Short article: Hepatitis delta in patients with resolved hepatitis B virus infection.

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.

Treatment of hepatitis C with new fixed dose combinations.

INTRODUCTION: 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.

Characterization of Free Phenytoin Concentrations in End-Stage Renal Disease Using the Winter-Tozer Equation.

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.

New antivirals for the treatment of chronic hepatitis B.

INTRODUCTION: 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.

HTLV infection in HCV-antibody positive patients in Spain.

Since hepatitis C virus (HCV) and human T-lymphotropic virus (HTLV) share transmission routes, dual infection could be frequent. In Spain, HTLV underdiagnosis is highlighted by the high proportion of patients presenting either with tropical spastic paraparesis (TSP) or adult T-cell leukemia (ATL) at first diagnosis. We examined whether the renewed efforts for expanding HCV testing may provide a sentinel population that might selectively be targeted to unveil asymptomatic HTLV carriers. The presence of anti-HTLV antibodies was examined in 3,838 consecutive individuals with reactive HCV serology attended during the last three years at 13 hospitals distributed across the Spanish geography. Overall 71% were male and the median age was 41-years old. Foreigners represented 9% of the study population. A total of 50 individuals (1.3%) were seroreactive for HTLV, being 30 confirmed as HTLV-2 and two as HTLV-1 (0.12%). The remaining 18 had indeterminate Western blot patterns. Most individuals with HTLV-2 and HTLV indeterminate serology were HIV-positive, former injection drug users and native Spaniards. In contrast, the two HTLV-1 infections were found in men coming from Brazil and the Dominican Republic, respectively. In summary, the overall prevalence of HTLV infection in individuals living in Spain seropositive for HCV is 1.3%, more than 10-fold greater than in general outclinics in Spain. However, immigrants from HTLV-1 endemic regions and former injection drug users with HTLV-2 infection are by far the major contributory groups in HCV patients. Therefore, testing for HTLV in newly diagnosed HCV individuals would not contribute much to improve late HTLV diagnosis in Spain.

Hepatitis delta and HIV infection.

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.

The global spread of HIV-1 subtype B epidemic.

Human immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa through Haiti to United States. However, the pattern of the subsequent spread still remains poorly understood. Here we analyze a large dataset of globally representative HIV-1 subtype B strains to map their spread around the world over the last 50years and describe significant spread patterns. We show that subtype B travelled from North America to Western Europe in different occasions, while Central/Eastern Europe remained isolated for the most part of the early epidemic. Looking with more detail in European countries we see that the United Kingdom, France and Switzerland exchanged viral isolates with non-European countries than with European ones. The observed pattern is likely to mirror geopolitical landmarks in the post-World War II era, namely the rise and the fall of the Iron Curtain and the European colonialism. In conclusion, HIV-1 spread through specific migration routes which are consistent with geopolitical factors that affected human activities during the last 50years, such as migration, tourism and trade. Our findings support the argument that epidemic control policies should be global and incorporate political and socioeconomic factors.

Hepatic decompensation with sofosbuvir plus simeprevir in a patient with Child-Pugh B compensated cirrhosis.

A 75-year-old male with compensated Child-Pugh B cirrhosis initiated sofosbuvir plus simeprevir, and developed hepatic decompensation and died a few days thereafter. High exposure to simeprevir leading to hepatotoxicity most likely explained this fatal outcome. This observation, along with similar cases recently reported in the literature, should raise awareness of the potential for decompensation in patients with advanced cirrhosis treated with simeprevir.

Hepatitis C cure with antiviral therapy--benefits beyond the liver.

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.

New hepatitis C therapies for special patient populations.

INTRODUCTION: Chronic hepatitis C virus (HCV) infection has become a curable disease. More than 90% sustained virologic response rates have been obtained with 8-24 weeks of treatment with distinct combinations of direct-acting antivirals (DAA) in most registration trials. However, outcomes in real-world patients tend to be lower and treatment of special patient populations is often challenging. AREAS COVERED: We address the treatment of chronic hepatitis C with DAA in major special patient populations, such as HIV-positive persons, transplant recipients, patients with advanced cirrhosis, renal insufficiency, hepatitis B or D coinfection, injection drug users (IDUs) and prior DAA failures. EXPERT OPINION: Drug interactions between DAA and medications given to persons with HIV infection or transplant recipients can result in treatment failure and adverse events. Severe organ dysfunction as in kidney insufficiency or decompensated cirrhosis may lead to DAA overexposure and toxicities. Dysfunctional social circumstances and behavior are associated to poor drug adherence and increased risk for HCV re-infection in active IDUs. Finally, DAA response might be impaired by viral interference in patients with hepatitis B or D coinfection or drug resistance in HCV either at baseline or after prior DAA failures.

