Prophylaxis in liver transplant recipients using a fixed dosing schedule of hepatitis B immunoglobulin

Safe use of livers from donors with positive hepatitis B core antibody

Thirty-five patients received liver transplants using liver donors who had positive test results for the hepatitis B core antibody (HBcAb). In the same time frame, 195 patients received HBcAb-negative liver donors. Mean follow up for patients receiving HBcAb-positive donors was 25 months. All patients receiving HBcAb-positive donors were monitored for recurrence of hepatitis B (HBV) with HBV DNA assays. There was no de novo HBV in recipients of HBcAb-negative grafts. In the group of patients receiving HBcAb-positive donors, 4 of 35 patients died within 3 months after transplant with no evidence of HBV recurrence at time of death. Four patients were transplanted for HBV-related disease and were postoperatively placed on lamivudine and hepatitis B immune globulin (HBIG). HBV recurrence was seen in one of these patients. Of the remaining 27 patients, three of three mismatched patients (HBcAb-positive donor to HBcAb-negative recipient) developed de novo HBV (100%). Of 24 matched patients (HBcAb-positive donor to HBcAb-positive recipient), only two (7%) developed recurrent HBV allograft reinfection. All de novo and recurrent HBV infections were successfully managed with HBIG and lamivudine therapy. Survival for this subgroup of patients receiving HBcAb-positive donors for non-HBV-related liver disease was 100%. We conclude that the judicious use of HBcAb-positive donors is reasonably safe and associated with low morbidity and mortality, with the appropriate follow-up protocols. Additionally, lamivudine use can be reserved for those cases with de novo or recurrent HBV in the liver allograft, or, selectively, as prophylaxis in those recipients patients who are naïve to HBV and receive an HBcAb-positive donor.

Survival and prognostic indicators in patients with hepatitis B virus-related cirrhosis after onset of hepatic decompensation

GOALS

To determine the 2-year survival and prognostic indicators of hepatitis B virus-related cirrhosis after the onset of hepatic decompensation.

BACKGROUND

Chronic hepatitis B (CHB) patients with cirrhosis and resultant hepatic decompensation have reduced survival. However, the natural history of these patients has not been well characterized in previous studies. Better understanding of survival and prognostic indicators is essential in management of these patients, especially in determining who should be candidates for orthotopic liver transplantation.

STUDY

This is a retrospective longitudinal study of 96 patients with CHB-related cirrhosis after the onset of hepatic decompensation. The overall survival was ascertained, and clinical and laboratory variables were analyzed. Significant prognostic indicators for survival at 2 years were determined using univariate and multivariate analyses with Cox regression model.

RESULTS

The overall survival was 80% at 2 years after onset of decompensation. With univariate and multivariate analyses, hepatic encephalopathy and hypoalbuminemia less than 2.8 g/dL were significant prognostic indicators of poor survival probability. The hazard ratios were 5.22 (95% confidence interval, 1.67-16.3) and 8.57 (95% confidence interval, 1.94-37.8), respectively. Patients with hypoalbuminemia less than 2.8 g/dL had a 2-year survival of only 62%.

CONCLUSIONS

Our study showed that of CHB patients who developed the first episode of hepatic decompensation, those with hepatic encephalopathy or significant hypoalbuminemia or both have worse prognoses. They should be considered potential candidates for liver transplantation.

New era of liver transplantation for hepatitis B: a 17-year single-center experience

OBJECTIVE

To evaluate the variables affecting orthotopic liver transplantation (OLT) outcome for hepatitis B virus (HBV) in a large patient cohort over a 17-year period.

SUMMARY BACKGROUND DATA

Historically, OLT for chronic HBV infection has been associated with aggressive reinfection and poor survival results. More recently, OLT outcome has been improved with the routine use of antiviral therapy with either hepatitis B immune globulin (HBIg) or lamivudine; however, HBV recurrence remains common. The authors studied the factors affecting HBV recurrence and outcome of transplantation, including the effects of combination viral prophylaxis with HBIg and lamivudine.

METHODS

A retrospective review of 166 OLT recipients for chronic HBV over a 17-year period at a single center was performed. Median follow-up was 29 months. HBV recurrence was defined by HBsAg seropositivity after OLT. HBIg monotherapy was used in 28 (17%) patients, lamivudine monotherapy in 20 (12%), and HBIg and lamivudine combination in 89 (54%); 29 (17%) did not receive any HBV prophylaxis. Hepatocellular carcinoma (HCC) was present in 43 patients (26%) and urgent United Network for Organ Sharing (UNOS) status was assigned to 27 patients (16%). Univariate and multivariate analyses were performed to identify factors that affected OLT outcome.

RESULTS

Overall 1-, 3-, and 5-year patient survival rates were 85.8%, 73.6%, and 71.8%, respectively. As expected, HBV recurrence-free survival rates were significantly lower than overall survival rates (76.4%, 58.7%, and 48.3%). When compared with a nontreated cohort, OLT recipients receiving combination viral prophylaxis with HBIg and lamivudine showed markedly reduced HBV recurrence rates and significantly improved 1- and 3-year recurrence-free survival rates. By univariate estimates, patient survival was reduced in the presence of HCC, in the Asian population, and urgent candidates by UNOS classification. Graft loss rates were significantly increased in urgent OLT candidates, Asians, patients with pretransplant positive DNA, and in the presence of HCC. Factors that were significant by univariate analysis or thought to be clinically relevant were subjected to multivariate analysis. By multivariate estimates, urgent UNOS or presence of HCC adversely affected patient and graft survival rates, whereas combination prophylactic therapy strongly predicted improved patient and graft survival rates as well as recurrence-free survival rates.

CONCLUSIONS

Orthotopic liver transplantation for HBV under combination viral prophylaxis results in survival rates equivalent to other indications. Pretransplant viral replication, UNOS status, and the presence of HCC are all sensitive markers for posttransplantation outcome. Viral prophylactic therapy has effectively reduced HBV recurrence and prolonged survival outcomes. The combination of HBIg and lamivudine is the prophylactic regimen of choice.

