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HIV-2 is a neglected virus despite estimates of 1–2 million people being infected worldwide. AIDS develops more slowly in HIV-2 than HIV-1. Outside endemic regions, HIV-2 is mostly found in immigrants from west Africa or their sex partners. There are four major caveats when treating HIV-2. First, some antiretrovirals are not or only partially active against HIV-2. Second, CD4 declines in HIV-2 occur slowly, but CD4 recovery is smaller with antiretroviral treatment. Third, both virological failure and rapid emergence of drug resistance occur more frequently in HIV-2 than HIV-1. Finally, misdiagnosis of HIV-2 in patients wrongly considered as infected with HIV-1 or in those dually infected may result in treatment failures with undetectable HIV-1 RNA. Integrase inhibitors, and especially dolutegravir, should be part of any preferred HIV-2 antiretroviral combination nowadays.

Background: The Winter-Tozer (WT) equation has been shown to reliably predict free phenytoin levels in healthy patients. In patients with end-stage renal disease (ESRD), phenytoin-albumin binding is altered and, thus, affects interpretation of total serum levels. Although an ESRD WT equation was historically proposed for this population, there is a lack of data evaluating its accuracy. Objective: The objective of this study was to determine the accuracy of the ESRD WT equation in predicting free serum phenytoin concentration in patients with ESRD on hemodialysis (HD). Methods: A retrospective analysis of adult patients with ESRD on HD and concurrent free and total phenytoin concentrations was conducted. Each patient’s true free phenytoin concentration was compared with a calculated value using the ESRD WT equation and a revised version of the ESRD WT equation. Results: A total of 21 patients were included for analysis. The ESRD WT equation produced a percentage error of 75% and a root mean square error of 1.76 µg/mL. Additionally, 67% of the samples had an error >50% when using the ESRD WT equation. A revised equation was found to have high predictive accuracy, with only 5% of the samples demonstrating >50% error. Conclusion: The ESRD WT equation was not accurate in predicting free phenytoin concentration in patients with ESRD on HD. A revised ESRD WT equation was found to be significantly more accurate. Given the small study sample, further studies are required to fully evaluate the clinical utility of the revised ESRD WT equation.

Background The hepatitis delta virus (HDV) causes the most aggressive form of chronic viral hepatitis. As HDV replication requires hepatitis B virus (HBV), HDV screening is limited to HBsAg+ carriers. To date, individuals with HDV-antibodies and markers of resolved hepatitis B are considered cured. However, a subset shows elevated liver enzymes and hepatic fibrosis. Could they represent HBsAg-seronegative occult HDV infections? Methods We tested for HDV-antibodies 406 individuals with markers of past HBV exposure. Results Overall, 20 (4.9%) were reactive for HDV-antibodies. All were negative for serum HDV-RNA, including four with elevated liver enzymes. Conclusion These results support the current policy of screening for hepatitis delta only in HBsAg+ individuals.

In October 2018 a large number of international experts with complementary expertise came together in Taormina to participate in a workshop on occult hepatitis B virus infection (OBI). The objectives of the workshop were to review the existing knowledge on OBI, to identify issues that require further investigation, to highlight both existing controversies and newly emerging perspectives, and ultimately to update the statements previously agreed in 2008. This paper represents the output from the workshop.

Vemurafenib tolerability was assessed in a large, open-label, multicentre study in patients with BRAF V600 mutated advanced melanoma. We investigated safety, tolerability and efficacy of vemurafenib in Spanish patients participating in that study. Patients with previously treated or treatment-naive, unresectable stage IIIC or stage IV, BRAF V600 mutation-positive melanoma received vemurafenib 960 mg twice daily until disease progression, unacceptable toxicity, withdrawal of consent or death. The primary endpoint was safety; secondary endpoints included overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). 301 Spanish patients were included, 70 % with M1c disease, 22 % with brain metastases and 51 % with prior systemic therapy for metastatic disease. Most frequent adverse events included fatigue (48 %), arthralgia (45 %), rash (41 %), photosensitivity (34 %) and skin neoplasms (21 %). Grade 3/4 adverse events occurred in 156 patients (52 %), including cutaneous squamous cell carcinoma (including keratoacanthoma; 16 %), fatigue (6 %) and arthralgia (5 %). The ORR was 28 % (95 % CI 23–34 %). Responses occurred in patients with brain metastases (18 %), elevated baseline lactate dehydrogenase (19 %) and poor performance status (15 %), and elderly patients (22 %). Median PFS was 5.8 (95 % CI 5.0–6.4) months; median OS was 10.5 (95 % CI 9.5–13.5) months. Our results for Spanish patients in the vemurafenib safety study indicate similar efficacy and a comparable safety profile in Spanish patients with no new safety signals compared with the overall population. Clinical benefit was demonstrated in poor-prognosis patients and in those with favourable baseline characteristics, suggesting that poor-prognosis patients may also benefit from vemurafenib treatment.

Hepatitis delta virus (HDV) infection is a neglected disease despite causing the most severe form of viral hepatitis. Over 15 million people are infected worldwide. IFN-α is largely inefficient and poorly tolerated. The discovery of sodium taurocholate cotransporting polypeptide as the cell receptor for HBV (and consequently for HDV) has allowed development of viral entry inhibitors (i.e., myrcludex-B). More recently, prenylation inhibitors (i.e., lonafarnib) that disrupt virion assembly are being tested. At this time, sustained suppression of HDV replication is the primary goal of hepatitis delta treatment, being associated with normalization of liver enzymes and histological improvement. The lack of persistent forms of HDV-RNA could provide unique opportunities for hepatitis delta cure using specific antivirals, even in the face of persistent HBV cccDNA.

Liver disease is the major complication of chronic HCV infection. However, extrahepatic complications are common (50–75%), including mixed cryoglobulinaemia and B-cell lymphomas. Given that chronic hepatitis C has become curable using expensive oral direct-acting antivirals (DAAs), it seems worth revisiting the whole spectrum and burden of disease in HCV carriers. Herein, we update the most clinically significant medical complications associated with chronic hepatitis C and the evidence of benefits that would derive from a wide use of curative DAA therapies. Chronic HCV infection is associated with a broad spectrum of clinical conditions, including distinct rheumatic disorders (polyarthritis, sicca syndrome), lymphoproliferative conditions (mixed cryoglobulinaemia, monoclonal gammapathies and B-cell lymphomas) and damage at other organs due to persistent systemic inflammation, leading to renal, bone, neurological and/or cardiovascular disease. Eradication of HCV with DAAs is associated with amelioration and/or resolution of most liver-related and extrahepatic complications. Ultimately, gains in quality of life and survival favour treating everyone with hepatitis C regardless of liver fibrosis stage.