IFNL4 rs368234815 polymorphism is associated with innate resistance to HIV-1 infection.

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.

Emerging challenges in managing hepatitis B in HIV patients.

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.

Hepatitis C seroconversions in HIV infection across Europe: which regions and patient groups are affected?

BACKGROUND & AIMS: In the last decade, several outbreaks of sexually acquired acute hepatitis C (HCV) infection have been described in HIV-positive men who have sex with men (MSM). The aims of this study were to determine whether there has been an increase in the number of acute HCV infections in different parts of Europe. METHODS: HCV seroconversion was defined as an HCV-antibody test change from negative to positive within the observation period in EuroSIDA. Binomial regression was performed to determine factors associated with being tested for HCV and HCV seroconversion. RESULTS: A total of 223 HCV seroconversions were observed from 16,188 tests [1.38% (95%CI 1.20-1.56)] among 5736 patients between 2002 and 2013. Overall the odds of acquiring HCV infection increased by 4% per year (OR 1.04 [95%CI 0.99-1.09]; P = 0.10). Overall 63.2% (141/223) of all seroconversions were seen among MSM. Similar patterns were observed across all European regions (P = 0.69, test for interaction) and HIV transmission risks groups (P = 0.69, test for interaction). In multivariate analysis, North, South and East Europe had higher odds of HCV seroconversion compared with Western Europe [OR 1.90 (1.28-2.81), 1.55 (0.99-2.45) and 1.86 (1.21-2.84); P = 0.0014, P = 0.058 and P = 0.0044 respectively]. CONCLUSIONS: Within EuroSIDA a significant increase in HCV seroconversions can be observed after accounting for increased levels of testing for HCV in recent years. This highlights the need for increased HCV prevention efforts among HIV-positive persons in Europe.

Dolutegravir for the treatment of HIV-2 infection.

BACKGROUND: Therapeutic options are limited for HIV-2 infected persons, largely in part due to the lack of susceptibility to HIV-1 non-nucleoside reverse transcriptase inhibitors and poor susceptibility to some HIV-1 protease inhibitors. This is particularly worrisome for HIV-2 patients with prior antiretroviral failure. OBJECTIVES: Report the virological response to dolutegravir in HIV-2-infected individuals. STUDY DESIGN: Retrospective observational assessment of all HIV-2 individuals treated with dolutegravir in Spain. RESULTS: From 297 HIV-2-infected individuals recorded at the Spanish national registry, 26% received antiretroviral therapy. Six out of 8 failing on raltegravir selected for integrase resistance mutations N155H (4), Y143G (1) and Q148R (1). Two patients bearing N155H subsequently received dolutegravir. Both experienced initially more than 1.5 log drop in plasma HIV-2 RNA and significant CD4 gains. Whereas one kept on undetectable viremia 6 months later, the other experienced viral rebound. CONCLUSION: Dolutegravir may be a good therapeutic option for patients with HIV-2 infection, including those that previously failed other integrase inhibitors.

Differential regulation of cytotoxicity pathway discriminating between HIV, HCV mono- and co-infection identified by transcriptome profiling of PBMCs.

BACKGROUND: Despite the easy accessibility and diagnostic utility of PBMCs and their potential to show distinct expression patterns associated with the accelerated disease progression in HIV/HCV co-infection, there has not been a systematic study focusing on the global dysregulations of the biological pathways in PBMCs from HIV, HCV mono- and co-infected individuals. This study aimed at identifying the transcriptome distinctions of PBMCs between these patient groups. METHODS: Genome-wide transcriptomes of PBMCs from 10 HIV/HCV co-infected patients, 7 HIV+ patients, 5 HCV+ patients, and 5 HIV/HCV sero-negative healthy controls were analyzed using Illumina microarray. Pairwise comparisons were performed to identify differentially expressed genes (DEGs), followed by gene set enrichment analysis (GSEA) to detect the global dysregulations of the biological pathways between HIV, HCV mono- and co-infection. RESULTS: Forty-one, 262, and 44 DEGs with fold change > 1.5 and FDR (false discovery rate) <0.05 for the comparisons of HCV versus co-infection, HIV versus co-infection, and HIV versus HCV were identified, respectively. Significantly altered pathways (FDR < 0.05), featured by those involved in immune system, signaling transduction, and cell cycle, were detected. Notably, the differential regulation of cytotoxicity pathway discriminated between HIV, HCV mono- and co-infection (up-regulated in the former versus the latter group: co-infection versus HIV or HCV, HIV versus HCV; FDR <0.001 ~ 0.019). Conversely, the cytokine-cytokine receptor interaction pathway was down-regulated in co-infection versus either HCV (FDR = 0.003) or HIV (FDR = 0.028). For the comparison of HIV versus HCV, the cell cycle (FDR = 0.016) and WNT signaling (FDR = 0.006) pathways were up- and down-regulated in HIV, respectively. CONCLUSIONS: Our study is the first to identify the differential regulation of cytotoxicity pathway discriminating between HIV, HCV mono- and co-infection, which may reflect the distinct patterns of virus-host cell interactions underlying disease progression. Further inspection of cytotoxicity pathway has pinned down to the expression of the KIR genes to be associated with specific patterns of particular virus-host interactions. Between HIV and HCV, the altered cell cycle and WNT signaling pathways may suggest the different impact of HIV and HCV on cell proliferation and differentiation.

