Hepatitis C outreach project and cross-sectional epidemiology in high-risk populations in Trondheim, Norway.

BACKGROUND: Hepatitis C is highly prevalent among people who use drugs (PWUD), and the hepatitis C virus (HCV) epidemic is less characterised in Norway. The aims of the study were to assess the prevalence and treatment willingness in high-risk populations by reaching out to frequently visited sites for high-risk populations. METHODS: Individuals from high-risk populations were included from September 2015 to March 2017. Two dedicated study nurses frequently visited the local opioid substitution clinic, outpatient clinics, PWUD day centres, local prison, and refugee centre in Trondheim, Norway. Demographic data, risk behaviour, and clinical symptoms were obtained by study questionnaire. Subjects with anti-HCV+ rapid test were subsequently tested for HCV RNA and genotyped. Viraemic patients were offered referral for HCV treatment evaluation. RESULTS: A total of 381 participants were included in the study: 52 immigrants, 62 prisoners, and 267 PWUD. The anti-HCV prevalence rates were 0% (n = 0) in immigrants, 40% (n = 25) in prisoners, and 61% (n = 164) in PWUD, with 24% (n = 15) of prisoners and 42% (n = 108) of PWUD being viraemic. Of those qualifying for treatment (n = 31), 30 wished to be evaluated. CONCLUSION: This study showed high HCV prevalence in prisoners and PWUD and that infected high-risk patients were interested in treatment evaluation.

Sick leave and disability pension in patients with chronic hepatitis C compared with a matched general population: a nationwide register study.

OBJECTIVE: The objective of this study was to evaluate sick leave and disability pension in patients with chronic hepatitis C virus (HCV) infection as compared with a matched general population cohort. DESIGN: Retrospective register study. SETTING: Nationwide in Sweden. PARTICIPANTS: This register-based study used the Swedish National Patient Register to identify working-age patients with HCV in 2012 (n=32 021) who were diagnosed between 1999 and 2007 (n=19 362). Sick leave and disability pension data were retrieved from Statistics Sweden (1994-2012), with up to five matched individuals from the general population. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was workdays lost due to sick leave episodes (>14 days) and disability pension overall. The secondary outcome was workdays lost per subgroup of patients with chronic HCV. RESULTS: In 2012, 14% of the HCV patients had ≥1 registered sick leave episode compared with 10% in the matched comparator cohort. For disability pension benefits, results were 30% versus 8%, respectively. Overall, in 2012, 57% of patients with HCV did not have any registered workdays lost, whereas 30% were absent ≥360 days compared with 83% and 9% in the matched cohort, respectively. The mean total number of annual workdays lost in 2012 was 126 days in the HCV patient cohort compared with 40 days in the matched general population comparator cohort. Annual days lost increased from a mean of 86 days 5 years before diagnosis to 136 days during the year of diagnosis. CONCLUSIONS: These results show that Swedish HCV patients used more sick days and have a higher frequency of disability pension compared with a comparator cohort from the general Swedish population. Whether earlier diagnosis of HCV and treatment might impact work absence in Sweden warrants further investigation.

High risk of non-alcoholic liver disease mortality in patients with chronic hepatitis C with illicit substance use disorder.