Treatment of hepatitis B and C following liver transplantation

Advanced liver disease from hepatitis B virus (HBV) and hepatitis C virus (HCV) is the leading indication for orthotopic liver transplantation (OLT) worldwide. Our understanding of recurrent liver disease related to HBV and HCV in the setting of OLT has evolved rapidly in the past decade. Recurrent viral hepatitis may lead to graft failure, death, or the need for retransplantation. Until about a decade ago, HBV was considered a contraindication to OLT due to its frequent recurrence and development of associated liver disease. Medical therapy with hepatitis B immune globulin and nucleoside analogues has diminished the risk of HBV recurrence and led to improvement in patient and graft survival. Consequently, OLT is now considered to be the standard of care in patients with end-stage liver disease related to HBV. HCV recurrence after OLT is almost universal. Although short-term survival in patients undergoing OLT for HCV is similar to survival for those transplanted for other indications, recurrent HCV may have an impact on long-term patient and graft survival. A specific and effective therapy has not been defined for recurrent HCV following transplantation, but the combination of interferon and ribavirin appears promising. Optimal strategies to eradicate these viruses or to slow disease progression are continually being investigated in light of the disparity between supply and demand in a diminishing organ pool for OLT candidates.

Effect of race on outcome of orthotopic liver transplantation: a cohort study

BACKGROUND

There is significant evidence to suggest that long-term survival after renal transplantation is significantly lower in African Americans than in other races. We aimed to establish whether there was a difference in survival in African Americans compared with other races after orthotopic liver transplantation (OLT) and whether race was an independent predictor of survival.

METHODS

We collected data from the United Network of Organ Sharing transplant registry for all liver transplants done between 1988 and 1996 in the USA. We also recorded information on age, sex, race, blood group, and cause of death for the donors and recipients.

FINDINGS

2-year graft survival was significantly lower for African Americans (601 of 884, 68%) and Asians (266 of 416, 64%) compared with white Americans (8703 of 11762, 74%) and Hispanics (878 of 1220, 72%). 2-year and 5-year patient survival were significantly lower for African Americans (654 of 884 [74%], 270 of 565 [48%]) and Asians (287 of 416 [69%], 92 of 252 [37%]) compared with white Americans (9786 of 11762 [83%], 4357 of 7514 [58%]) and Hispanics (964 of 1220 [79%], 341 of 657 [52%]). Compared with white Americans, African American (hazard ratio 1.36, 95% CI 1.16-1.60, p<0.0001) and Asian (1.25, 1.01-1.56, p=0.03) race were independent predictors of poor survival at 2 years.

INTERPRETATION

African Americans and Asians have a worse outcome after OLT compared with white Americans and Hispanics. The higher rate of chronic rejection in African Americans and a relatively worse outcome in other minority races merits further examination.

A concise update on the status of liver transplantation for hepatitis B virus: the challenges in 2002

Significant improvements in both patient and graft survival after orthotopic liver transplantation (OLT) for hepatitis B virus (HBV)-related liver failure have been made during the last decade. Recurrence of HBV infection has decreased, even in high-risk patients. Despite ongoing progress, challenges remain for the next millennium, including the determination of cost-effective dosing strategies, treatment of HBV infection in liver transplant recipients, and ramifications of the use of new antiviral agents, specifically, the appearance of resistant strains. This review summarizes the relevant history of OLT for chronic viral hepatitis B, details accepted preventive and therapeutic treatments, and discusses ongoing experimental trials. Emphasis also is placed on new approaches in transplantation as they impact on the care of HBV-infected patients.

Human polyclonal anti-hepatitis B surface antigen immunoglobulin reduces the frequency of acute rejection after liver transplantation for chronic hepatitis B

BACKGROUND

Use of polyclonal anti-hepatitis B surface antigen immunoglobulin (HBIg) has been shown to reduce hepatitis B virus (HBV) recurrence after liver transplantation (LT) and to decrease the frequency of acute cellular rejection (ACR). However, the protective role of HBIg against ACR remains controversial, since HBV infection has been also associated with a lower incidence of ACR.

AIM

To assess the relationship between HBIg immunoprophylaxis and the incidence of rejection after LT.

METHODS

260 patients (158 males, 43 +/- 14 years old) submitted to LT were retrospectively evaluated and divided into three groups, according to the presence of HBsAg and the use of HBIg. Group I was comprised of HBsAg-positive patients (n = 12) that received HBIg for more than 6 months. Group II was comprised of HBsAg-positive patients that historically have not received HBIg or have been treated irregularly for less than 3 months (n = 10). Group III was composed of 238 HBsAg-negative subjects that have not received HBIg.

RESULTS

HBIg-treated patients (group I) had significantly less ACR episodes, when compared to group II and III. No differences between groups II and III were observed.

CONCLUSIONS

Long-term HBIg administration contributes independently to reduce the number of ACR episodes after LT.

Prevention of fungal and hepatitis virus infections in liver transplantation

Invasive fungal infections, especially those caused by Candida albicans, and recurrence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection after transplantation are common complications in orthotopic liver transplant (OLT) recipients. Candida species account for >50% of all invasive fungal infections, which occur in 10%--15% of OLT recipients. The epidemiology and pathogenesis of invasive fungal infections are unique to each type of organism. Fluconazole is effective and safe in the prevention of Candida infection after OLT. Preventive measures against Aspergillus or Cryptococcus remain ill defined. Both HBV and HCV recur almost universally after OLT in infected individuals. The natural course of HBV and HCV, leading to end-stage liver damage, is accelerated. In OLT patients, administration of immunoglobulin with high titers against HBV, alone and/or in combination with lamivudine, immediately after transplantation reduces the recurrence of HBV. The combination of interferon and ribavirin is mildly effective in OLT patients who have evidence of recurrent hepatitis, and additional alternatives are being evaluated.

Randomized trial of lamivudine versus hepatitis B immunoglobulin for long-term prophylaxis of hepatitis B recurrence after liver transplantation

BACKGROUND/AIMS

The long-term prophylaxis of hepatitis B after liver transplantation requires further optimization. In a randomized trial we investigated a regimen where the initially given hepatitis B immunoglobulin (HBIg) is replaced by long-term lamivudine treatment.

METHODS

Twenty-four liver transplant recipients (all HBsAg-positive/HBV DNA-negative before transplantation), who had received HBIg for at least 6 months without HBV recurrence, were randomized to receive lamivudine (n = 12) or HBIg (n = 12) for 52 weeks. The efficacy criteria involved seronegativity for HBsAg and undetectable HBsAg/ HBcAg in the liver.

RESULTS

Twenty-one of 24 patients completed the study without hepatitis B virus (HBV) recurrence (11 on HBIg, ten on lamivudine), while three patients became HBsAg-positive. Amongst those without HBV recurrence HBV DNA was detectable only by polymerase chain reaction, intermittently in serum and lymphocytes, and in liver specimens from six of eight patients receiving HBIg and five of seven receiving lamivudine. YMDD variant was found in four cases with no viral antigen expression. Eight patients continued lamivudine after the study and during an additional 6-22 months remained HBsAg-negative with normal graft function.