Mondelli, Mario U/0000-0003-1811-3153; Leblebicioglu, Hakan/0000-0002-6033-8543; Soriano, Vicente/0000-0002-4624-5199; Ruta, Simona/0000-0002-2492-6073; Lazarevic, Ivana/0000-0001-6795-1378; Harxhi, Arjan/0000-0001-8518-7377 WOS: 000364572800020 PubMed: 26166544 The prevalence and management of chronic hepatitis B virus (HBV) infection differ among European countries. The availability and reimbursement of diagnostics and drugs may also vary, determining distinct treatment outcomes. Herein, we analyse differences in medical facilities for the care of patients with chronic HBV infection across Europe. A survey was sent to the members of the ESCMID Study Group for Viral Hepatitis, all of whom are experts in chronic HBV infection management. The comprehensive survey asked questions regarding hepatitis B surface antigen (HBsAg) prevalence, the availability of diagnostics and drugs marketed, and distinct clinical practice behaviours in the management of chronic HBV infection. World Bank data were used to assess the economic status of the countries. With 16 expert physicians responding (69%), the HBsAg prevalence rates were 5%) in Albania and Iran. Regarding the availability and reimbursement of HBV diagnostics (HBV DNA and liver stiffness measurement), HBV drugs (interferon, lamivudine, tenofovir, and entecavir), HBV prophylaxis, and duration of HBeAg-positive and HBeAg-negative HBV infection, the majority of high-income and middle-income countries had no restrictions; Albania, Iran and Serbia had several restrictions in diagnostics and HBV drugs. The countries in the high-income group were also the ones with no restrictions in medical facilities, whereas the upper-middle-income countries had some restrictions. The prevalence of chronic HBV infection is much higher in southern and eastern than in western European countries. Despite the availability of European guidelines, policies for diagnostics and treatment vary significantly across European countries. Clinical Microbiology and Infection (C) 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Patients infected with HIV are at increased risk for cardiovascular disease despite successful antiretroviral therapy. Likewise, chronic hepatitis C virus (HCV) infection is associated with extrahepatic complications, including cardiovascular disease. However the risk of cardiovascular disease has not been formally examined in HIV/HCV-coinfected patients. A retrospective study was carried out to assess the influence of HCV coinfection on the risk of cardiovascular events in a large cohort of HIV-infected patients recruited since year 2004. A composite event of cardiovascular disease was used as an endpoint, including myocardial infarction, angina pectoris, stroke or death due to any of them. A total of 1136 patients (567 HIV-monoinfected, 70 HCV-monoinfected and 499 HIV/HCV-coinfected) were analysed. Mean age was 42.7 years, 79% were males, and 46% were former injection drug users. Over a mean follow-up of 79.4 ± 21 months, 3 patients died due to cardiovascular disease, whereas 29 suffered a first episode of coronary ischaemia or stroke. HIV/HCV-coinfected patients had a greater incidence of cardiovascular disease events and/or death than HIV-monoinfected individuals (4% vs 1.2%, P = 0.004) and HCV-monoinfected persons (4% vs 1.4%, P = 0.5). After adjusting for demographics, virological parameters and classical cardiovascular disease risk factors (smoking, hypertension, diabetes, high LDL cholesterol), both HIV/HCV coinfection (HR 2.91; CI 95%: 1.19-7.12; P = 0.02) and hypertension (HR 3.65; CI 95%: 1.34-9.94; P = 0.01) were independently associated with cardiovascular disease events and/or death in HIV-infected patients. Chronic hepatitis C and hypertension are independently associated with increased cardiovascular disease risk in HIV-infected patients. Therefore, treatment of chronic hepatitis C should be prioritized in HIV/HCV-coinfected patients regardless of any liver fibrosis staging.

Roughly 10 % of HIV-positive individuals worldwide have concomitant chronic hepatitis B virus (HBV) infection, with large differences between geographical regions and/or risk groups. Hepatitis B is a preventable infection with vaccines. However, it cannot be eradicated once acquired, resembling HIV and in contrast with HCV. In developed countries, hepatitis B exhibits particular features in the HIV population. First, HBV infection is less frequently misdiagnosed than in the general population. Second, nucleos(t)ide analogs active against HBV are widely used as part of antiretroviral combinations and are taken by most HIV patients. Lastly, as the HIV population ages given the success of antiretroviral therapy, non-AIDS co-morbidities are becoming a major cause of disease, for which specific drugs are required, increasing the risk of interactions and hepatotoxicity. Furthermore, concern on HBV reactivation is rising as immunosuppressive drug therapies are increasingly been used for cancers and other non-malignant conditions. In this scenario, new challenges are emerging in the management of hepatitis B in HIV-positive individuals. Among them, major interest is focused on failures to suppress HBV replication, HBV breakthroughs and reactivations, the meaning of isolated anti-HBc, screening for liver cancer, and the complexity arising when hepatitis viruses C and/or D are additionally present. This review will focus on these challenges and the major advances in HBV coinfection in HIV.

OBJECTIVES: The long-term side effects of stavudine (d4T) led to recommendations in 2009 to phase out use of this drug. We aimed to describe temporal patterns of d4T use across Europe. METHODS: Patients taking combination antiretroviral therapy (cART) in EuroSIDA with follow-up after 1 January 2006 were included in the study. cART was defined as d4T-containing [d4T plus at least two other antiretrovirals (ARVs) from any class] or non-d4T-containing (at least three ARVs from any class, excluding d4T). Poisson regression was used to describe temporal changes in the prevalence of d4T use and factors associated with initiating d4T. RESULTS: A total of 5850 patients receiving cART on 1 January 2006 were included in the current analysis, rising to 7768 patients on January 1 2013. During this time, the prevalence of d4T use fell from 11.2% to 0.7%, with an overall decline of 19% per 6 months [95% confidence interval (CI) 19-20%]. d4T use declined fastest in Northern Europe [26% (95% CI 23-29%) per 6 months], and slowest in Eastern Europe [17% (95% CI 16-19%) per 6 months]. In multivariable Poisson regression models, new d4T initiations decreased by 14% per 6 months [adjusted incidence rate ratio (aIRR) 0.86; 95% CI 0.80-0.91]. Factors associated with initiating d4T were residence in Eastern Europe (aIRR 4.31; 95% CI 2.17-9.98) versus other European regions and HIV RNA > 400 copies/mL (aIRR 3.11; 95% CI 1.60-6.02) versus HIV RNA < 400 copies/mL. CONCLUSIONS: d4T use has declined sharply since 2006 to low levels in most regions; however, a low but persistent level of d4T use remains in Eastern Europe, where new d4T initiations post 2006 are also more common. The reasons for the regional differences may be multifactorial, but it is important to ensure that all clinicians treating HIV-positive patients are aware of the potential harmful effects associated with d4T.