Aims: Hepatitis C virus (HCV) is a slowly progressive disease, often transmitted among people who inject drugs (PWID). Mortality in PWID is high, with an overrepresentation of drug-related causes. This study investigated the risk of death in patients with chronic hepatitis C virus (HCV) infection with or without illicit substance use disorder (ISUD).Methods: Patients with HCV were identified using the Swedish National Patient Registry according to the International Classification of Diseases-10 (ICD-10) code B18.2, with ≤5 matched comparators from the general population. Patients with ≥2 physician visits with ICD-10 codes F11, F12, F14, F15, F16, or F19 were considered to have ISUD. The underlying cause of death was analyzed for alcoholic liver disease, non-alcoholic liver disease, liver cancer, drug-related and external causes, non-liver cancers, or other causes. Mortality risks were assessed using the standardized mortality ratio (SMR) with 95% CIs and Cox regression analyses for cause-specific hazard ratios.Results: In total, 38,186 patients with HCV were included, with 31% meeting the ISUD definition. Non-alcoholic liver disease SMRs in patients with and without ISUD were 123.2 (95% CI, 103.7-145.2) and 69.4 (95% CI, 63.8-75.3), respectively. The significant independent factors associated with non-alcoholic liver disease mortality were older age, being unmarried, male sex, and having ISUD.Conclusions: The relative risks for non-alcoholic liver disease mortality were elevated for patients with ISUD. Having ISUD was a significant independent factor for non-alcoholic liver disease. Thus, patients with HCV with ISUD should be given HCV treatment to reduce the risk for liver disease.

Frequent loss to follow-up after diagnosis of hepatitis C virus infection: A barrier towards the elimination of hepatitis C virus.

BACKGROUND: Previous studies on hepatitis C cascade of care have been mainly focused on diagnosis and treatment rate, while less attention has been given to patients lost to follow-up (LTFU) after diagnosis. Analyses of this latter issue on population level are missing. AIMS: In this nationwide study of people with HCV, we aimed to estimate the proportion LTFU after HCV diagnosis, characterize them, and analyze their other healthcare contacts. METHODS: Patients diagnosed with chronic HCV in the Swedish National Patient Register during 2001-2011 and still alive December 31, 2013, were included. The number of cured patients without need of follow-up was estimated. Visits to HCV specialist care during 2012-2013 were analysed. For those LTFU, other specialist care contacts were studied. RESULTS: In total 29 217 patients were included, with 24 733 with need of HCV care. 61% (n = 15 007) of them were LTFU from HCV care in 2012-2013 and 58% did not attend HCV care during the second year after HCV diagnosis. The departments of surgery/orthopaedic or psychiatry/dependency were the most common other non-primary healthcare contacts. Predictors for LTFU were young age, male sex, low education, presence of psychiatric/dependency diagnosis, unmarried and longer duration since diagnosis of HCV. CONCLUSIONS: This study showed that almost two-thirds of patients were LTFU after HCV diagnosis, with frequent occurrence early after diagnosis. Efforts to link patients back to HCV care, in combination with early and easy access to HCV treatment and harm reduction, are necessary to reach the HCV elimination goal.

Lower risk of multiple sclerosis in patients with chronic hepatitis C: a nationwide population-based registry study.

BACKGROUND: Multiple sclerosis (MS) is an immune-mediated neurological disease that causes demyelination. The etiology is unknown, but patients with a previous viral infection, such as Epstein-Barr virus, have been shown to be at a higher risk of developing MS. In contrast, people living with HIV have a lower risk of developing MS. Hepatitis C virus (HCV) mainly infects the liver, but patients with HCV can experience several extrahepatic manifestations and studies have shown an association with several autoimmune conditions such as neuropathy and myelitis. The present study aimed to investigate the risk of MS in patients with chronic HCV infection compared with matched comparators. METHODS: Patients were identified using the nationwide Swedish inpatient (2001-2013) and outpatient care registers (2001-2013) for HCV (B18.2) and MS (G35) according to the International Classification of Diseases-10. Up to five comparators (matched on age/sex/place of residency) were drawn from the general population for each HCV patient. Follow-up started at the first HCV visit from 2001 and the patients' accrued person-time until death, emigration or 31 December 2013. Risk of MS diagnosis was calculated as standardized incidence ratio (SIR) with 95% confidence intervals (CIs). RESULTS: HCV patients were at lower risk of MS diagnosis (SIR 0.37; 95% CI 0.26-0.50). The incidence of MS during the study in the HCV cohort was 0.087% compared with 0.27% in the matched comparator cohort. CONCLUSION: Surprisingly, these data suggest HCV patients to have a lower risk of MS diagnosis.

