In vivo combination of human anti-envelope glycoprotein E2 and -Claudin-1 monoclonal antibodies for prevention of hepatitis C virus infection.

Despite the development of direct-acting antivirals (DAAs), hepatitis C virus (HCV) infection remains a major cause for liver disease and cancer worldwide. Entry inhibitors block virus host cell entry and, therefore, prevent establishment of chronic infection and liver disease. Due to their unique mechanism of action, entry inhibitors provide an attractive antiviral strategy in organ transplantation. In this study, we developed an innovative approach in preventing HCV infection using a synergistic combination of a broadly neutralizing human monoclonal antibody (HMAb) targeting the HCV E2 protein and a host-targeting anti-claudin 1 (CLDN1) humanized monoclonal antibody. An in vivo proof-of-concept study in human liver-chimeric FRG-NOD mice proved the efficacy of the combination therapy at preventing infection by an HCV genotype 1b infectious serum. While administration of individual antibodies at lower doses only showed a delay in HCV infection, the combination therapy was highly protective. Furthermore, the combination proved to be effective in preventing infection of primary human hepatocytes by neutralization-resistant HCV escape variants selected during liver transplantation, suggesting that a combination therapy is suited for the neutralization of difficult-to-treat variants. In conclusion, our findings suggest that the combination of two HMAbs targeting different steps of virus entry improves treatment efficacy while simultaneously reducing treatment duration and costs. Our approach not only provides a clinical perspective to employ HMAb combination therapies to prevent graft re-infection and its associated liver disease but may also help to alleviate the urgent demand for organ transplants by allowing the transplantation of organs from HCV-positive donors.

Prevention of allograft HCV recurrence with peri-transplant human monoclonal antibody MBL-HCV1 combined with a single oral direct-acting antiviral: A proof-of-concept study.

Patients with active hepatitis C virus (HCV) infection at transplantation experience rapid allograft infection, increased risk of graft failure and accelerated fibrosis. MBL-HCV1, a neutralizing human monoclonal antibody (mAb) targeting the HCV envelope, was combined with a licensed oral direct-acting antiviral (DAA) to prevent HCV recurrence post-transplant in an open-label exploratory efficacy trial. Eight subjects received MBL-HCV1 beginning on the day of transplant with telaprevir initiated between days 3 and 7 post-transplantation. Following FDA approval of sofosbuvir, two subjects received MBL-HCV1 starting on the day of transplant with sofosbuvir initiated on day 3. Combination treatment was administered for 8-12 weeks or until the stopping rule for viral rebound was met. The primary endpoint was undetectable HCV RNA at day 56 with exploratory endpoints of sustained virologic response (SVR) at 12 and 24 weeks post-treatment. Both subjects receiving mAb and sofosbuvir achieved SVR24. Four of eight subjects in the mAb and telaprevir group met the primary endpoint; one subject achieved SVR24 and three subjects relapsed 2-12 weeks post-treatment. The other four subjects experienced viral breakthrough. There were no serious adverse events related to study treatment. This proof-of-concept study demonstrates that peri-transplant immunoprophylaxis combined with a single oral direct-acting antiviral in the immediate post-transplant period can prevent HCV recurrence.

Studies on the role of neutralizing antibodies against envelope genes in resolving HCV pseudo-particles infection.

Characterization of antibodies targeting the attachment and entry of the viral particles into host cells is important for studding antibody mediated neutralization. Antibodies against the envelope glycoproteins (EGP) have neutralizing capacity and can prevent HCV infections. System based on HCV pseudo typed-particles (HCVpp) stably expressing EGP can be used for screening of HCV anti envelope neutralizing antibodies in the serum of patients with acute and chronic HCV infections. The aim of the current study was to check HCVpp as a useful tool for the detection of anti-HCV envelope antibodies in the serum of HCV infected patients and to test the binding potential of these antiviral molecules to EGP of HCV 3a. Previously developed HCVpp harboring unmodified glycoproteins from local isolates in 293T cell line were used in this study. HCVpp were pre incubated with different concentrations of anti E1 antibody and different E2 antibodies to check antiviral activity. Further we used serum samples with low/medium (≤800,000 IU/mL), and high (>800,000 IU/mL) viral titer from chronic HCV male and female patients. Infection was done in Huh-7 cells for 1 h at 37 oC. Infectivity was checked through Luciferase assay. Considerable decrease in HCVpp infectivity with anti-envelope antibodies was observed in dose dependent manner. Maximum inhibition was seen when 5 µg/ml of monoclonal anti E1 antibody used. Further increase in concentration exhibited no decrease in infectivity which suggests that other factors are also involved in causing infection. Various well characterized E2-specific monoclonal antibodies (mAbs) have been screened for their capability to reduce infection in Huh-7 cells. Three of the four mAbs specific for the E2 had no effect on the infectivity of HCVpp. Confirmation sensitive antibody H53 showed maximum inhibition of infectivity. HCV ELISA positive samples from both male and female patients were used to neutralize the HCVpp. The neutralizing antibody response was observed in both males and females patients and do not assemble the rapidly evolving HCV envelope glycoproteins. That is why in spite the presence of neutralizing antibodies in the blood they fail to resolve infections. Moreover E1 antibodies insignificantly (>0.05) inhibit HCVpp infectivity while E2 antibodies significantly (<0.05) inhibit HCVpp infection. Based on the results of this study it is concluded that anti-envelope antibodies particularly the anti-E2 could be extremely valuable for characterizing the humoral immune response to HCV and for evaluating the potential for developing passive and active immunization for hepatitis C along with interferon therapy.