Background Sustained HCV clearance after hepatitis C therapy is associated with reduced liver-related complications and death. It is unknown if treatment may provide any clinical benefit in patients that fail therapy. This could be particularly relevant in HIV–HCV-coinfected patients, in whom liver disease progresses more rapidly. Methods This was a retrospective study of clinical end points in a large cohort of HIV–HCV-coinfected patients with compensated liver disease followed since 2004. Patients were stratified into three groups: treated and cured, treatment failures and non-treated. Follow-up ended at the time of last visit, first liver decompensation event or death. Results A total of 527 HIV–HCV-coinfected patients were examined, of whom 339 (64.3%) had been treated with pegylated interferon/ribavirin. During a mean follow-up of 70.5 months, hepatic decompensation events or liver-related deaths occurred less frequently in cured patients (4/138; 2.9%) than in treatment failures (28/201; 13.9%) or untreated (25/188; 13.3%) patients ( PConclusions Sustained HCV clearance following pegylated interferon/ribavirin therapy is associated with a reduced incidence of liver complications and death in HIV–HCV-coinfected patients. In the subset of patients with baseline advanced liver fibrosis, treatment provides clinical benefit despite lack of sustained virological response. The transient antiviral and/or anti-inflammatory effect of interferon, more recognizable in IL28B-CC carriers, could explain this finding.

Objective. To assess hepatitis C virus (HCV) antibody prevalence in the EuroSIDA cohort, along with survival, human immunodeficiency virus (HIV)-1 disease progression, virologic response (plasma HIV -1 RNA load of

The advent of oral direct-acting antivirals (DAA) has revolutionized the hepatitis C virus (HCV) therapeutic landscape providing cure rates over 90%. However, a subset of patients remains at higher risk for treatment failure, including those infected with: i) genotype 3 and cirrhosis; ii) resistance-associated substitutions (RAS) occurring either as natural polymorphisms or selected after prior DAA failure; and iii) poor drug adherence associated with social disabilities (homeless, psychiatric illnesses, injection drug use, alcoholism, etc.). Whereas discovery of new DAA with increased antiviral activity across all genotypes and over RAS may enhance efficacy, development of fixed dose combinations (FDC) may be the best way to improve drug adherence in difficult-to-treat HCV populations. Areas covered: Three FDC regimens are in the last steps of clinical development for treating hepatitis C. Two distinct nucleotide analogues that inhibit the HCV polymerase, sofosbuvir and uprifosbuvir, are part of the FDC from Gilead and Merck, respectively. The AbbVie dual FDC does not include a polymerase inhibitor. All three new FDC include second-generation NS3 protease inhibitors and NS5A inhibitors active across all HCV genotypes and over common RAS. Expert opinion: Hepatitis C cure rates over 95% are expected with all three next-coming DAA, even in the most difficult-to-treat and/or cure patient populations. These regimens would be particularly needed for the growing number of prior DAA failures. Co-formulations and 8-week shorter treatment lengths will help to overcome drug adherence challenges in certain populations.

Current treatment with oral nucleos(t)ides entecavir or tenofovir provide sustained suppression of HBV replication and clinical benefit in most chronic hepatitis B virus (HBV) infected persons. However, HBV rebound generally occurs upon drug discontinuation due to persistence of genomic HBV reservoirs as episomic cccDNA and chromosomic integrated HBV-DNA. There is renewed enthusiasm on HBV drug discovery following recent successes with antivirals for hepatitis C and immunotherapies for some cancers. Areas covered: New drugs that target distinct steps of the HBV life cycle are been developed, including inhibitors of viral entry, new polymerase inhibitors, capsid and assembly inhibitors, virus release blockers, and disruptors of cccDNA formation and transcription. Alongside these antivirals, agents that enhance anti-HBV specific immune responses are being tested, including TLR agonists, checkpoint inhibitors and therapeutic vaccines. Expert opinion: The achievement of a 'functional cure' for chronic HBV infection, with sustained HBsAg clearance and undetectable viremia once medications are stopped, represents the next step in the pace towards HBV elimination. Hopefully, the combination of new drugs that eliminate or functionally inactivate the genomic HBV reservoirs (cccDNA and integrated HBV-DNA) along with agents that enhance or activate immune responses against HBV will lead to a 'definitive cure' for chronic HBV infection.

Introduction: Human genetic testing is rapidly entering into most medical disciplines, mainly as a way to predict hereditary conditions including predisposition to cancers or degenerative diseases. Another area of interest for human genomics is to ascertain the therapeutic effect and prevent potential toxicities and/or drug-drug interactions of medication.Areas covered: Several human genotypes have been associated with differences in the metabolism and transport of antiretroviral agents that ultimately affect drug exposure. The accelerated discovery of new gene mutations and polymorphisms that influence the effects of antiretroviral drugs provides a unique opportunity for a personalized medicine approach in the management of lifelong HIV therapy.Expert opinion: Integration of human genomic screening into HIV clinical management will be cost-effective, maximizing the benefit of drugs with the lowest risk of side effects for a given patient.

The interferon (IFN)L4 polymorphism rs368234815 is associated with hepatitis C virus (HCV) spontaneous clearance and response to IFN-based treatments. The role of this polymorphism in HIV-1 infection is controversial. We investigated whether genetic variation at IFNL4 is associated to HIV-1 acquisition. The HCV protective allele TT was associated with decreased likelihood of HIV-1 infection in male intravenous drug users [odds ratio (OR): 0.3; P = 0.006], and this association was not modified by the genotype of CCR5. These results suggest that genetic susceptibility to HCV and HIV-1 infection shares common molecular pathways.