Reduced ITPase activity and favorable IL28B genetic variant protect against ribavirin-induced anemia in interferon-free regimens.

BACKGROUND: Genetic variants of inosine triphosphatase (ITPA) that confer reduced ITPase activity are associated with protection against ribavirin(RBV)-induced hemolytic anemia in peginterferon(IFN)/RBV-based treatment of hepatitis C virus (HCV). Patients with reduced ITPase activity showed improved treatment efficacy when treated with IFN/RBV. In addition, a genetic polymorphism near the IL28B gene is associated with an improved response to IFN/RBV treatment. RBV has been an important component of IFN-containing regimens, and is currently recommended in combination with several IFN-free regimens for treatment of harder to cure HCV infections. AIM: To evaluate whether genetic variations that reduce ITPase activity impact RBV-induced anemia in IFN-free/RBV regimens. METHODS: In this study, genetic analyses were conducted in the PEARL-IV trial to investigate the effect of activity-reducing ITPA variants as well as IL28B polymorphism on anemia, platelet (PLT) counts, and virologic response in HCV genotype1a-infected patients treated with the direct-acting antiviral (DAA) regimen of ombitasvir/paritaprevir/ritonavir and dasabuvir±RBV. RESULTS: Reduction in ITPase activity and homozygosity for the IL28Brs12979860 CC genotype protected against RBV-induced anemia. In patients receiving RBV, reduced ITPase activity was associated with reduced plasma RBV concentration and higher PLT counts. ITPase activity had no impact on response to DAA treatment, viral kinetics, or baseline IP-10 levels. CONCLUSIONS: Our study demonstrates that genetics of ITPA and IL28B may help identify patients protected from RBV-induced anemia when treated with IFN-free regimens. Our work demonstrates for the first time that IL28B genetics may also have an impact on RBV-induced anemia. This may be of particular significance in patients with difficult-to-cure HCV infections, such as patients with decompensated cirrhosis where RBV-containing regimens likely will continue to be recommended.

Higher risk of renal disease in chronic hepatitis C patients: Antiviral therapy survival benefit in patients on hemodialysis.

BACKGROUND & AIMS: Several studies have shown that chronic hepatitis C (CHC) infection has a negative impact on kidney function, as well as survival, in patients with chronic kidney disease (CKD) or on hemodialysis. The aim of this nationwide registry study was to describe renal disease in Swedish patients with CHC. METHODS: In the present study, patients were identified for CHC (B18.2) and CKD (N18) according to the International Classification of Diseases (ICD)-10 in the nationwide Swedish inpatient care day surgery (1997-2013) and non-primary outpatient care (2001-2013) patient registries. Hemodialysis was defined using the procedure code in the non-primary outpatient care. For each patient, up to five non-CHC diagnosed age/sex/place of residency-matched comparators were drawn from the general population at the time of diagnosis. Follow-up started at the date of CHC diagnosis and patients accrued person-time until, whichever came first, death, emigration or December 31st, 2013. RESULTS: Between 2001 and 2013, 42,522 patients received a CHC diagnosis. Of these patients, 2.5% (1,077/45,222) were diagnosed with CKD during 280,123 person-years, compared with 0.7% (1,454/202,694) in the matched general population comparators (1,504,765 person-years), resulting in a standardized incidence ratio (SIR) of 4.0. There was a 3.3-7.0-fold risk of patients with CHC requiring hemodialysis. Overall, 17% of patients with CHC receiving hemodialysis were treated for CHC; 24% in the treated cohort died compared with 56% of the untreated cohort (p <0.0001), with antiviral treatment improving survival with an odds ratio of 3.901 (p = 0.001). CONCLUSIONS: The results from this nationwide registry study showed that patients with CHC are at a higher risk of developing CKD. Furthermore, hepatitis C treatment seemed to improve survival for patients with CHC on hemodialysis compared with untreated patients. LAY SUMMARY: Hepatitis C is an infectious disease that mainly infects the liver, but has also been shown to have negative effects on other organs. This nationwide study demonstrates an increased risk of hepatitis C patients developing reduced kidney function and the need for dialysis. The study also showed improved survival in dialysis patients who received antiviral treatment.