Drug interactions with new hepatitis C oral drugs.

INTRODUCTION: Chronic hepatitis C virus (HCV) infection has recently become a curable disease with antiviral therapy. The knowledge of drug interactions using direct-acting antivirals (DAA) may permit maximizing antiviral efficacy and avoiding drug-related toxicities. Ageing in the chronic hepatitis C population, along with added co-morbidities that require other medications, has increased the attention on drug interactions using DAA. AREAS COVERED: This review provides an update of the most clinically significant pharmacokinetic and pharmacodynamic drug interactions occurring between currently available DAA and other medications. The review also revisits how drug interactions with DAA can be prevented and managed. EXPERT OPINION: Interactions between DAA and other drugs are frequent in clinical practice. The most frequent drug interactions modify drug metabolism by inducing or inhibiting the cytochrome P450, leading to abnormal drug exposures. Through this mechanism HCV protease inhibitors, especially when co-formulated with ritonavir as pharmacoenhancer, and non-nucleoside HCV polymerase inhibitors interact with other medications. In contrast, NS5B nucleos(t)ide analog inhibitors (i.e., sofosbuvir) and some HCV NS5A inhibitors (i.e., ledipasvir), which do not or only marginally affect CYP450, are relatively free of significant pharmacokinetic interactions. However, exposure to HCV nucleos(t)ide analogs may be influenced by induction/inhibition of drug transporters (i.e., P-glycoprotein) as well as by pharmacodynamic interference with other nucleos(t)ide analogs used as antivirals or cancer drugs. Drug interactions for some NS5A inhibitors (i.e., daclatasvir) are generally moderate and can be managed with dose adjustments.

Liver fibrosis progression despite HCV cure with antiviral therapy in HIV-HCV-coinfected patients.

BACKGROUND: Accelerated liver fibrosis and more frequent hepatic decompensation events and liver-related deaths are characteristically seen in chronic hepatitis C patients coinfected with HIV compared with HCV-monoinfected individuals. Quantitative estimates of long-term clinical benefits derived from curing HCV with antiviral therapy in coinfected patients are scarce, despite being needed for accurate cost-effectiveness decisions using expensive direct-acting antivirals in this population. METHODS: We retrospectively examined all HIV-HCV-coinfected patients followed at one reference clinic in Madrid since 2004. Liver fibrosis was measured longitudinally using elastometry; changes above 30% in kilopascal units were considered as significant. RESULTS: A total of 568 HIV-HCV-coinfected patients were examined. Pegylated interferon/ribavirin therapy had been given to 396 (69.7%) of whom 138 (34.8%) had achieved sustained virological response (SVR). Mean follow-up was of 6.8 (±1.5) years for hepatic events and 4.4 (±0.8) years for liver fibrosis. Hepatic decompensation events, liver-related deaths and significant liver fibrosis progression occurred less frequently in SVR than in non-treated/treatment failures. Although regression of liver fibrosis occurred in most SVR patients, fibrosis significantly progressed in 7.2% of them, in association with higher plasma HIV RNA (P=0.005) and longer exposure to HIV protease inhibitors (P=0.009). CONCLUSIONS: Achievement of SVR dramatically reduces the risk of hepatic decompensation events and liver-related deaths in HIV-HCV-coinfected patients. Although liver fibrosis generally improves following HCV cure, worsening may occur in association with uncontrolled HIV replication and prolonged exposure to protease inhibitors. Thus, periodic assessment of liver fibrosis is warranted after SVR and screening for liver cancer should continue in coinfected patients with advanced liver fibrosis.