Background Because of their high cost, the use of direct-acting antivirals (DAAs) is being restricted by many governments to chronic HCV-infected individuals with advanced liver fibrosis. However, response rates are lower and toxicities more frequent in this subset of patients. Methods All HIV–HCV-coinfected patients followed for at least 3 years at one reference clinic were identified. Liver fibrosis progression (LFP) was defined as a shift from Metavir F0–F2 to F3–F4 estimates (>9.5 KPa) using elastometry. Results A total of 527 HIV–HCV-coinfected patients were identified, of whom 344 had F0–F2 at baseline. Pegylated interferon/ribavirin therapy was given to 205 patients with null/mild fibrosis, of whom 92 (44.9%) achieved sustained virological response (SVR). After a mean follow-up of 53 months, LFP occurred in 5.4% SVR, 25.7% non-SVR and 18% untreated patients ( P=0.005). In multivariate analysis, only achievement of SVR prevented LFP (adjusted hazard ratio 2.1; 95% CI 1.1, 4.1; P=0.01). In 139 untreated patients, only greater baseline elastometry values predicted LFP in multivariate analysis (adjusted hazard ratio 1.84; 95% CI 1.03, 3.3; P=0.03). The area under the receiver operating characteristic (AUROC) curve was 79%. A discriminant threshold of 7.1 kPa gave 68% sensitivity and 82% specificity. Conclusions In the absence of successful treatment, more than 20% of HIV–HCV-coinfected patients with null/mild liver fibrosis progress to advanced fibrosis within 5 years. Patients with >7.1 kPa (Metavir F2) display the highest risk. Therefore, all coinfected patients with any significant liver fibrosis should be considered as candidates for new DAA-based therapies.

Chronic hepatitis C virus (HCV) infection occurs globally in 20 % of HIV-seropositive patients. In coinfected individuals, HCV-related liver disease is a leading cause of morbidity and mortality. The advent of new direct-acting antivirals (DAA) has been particularly awaited for this population, in whom treatment with peginterferon plus ribavirin depicts limited efficacy and poor tolerability. However, pharmacologic interactions, drug resistance, medication adherence and pricing are major challenges using DAA in HIV/HCV-coinfected patients. Moreover, if the benefit of new antiviral therapies for hepatitis C wants to be recognized at population scale, underdiagnosis and access to particularly difficult to reach populations must be ensured.

Chronic hepatitis B virus (HBV) infection is common in HIV-positive individuals. Although HBV vaccination is mandatory for HIV-positive individuals with negative-HBV markers, lower rates of protection are achieved. HIV infection accelerates the course of liver disease caused by chronic HBV infection, leading to end-stage hepatic illness and increasing the risk of hepatocellular carcinoma. Anti-HBV active agents, especially tenofovir, improve outcomes. Lamivudine alone should be limited to patients with low serum HBV-DNA levels, since selection of drug resistance often compromises long-term benefits, leads to cross-resistance with other antivirals, and favors the potential emergence of HBV-vaccine escape mutants.

Liver disease is currently one of the leading causes of hospitalization and death in HIV-positive individuals. Coinfection with the hepatitis C virus (HCV) is a major contributor to this trend. Besides hepatic damage, which is enhanced in the presence of HIV-associated immunosuppression, HCV may contribute to disease in coinfected individuals by potentiating immune activation and chronic inflammation, which ultimately account for an increased risk of cardiovascular events, kidney disease, and cancers in this population. Fortunately, hepatitis C therapeutics has entered a revolutionary era in which we hope that most patients treated with the new oral direct-acting antivirals (DAA) will be cured. However, many challenges preclude envisioning a prompt elimination of HCV from the coinfected population. Issues that should be addressed include the following: (1) rising incidence of acute hepatitis C in men who have sex with men, and expansion/recrudescence of injection drug use in some settings/regions; (2) adverse drug interactions between antiretrovirals and DAA; and (3) high cost of DAA, which may lead many to defer or fail to access appropriate therapy.

It is unclear to what extent T cell reconstitution may be possible in HIV-1-infected individuals on continuous successful highly active antiretroviral therapy (HAART). Herein, we analysed distinct phenotypic markers of immune recovery in patients with undetectable viraemia for 8 years, taking as reference untreated patients and healthy controls.Seventy-two subjects were examined: 28 HIV-1+ patients on successful long-term HAART, 24 HIV-1+ untreated viraemic patients and 20 age-matched healthy controls. Analysis of naive and memory CD4 and CD8 T cells was combined with measurements of activation status (expression of CD38) and with thymic function (expression of CD31). Statistical significance was determined by non-parametric tests.After long-term HAART, the majority of parameters were normalized compared with age-matched control values, including T cell activation and thymic function. However, absolute counts of naive and central memory CD4 T cells remained below normal levels. The only parameters significantly associated with CD4 counts at the end of follow-up were the pre-HAART CD4 count ( β ± SD = 0.54 ± 0.16, P = 0.003) and the level of CD4 central memory cells at the end of follow-up (β ± SD = 1.18 ± 0.23, P0.0001). Only patients starting HAART with CD4 counts350 cells/mm(3) reached a complete normalization of CD4 counts.Even after long-term successful HAART, complete CD4 restoration may be attainable only in patients starting therapy with moderately high CD4 counts, prompting early initiation of antiretroviral therapy. Incomplete CD4 restoration may be associated with a defective restoration of central memory CD4 T cells, a cell subset with a pivotal role in T cell homeostasis.

Background Achievement of early viral suppression is important in patients with chronic HCV infection treated with telaprevir (TLV) or boceprevir (BOC) to avoid selection of drug resistance and attain cure. No head-to-head studies comparing TLV and BOC have been performed so far. Methods All consecutive individuals who initiated triple HCV therapy with TLV or BOC outside clinical trials at three European clinics were evaluated. Rapid virological response (RVR) was defined as unquantifiable HCV RNA (Results A total of 106 patients were evaluated, 33 treated with BOC and 73 with TLV. Median age, gender, body mass index, baseline HCV RNA, HCV subtype 1a (45% versus 42%) and IL28B-CC alleles (29% versus 23%) did not differ significantly in BOC and TLV groups, respectively. HIV coinfection was more prevalent in patients on TLV than BOC (24% versus 44%). Conversely, more patients on BOC than TLV had previously failed pegylated interferon plus ribavirin (82% versus 64%). RVR was achieved by 82% of patients on TLV versus 59% on BOC ( P=0.001). Multivariate logistic regression analysis confirmed that TLV use was the strongest predictor of RVR (OR 3.54 [95% CI 1.23, 10.24]; P=0.02), others being HCV subtype 1b versus 1a (OR 3.26 [95% CI 1.17, 9.09]; P=0.02) and low baseline HCV RNA (OR 0.41 [95% CI 0.16, 1.03]; P=0.06). Prior interferon exposure, HIV coinfection or absence of advanced liver fibrosis did not influence the likelihood of RVR. Conclusions Compared to BOC, triple therapy with TLV produces greater RVR rates. TLV might be a better option in more difficult-to-cure patients, such as those with high baseline HCV RNA and/or HCV 1a subtype. HIV coinfection does not influence early HCV RNA responses.

