cells and also the quantification of plasma sCD14 levels. Microbial translocation was studied by the plasma levels of 16S rDNA and lipopolysaccharide (LPS). A total of 150 HIV-infected patients were enrolled in this study, including 46 individuals also infected with HCV (30.6%). HIV/HCV coinfection did not decrease mtDRV/rtv efficacy, since similar rates of HIV-1 intermittent viremia (HCV: 26.6% vs. no-HCV: 34.7%) and episodes of virological failure (HCV: 22.2% vs. no-HCV: 11.2%, p-value = 0.381) were found. No major differences were found between both groups at baseline, although higher HLA-DR(+)CD38(+)CD4(+) T cell counts were found in the coinfected group (HCV: 6.65% vs. no-HCV: 4.55%, p-value = 0.032); this difference was maintained in the 24 months of follow-up. After the 24-month follow-up, both groups, HIV-monoinfected patients and HIV/HCV-coinfected patients, presented similar immune activation and microbial translocation profiles. In conclusion, the use of a simplified mtDRV/rtv strategy compromises neither HIV nor HCV viremic control in coinfected patients, although a higher immune activation of CD4(+) T cells was found.

Does Once-Daily Raltegravir Have Any Role in the Antiretroviral Treatment?

Administering raltegravir once daily would make adherence to antiretroviral treatment easier, especially if the concomitant drugs are also administered once daily. We report our experience on the use of raltegravir, both once- and twice-daily.Retrospective review of HIV-infected patients on treatment with raltegravir 800 mg once or 400 mg twice a day plus 2 analogs. Patients were classified as group A (subjects switched to raltegravir due to adverse events on a previous regimen or drug-drug interactions) and group B (subjects who restarted antiretroviral treatment after a previous drop-out). The primary clinical endpoint was the percentage of subjects with virological suppression after 96 weeks. Treatment's effectiveness (noncomplete/missing equals failure) was also evaluated. Pharmacokinetic study was performed in unselected patients. Plasma raltegravir concentrations were determined by high-performance liquid chromatography coupled with mass spectrometry.A total of 133 patients were included in the study (74 and 59 on raltegravir once- and twice-daily). There were only 4 virological failures in the entire cohort during the follow-up. Thus, the Kaplan-Meier estimation of efficacy by on-treatment analysis was 96.3% (CI95, 92.8-99.8) at week 96, independently of the dosing regimen and of the raltegravir concentrations. Similar exposures to raltegravir based on AUC0-τ, but higher Cmax and significantly lower Ctrough were observed when raltegravir was given once daily compared with 400 mg twice daily. In fact, 14 out of 56 Ctrough concentrations (25%) from patients taking raltegravir once daily were below the IC95 of wild-type HIV-1 clinical isolates while only 2 samples from patients receiving 400 mg twice a day were below this value, although no relationship between Ctrough and efficacy was found. The main limitations of the study are that the raltegravir dosing regimen was not randomized and more than 50% of the patients were virologically suppressed at baseline.Regimens comprising raltegravir 800 mg once daily plus 2 nucleos(t)ide reverse transcriptase inhibitors can be an efficacious and safe option, particularly in virologically suppressed patients and those with a viral load <100,000 copies/mL.

Differential effects of viremia and microbial translocation on immune activation in HIV-infected patients throughout ritonavir-boosted darunavir monotherapy.

The purpose of this article is to evaluate the evolution of microbial translocation (MT) and its role in CD4 and CD8 T cells immune activation (IA) in HIV-1-infected patients on ritonavir-boosted darunavir monotherapy (mtDRV/rtv).Prospective study of consecutive HIV-1-infected patients switched to mtDRV/rtv as a simplification regimen. Subjects were classified according to the virological behavior during a 24-month follow-up as continuous undetectable viral load, blips, intermittent viremia, and virological failure (VF). MT was evaluated by plasma LPS and 16S genomic rDNA (16S rDNA) levels, whereas IA was assessed by the coexpression of HLA-DR and CD38 in CD4 and CD8 T cells, and plasma sCD14 levels.Seventy-one patients were included in this substudy of the MonDar cohort (ClinicalTrials.gov: NCT01505722). At baseline, CD4 (ρ = -0.352, P = 0.01) and CD8 T-cell activation (ρ = -0.468, P < 0.001) were correlated with time with viral suppression, but not with MT markers. A significant decrease in plasma LPS levels was found only in patients without VF (baseline, 77.8 vs month 24, 60.4 pg/mL; P < 0.001]. Both plasma 16S rDNA and sCD14 levels were unchanged irrespective of the viral behavior. The only variable independently associated with a decrease in CD4 and CD8 T cells activation was an undetectable HIV-1 viremia (ß = 4.78, P < 0.001 and ß = 2.93, P = 0.005, respectively).MT does not have a pivotal role in T-cell activation, at least in patients with long-term viral suppression. The viremic episodes and VF are the main factors related to CD4 and CD8 T-cells IA, even during mtDRV/rtv.

Cellular HIV reservoir replenishment is not affected by blip or intermittent viremia episodes during darunavir/ritonavir monotherapy.