Prevalence and comorbidities of chronic hepatitis C: a nationwide population-based register study in Sweden.

PURPOSE: The aim of this study was to estimate the prevalence of physician-diagnosed and registered chronic hepatitis C (CHC), and to estimate the reported frequencies of Charlson comorbidities compared with matched comparators from the general population. MATERIALS AND METHODS: Patients were identified according to ICD codes for CHC in the Swedish National Patient Register (1997-2013). Prevalence was estimated according to different patient identification algorithms and for different subgroups. Charlson comorbidities were ascertained from the same register and compared with age/sex/county of residence matched general population comparators. RESULTS: A total of 34,633 individuals with physician-diagnosed CHC were alive in Sweden in 2013 (mean age, 49 years; 64% men), corresponding to a physician-diagnosed prevalence of 0.36%. The prevalence varied by case definition (0.22%-0.36%). The estimate dropped to 0.14% for monitored CHC disease (defined as ≥1 CHC-related visit in 2013). Overall, 41.3% of the CHC patients had ≥1 physician-registered Charlson comorbidity; the most common was liver diseases (22.1%). Compared with matched comparators from the general population (n = 171,338), patients with CHC had more physician-diagnosed and registered diseases such as chronic pulmonary disease (10.2% vs. 4.0%), diabetes (10.6% vs. 5.5%) and liver-related cancer (1.3% vs. 0.2%; all p < .01). No information on behavioural factors, such as smoking, alcohol consumption or on-going illicit drug use, was available. CONCLUSION: The physician-diagnosed prevalence of CHC was slightly lower than previously reported estimates, and varied by case definition. The additional comorbidities observed in the CHC group should be taken into consideration, as these comorbidities add to the disease burden.

Impact of soluble CD26 on treatment outcome and hepatitis C virus-specific T cells in chronic hepatitis C virus genotype 1 infection.

BACKGROUND: Interferon and ribavirin therapy for chronic hepatitis C virus (HCV) infection yields sustained virological response (SVR) rates of 50-80%. Several factors such as non-1 genotype, beneficial IL28B genetic variants, low baseline IP-10, and the functionality of HCV-specific T cells predict SVR. With the pending introduction of new therapies for HCV entailing very rapid clearance of plasma HCV RNA, the importance of baseline biomarkers likely will increase in order to tailor therapy. CD26 (DPPIV) truncates the chemokine IP-10 into a shorter antagonistic form, and this truncation of IP-10 has been suggested to influence treatment outcome in patients with chronic HCV infection patients. In addition, previous reports have shown CD26 to be a co-stimulator for T cells. The aim of the present study was to assess the utility of CD26 as a biomarker for treatment outcome in chronic hepatitis C and to define its association with HCV-specific T cells. METHODS: Baseline plasma from 153 genotype 1 and 58 genotype 2/3 infected patients enrolled in an international multicenter phase III trial (DITTO-HCV) and 36 genotype 1 infected patients participating in a Swedish trial (TTG1) were evaluated regarding baseline soluble CD26 (sCD26) and the functionality of HCV-specific CD8(+) T cells. RESULTS: Genotype 1 infected patients achieving SVR in the DITTO (P = 0.002) and the TTG1 (P = 0.02) studies had lower pretreatment sCD26 concentrations compared with non-SVR patients. Sixty-five percent of patients with sCD26 concentrations below 600 ng/mL achieved SVR compared with 39% of the patients with sCD26 exceeding 600 ng/mL (P = 0.01). Patients with sCD26 concentrations below 600 ng/mL had significantly higher frequencies of HCV-specific CD8(+) T cells (P = 0.02). CONCLUSIONS: Low baseline systemic concentrations of sCD26 predict favorable treatment outcome in chronic HCV infection and may be associated with higher blood counts of HCV-specific CD8(+) T cells.