Background: Outbreaks of acute hepatitis C in HIV-positive men who have sex with men (MSM) are being reported in large cities in western countries along with increasing rates of sexually transmitted diseases. Methods: All HIV individuals attended at a large outclinic in Madrid within the last 5 years were examined. Incident syphilis was diagnosed based on rapid plasma reagin (RPR) reactivity, being negative previously or showing >4-fold increase. Acute hepatitis C was diagnosed based on HCV antibody seroconversion and/or positive serum HCV-RNA after being negative within the last year. Results: A total of 859 episodes of syphilis and 19 of acute hepatitis C were diagnosed during the study period. Syphilis was recognized in 65/2,094 (3.1%) individuals attended in 2008 and rose up to 261/2,512 (10.4%) in 2012 (P < 0.001). Acute hepatitis C was diagnosed in only one subject in 2008 but rose up to 7 in 2012 (P = 0.12). All 19 HIV patients with acute hepatitis C were MSM. Syphilis was diagnosed concomitantly in seven. All eight individuals who were treated with peginterferon/ribavirin were cured, whereas only one untreated experienced spontaneous clearance (P = 0.004). Two clusters of infections by HCV genotypes 4 and 1a were identified by phylogenetic analyses. Conclusions: The incidence of acute hepatitis C is low but steadily increasing in HIV-positive MSM in Madrid (

The aim of this study was to assess the impact of the genetic pattern (GP) defined by the single nucleotide polymorphisms (SNPs) rs14158 of low-density lipoprotein receptor (LDLR) and rs12979860 of interleukin-28B (IL28B) genes on the outcome and features of hepatitis C virus (HCV) infection in patients with and without human immunodeficiency virus (HIV) coinfection. 314 HIV/HCVcoinfected and 109 HCV-monoinfected patients treated with pegylated interferon (Peg-IFN) plus ribavirin (RBV), as well as 51 patients with HCV spontaneous clearance (SC), were included. Variations in both SNPs were determined by the TaqMan polymerase chain reaction (PCR) assay. In the 286 patients chronically infected by HCV genotypes 1 or 4, both rs14158 CC and rs12979860 CC were associated with a higher rate of sustained virological response (SVR), and these effects were complementary in both HCVmonoinfected and HIV/HCV-coinfected patients. Thus, 24 % of patients with rs14158/rs12979860 TT-TC/TT-TC, 33 % with TT-TC/CC, 44.2 % with CC/TT-TC, and 75.8 % harboring CC/CC attained SVR (p

A total of 1,220 subjects from Equatorial Guinea living in Spain (median age = 41 years; 453 male and 767 female) was examined for antibodies to human immunodeficiency virus (HIV) and Hepatitis B (HBV), C (HCV), and D (HDV) viruses. Extracted RNA and DNA from the positive samples were used to quantify viral load. The prevalence of HIV antibodies, HCV RNA, and HBV surface antigen (HBsAg) was 10.8% (N = 132), 11.6% (N = 141), and 7.9% (N = 96), respectively. The most prevalent HIV variant was CRF02_AG (38.5%; N = 40). HCV genotype 4 (60%; N = 36) and HBV genotype A3 (32%; N = 8) were the hepatitis variants most frequently found. Superinfection with HDV was seen in 20.9% (N = 24) of HBsAg carriers. A control group of 276 immigrants from other sub-Saharan countries showed similar rates of HIV and HBsAg, although no HCV cases were found. Immigrants constitute a major source of HIV and hepatitis viruses in Spain; therefore, it is important that control measures are intensified.

BACKGROUND The interaction between interferon-stimulated genes (ISGs) expression, IL28B genotypes and hepatitis C treatment outcomes has been mainly evaluated in the liver tissue from hepatitis C virus (HCV)-monoinfected patients but with controversial results. Herein, we examined whether more easily accessible peripheral blood mononuclear cells (PBMCs) could be used for this purpose in HIV-HCV coinfected patients, a population in whom HCV-induced liver disease progression occurs more rapidly and treatment response is lower. METHODS Gene expression profiles were examined using the human whole genome Agilent microarray platform in PBMCs collected from HIV/HCV-coinfected patients who had completed a course of peginterferon/ribavirin therapy with validated outcomes. Patients were split out according to the achievement of sustained virological response (SVR) and IL28B rs12979860 genotypes. The GeneSpringGX software was used to select genes differentially expressed in the different groups. RESULTS Nineteen HIV/HCV-coinfected individuals receiving antiretroviral therapy and having undetectable plasma HIV-RNA were examined. Global gene expression profiles showed 42 genes differentially expressed according to treatment outcome and 56 according to IL28B genotype. Common genes were not found and functions differed for genes belonging to either group. Whereas at least 26 out of 37 repressed genes (70.3%) in SVR patients were ISGs, none of the 56 differentially expressed genes in carriers of distinct IL28B variants were ISGs (P

Viral liver diseases are frequent comorbidities and major contributors to death in HIV-positive individuals on antiretroviral therapy. Although cure of hepatitis C and control of hepatitis B with antivirals avert liver disease progression in most HIV-coinfected patients, the lack of satisfactory treatment for hepatitis delta virus (HDV) infection remains a major threat for developing cirrhosis and liver cancer in this population. In the European Union (EU) and North America, sexual contact has replaced injection drug use that has been the major transmission route for HDV in HIV-positive persons. PegIFNα is the only approved HDV therapy; however, sustained HDV-RNA clearance is achieved by less than 25%. The recent discovery of sodium taurocholate cotransporting polypeptide as the key hepatitis B virus (HBV) and HDV cell entry receptor has opened the door to a new therapeutic era. Indeed, promising results have been released using Myrcludex-B, a sodium taurocholate cotransporting polypeptide inhibitor. More encouraging are data with new classes of HDV blockers, such as prenylation inhibitors (i.e. lonafarnib) and nucleic acid polymers. At this time, sustained suppression of HDV replication is the primary goal of HDV therapy, as it is associated with normalization of liver enzymes and histological improvement. Of note, the use of specific antivirals for HDV must be given along with anti-HBV agents to prevent HBV rebounds following removal of viral interference. The lack of persistent forms of HDV-RNA could provide a unique opportunity for curing hepatitis delta, even without eliminating HBV circular covalently closed DNA. Ultimately, suppression of HDV replication along with hepatitis B surface antigen clearance once drugs are off would be the best reflect of hepatitis delta cure.

