Oded Jurim

Preclinical Evaluation of Two Neutralizing Human Monoclonal Antibodies against Hepatitis C Virus (HCV): a Potential Treatment To Prevent HCV Reinfection in Liver Transplant Patients

ABSTRACT Passive immunotherapy is potentially effective in preventing reinfection of liver grafts in hepatitis C virus (HCV)-associated liver transplant patients. A combination of monoclonal antibodies directed against different epitopes may be advantageous against a highly mutating virus such as HCV. Two human monoclonal antibodies (HumAbs) against the E2 envelope protein of HCV were developed and tested for the ability to neutralize the virus and prevent human liver infection. These antibodies, designated HCV-AB 68 and HCV-AB 65, recognize different conformational epitopes on E2. They were characterized in vitro biochemically and functionally. Both HumAbs are immunoglobulin G1 and have affinity constants to recombinant E2 constructs in the range of 10−10 M. They are able to immunoprecipitate HCV particles from infected patients sera from diverse genotypes and to stain HCV-infected human liver tissue. Both antibodies can fix complement and form immune complexes, but they do not activate complement-dependent or antibody-dependent cytotoxicity. Upon complement fixation, the monoclonal antibodies induce phagocytosis of the immune complexes by neutrophils, suggesting that the mechanism of viral clearance includes endocytosis. In vivo, in the HCV-Trimera model, both HumAbs were capable of inhibiting HCV infection of human liver fragments and of reducing the mean viral load in HCV-positive animals. The demonstrated neutralizing activities of HCV-AB 68 and HCV-AB 65 suggest that they have the potential to prevent reinfection in liver transplant patients and to serve as prophylactic treatment in postexposure events.

Effectiveness of Acute Normovolemic Hemodilution to Minimize Allogeneic Blood Transfusion in Major Liver Resections

Background Liver resection is a major operation for which, even with the improvements in surgical and anesthetic techniques, the reported rate of blood transfusion was rarely less than 30%. About 60% of transfused patients require only 1 or 2 units of blood, a blood requirement that may be accommodated by the use of acute normovolemic hemodilution (ANH). Methods The efficacy, hemodynamic effects, and safety of ANH were investigated in a randomized, active-control study in patients with American Society of Anesthesiologists status I–II who were undergoing major liver resection with fentanyl–nitrous oxide–isoflurane anesthesia. Patients were randomized to the ANH (n = 39) or control group (n = 39). Patients in the ANH group underwent hemodilution to a target hematocrit of 24%. The indication for blood transfusion was standardized. In both groups transfusion was started at a hematocrit of 20%. The primary efficacy endpoint was the avoidance of allogeneic blood transfusion in the intraoperative period and first 72 h after surgery. Various laboratory and hemodynamic parameters as well as postoperative morbidity were monitored to define the safety of ANH in this patient population. Results During the perioperative period, 14 control patients (36%) received at least one unit of allogeneic blood compared with 4 patients (10%) in the ANH group (P < 0.05). The hemodilution process was not associated with significant changes in patients’ hemodynamics. Morbidity was similar between the control and the ANH groups. Postoperative hematocrit levels and biochemical liver, renal, and standard coagulation test results were similar in both groups. Conclusions Acute normovolemic hemodilution in patients with American Society of Anesthesiologists status I–II undergoing major liver resection may allow a significant number of patients to avoid exposure to allogeneic blood.

The Hepatitis C Virus (HCV)–Trimera Mouse: A Model for Evaluation of Agents against HCV

The lack of small-animal models that are suitable for evaluation of agents used to treat infection with hepatitis C virus (HCV) severely hinders the assessment of potential new therapies for the disease. This study created such a model, termed the HCV-Trimera model. The HCV-Trimera model was developed by using lethally irradiated mice, reconstituted with SCID mouse bone marrow cells, in which human liver fragments infected ex vivo with HCV had been transplanted. Viremia (positive-strand HCV RNA levels) in HCV-Trimera mice peaked at approximately day 18 after liver transplantation, and an infection rate of 85% was reached. Viral replication in liver grafts was evidenced by the presence of specific negative-strand HCV RNA. The usefulness of this model for evaluation of anti-HCV agents was demonstrated by the ability of a small molecule (an HCV internal ribosomal entry site inhibitor) and an anti-HCV human monoclonal antibody (HCV AB(XTL)68) to reduce virus loads in HCV-Trimera mice in a dose-dependent manner.

Epidural Anesthesia and Analgesia in Liver Resection

IMPLICATIONSnIn patients undergoing major liver resection, the decision to introduce an epidural catheter and the timing of its removal should be made with care because of the prolonged changes in platelet count and in prothrombin time that develop in some patients.

Vascular complications post orthotopic liver transplantation.

From October 1991 to May 1998, 63 OLT in 57 patients were performed at Hadassah Hebrew University Medical Center. These included 58 whole liver transplantations, four reduced size, and one living-related liver transplantation. There were 25 females and 32 males with a mean age of 40.7 year (range 3.5–68). The follow-up was a mean of 21 months (range of 0.1–78). In 52 OLT donor liver arterial inflow was based on recipient hepatic artery (HA), and in 10 OLT on recipient aorta (Ao). In one OLT, this information was not available. Portal vein (PV) reconstruction was by end-to-end anastomosis in all transplants except in one OLT with recipient PV thrombosis (PVT), in which an interposition donor iliac vein was used. Inferior vena cava (IVC) reconstruction was performed in a standard manner in 53 OLT, and piggy-back in 10 OLT. Vascular complications were diagnosed based on clinical, ultrasonographic, angiographic, and operative findings. Statistical analysis was performed using Fisher’s exact test with significance accepted at P , .05.