Limited effect on NS3-NS4A protein cleavage after alanine substitutions within the immunodominant HLA-A2-restricted epitope of the hepatitis C virus genotype 3a non-structural 3/4A protease.

It has been well established that immunological escape mutations within the hepatitis C virus genotype (gt) 1a non-structural (NS) 3/4A protease are partly prevented by a reduction in viral protease fitness. Surprisingly little is known about whether similar mutations affect proteases from other genotypes. In the present study, we assessed both the HLA-A2-restricted CTL response and gt3a NS3/4A protease fitness. Similar to gt1, the 1073-1081 epitope was immunodominant within the gt3a-specific HLA-A2-restricted CTL response, despite sequence similarity of only 56 % between the gt1a and gt3a genes. However, unlike the gt1a NS3/4A protease, all residues within the gt3a 1073-1081 epitope could be replaced sequentially by alanine while retaining protease activity, at least in part.

Influenza A vaccines using linear expression cassettes delivered via electroporation afford full protection against challenge in a mouse model.

Alternative DNA vaccine constructs such as fully synthetic linear expressing cassettes (LECs) offer the advantage of accelerated manufacturing techniques as well as the lack of both antibiotic resistance genes and bacterial contaminants. The speed of manufacture makes LEC technology a possible future vaccination strategy for pandemic influenza outbreaks. Previously, we reported on a novel concept of DNA delivery to dermal tissue by a minimally invasive electroporation (EP) surface device powered using low voltage parameters. This device allows electroporation without penetration of electrodes into the skin. In addition to enhancing the delivery of traditional plasmid DNA vaccines, this device may also offer a safe, tolerable and efficient method to administer LECs. To assess immunogenicity and efficacy of EP-enhanced LEC delivery in mice, we designed and tested two influenza antigens in the form of LEC constructs delivered using the newly developed surface dermal EP device. Strong CTL and antibody responses were induced by the LEC versions of the DNA vaccine. When challenged with A/Canada/AB/RV1532/2009 viruses, mice immunized with LEC encoding the M2 and NP antigens recovered faster than naïve or mice immunized ID without EP. Mice immunized with equal-molar doses of LEC encoding the M2 and NP antigens demonstrated 100% survival following a lethal (100× LD50) challenge of the heterologuos and highly pathogenic H5N1 influenza virus (A/Vietnam/1203/04). These results suggest that influenza DNA vaccines based on LEC technology combined with the surface delivery platform are capable of fully protecting mice in a lethal challenge and the LEC based DNA constructs may serve as viable vaccine candidates.

Hepatitis C virus non-structural 3/4A protein interferes with intrahepatic interferon-γ production.