Background. Noncirrhotic portal hypertension (NCPH) is a rare but potentially life-threatening complication in patients with human immunodeficiency virus (HIV). Cases of NCPH have been reported in HIV-negative individuals as result of treatment with thiopurines for leukemia or inflammatory bowel disease. Exposure to didanosine, which is also a purine analogue, predisposes to NCPH in the HIV setting. However, it is unclear why NCPH only develops in a small subset of didanosine-treated patients. Methods. A multicenter, case-control study was conducted to investigate the role of pharmacogenomics in NCPH in HIV patients with prior didanosine exposure. Three controls were chosen for each case, adjusted for sex, age, CD4 counts, plasma HIV-RNA, and site. Tagging 36 single-nucleotide polymorphisms (SNPs) at enzymes involved in the purine metabolism (inosine triphosphatase, 5′-nucleotidase cytosolic-II, purine nucleoside phosphorylase and xanthine oxidase) was performed using SNPlex microarray technology. Results. Eighty individuals were examined; 22 with NCPH and 58 matched controls. Two SNPs at the 5′nucleotidase gene were associated with NCPH: rs11191561 (48% CG/GG vs 17% CC; P= .003) and rs11598702 (40% CC/CT vs 9% TT; P= .003). SNPs at another 2 loci at the xanthine oxidase gene were also associated with NCPH: rs1429376 (71% AA vs 23% CC/AC; P= .015) and rs1594160 (71% AA vs 23% CC/AC; P= .015). There was a cumulative risk of NCPH for these 4 SNPs: 7%, 26%, 42%, 50%, and 100%, respectively, for 0, 1, 2, 3, or all SNPs (P= .001). Conclusions. SNPs at the 5′-nucleotidase and xanthine oxidase genes influence the risk of NCPH in HIV patients treated with didanosine.

Several HCV polymerase inhibitors are in advanced stages of clinical development. They are nucleos(t)ide and non-nucleoside analogs. Nucleos(t)ides inhibit viral replication acting as chain terminators whereas non-nucleosides block allosterically the HCV polymerase. Sofosbuvir is an uridine analog and currently the most promising HCV polymerase inhibitor, being active across all HCV genotypes. It has good tolerability and a robust barrier to resistance. In contrast, non-nucleoside analogs have low to moderate antiviral potency, a low barrier to resistance and inhibit only HCV genotype 1.Studies conducted with distinct HCV polymerase inhibitors as part of interferon-free combinations have opened a new landscape in which shorter treatment duration and all-oral regimens are envisioned as the future curative treatment for most chronic hepatitis C patients.Antiviral drug development for HCV is progressing at a feverish pace. Amongst HCV polymerase inhibitors, sofosbuvir has positioned as unique companion with ribavirin as therapy for most HCV genotypes 2 or 3, and along with NS5A inhibitors for other HCV genotypes. Non-nucleoside HCV polymerase inhibitors are being developed only as part of all-oral combinations with protease inhibitors. The expected high cost of DAAs will preclude their prompt and wider use, allowing room for using alternative cheaper options in easier-to-treat patient populations.

The concentration of circulating viral RNA at baseline and during antiviral therapy predicts response in both HIV infection and chronic hepatitis C.Retrospective review of longitudinal plasma HCV-RNA determinations in untreated chronic hepatitis C patients. As comparison, longitudinal plasma HIV-RNA measurements were performed in untreated HIV individuals.A total of 3169 HCV-RNA determinations over 43.0±31.6 months were available for 818 chronic hepatitis C patients. For 333 HIV individuals, 1998 HIV-RNA measurements were examined over 27.3±17.5 months. Overall 44% consecutive specimens had0.5 log variation in HCV-RNA values compared to 23% for HIV-RNA (p0.001). These rates were 15% and 4%, respectively, for variations1 log (p0.001). In multivariate analysis (odds ratio, 95% confidence interval, p), the likelihood of experiencing HCV-RNA variations0.5 log IU/mL was greater in patients with lower HCV-RNA (0.35 per log[0.26-0.47], 0.001), HIV coinfection (2.57[91.56-4.23],0.001) and IL28B-CC (1.87[1.28-2.74], 0.001).Fluctuation in circulating HCV-RNA may be clinically meaningful in a substantial proportion of chronic hepatitis C patients. It may influence the best time to prescribe antiviral therapy. Moreover, decisions based on early viral kinetics, such as early stopping rules, may require testing of baseline specimens the closest to treatment initiation.

The influence of HCV-RNA levels and genotype on HCV disease progression is not well studied. The prognostic value of these markers was investigated in HIV/HCV co-infected individuals from the EuroSIDA cohort. EuroSIDA is a prospective cohort of 18,295 HIV-1 infected patients in 105 centres across Europe, Israel, and Argentina. All subjects with known HCV antibody (HCVAb) status (n=13,025) were enrolled in the present study. 4044 (31.0%) patients had detectable HCVAb. After adjustment, HCVAb+ patients had an increased incidence of liver-related death (LRD) compared to HCVAb- individuals (IRR 8.90; 95% CI 5.60-14.14, p

HIV controllers are a valuable source for the identification of HIV-neutralizing antibodies, as chronic infection over decades allows extensive affinity maturation of antibodies for improved Ag recognition. We analyzed a small cohort of elite controllers (ECs) for HIV-neutralizing antibodies using a panel of standardized HIV-1 pseudovirions on TZM-bl cells. An HIV-1 Env-tailored phage display library was generated to select epitopes targeted by neutralizing antibodies in the EC26 plasma sample showing the broadest neutralizing activity. Selected Env fragments were mostly allocated to the membrane proximal external region of gp41. After preabsorbing the EC26 plasma with the selected phage EC26-2A4, we achieved 50% depletion of its neutralizing activity. Furthermore, antibodies affinity-purified with the EC26-2A4 epitope from EC26 plasma showed neutralizing activity, proving that the selected phage indeed contains an epitope targeted by neutralizing plasma antibodies. Epitope fine mapping of the purified plasma antibodies on peptide arrays identified a new epitope overlapping, but clearly distinct, from the prominent 2F5 epitope. Of note, the purified antibodies did not show autoreactivity with cardiolipin, whereas low reactivity with phosphatidylserine comparable to mAb 2F5 was observed. Thus, this new epitope represents a promising candidate for further analysis in view of HIV vaccine development.

