Prophylaxis of hepatitis B recurrence after liver transplantation with lamivudin and hepatitis B immunoglobulin

Hark back: passive immunotherapy for influenza and other serious infections

The world is experiencing a pandemic of swine-origin influenza virus H1N1. A vaccine to prevent disease is now available, and millions have or will become ill before they can be vaccinated. The ability to use swine-origin influenza virus vaccines as a public health tool has been described as a "race against time." Oseltamivir and related drugs are being used in an effort to reduce morbidity and mortality, but their efficacy for treating severe influenza is suboptimal, and possible wide-spread emergence of oseltamivir-resistant mutants is a concern. Another approach for prevention and treatment of serious influenza is infusion of hyperimmune plasma. The United States has thousands of licensed blood product collection centers that produce millions of liters of plasma licensed by the Food and Drug Administration on an annual basis for the treatment of serious conditions. Immunotherapy using infusion of convalescent plasma (or hyperimmune intravenous immunoglobulin) has been reported to be an effective treatment for severe influenza and other virulent pathogens in animal models and humans. Plasma obtained from those that have recovered or were early recipients of vaccine offers a resource for production of an immediately available and potentially effective therapy at the local, state, and national level. Past, current, and future uses of immunotherapy and current advisory body recommendations for this approach are presented.

Hepatitis B immunoglobulin in preventing reinfection following liver transplantation

Before the availability of hepatitis B immunoglobulin (HBIG) in hepatitis B-positive transplant recipients, the acute mortality was very high, in many centers up to 50% within 60 days post-transplant. The overall reinfection rate was approximately 60% within the initial 6 months, increasing to 80-90% within the initial 12 months and, in many cases, leading to allograft loss and death or retransplantation. These recurrent infections were often more severe and more rapidly progressing than the initial infection, probably due to high-dose immunosuppressive regimens. The poor prognosis before introduction of HBIG made hepatitis B liver disease an absolute contraindication for liver transplantation, leaving these patients with very limited treatment options. This changed in the late 1980s with the introduction of HBIG, which reduced the incidence of hepatitis B in the transplanted liver to approximately 15-50%, with concomitant improvement in graft and overall survival. The prognosis was further improved by a combination of long-term HBIG and antiviral therapy, in particular lamivudine, which reduced the reinfection rate, in most cases to between 0 and 5%. Owing to the cost and relative inconvenience of HBIG, some transplant centers have experimented with early discontinuation of HBIG and replacement with antiviral monotherapy. A number of studies, however, have found significantly higher recurrence rates associated with lamivudine monotherapy (40-50%) compared with combination therapy and, hence, lamivudine monotherapy is not recommended.

Viral persistence after liver transplantation for hepatitis B virus: a cross-sectional study

BACKGROUND

Prophylaxis to prevent recurrent HBV infection in liver transplant (LT) recipients has evolved over time, and we manage patients who receive lamivudine monoprophylaxis, lamivudine with HBV immunoglobulin (HBIg), and lamivudine and adefovir with HBIg.

METHODS

Serum was examined with sensitive assays to detect the persistence of HBV, and to identify mutations that might confer resistance to the antiviral prophylaxis. Forty patients were studied, and sera were collected 20 days to 13.3 years after LT.

RESULTS

Overall, HBV DNA was detected in serum of 67.5% of patients (8 of 10 of lamivudine monoprophylaxis patients, 15 of 24 of those receiving lamivudine and HBIg, and 4 of 6 of those receiving lamivudine, adefovir and HBIg). Thus, HBV infection persists for most of the patients despite successful prophylaxis after LT. Of those patients with detectable serum HBV DNA, three of eight of the lamivudine monoprophylaxis group had sequences associated with resistance to lamivudine (YMDD mutants), compared with only 1 of 15 of the lamivudine and HBIg cohort. Three of the lamivudine and HBIg cohort had the I126A Hepatitis B surface antigen escape variant. In those serum HBV DNA-positive patients who were receiving lamivudine, adefovir, and HBIg, only one of four had YMDD mutant, and none had Hepatitis B surface antigen escape variants. None of the 40 patients suffered clinical HBV recurrence.

CONCLUSIONS

Our observations imply that the selection of resistant virus may be essential, but is not sufficient to cause overt failure of prophylaxis with development of clinical disease. It seems likely that the patients' immune response contributes, at least partially, to the long-term control of infection in these patients.