CONCLUSIONS

Substitution of HBIg with lamivudine is effective for prevention of HBV recurrence in low-risk liver transplant recipients and offers a convenient and cost-effective alternative for long-term HBV prophylaxis.

Lamivudine and low-dose hepatitis B immune globulin for prophylaxis of hepatitis B reinfection after liver transplantation possible role of mutations in the YMDD motif prior to transplantation as a risk factor for reinfection

BACKGROUND/AIMS

Reinfection with hepatitis B virus (HBV) after liver transplantation (OLT) is associated with an unfavourable clinical course. Lamivudine/hepatitis B immune globulin (HBIG) combination treatment reduces reinfection rates. However, it is unclear at what time point lamivudine should be started and which HBIG doses are sufficient.

METHODS

Twenty-one patients receiving combination treatment were studied. Lamivudine was started up to 16.5 months before OLT and continued thereafter. HBIG was started intraoperatively and continued according to anti-HBs-titers. Median follow-up after OLT was 20 months.

RESULTS

Eleven patients received lamivudine pretreatment for >2 (median 6) months due to initial HBV-DNA-positivity (median 749 pg/ml). After initial lamivudine response HBV-DNA increased in two of them to concentrations above 10 pg/ml prior to OLT. Both had developed mutations in the YMDD motif and suffered from HBV reinfection 13 and 75 days postoperatively. Individual HBIG consumption was highly variable (range 787-4,766 lU/month). Twenty-two percent of anti-HBs titers measured before HBIG administration were below 100 IU/l.

CONCLUSIONS

Combined reinfection prophylaxis with lamivudine and HBIG is effective in patients with controlled viral replication at the time of OLT. However, pretransplantation lamivudine resistance is a risk factor for reinfection. Low dose HBIG maintenance therapy individualized according to anti-HBs-titers appears to be tenable.

Prevention of hepatitis B virus recurrence after liver transplantation in cirrhotic patients treated with lamivudine and passive immunoprophylaxis

BACKGROUND/AIMS

Treatment with hepatitis B virus immune globulins (HBIG) or lamivudine has reduced the rate of hepatitis B recurrence after liver transplantation to approximately 50%.

METHODS

To further decrease hepatitis B recurrence, 33 hepatitis B virus (HBV)-related cirrhotic patients were treated with lamivudine before liver transplantation and with lamivudine together with low-dose HBIG (46 500 IU the first month followed by 5,000 lU/monthly) after surgery.

RESULTS

While on lamivudine, serum HBV DNA level decreased significantly in all patients and in 11 (33%) the Child-Pugh score improved. Twenty-six patients were transplanted. Among the 25 who survived for longer than 12 months, only one (4%) experienced a hepatitis B recurrence over an average follow-up of 31 months, a rate significantly lower (P = 0.0002) than the 50% recurrence rate among a historical control group of 12 patients. However, low-level HBV replication was detected sporadically throughout the follow-up in 64% of patients.

CONCLUSIONS

Over the medium-term, combined prophylaxis with lamivudine and HBIG significantly decreases the risk of hepatitis B recurrence after liver transplantation. Though low-level HBV infection recurred in two thirds of patients, the pathogenic expression of HBV was prevented.

A study of the pharmacokinetic profile of low-dose hepatitis B immune globulin in long-term liver transplant recipients for chronic hepatitis B infection

Post-transplant protocols for hepatitis B (HBV) prophylaxis using high-dose intravenous hepatitis B immune globulin (10,000 IU) with or without lamivudine are commonly reported. Our centre has previously reported a low-dose intramuscular (i.m.) protocol and lamivudine with excellent results. There have been, however, no pharmacokinetic studies of i.m. hepatitis B immune globulin (HBIG) in this setting. The objective of this study was to determine the pharmacokinetic profile of i.m. HBIG in long-term post-liver-transplant recipients to determine a rational dosing protocol. Six stable liver transplant recipients receiving monthly i.m. HBIG injections for greater than one year were enrolled in this study. All patients had no detectable HBV DNA levels. HBIG titers (anti-HBs) were measured predose, then three times weekly for four weeks and then twice weekly until the serum HBIG titers were 100 IU/L or less. The pharmacokinetic parameters were calculated using noncompartment methods. The mean time to maximum concentration was 10.5 d (range 4-20 d) and the mean half-life was 20 d (range 13.5-23.5 d). Based on these pharmacokinetic parameters in stable long-term post-transplant patients, a rational dosing protocol was developed that allows for more appropriate utility of HBIG and improved patient convenience.

Liver transplantation in Asian patients with chronic hepatitis B using lamivudine prophylaxis

OBJECTIVE

To report the results of liver transplantation in 31 Asian patients with chronic hepatitis B using lamivudine prophylaxis in an open-label study.

SUMMARY BACKGROUND DATA

Chronic hepatitis B is a prevalent cause of end-stage liver disease in Asia, but the results of liver transplantation in these patients are poor.

METHODS

Thirty-one Asian patients with chronic hepatitis B underwent liver transplantation using lamivudine prophylaxis (100 mg daily). Twenty-three (74%) patients had detectable serum hepatitis B envelope antigen (n = 18) or hepatitis B virus DNA (n = 11) before treatment, and seven had associated hepatocellular carcinoma. Lamivudine was continued indefinitely after transplantation, and hepatitis B immune globulin was not used.

RESULTS

The actuarial patient and graft survival rates were 84% and 81%, respectively. Five patients died of causes unrelated to hepatitis B, and 26 patients were alive at a median follow-up of 16 months (range 6-47) after transplantation. One (3.8%) patient developed recurrent hepatitis B resulting from viral breakthrough at week 53 and survived after retransplantation using adefovir and hepatitis B immune globulin treatment. The remaining 25 surviving patients had no biochemical or histologic evidence of recurrent hepatitis, and serum hepatitis B virus DNA remained negative by polymerase chain reaction. In six patients, hepatitis B surface antigen (HBsAg) persisted or reappeared in serum. Among 19 patients who became negative for HBsAg from 5 to 431 days after transplantation, 13 developed anti-HBsAb that lasted a median of 6 months (range 1-21). None of the seven patients with hepatocellular carcinoma developed recurrent tumor.