Summary Due to the poor rate of response to hepatitis C virus (HCV) with pegylated interferon and ribavirin treatment in HCV/HIV coinfected patients, key factors for predicting failure would be useful. We performed a retrospective study on 291 patients on HCV treatment, who had early virological response (EVR) data. IL28B and IL28RA polymorphisms were performed using the GoldenGate® assay. Unfavourable genotypes at IL28B (rs12980275 AG/GG and rs8099917 GT/GG) and an unfavourable allele at IL28RA (rs10903035 G) were associated with early treatment failure. However, only the rs12980275 AG/GG genotype and rs10903035 G allele remained independently associated with early failure in the overall population (OR = 4.15 (95% CI = 1.64–10.54) and OR = 2.00 (95% CI = 1.19–3.36), respectively) as well as in GT1/4 patients (OR = 5.07 (95% CI = 1.81–14.22) and OR = 2.03 (95% CI = 1.13–3.66), respectively). Next, a decision tree showed early treatment failure increased from 37.1% to 65.5% when the unfavourable rs12980275 AG/GG and rs10903035 AG/GG genotypes and HCV-RNA≥ 500.000 IU/mL were taken into account in GT1/4 patients. In contrast, the failure rate decreased from 37.1% to 11.9% when the favourable rs12980275 AA and rs10903035 AA genotypes were detected. The percentage of patients correctly classified was 78.4%, and AUROC was 0.802 ± 0.028. Regarding GT3 patients, the presence of the GCGCA haplotype (all unfavourable alleles) was associated with early treatment failure, while no association was observed for the IL28B polymorphisms. In conclusion, the IL28RA polymorphism was associated with early treatment failure independently of the IL28B SNPs. The combination of IL28B and IL28RA polymorphisms might be a valuable tool for predicting early treatment failure before starting HCV treatment.

Double negative (DN) T cells are CD3(+), CD4(-), CD8(-) cells with either T-cell receptors (TCR) αβ or TCR γδ whose importance on protection against HIV infection is unknown. Since HIV-exposed seronegative individuals correspond to an ideal group in whom correlates of protection are expected, the role of these cells was studied in 13 HIV-serodiscordant couples in a stable relationship and reporting unprotected sexual intercourses. HIV-specific immune responses mediated by DN T-cells were evaluated by measuring intracellular IFNγ and MIP1β (CCL4) production in response to HIV-Gag peptides. Thirty-five healthy controls not exposed to HIV were tested similarly and used to define a threshold for positive responses. Interestingly, Gag-specific DN T-cell responses were found in 3/13 (23%) HIV-exposed seronegative individuals (Group A), involving both DN/αβ(+) and DN/γδ(+) T-cells through MIP1β and IFNγ production. 4/13 (30%) of partners infected with HIV (Group B) also showed Gag-specific responses but were mediated exclusively by DN/γδ(+) T-cells, mainly through IFNγ production. DN T-cells in Group A individuals can display differential HIV-specific immune responses, which might contribute to the low susceptibility to infection with HIV shown by individuals in Group A.

The results from clinical trials testing new direct-acting antivirals (DAAs) for chronic hepatitis C were the major focus of interest at the 2012 annual meeting of the European Association for the Study of the Liver. Besides triple combinations, in which any one of the new DAAs is given along with peginterferon-α/ribavirin, clinical trials exploring interferon-free oral regimens combining several DAAs attracted major attention. The good tolerance, broad hepatitis C virus (HCV) genotype activity, and high resistance barrier of sofosbuvir make this nucleotide analogue one of the most promising DAAs. Among HCV protease inhibitors, the safety, potency, and convenient dosing of simeprevir, asunaprevir, faldaprevir, and ABT-450/r were particularly highlighted. Among NS5A inhibitors, the good performance of daclatasvir encourages further clinical development. Finally, intriguing results were released about the role of interleukin 28B (IL-28B) polymorphisms using interferon-free regimens, indirectly supporting the role of innate immunity for clearing HCV definitively.

Human infection with the xenotropic murine leukemia virus-related virus (XMRV) has been associated controversially with prostate cancer and chronic fatigue syndrome. Information is lacking about the mechanisms of transmission and potential risk groups for XMRV infection. Plasma and peripheral blood mononuclear cells (PBMCs) from individuals with retroviral infections, chronic viral hepatitis, autoimmune diseases, prostate cancer, chronic fatigue syndrome, and blood donors were tested for XMRV markers. Antibodies to XMRV proteins p15E and gp70 were examined using research assays. DNA extracted from PBMCs was tested for the presence of XMRV gag and env sequences. A total of 1103 specimens belonging to individuals with chronic fatigue syndrome and/or fibromyalgia (437), prostate cancer (69), HIV-1 (149), HTLV-1/2 (31), chronic hepatitis B (81), chronic hepatitis C (72), autoimmune diseases (18), and blood donors (246) were examined. Overall, three samples (0.3%) were p15E seroreactive (two HTLV-1 and one HCV patient). Another 15 (1.4%) were gp70 seroreactive (six chronic fatigue syndrome-fibromyalgia, four blood donors, two HIV-1, one prostate cancer, one HBV, and one HCV). Four specimens were initially positive for XMRV gag sequences, but none could be confirmed by repeated testing. In summary, no evidence of XMRV infection was found in populations with retroviral and viral hepatitis infections in Spain. Likewise, XMRV was not recognized in patients with autoimmune diseases, chronic fatigue syndrome-fibromyalgia, prostate cancer, or healthy blood donors.