BACKGROUND: The non-structural (NS) 3/4A protease/helicase of the hepatitis C virus is known to modulate signalling pathways in the infected hepatocyte by cleaving CARD adaptor inducing IFNß (Cardif), T-cell protein tyrosine phosphatase (TC-PTP) and TIR domain-containing adaptor inducing IFNß (TRIF), but the effects of NS3/4A in vivo still remain unclear. AIM: To investigate the influence of NS3/4A on intracellular and intercellular signalling in vivo by analysing the intrahepatic inflammatory response of naïve, lipopolysaccharide (LPS)/D-galactosamine (D-galN) or tumour necrosis factor-α (TNFα)/D-galN-treated NS3/4A-transgenic (Tg) mice. METHODS: The intrahepatic immunity of naïve and LPS/D-galN- or TNFα/D-galN-treated NS3/4A-Tg mice was determined using western blot, ELISA, real-time PCR, flow cytometry and survival monitoring. The injection of cytokines or antibodies against signalling components was performed to analyse the relevance of the respective pathways for the investigated issues. A Tg mouse lineage expressing an inactivated NS3/4A protease (NS3/4A(Ile1073Ala)-Tgs) was generated to examine if protective effects were NS3/4A protease dependent. RESULTS: The activation of hepatic signal transducer and activator of transcription 1 and 2 was impaired in NS3/4A-Tg mice after treatment with LPS/D-galN or TNFα/D-galN. This was paralleled by a reduction in hepatic interferon-γ (IFNγ). Reconstitution of IFNγ reverted the resistance to LPS/TNFα in NS3/4A-Tg mice. Subsequently, blocking IFNγ in vivo rendered wild-type mice resistant against treatment with LPS/TNFα. A new Tg mouse expressing an inactivated NS3/4A protease had the same phenotype as wild-type mice with respect to hepatic IFNγ levels and sensitivity to LPS/d-galN. Finally, the chemokine profile was altered in the NS3/4A-Tg mice towards an anti-inflammatory state, which helps to explain the altered immune cell subsets and reduction in hepatic IFNγ production. CONCLUSIONS: Our data demonstrate that the NS3/4A protease reduces the intrahepatic production of IFNγ and alters TNFα-mediated effects, thereby impairing the hepatic inflammatory response. This may contribute to viral persistence.

Response prediction in chronic hepatitis C by assessment of IP-10 and IL28B-related single nucleotide polymorphisms.

BACKGROUND: High baseline levels of IP-10 predict a slower first phase decline in HCV RNA and a poor outcome following interferon/ribavirin therapy in patients with chronic hepatitis C. Several recent studies report that single nucleotide polymorphisms (SNPs) adjacent to IL28B predict spontaneous resolution of HCV infection and outcome of treatment among HCV genotype 1 infected patients. METHODS AND FINDINGS: In the present study, we correlated the occurrence of variants at three such SNPs (rs12979860, rs12980275, and rs8099917) with pretreatment plasma IP-10 and HCV RNA throughout therapy within a phase III treatment trial (HCV-DITTO) involving 253 Caucasian patients. The favorable SNP variants (CC, AA, and TT, respectively) were associated with lower baseline IP-10 (P = 0.02, P = 0.01, P = 0.04) and were less common among HCV genotype 1 infected patients than genotype 2/3 (P<0.0001, P<0.0001, and P = 0.01). Patients carrying favorable SNP genotypes had higher baseline viral load than those carrying unfavorable variants (P = 0.0013, P = 0.029, P = 0.0004 respectively). Among HCV genotype 1 infected carriers of the favorable C, A, or T alleles, IP-10 below 150 pg/mL significantly predicted a more pronounced reduction of HCV RNA from day 0 to 4 (first phase decline), which translated into increased rates of RVR (62%, 53%, and 39%) and SVR (85%, 76%, and 75% respectively) among homozygous carriers with baseline IP-10 below 150 pg/mL. In multivariate analyses of genotype 1-infected patients, baseline IP-10 and C genotype at rs12979860 independently predicted the first phase viral decline and RVR, which in turn independently predicted SVR. CONCLUSIONS: Concomitant assessment of pretreatment IP-10 and IL28B-related SNPs augments the prediction of the first phase decline in HCV RNA, RVR, and final therapeutic outcome.

Heterologous T cells can help restore function in dysfunctional hepatitis C virus nonstructural 3/4A-specific T cells during therapeutic vaccination.