CONCLUSIONS

Asian patients with chronic hepatitis B may achieve a good outcome after liver transplantation using lamivudine prophylaxis.

Histologic recurrence-free outcome after orthotopic liver transplantation for chronic hepatitis B

Recurrent hepatitis B (HB) following orthotopic liver transplantation (OLT) for chronic disease is common. However, an unpredictable minority of patients follow a recurrence-free course. Clinical, virologic, and pathologic data from patients surviving longer than 60 days (n=24) with pathologically confirmed nonrecurrence of HB following OLT for chronic HB were reviewed to identify factors associated with nonrecurrence of HB. Nine of 24 patients had no histologic and immunohistologic evidence of recurrent HB. In addition to pre-OLT hepatitis B e antigen (HBeAg) negativity, coexisting delta and anti-HB therapy/prophylaxis, other acquired viral infections and their therapy, and severe acute rejection due to noncompliance were considered the possible protective factors against HB recurrence in these 9 patients. Histologic and, particularly immunopathologic, evaluation of liver biopsies must be utilized in definitively diagnosing recurrence of HB.

Hepatitis B in transplantation

Hepatitis B has been a major challenge within the field of transplantation over the past few decades. Due to aggressive recurrence post-transplant, patients with hepatitis B have been excluded from the benefits of both solid organ and bone marrow transplants. Progress has been made, however, through an improved understanding of the biology of hepatitis B and the development of new antiviral strategies that can reliably suppress the virus. Patients with hepatitis B are now candidates for transplantation in an increasing number of circumstances. Careful pre-transplant evaluation is mandatory, together with a tailored antiviral regimen depending on the replicative status of the virus and the organ being transplanted. Minimizing steroid dose following transplantation is an important part of the strategy to reduce the risk of viral reactivation. Lamivudine has been an important development and it has assumed an increasing role in the management of these patients. As additional antivirals are developed, increasingly effective drug combinations will prevent viral recurrence as well as the emergence of drug-resistant mutants, which plagues the use of single agents. It is a rapidly evolving field and there is every reason for continued optimism.

Passive immunity in prevention and treatment of infectious diseases

Antibodies have been used for over a century in the prevention and treatment of infectious disease. They are used most commonly for the prevention of measles, hepatitis A, hepatitis B, tetanus, varicella, rabies, and vaccinia. Although their use in the treatment of bacterial infection has largely been supplanted by antibiotics, antibodies remain a critical component of the treatment of diptheria, tetanus, and botulism. High-dose intravenous immunoglobulin can be used to treat certain viral infections in immunocompromised patients (e.g., cytomegalovirus, parvovirus B19, and enterovirus infections). Antibodies may also be of value in toxic shock syndrome, Ebola virus, and refractory staphylococcal infections. Palivizumab, the first monoclonal antibody licensed (in 1998) for an infectious disease, can prevent respiratory syncytial virus infection in high-risk infants. The development and use of additional monoclonal antibodies to key epitopes of microbial pathogens may further define protective humoral responses and lead to new approaches for the prevention and treatment of infectious diseases.

Successful orthotopic liver transplantation for lamivudine-associated YMDD mutant hepatitis B virus

YMDD hepatitis B virus (HBV) mutants emerge in more than one third of patients treated with lamivudine. The development of escape mutants potentially limits the efficacy of this new therapy for chronic HBV infection. Transplant centers may be hesitant to perform orthotopic liver transplantation (OLT) in patients with progressive liver disease who develop the YMDD mutant because of concerns of graft reinfection. We describe a 56-year-old man with chronic liver disease caused by HBV who successfully underwent OLT after the emergence of a YMDD mutant and progressive liver disease. Perioperatively, he received high-dose intravenous hepatitis B immune globulin (HBIG) treatment with continued lamivudine treatment. Thirty-two months after OLT, there was no evidence of HBV reinfection with the use of lamivudine and high-dose HBIG. Our experience suggests that the emergence of a YMDD HBV mutant is not a contraindication to OLT. The combination of lamivudine and high-dose HBIG can protect against reinfection of the hepatic allograft with the YMDD HBV escape mutant.

An efficacy and cost-effectiveness analysis of combination hepatitis B immune globulin and lamivudine to prevent recurrent hepatitis B after orthotopic liver transplantation compared with hepatitis B immune globulin monotherapy

Orthotopic liver transplantation (OLT) for hepatitis B virus (HBV) infection was limited until recently by poor graft and patient outcomes caused by recurrent HBV. Long-term immunoprophylaxis with hepatitis B immune globulin (HBIG) dramatically improved post-OLT survival, but recurrent HBV still occurred in up to 36% of the recipients. More recently, combination HBIG and lamivudine has been shown to effectively prevent HBV recurrence in patients post-OLT. The aim of the current study is to determine long-term outcome and cost-effectiveness of using combination HBIG and lamivudine compared with HBIG monotherapy in patients who undergo OLT for HBV. A retrospective chart review identified 59 patients administered combination HBIG and lamivudine and 12 patients administered HBIG monotherapy as primary prophylaxis against recurrent HBV. Lamivudine, 150 mg/d, was administered orally indefinitely. HBIG was administered under a standard protocol (10,000 IU intravenously during the anhepatic phase, then 10,000 IU/d intravenously for 7 days, then 10,000 IU intravenously monthly) indefinitely. A decision-analysis model was developed to evaluate the potential economic impact of prophylaxis against HBV with combination therapy compared with monotherapy. Recurrent HBV was defined as the reappearance of hepatitis B surface antigen (HBsAg) after its initial disappearance post-OLT. In the combination-therapy group, no patient redeveloped serum HBsAg or HBV DNA during mean follow-ups of 459 and 416 days, respectively. In the monotherapy group, 3 patients (25%) had reappearance of HBsAg in serum during a mean follow-up of 663 days. Combination therapy resulted in a dominant, cost-effective strategy with an average cost-effectiveness ratio of $252,111/recurrence prevented compared with $362,570/recurrence prevented in the monotherapy strategy. Combination prophylaxis with HBIG and lamivudine is highly effective in preventing recurrent HBV, may protect against the emergence of resistant mutants, and is significantly more cost-effective than HBIG monotherapy with its associated rate of recurrent HBV.