Immunogenicity of hepatitis B vaccine in multi-transfused thalassemic patients with and without hepatitis C infection: a comparative study with healthy controls.

BACKGROUND: Hepatitis C virus (HCV) infection is highly prevalent in thalassemic patients. This may decrease serum antibody response to hepatitis B virus (HBV) vaccine. There is also some alteration in the immune system of multi-transfused thalassemic patients as a consequence of iron overload. We deduced that HCV infection may reduce the effectiveness of HBV vaccine in multi-transfused thalassemic patients. MATERIAL/METHODS: Subjects were cited and studied prospectively in three groups. Group 1:125 multi-transfused thalassemic patients with negative serum HCV antibody, Group 2:96 multi-transfused thalassemic patients with positive serum HCV antibody on at least 2 different occasions, and Group3:100 healthy subjects. Subjects in all groups had negative serum HBsAg, anti-HBc, and anti-HBs, and they received three 20-microg doses of recombinant HBV vaccine in months 0,1, and 6. The anti-HBs titer was obtained one month after the last dose of vaccine and was considered seroprotective if > or =10 IU/l. RESULTS: The seroprotection rate was 83.2% in Group 1 and 80.2% in Group 2 (P = 0.74). It was 86% in healthy subjects, which didn't significantly differ from HCV-positive and -negative thalassemics (P = 0.56). Moreover, the mean values of ALT among the responder and non-responder thalassemic patients were 55.5 +/- 41.9 and 57.4 +/- 48.5 U/l, respectively (p = 0.802). During the vaccination periods, patients in all 3 groups did not show any significant adverse reactions. CONCLUSIONS: Our study shows that three standard doses of HBV vaccine are immunogenic and safe in multi-transfused thalassemic patients with or without HCV infection.

Detección de hepatitis C en la población laboral de Unión Fenosa y Necso / Detection of hepatitis C among the population of Union Fenosa and Necso

Debido a la frecuencia de la hepatitis por virus C (HCV) en nuestro medio(1) , su trascendencia clínica(2) y su difícil diagnóstico (al ser asintomática en la mayoría de los casos)(3,4), hemos realizado un estudio para la detección de posibles portadores de virus C. Para ello, hemos revisado las historias clínicas de los trabajadores, seleccionando a los posibles portadores según criterios analíticos y clínicos, y excluyendo determinadas patologías. En este trabajo presentamos el protocolo que hemos utilizado y los resultados obtenidos (AU)

Incidence of hepatitis C in patients receiving different preparations of hepatitis B immunoglobulins after liver transplantation.

BACKGROUND: Recurrence of hepatitis B virus (HBV) or hepatitis C virus (HCV) infection after liver transplantation is a clinical problem. Polyclonal immunoglobulins against hepatitis B surface antigen (HBIGs) prevent the recurrence of HBV infection, but no effective prophylaxis is available for HCV infection. Before screening of blood donors was introduced in France, HBIGs may have contained antibody to HCV (anti-HCV). OBJECTIVE: To determine the influence of HBIG on the occurrence of hepatitis C after liver transplantation before and after 1990. DESIGN: Retrospective cohort study. SETTING: Liver transplantation unit of a university hospital. PATIENTS: 428 consecutive patients who had liver transplantation because of cirrhosis between 1984 and 1994. MEASUREMENTS: Detection of serum HCV RNA before and 1 year after transplantation and findings on liver graft biopsy. RESULTS: Among the 218 patients who had HCV infection before transplantation, the incidence of HCV viremia after transplantation was lower in those receiving HBIG than in those not receiving HBIG (25 of 46 patients [54%] compared with 162 of 172 patients [94%]; P < 0.001). In patients receiving HBIG, the incidence of HCV viremia after transplantation was lower among those who had transplantation before March 1990 than among those who had transplantation after this date (15 of 33 patients [45%] compared with 10 of 13 patients [77%]; P = 0.05). Among the 210 patients without HCV infection before transplantation, acquired infection was significantly less frequent in those receiving HBIG than in those not receiving HBIG (18 of 68 patients [26%] compared with 40 of 86 patients [47%]; P < 0.001). Passively transmitted anti-HCV was transiently detected in patients receiving HBIG before March 1990. Multivariate analysis in patients with HCV infection before transplantation showed that the absence of HBIG and transplantation after March 1990 were independent significant risk factors for chronic hepatitis C after transplantation. CONCLUSIONS: Polyclonal immunoglobulins that are treated for viral decontamination and contain anti-HCV could prevent HCV infection.