Hepatitis-C-associated cryoglobulinemia after liver transplantation

: Mixed cryoglobulinemia is well known to be associated with hepatitis C virus (HCV) infection. We report two cases in which cryoglobulinemia appeared or became grossly exacerbated after orthotopic liver transplantation. In both cases, there was co-appearance of cryoglobulinemia with the reinfection of the grafted liver with HCV. It is postulated that the cryoglobulinemia might be related to secondary HCV infection in these patients.

The protective effect of acadesine on lung ischemia-reperfusion injury.

The purine precursor acadesine is highly effective in preventing ischemia-reperfusion (I-R) injury of the heart and intestine. The aim of this study was to test the effect of acadesine on I-R–induced lung injury. The lobar artery of the left lower lung lobe in intact-chest, spontaneously breathing cats was occluded for 2 h (Group 1, ischemia) and reperfused for 3 h (Group 2, I-R). Animals were subjected to one of the following three protocols: acadesine administered IV 15 min before ischemia (Group 3), 15 min before reperfusion (Group 4), or 30 min after reperfusion (Group 5). Acadesine was administered at an initial dose of 2.5 mg · kg−1 · min−1 for 5 min, followed by 0.5 mg · kg−1 · min−1 until the end of reperfusion. Injury was assessed by histologic examination. The right lower lobe served as control. Compared with the right lower lobe, which showed no abnormal findings in any group (percentage of injured alveoli, 2% ± 1% to 4% ± 2%), the left lower lung lobe in the I-R group revealed a disrupted alveolar structure with 63% ± 9% injured alveoli. Ischemia alone did not produce alterations in alveolar structure. Acadesine significantly reduced the number of injured alveoli when given before ischemia (4% ± 1%) or reperfusion (6% ± 2%) but not when administered after reperfusion (62% ± 8%). In conclusion, acadesine, when administered before ischemia or reperfusion, can blunt I-R–induced lung injury. The mechanism underlying the protection remains to be elucidated.

Bladder neck closure in children: a decade of followup.

PURPOSEnBladder neck closure necessitates lifelong clean intermittent catheterization. Concerns have been raised regarding well-being and compliance in patients on long-term clean intermittent catheterization. Noncompliance may result in subsequent hydronephrosis, incontinence, infection, cystolithiasis and perforation. We analyzed our long-term results with bladder neck closure followed at least 10 years for patient compliance with clean intermittent catheterization, upper tract preservation, continence, complications and subsequent procedures.nnnMATERIALS AND METHODSnAll patients followed at least 10 years after bladder neck closure were included in this study.nnnRESULTSnSeven boys and 5 girls with a mean age of 7.0 years and urinary incontinence underwent bladder neck closure and continent urinary diversion between 1993 and 1998. The primary diagnosis was exstrophy in 5 patients, spinal dysraphism in 3, trauma in 2, sacral agenesis in 1 and a duplicated hindgut in 1. Mean followup was 12.4 years (range 10 to 14). All patients performed clean intermittent catheterization 4 to 6 times daily. Hydronephrosis improved or remained stable in the 11 patients who underwent bladder augmentation. Mild new hydronephrosis developed in 1 patient and resolved after increasing clean intermittent catheterization frequency. Bladder neck closure successfully cured incontinence in all of the last 6 patients who underwent modified bladder neck closure with a posterior bladder neck flap, while 2 of the earlier 6 bladder neck closures required revision for a subsequent 100% success rate. Additional operations were required in 6 patients. To our knowledge this is the longest followup after bladder neck closure reported in the literature.nnnCONCLUSIONSnPatient compliance with long-term clean intermittent catheterization is good after bladder neck closure. Bladder neck closure provides excellent long-term safety for the upper urinary tract and continence. It is associated with relatively low morbidity, which is correctible.

Disseminated Intravascular Coagulopathy Caused by Acetic Acid Ingestion

A case of disseminated intravascular coagulopathy following ingestion of 100% acetic acid is presented. The patient was successfully treated with fresh frozen plasma and cryoprecipitate. Complete resolution of the bleeding diathesis and the disturbed coagulation tests was achieved.

The role of ERCP in biliary complications after liver transplantation.

Twelve patients underwent 34 diagnostic/therapeutic ERCP after OLT. There were five males and seven females, mean age at OLT was 37.8 years (range 15–59 years). Mean post-OLT follow-up was 46.3 months (range 4–79 months). Mean number of ERCP procedures was 2.8 for each patient (range 1–6). Eleven of 34 ERCP procedures were performed within 6 months post-OLT; however, 23 procedures were performed later. ERCP studies revealed biliary leakage from the anastomosis in three patient procedures (n 5 3), anastomotic biliary stricture (n 5 5), nonanastomotic biliary stricture (n 5 2) and normal biliary tree (n 5 2). All three patients with biliary leakage were successfully treated by ERCP stenting for 1 to 2 months. Three of five patients with biliary anastomotic strictures were treated successfully by dilatation, another patient was treated by papillotomy. The fifth patient had a mild stenosis and did not need intervention. Two patients were treated by stent insertion following balloon dilatation. Both cases with nonanastomotic biliary strictures had hepatic artery occlusion and required intervention with PTC drainage and washing. ERCP complications included asymptomatic hyperamylasemia following 12 procedures, symptomatic pancreatitis in 2 cases, and cholangitis in 5. All patients with complications recovered under conservative treatment. DISCUSSION