Passive immunity in prevention and treatment of infectious diseases

Antibodies have been used for over a century in the prevention and treatment of infectious disease. They are used most commonly for the prevention of measles, hepatitis A, hepatitis B, tetanus, varicella, rabies, and vaccinia. Although their use in the treatment of bacterial infection has largely been supplanted by antibiotics, antibodies remain a critical component of the treatment of diptheria, tetanus, and botulism. High-dose intravenous immunoglobulin can be used to treat certain viral infections in immunocompromised patients (e.g., cytomegalovirus, parvovirus B19, and enterovirus infections). Antibodies may also be of value in toxic shock syndrome, Ebola virus, and refractory staphylococcal infections. Palivizumab, the first monoclonal antibody licensed (in 1998) for an infectious disease, can prevent respiratory syncytial virus infection in high-risk infants. The development and use of additional monoclonal antibodies to key epitopes of microbial pathogens may further define protective humoral responses and lead to new approaches for the prevention and treatment of infectious diseases.

Preclinical evaluation of two human anti-hepatitis B virus (HBV) monoclonal antibodies in the HBV-trimera mouse model and in HBV chronic carrier chimpanzees

Two human monoclonal antibodies (mAbs) against hepatitis B surface antigen (HBsAg) generated in the Trimera mouse system are described. Both mAbs 17.1.41 and 19.79.5 are of the IgG1 isotype and have high affinity constants for HBsAg binding in the range of 10(-10) mol/L. Monoclonal antibody 17.1.41 recognizes a conformational epitope on the a determinant of HBsAg whereas mAb 19.79.5 recognizes a linear one. The 2 mAbs bind to a panel of hepatitis B virus (HBV) subtypes with distinct patterns. The neutralizing activity of these antibodies was tested in 2 different animal model systems. Administration of each mAb to HBV-Trimera mice, a system that provides a mouse model for human hepatitis B infection, reduced the viral load and the percentage of HBV-DNA-positive mice in a dose-dependent manner. These 2 mAbs were more effective than a polyclonal antibody preparation (Hepatect; Biotest Pharma, Dreieich, Germany) in both inhibition of HBV liver infection and reduction of viral load. A single administration of a mixture of these mAbs into HBV chronic carrier chimpanzees resulted in immediate reduction in HBsAg levels followed by recurrence to initial levels within few days. Thus, these mAbs may be potential candidates for preventive therapy or in combination with other antiviral agents against HBV. Further studies in humans are needed to assess these mAbs in various clinical indications.

Hepatitis C-induced hepatic allograft injury is associated with a pretransplantation elevated viral replication rate

Hepatitis C virus (HCV) allograft infection after liver transplantation follows a variable but accelerated course compared with the nontransplantation population. Predictors of outcome and mechanisms of reinfection remain elusive. The accelerated HCV-induced allograft injury associated with a 10- to 20-fold increase in serum viral quantity posttransplantation was hypothesized to be the result of elevated intrahepatic viral replication rates. Patients (N = 23) with HCV-induced end-stage liver disease who underwent liver transplantation between October 1995 and December 1998 were prospectively studied. HCV-induced allograft injury was defined by posttransplantation persistent biochemical hepatitis or allograft fibrosis not explained by other diagnoses. Liver biopsies (N = 92) were obtained by protocol and when clinically indicated. Negative-strand HCV RNA (putative intermediate for replication) was detected by a strand-specific reverse-transcription polymerase chain reaction (RT-PCR) assay and semiquantatively compared with constitutively expressed 18S rRNA. Recipients with increased pretransplantation replication were at increased risk for the development of posttransplantation biochemical hepatitis (P =.03), an increased rate of allograft fibrosis (P =.006), and increased mortality rate (40.0% vs. 0.0%; P =.02). There was no correlation with quantities of genomic HCV RNA in the serum with relative intrahepatic viral replication either before or after liver transplantation. The relative rate of HCV replication within the allograft was not elevated in the posttransplantation period compared with that seen within the explanted liver. Accelerated allograft injury caused by HCV may be predicted by viral replication rates within the explanted liver. The stable intrahepatic replication rate after transplantation suggests that elevated serum viral loads are the result of decreased viral clearance, possibly secondary to immunosuppressive therapy.

Antibodies for the prevention and treatment of viral diseases

This paper reviews current use and evolving role of polyclonal and monoclonal antibody products for the prevention and treatment of viral diseases. Antibodies continue to be indicated for prophylaxis either prior to an anticipated exposure especially in situations of travel, or more commonly following an exposure. The predominant indication for use of antibody products is to prevent infection. With the availability of vaccines for the prevention of chickenpox, hepatitis A, hepatitis B, measles, rabies and smallpox, the role of passive immunization is reserved for susceptible individuals and those at high risk for complications of infection. Risks of transmission of infections associated with use of human plasma-derived products have been reduced by improvements in donor screening and virus removal and inactivation procedures. An additional safety concern has been addressed by the removal of thimerosal as a preservative. Within the last 5 years, two antibodies have been licensed for a viral indication, RespiGam and Synagis both for prevention of respiratory syncytial virus infection. RespiGam is a human plasma derived antibody and Synagis is a humanized monoclonal antibody, the first such antibody to be licensed for an infectious disease indication. CytoGam for prevention of cytomegalovirus infection in kidney transplant patients has recently been granted an expanded indication to include use in lung, liver, pancreas and heart transplant patients. As the use of therapeutics becomes more sophisticated, researchers may find better ways of using antibody products.

End-stage liver disease and liver transplantation: role of lamivudine therapy in patients with chronic hepatitis B

Chronic infection with hepatitis B virus (HBV) is a common cause of advanced liver disease, including end-stage liver disease. Liver transplantation is generally regarded as the treatment of choice for decompensated cirrhosis. Although long-term prophylaxis with hepatitis B immune globulin (HBIg) has improved significantly the outcome after transplantation, about 20-36% of transplant recipients still develop recurrent hepatitis B and have reduced survival. Moreover, HBIg prophylaxis has a number of disadvantages, including high cost, difficulty in administration and tolerability problems. Lamivudine, an oral nucleoside analogue, is a potent inhibitor of HBV replication and has been investigated in end-stage liver disease and liver transplantation. Treatment with lamivudine results in suppression of viral replication, and clinical improvement and stabilisation of some patients with end-stage liver disease, leading to increased pre-transplant survival as well as a reduced need for transplantation. Prophylaxis with lamivudine is also effective in preventing recurrent HBV infection and graft reinfection after transplantation, although a combination of lamivudine plus HBIg is preferable to prevent the emergence of YMDD variant HBV (tyrosine-methionine-aspartate-aspartate amino acid motif of HBV polymerase). Lamivudine is also effective for the treatment of recurrent hepatitis B after transplantation, based on improvement in virological parameters of infection as well as clinical and histological manifestations of disease. In all of these clinical settings, lamivudine is well tolerated and dose reduction is not required. In conclusion, lamivudine has a potential role for the treatment of patients with hepatitis B-related end-stage liver disease, for prophylaxis in patients undergoing liver transplantation, and in the treatment of recurrent or de novo HBV infection after transplantation.