The hepatitis C virus (HCV)-specific T cell response in patients with chronic HCV is dysfunctional. In this study, we aimed at restoring immunological function through therapeutic vaccination in a transgenic mouse model with impaired HCV-specific T cell responses due to a persistent presence of hepatic HCV nonstructural (NS)3/4A Ags. The HCV-specific T cells have an actively maintained dysfunction reflected in reduced frequency, impaired cytokine production, and impaired effector function in vivo, which can be partially restored by blocking regulatory T cells or programmed cell death ligand 1. We hypothesized that the impairment could be corrected by including sequences that created a normal priming environment by recruiting "healthy" heterologous T cells and by activating innate signaling. Endogenously expressed hepatitis B core Ag (HBcAg) can recruit heterologous T cells and activate TLR (TLR7) signaling. Hence, by combining HCV NS3/4A with different forms of HBcAg we found that heterologous sequences somewhat improved activation and expansion of NS3/4A-specific T cells in a wild-type host. Importantly, the signals provided by HBcAg effectively restored the activation of HCV-specific T cells in a tolerant NS3/4A-transgenic mouse model. The adjuvant effect could also be transferred to the priming of dysfunctional HLA-A2-restricted NS3-specific T cells in vivo. Thus, recruiting healthy heterologous T cells to the site of priming may also help restore HCV-specific responses present in a chronically infected host.

Coexpressed RIG-I agonist enhances humoral immune response to influenza virus DNA vaccine.

Increasing levels of plasmid vector-mediated activation of innate immune signaling pathways is an approach to improve DNA vaccine-induced adaptive immunity for infectious disease and cancer applications. Retinoic acid-inducible gene I (RIG-I) is a critical cytoplasmic double-stranded RNA (dsRNA) pattern receptor required for innate immune activation in response to viral infection. Activation of RIG-I leads to type I interferon (IFN) and inflammatory cytokine production through interferon promoter stimulator 1 (IPS-1)-mediated activation of interferon regulatory factor 3 (IRF3) and NF-κB signaling. DNA vaccines coexpressing antigen and an expressed RNA (eRNA) RIG-I agonist were made, and the effect of RIG-I activation on antigen-specific immune responses to the encoded antigen was determined. Plasmid vector backbones expressing various RIG-I ligands from RNA polymerase III promoters were screened in a cell culture assay for RIG-I agonist activity, and optimized, potent RIG-I ligands were developed. One of these, eRNA41H, combines (i) eRNA11a, an immunostimulatory dsRNA expressed by convergent transcription, with (ii) adenovirus VA RNAI. eRNA41H was integrated into the backbone of DNA vaccine vectors expressing H5N1 influenza virus hemagglutinin (HA). The resultant eRNA vectors potently induced type 1 IFN production in cell culture through RIG-I activation and combined high-level HA antigen expression with RNA-mediated type I IFN activation in a single plasmid vector. The eRNA vectors induced increased HA-specific serum antibody binding avidity after naked DNA intramuscular prime and boost delivery in mice. This demonstrates that DNA vaccine potency may be augmented by the incorporation of RIG-I-activating immunostimulatory RNA into the vector backbone.

Immunotherapy with histamine dihydrochloride for the prevention of relapse in acute myeloid leukemia.

Most patients with acute myeloid leukemia (AML) achieve complete remission (CR) after induction chemotherapy. Despite ensuing courses of consolidation chemotherapy, a large fraction of patients will experience relapses with poor prospects of long-term survival. Histamine dihydrochloride (HDC) in combination with the T-cell-derived cytokine IL-2 was recently approved within the EU as a remission maintenance immunotherapy in AML. HDC reduces myeloid cell-derived suppression of anti-leukemic lymphocytes, and aims to unravel a therapeutic benefit of IL-2 in AML by improving natural killer and T-cell activation. A randomized Phase III trial with 320 AML patients in CR demonstrated a significant reduction of relapse risk after immunotherapy with HDC plus low-dose IL-2 in the post-consolidation phase. HDC is the first approved therapeutic to target the state of immunosuppression in AML; further development in this area may comprise supplementary or alternative counter-suppressive agents with the aim to improve the efficacy of cancer immunotherapy.

Systemic and intrahepatic interferon-gamma-inducible protein 10 kDa predicts the first-phase decline in hepatitis C virus RNA and overall viral response to therapy in chronic hepatitis C.