OBJECTIVE: To assess the impact of blips and persistent viremia episodes on cell-associated HIV-DNA reservoir in extensively pretreated patients receiving ritonavir-boosted darunavir monotherapy (MtDRV/rtv) for 24 months. DESIGN AND METHODS: Patients from the MonDAR prospective study (NCT01606722) who received at least 6 months of MtDRV/rtv and had at least two available peripheral blood mononuclear cells (PBMCs) samples were selected and classified according to the viral outcome as continuous undetectable viremia (cUV; n = 40), blips (n = 31), intermittent viremia (IV; n = 23), and virological failure (VF, two consecutive viral loads >200 copies/ml; n = 20). Proviral HIV-DNA was quantified by real-time PCR in PBMCs samples at baseline, and months 6, 12, 18 and 24. Additionally, HIV-DNA levels were exhaustively analyzed at virological failure and blip episodes. RESULTS: The HIV-DNA levels remained constant during the 24 months in every group. Neither blips nor intermittent viremia influenced the HIV-DNA levels at short-term or at middle term. By contrast, virological failure episodes gave rise to a significant increase in proviral DNA (2.15 vs. 2.32 log10 HIV-DNA copies/10 PBMCs; P = 0.042). Basal proviral DNA levels more than 2 log10 copies/10 PBMCs predicted the time to viral rebound at any given cut-off point (>20, >50, and >200 copies/ml. HR: 3.02, 2.61, and 3.02, respectively; P ≤ 0.03. Besides, an adherence less than 95% was also strongly associated with virological failure (HR, 3.17; P = 0.021). CONCLUSION: Blip episodes and intermittent viremia did not affect the cellular HIV reservoir dynamic during MtDRV/rtv. Higher adherence and an HIV-DNA levels less than 2 log10 copies/10 PBMCs at baseline were associated with a lower risk of virological failure.

Darunavir minimum plasma concentration and ritonavir-boosted darunavir monotherapy outcome in HIV-infected patients.

BACKGROUND: This study aimed to evaluate whether low darunavir (DRV) minimum plasma concentration (Cmin) values contribute to virological outcomes during DRV/ritonavir monotherapy (mtDRV/rtv). METHODS: This was a prospective observational single-arm 96-week efficacy study in virologically suppressed subjects on triple therapy switched to mtDRV/rtv (800/100 mg every 24 h). Previous virological failures (VF) on protease-inhibitor-based regimens were allowed if the historical resistance tests showed no major resistance mutation to DRV/rtv. VF was defined as two consecutive HIV RNA measurements of >200 copies/ml. Efficacy was analysed by per-protocol and by intention-to-treat analyses. Plasma DRV Cmin values were measured by LC-MS/MS. RESULTS: A total of 150 subjects were included. At week 96, the efficacy rate on treatment was 83.6% (95% CI 77.2%, 90.0%) by per-protocol analysis and 67.6% (95% CI 60.0%, 75.2%) by intention-to-treat. In the whole cohort the median (IQR) DRV Cmin was significantly higher during the periods of undetectable than of detectable viraemia (1.82 µg/ml [1.47-2.46] versus 1.56 µg/ml [0.93-2.32]; P=0.006) as well as in the subjects with blips and VF. However, a cutoff point sufficiently sensitive and specific could not be found. CONCLUSIONS: The DRV Cmin values are related to viral control during mtDRV/rtv, but therapeutic drug monitoring cannot be recommended routinely as a precise cutoff point is unknown. Adherence is a key success factor on this regimen.

Liver fibrosis, host genetic and hepatitis C virus related parameters as predictive factors of response to therapy against hepatitis C virus in HIV/HCV coinfected patients.

OBJECTIVE: To establish the role of liver fibrosis as a predictive tool of response to pegylated interferon alpha (Peg-IFN) and ribavirin (RBV) treatment in human immunodeficiency (HIV)/hepatitis C virus (HCV) coinfected patients, in addition to recognized predictive factors (HCV load, HCV genotype, IL-28B polymorphism). PATIENTS AND METHODS: A sample of 267 HIV/HCV coinfected patients was treated with Peg-IFN and RBV. Predictive factors of rapid (RVR) and sustained (SVR) virological response were analyzed. Independent variables were age, sex, IL28B, -238 TNF-α and -592 IL-10 polymorphisms, HCV genotype, HCV-RNA levels, significant fibrosis or cirrhosis and CD4+ T cell count. RESULTS: Patients infected by HCV genotype 1 (n = 187) showed RVR and SVR in 12% and 39% of cases, respectively. The parameters associated with RVR were IL28B genotype CC and plasma HCV-RNA levels <600,000 IU/ml. Advanced liver fibrosis was negatively associated with SVR in patients without RVR. A SVR was obtained in 42% of subjects with HCV genotype 4, and the independent factors associated with SVR were IL28B genotype CC and an HCV-RNA <600,000 IU/ml. A SVR was obtained in 66% of patients with HCV genotypes 2/3; in this case, the independent parameter associated with SVR was the absence of significant liver fibrosis. TNF-α and IL-10 polymorphisms were not associated with SVR, although a significantly higher percentage of -238 TNF-α genotype GG was detected in patients with significant liver fibrosis. CONCLUSIONS: In HIV/HCV coinfected patients with HCV genotypes 1 or 4, RVR, mainly influenced by genotype IL28B and HCV-RNA levels, reliably predicted SVR after 4 weeks of therapy with Peg-IFN plus RBV. In patients infected by HCV genotype 3, an elevated relapse rate compromised the influence of RVR on SVR. Relapses were related to the presence of advanced liver fibrosis. Liver cirrhosis was associated with a -238 TNF-α polymorphism in these patients.