Combination low-dose hepatitis B immune globulin and lamivudine therapy provides effective prophylaxis against posttransplantation hepatitis B

Although antiviral prophylaxis with lamivudine monotherapy appears to reduce post-liver transplantation recurrence of hepatitis B virus (HBV) infection, breakthrough infections occur in at least 20% of the patients because of the development of drug resistance. Combined lamivudine and intravenous hepatitis B immune globulin (HBIG) therapy (10,000-IU doses) may reduce this risk, but its use is limited by cost ( approximately US $45,000/yr) and availability. We report the experience at liver transplant centers in Australia and New Zealand in which lamivudine has been used in combination with much lower doses of HBIG than used in conventional HBIG prophylaxis. Lamivudine, 100 mg/d, was administered to hepatitis B surface antigen (HBsAg)-positive candidates on listing for transplantation and was continued posttransplantation. HBIG, 400 or 800 IU, was administered intramuscularly (IM) daily for 1 week from transplantation and monthly thereafter. Thirty-seven HBsAg-positive patients underwent transplantation using this protocol. Thirty-six of these patients were HBV DNA positive by polymerase chain reaction (PCR) or hybridization assay. Thirty-four patients had chronic HBV, 2 patients had hepatitis B and C, and 1 patient had hepatitis B, C, and D. Five patients died within 1 month of transplantation and are not included in the analysis. Mean follow-up in the remaining 32 patients was 18.4 months (range, 5 to 45 months). Treatment was well tolerated, with no significant adverse events. Thirty-one of 32 patients were HBsAg negative, and all 32 patients were HBV DNA negative by PCR at latest follow-up. The cost of treatment was US $967 for lamivudine and between $2,290 and $4,480/yr for IM HBIG. Lamivudine and low-dose HBIG treatment prevents posttransplantation recurrence of hepatitis B and is likely to be more cost-effective than high-dose HBIG regimens.

Lamivudine after hepatitis B immune globulin is effective in preventing hepatitis B recurrence after liver transplantation

The prevention of recurrent hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT) with hepatitis B immunoglobulin (HBIG) is expensive and requires indefinite parenteral administration. Lamivudine is a nucleoside analogue capable of inhibiting HBV replication. The aim of this study is to determine the efficacy of lamivudine in the prevention of recurrent HBV infection after a course of HBIG in patients who were hepatitis B surface antigen (HBsAg) positive and hepatitis Be antigen (HBeAg) negative before OLT. Patients at high risk for recurrent HBV infection (HBeAg positive and HBV DNA positive) were excluded. Thirty HBsAg-positive, HBeAg-negative patients underwent OLT from January 1993 to June 1997. All 30 patients were administered HBIG after OLT and, after 2 years, were given the option of continuing with HBIG or switching to lamivudine. Five patients were excluded: 3 patients were lost to follow-up and 2 patients died of technical complications. Three patients terminated HBIG therapy at 8, 24, and 29 months after OLT, and reinfection with HBV occurred in 1 patient. Six patients elected to continue HBIG therapy for life; 1 patient died of melanoma and the remaining 5 patients are HBsAg negative, with an average follow-up of 73 months. Sixteen patients were converted to lamivudine after a course of HBIG, and all 16 patients are HBsAg negative, with an average follow-up of 51 months after OLT. Five patients have been on lamivudine monotherapy for more than 24 months. These results suggest that lamivudine administered after a posttransplantation course of HBIG can effectively prevent the recurrence of HBV infection in patients who are HBsAg positive and HBeAg negative before OLT.

Lamivudine for hepatitis B in liver transplantation: a single-center experience

BACKGROUND

Liver transplantation for hepatitis B virus (HBV) has been associated with a high rate of reinfection and graft failure. Lamivudine, a potent inhibitor of HBV replication, has been shown to prevent viral recurrence after transplantation.

METHODS

The effectiveness of lamivudine monotherapy for the management of HBV recurrence after liver transplantation was assessed. Lamivudine was used in three patient groups: (1) patients started before transplantation and continued after transplantation (n = 13); (2) patients treated after transplantation (n = 15); and (3) patients with de novo hepatitis B after transplantation (n = 4).

RESULTS

Median follow-up on lamivudine was 24 months. Active viral replication (HBV-DNA+) was seen in 17 (53%) of 32 at treatment initiation. All lost HBV-DNA at a mean of 2.4+/-1.6 months after lamivudine initiation. Twenty-six (81%) patients remain free of viral recurrence. Six (19%) patients have evidence of breakthrough infection with the YMDD mutant of HBV, two of whom progressed to graft failure. All four patients in group 1 who developed breakthrough had evidence of hepatitis B surface antigen expression in the explanted liver by immunohistochemistry despite being serum HBV-DNA negative before transplantation. No difference was observed among the three groups in DNA clearance or breakthrough rates.

CONCLUSIONS

Lamivudine achieves viral DNA clearance in almost all patients. Expression of viral antigens in the liver seems to identify patients at risk of developing HBV-DNA recurrence. Disease-free survival of 81% at 22 months is similar to data with hepatitis B immunoglobulin therapy. Given the safe clinical profile and high efficacy in the prevention of disease recurrence, lamivudine will favorably change the outlook of liver transplantation for HBV.

Hepatitis B immunoglobulin discontinuation followed by hepatitis B virus vaccination: A new strategy in the prophylaxis of hepatitis B virus recurrence after liver transplantation

It is widely agreed that hepatitis B virus immunoglobulin (HBIG) should be administered for at least 12 months to patients transplanted for hepatitis B virus (HBV)-related diseases to prevent HBV recurrence. No data are available, however, on how long this treatment should be used, and most centers currently administer HBIG on a life-long basis. Herein, we report the results of a new prophylactic strategy aiming at the discontinuation of HBIG treatment and consisting of the administration of double dose recombinant HBV vaccine (0, 1-, and 6-month schedule) to liver transplant recipients fulfilling the following criteria: (1) liver transplantation for conditions related to nonreplicative HBV infection (hepatitis B surface antigen [HBsAg] positive, hepatitis B e antigen [HBeAg] negative, and HBV DNA negative); (2) at least 18 months of HBIG administration; and (3) no HBV infection recurrence, normal or slightly altered liver graft function, and low-grade immunosuppression at the time of vaccination. Seventeen patients received HBV vaccination and 14 of them (82%) developed protective serum titers of anti-HBs (>10 IU/L). Six patients seroconverted after a first course of vaccination, whereas 8 patients required a second course (3 additional doses of vaccine). Responding patients were followed for a median of 14 months (range, 3-50) after seroconversion. During this period no HBV recurrence occurred and in only 2 patients a decrease of anti-HBs titers below 10 UI/L was observed. Our data suggest that in selected liver transplant recipients, posttransplantation HBV vaccination may be a useful and cost-effective strategy in the prophylaxis of HBV recurrence, allowing the discontinuation of life-long HBIG treatment.