UNLABELLED: High systemic levels of interferon-gamma-inducible protein 10 kDa (IP-10) at onset of combination therapy for chronic hepatitis C virus (HCV) infection predict poor outcome, but details regarding the impact of IP-10 on the reduction of HCV RNA during therapy remain unclear. In the present study, we correlated pretreatment levels of IP-10 in liver biopsies (n = 73) and plasma (n = 265) with HCV RNA throughout therapy within a phase III treatment trial (DITTO-HCV). Low levels of plasma or intrahepatic IP-10 were strongly associated with a pronounced reduction of HCV RNA during the first 24 hours of treatment in all patients (P < 0.0001 and P = 0.002, respectively) as well as when patients were grouped as genotype 1 or 4 (P = 0.0008 and P = 0.01) and 2 or 3 (P = 0.002, and P = 0.02). Low plasma levels of IP-10 also were predictive of the absolute reduction of HCV RNA (P < 0.0001) and the maximum reduction of HCV RNA in the first 4 days of treatment (P < 0.0001) as well as sustained virological response (genotype 1/4; P < 0.0001). To corroborate the relationship between early viral decline and IP-10, pretreatment plasma samples from an independent phase IV trial for HCV genotypes 2/3 (NORDynamIC trial; n = 382) were analyzed. The results confirmed an association between IP-10 and the immediate reduction of HCV RNA in response to therapy (P = 0.006). In contrast, pretreatment levels of IP-10 in liver or in plasma did not affect the decline of HCV RNA between days 8 and 29, i.e., the second-phase decline, or later time points in any of these cohorts. CONCLUSION: In patients with chronic hepatitis C, low levels of intrahepatic and systemic IP-10 predict a favorable first-phase decline of HCV RNA during therapy with pegylated interferon and ribavirin for genotypes of HCV.

In vivo electroporation enhances the immunogenicity of hepatitis C virus nonstructural 3/4A DNA by increased local DNA uptake, protein expression, inflammation, and infiltration of CD3+ T cells.

The mechanisms by which in vivo electroporation (EP) improves the potency of i.m. DNA vaccination were characterized by using the hepatitis C virus nonstructural (NS) 3/4A gene. Following a standard i.m. injection of DNA with or without in vivo EP, plasmid levels peaked immediately at the site of injection and decreased by 4 logs the first week. In vivo EP did not promote plasmid persistence and, depending on the dose, the plasmid was cleared or almost cleared after 60 days. In vivo imaging and immunohistochemistry revealed that protein expression was restricted to the injection site despite the detection of significant levels of plasmid in adjacent muscle groups. In vivo EP increased and prolonged NS3/4A protein expression levels as well as an increased infiltration of CD3+ T cells at the injection site. These factors most likely additively contributed to the enhanced and broadened priming of NS3/4A-specific Abs, CD4+ T cells, CD8+ T cells, and gamma-IFN production. The primed CD8+ responses were functional in vivo, resulting in elimination of hepatitis C virus NS3/4A-expressing liver cells in transiently transgenic mice. Collectively, the enhanced protein expression and inflammation at the injection site following in vivo EP contributed to the priming of in vivo functional immune responses. These localized effects most likely help to insure that the strength and duration of the responses are maintained when the vaccine is tested in larger animals, including rabbits and humans. Thus, the combined effects mediated by in vivo EP serves as a potent adjuvant for the NS3/4A-based DNA vaccine.

A complete mutational fitness map of the hepatitis C virus nonstructural 3 protease: relation to recognition by cytotoxic T lymphocytes.

The hepatitis C virus nonstructural (NS) 3/4A protease sequence is highly conserved for reasons not fully understood. We determined the protease activity in 181 NS3/4A gene products in which each protease residue was replaced by alanine or glycine. Unexpectedly, most (87%) protease residues could be replaced and protease activity would be retained. Using these data, we were able to identify a human leukocyte antigen A2-restricted epitope in which substitutions at 5 of 9 residues destroyed the protease. The NS3 protease shows an unexpectedly high plasticity, and it is therefore important to identify target sequences in which the appearance of mutations is restricted by viral fitness.