Background HCV subtype 1a has emerged as a predictor of poor response to triple hepatitis C therapy including boceprevir or telaprevir, which largely has been attributed to a lower resistance barrier in HCV-1a compared to -1b. Objectives We examined whether a lower efficacy of pegIFN/RBV on HCV-1a than HCV-1b could alternatively contribute to explain it. Study design All chronic hepatitis C patients who had completed a course of pegIFN/RBV therapy at our institution were examined. For this study we selected individuals that were IFN-naive and had been successfully subtyped as 1a or 1b. Moreover, only HIV-coinfected patients were included as they represented a more uniform population in terms of demographics and treatment exposure at our institution. The IL28B rs12979860 alleles were typed using the 5′ nuclease assay. Results A total of 96 individuals were examined, 58 of whom harbored HCV-1a and 38 HCV-1b. IL28B allele distribution was as follows: 33 CC and 63 CT/TT. SVR was achieved by 64% of CC vs 30% of CT/TT patients (p = 0.001). On the other hand, SVR was 53% in HCV-1b vs 34% in HCV-1a (p = 0.08). Interestingly, the effect of IL28B variants on SVR was mainly recognized in HCV-1a (63% in CC vs 20% in CT/TT; p = 0.001), being marginal on HCV-1b (64% in CC vs 46% in CT/TT; p = 0.27). Conclusions The rate of SVR to pegIFN/RBV therapy tends to be lower in HIV-infected patients with chronic hepatitis C due to HCV-1a than HCV-1b; being the impact of IL28B variants significantly stronger on HCV-1a than HCV-1b.

BACKGROUND Both viral and host factors influence response to peginterferon-α plus ribavirin (pegIFNα/RBV) in patients with chronic hepatitis C. The impact of these variables is more pronounced in HIV/Hepatitis C virus (HCV)-coinfected individuals, in whom treatment response rates are lower. METHODS Virological responses at multiple time points were assessed in all HIV/HCV-coinfected patients that completed a first course of pegIFNα/RBV. Viral responses were stratified by HCV geno/subtypes and IL28B rs12979860 variants. RESULTS A total of 331 HIV/HCV-coinfected patients were analyzed. HCV geno/subtype distribution was as follows: HCV-1a in 97, HCV-1b in 62, HCV-3 in 122, and HCV-4 in 50. Age, gender, CD4 counts, plasma HIV RNA and liver fibrosis stage did not differ significantly across HCV geno/subtypes. In contrast, mean serum HCV RNA was greater in HCV-1a compared with the rest (P < 0.0001). The proportion of IL28B CC variants was higher in HCV-3 compared with the rest (P = 0.001). Virological responses were better in HCV-1b than HCV-1a at any given time point during therapy. IL28B variants significantly influenced virological responses across all HCV-1 subtypes, with the strongest effect seen in HCV-1a. In a multivariate linear regression analysis, both HCV-1b and IL28B CC variants were significantly associated with greater HCV RNA drops at weeks 4 (R = 0.52, p < 0.0001) and 12 (R = 0.49, P < 0.0001) of therapy. CONCLUSIONS The response to pegIFNα/RBV therapy is lower in HCV-1a than HCV-1b in HIV/HCV-coinfected patients. The strongest influence of IL28B variants is seen in HCV-1a. This information may be relevant when using most directly acting antivirals in coinfected patients along with pegIFNα/RBV, given that selection of drug resistance occurs more frequently in HCV-1a than HCV-1b.

Introduction: HIV therapy has evolved rapidly since the 1990s; the arrival of more potent and safer antiretroviral drugs has transformed HIV infection into a chronic condition, which is rarely fatal. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are frequently used as a third agent – as part of a triple-combination therapy. Side effects and low barriers to resistance have been the major drawbacks of NNRTIs. Rilpivirine (RPV) is a next-generation non-nucleoside analogue, the unique features of which might favor choosing this drug over other NNRTIs. RPV is the latest NNRTI approved for the treatment of HIV infection. Along with its high efficacy and good safety profile, data on pharmacokinetics and drug interactions make RPV particularly attractive. Areas covered: This article aims to provide an in-depth analysis of the main features and data available from recent clinical trials that have tested the performance of RPV. Expert opinion: RPV is a safe and efficacious antiretroviral drug with a bett...

Human immunodeficiency virus type 2 (HIV-2) emerged in West Africa and has spread further to countries that share socio-historical ties with this region. However, viral origins and dispersal patterns at a global scale remain poorly understood. Here, we adopt a Bayesian phylogeographic approach to investigate the spatial dynamics of HIV-2 group A (HIV-2A) using a collection of 320 partial pol and 248 partial env sequences sampled throughout 19 countries worldwide. We extend phylogenetic diffusion models that simultaneously draw information from multiple loci to estimate location states throughout distinct phylogenies and explicitly attempt to incorporate human migratory fluxes. Our study highlights that Guinea-Bissau, together with Côte d’Ivoire and Senegal, have acted as the main viral sources in the early stages of the epidemic. We show that convenience sampling can obfuscate the estimation of the spatial root of HIV-2A. We explicitly attempt to circumvent this by incorporating rate priors that reflect the ratio of human flow from and to West Africa. We recover four main routes of HIV-2A dispersal that are laid out along colonial ties: Guinea-Bissau and Cape Verde to Portugal, Côte d’Ivoire and Senegal to France. Within Europe, we find strong support for epidemiological linkage from Portugal to Luxembourg and to the UK. We demonstrate that probabilistic models can uncover global patterns of HIV-2A dispersal providing sampling bias is taken into account and we provide a scenario for the international spread of this virus.

BACKGROUND CD4 gains in HIV patients on HAART result from release of T cells recently migrated from the thymus, redistribution from lymphoid tissues, proliferation in the periphery and/or reduced apoptosis. The relative contribution of each mechanism in CD4 restoration in patients with suppressed viremia switching antiretrovirals is unclear. METHODS HIV patients with undetectable viremia on HAART were identified at our clinic. A subset switched to raltegravir was compared with another group that kept therapy unmodified. Naive and memory CD4 T-cells were measured by flow cytometry using CD45RA and CD27, respectively. Activation was examined using CD38 and recent thymic emigrants using CD31. Apoptosis was analyzed measuring soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and Fas ligand (FasL). RESULTS Thirty-seven patients were examined, 19 switched to raltegravir and 18 controls, after a median of 26 months of suppressed viremia. At 6 months, mean CD4 cell counts significantly increased in raltegravir patients from 322 to 448 cells/μl (P = 0.026) but not in controls (from 312 to 330 cells/μl; P = 0.813). No significant changes were recognized in activation or CD31 expression in any group. In raltegravir patients, however, the proportion of naive CD4 T cells significantly increased (P = 0.014) as well as CD38 expression in these cells (P = 0.036). A positive correlation was found between CD38 and CD31 expression in naive CD4 T cells (R = 0.51, P < 0.001). TRAIL and FasL did not decline significantly in any group. CONCLUSION HIV patients with prolonged undetectable viremia on HAART experience more pronounced CD4 gains after raltegravir switching than keeping the same regimen. An increased production of naive CD4 T cells largely explains this effect.