Viral hepatitis A, B, and C

Mankind probably has known viral hepatitis for many centuries; however, the major and most dramatic developments in our knowledge of these diseases have taken place during the second half of the 20th century. During this relatively short period of time, the infectious nature of hepatitis A, B, and C has been proven, leading to their identification and description. The advent of serologic markers has provided the means for establishing the diagnosis. Epidemiologic studies have provided important information that led to exciting achievements in detection and prevention of transmission. Molecular biology studies and cell culture techniques have established our knowledge of the viral genomes, and led to the development of specific vaccines for hepatitis A and B. Anti-viral therapy has been developed and aggressive combination therapy has emerged as a promising strategy for chronic hepatitis B and C. This article reviews some of the main fields of progress and achievement related to viral hepatitis A, B, and C in the 20th century.

Screening for hepatocellular carcinoma

Screening for hepatocellular carcinoma has become widely practised in the management of patients with end-stage liver disease. However, the theoretical basis for this practice is largely lacking. Issues such as the selection of the target population and the correct method of confirming positive screening tests have yet to be resolved. Complicating the assessment of screening strategies is the poor literature on comparing different forms of therapy. Nonrandomized, uncontrolled studies that do not account for lead-time bias make it frequently impossible to know whether an applied treatment has really improved survival. Despite these difficulties, screening is reality, and strategies have to be devised to efficiently screen patients, find small tumours and apply effective treatments. Some practical strategies are discussed.

Lamivudine therapy in patients undergoing liver transplantation for hepatitis B virus precore mutant-associated infection: high resistance rates in treatment of recurrence but universal prevention if used as prophylaxis with very low dose hepatitis B immune globulin

Recurrent hepatitis B virus (HBV) infection remains a major cause of morbidity and mortality after liver transplantation. Recently, antiviral therapy, such as lamivudine, has become available for prophylaxis against HBV reactivation posttransplantation and for the treatment of HBV recurrent disease. We report our initial experience with lamivudine therapy in patients with precore mutant-associated HBV infection undergoing liver transplantation (n = 29). Outcomes were compared in three patient groups: group 1, precore mutant HBV infection not receiving lamivudine (n = 10); group 2, recurrent precore mutant HBV infection posttransplantation subsequently treated with lamivudine (n = 10); and group 3, HBV precore mutant patients undergoing liver transplantation and receiving lamivudine and low-dose hepatitis B immune globulin (HBIG) from the time of transplantation (n = 9). In group 1, HBV recurred in 9 of 10 patients, with subsequent graft loss in all 9 patients. In group 2, all patients developed HBV recurrence at a mean of 7.3 months posttransplantation and started lamivudine therapy at a median of 16 months posttransplantation. Follow-up on lamivudine therapy was for a median of 11 months. Six of these 10 patients developed mutations in the HBV polymerase gene associated with lamivudine resistance. There were two liver failure-related deaths in this group. In group 3 patients, there was one death from graft-versus-host disease. The remaining 8 patients have been followed up for a mean of 15.6 months posttransplantation, and all remain hepatitis B surface antigen negative and HBV DNA negative. In conclusion, lamivudine therapy in association with low-dose HBIG is effective in preventing HBV reactivation posttransplantation. Rescue therapy with lamivudine in patients with HBV recurrence is only moderately effective, with a 60% lamivudine resistance rate in patients treated for longer than 6 months.

Liver transplantation for chronic hepatitis B infection with the use of combination lamivudine and low-dose hepatitis B immune globulin

Current protocols for prophylaxis against allograft reinfection after liver transplantation for chronic hepatitis B virus (HBV) infection include the administration of large doses of hepatitis B immune globulin (HBIG), with considerable associated economic costs. Monotherapeutic prophylaxis with lamivudine has been complicated by the development of resistant strains of HBV. We studied the effectiveness of a posttransplantation prophylaxis protocol using combination lamivudine and low-dose HBIG in 7 consecutive patients with chronic HBV infection, 4 of whom were serum HBV DNA positive before pretransplantation lamivudine therapy. All patients were serum HBV DNA negative at transplantation and received lamivudine, 100 mg/d, posttransplantation. HBIG, 2170 IU, was administered intramuscularly intraoperatively and daily for 14 days. Maintenance HBIG therapy consisted of 2170 IU intramuscularly twice weekly, tapered to every 2 to 4 weeks by 12 months posttransplantation. Target serum HBIG (HBV surface antibody) titers were less than 500 IU/L for 6 months, then greater than 300 IU/L until 12 months posttransplantation. Induction serum HBIG titers were determined daily in 5 patients, and both serum HBIG and hepatitis B surface antigen were determined every 4 weeks in all patients. One patient died 61 days posttransplantation; the surviving patients (n = 6) were followed up for a mean of 532 days (range, 395 to 648 days). No patient has developed allograft reinfection. In the induction period, a target HBIG titer of greater than 500 IU/L was not achieved until a mean of 6.8 days (range, 5 to 10 days). In the maintenance period, all patients achieved the target HBIG titer. This suggests combination lamivudine and low-dose HBIG is effective in preventing allograft reinfection by HBV.

Intramuscular hepatitis B immune globulin combined with lamivudine for prophylaxis against hepatitis B recurrence after liver transplantation

Immunoprophylaxis using intravenous (IV) hepatitis B immune globulin (HBIG) decreases the recurrence of hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT). However, IV HBIG is expensive, has significant side effects, and is inconvenient to administer. An alternative approach for prophylaxis using intramuscular (IM) HBIG and oral lamivudine was prospectively evaluated in this study. Ten consecutive patients with cirrhosis with HBV infection who underwent OLT were included in this study. Nine of 10 patients received lamivudine, 150 mg/d, for an average duration of 8.6 months before OLT. Two of 10 patients with detectable HBV DNA at the time of OLT received 10,000 U (45 mL) of IV HBIG daily for 7 consecutive days, followed by 5 mL of IM HBIG weekly for the next 3 weeks, then every 3 weeks. The other 8 patients were HBV DNA negative at OLT and received one dose of IV HBIG (45 mL) during surgery, followed by 5 mL of IM HBIG weekly for 4 weeks, then every 3 weeks. All patients received lamivudine, 150 mg/d, after OLT. During a mean follow-up of 15.6 months, 9 of 10 patients achieved a protective hepatitis B surface antibody (HBsAb) titer greater than 200 IU/L and had no evidence of HBV recurrence. One patient failed to develop an adequate HBsAb titer and developed histological and virological evidence of recurrence. One patient died unrelated to HBV recurrence. Our preliminary data suggest that this combination prophylaxis with IM HBIG and lamivudine is effective and potentially cost saving.

Viral hepatitis and liver transplantation

This article highlights the importance of hepatotropic viruses as pathogens in patients undergoing transplantation, their contribution to morbidity and mortality after transplantation and the approach to treatment of these pathogens when they cause disease. Although many advances have been made in the management of viral hepatitis in the transplant setting, there remain unanswered questions about the long-term natural history of the disease. Understanding of the pathogenesis of infection in the setting of transplantation is emerging slowly, but complete understanding requires further investigation. New approaches to treating disease in patients with either HBV or HCV infection are under development and will most likely focus on the use of combinations of antiviral and immunomodulatory agents.

Retransplantation of the liver for recurrent hepatitis B virus infection: the Paul Brousse experience

Recurrent hepatitis B virus (HBV) infection of the liver graft is characterized by a severe outcome and high level of HBV replication. For many investigators, retransplantation appears contraindicated because of constant recurrence and a high mortality. We report our experience in this setting. Between January 1985 and December 1995, 10 patients who underwent retransplantation for HBV graft reinfection were studied. According to the antiviral treatment administered after HBV recurrence on the first liver graft and the protocol of antiviral prophylaxis after retransplantation, two groups were defined: group 1 underwent retransplantation before January 1992 (n = 5), and group 2 underwent retransplantation after January 1992 (n = 5). At the time of reinfection, serum HBV DNA was positive in all patients, hepatitis Be antigen (HBeAg) was positive in 6 patients. Antiviral therapy was administered to 7 patients (group 1, adenine arabinoside mono phosphate [ara-Amp; n = 3]; group 2, ara-Amp [n = 5], ganciclovir [n = 4]). After retransplantation, long-term antibody to HB surface antigen (anti-HBs) immunoglobulins were administered to achieve an anti-HBs titer greater than 100 IU/L in group 1 and to achieve an anti-HBs titer greater than 500 IU/L associated with prophylactic intravenous ganciclovir administration (5 mg/kg three times weekly) for 2 years in group 2. In group 1, all patients died, either perioperatively or secondary to HBV recurrence (1 year survival, 0%). In group 2, 1 patient died 50 months after retransplantation of HBV cirrhosis on the second graft, and 4 patients remained HBsAg negative at a mean of 41 months (range, 24 to 68 months) after retransplantation. The prognosis of retransplantation for HBV recurrence was dramatically improved by the administration of antiviral therapy before retransplantation and the maintenance of a high anti-HBs level combined with antiviral therapy after retransplantation.

Does Asian race affect hepatitis B virus recurrence or survival following liver transplantation for hepatitis B cirrhosis?

To assess whether Asian race is an independent variable affecting survival and hepatitis B virus (HBV) recurrence after liver transplantation, the results of 27 consecutive liver transplants performed between June 1994 and April 1997 for HBV cirrhosis were analysed. In the group of 13 Asians, 38% had associated hepatocellular carcinoma and 62% had positive hepatitis B virus early antigen (HBeAg) or elevated HBV-DNA before transplant. Prophylactic hepatitis B immunoglobulin (HBIG) was administered perioperatively and long term at 4-6 weekly interval. Four patients with elevated HBV-DNA received lamivudine before transplantation. The 3 year actuarial patient survival rate was 100% in both Asian and non-Asian patients. Twenty-six patients remained seronegative for hepatitis B virus surface antigen after transplantation. The incidence of post-transplant HBV recurrence was similar: 0% in Asians compared with 7% in non-Asians. There was no recurrence in the group of 12 patients who were HBV-DNA or HBeAg negative pretransplant.

Comparison of immune reactivity and pharmacokinetics of two hepatitis B immune globulins in patients after liver transplantation

Hepatitis B virus (HBV) immune globulin (HBIg) administration will prevent HBV graft reinfection in HBV patients after orthotopic liver transplantation (OLT). However, the expenditure for such prophylaxis is extremely high ranging between $2,000 to $10,000 per month in various countries for an undefined period and presumably for life. As a consequence, there is a need for introduction of additional and less expensive modes of treatment. In a preliminary clinical trial a new HBIg preparation has been shown to induce longer lasting levels of circulating antibodies to hepatitis B surface antigen (anti-HBs) in patients after OLT compared with previous experience with conventional HBIg preparations. In the present study the pharmacokinetics of this new HBIg, OMRI-Hep-B, were studied and compared with a conventional, licensed preparation, Hepatect. Fifteen post-OLT patients (2-8 years post-OLT, 18-62 years of age, 6 men, 9 women) were treated intravenously with 49 doses of OMRI-Hep-B or Hepatect given at least once, alternately, at 10,000 to 14,000 units per injection ( approximately 130 IU/kg body weight). The new HBIg was well tolerated and no adverse effects were observed. Administration of OMRI-Hep-B was shown to induce high and long-lasting levels of circulating anti-HBs antibodies and greater areas under the curve (AUC) compared with the conventional preparation. Thus, anti-HBs half-life was 22 +/- 1.3 days for OMRI-Hep-B recipients and 13 +/- 1.3 days for Hepatect recipients (P <.001). Time to reach trough anti-HBs levels of 150 mIU/mL was significantly longer after administration of OMRI-Hep-B than after Hepatect (79 +/- 4.5 and 52 +/- 3.8 days, respectively; P <.001). In summary, the pharmacokinetic profile of the new HBIg, and in particular its prolonged elimination half-life, may reduce the cost of administration by approximately 30% and improve the quality of life of patients by extending the interval between repeated immune globulin injections.