The questionable role of immunization against hepatitis B in HBV infected liver transplant patients

One-year extended, monthly vaccination prophylaxis combined with hepatitis B immune globulin for hepatitis B after liver transplantation

AIM

The feasibility of vaccination in liver transplant recipients is highly controversial, and the present study aimed to investigate the efficacy of a 1-year extended, monthly vaccine prophylaxis protocol of a second-generation recombinant vaccine for transplant recipients.

METHODS

The recombinant hepatitis B vaccine (10 µg) was administrated s.c. every month for 12 months as the vaccination protocol to 39 liver transplant recipients in stable condition, including those with hepatitis B-related chronic liver disease (n = 30), those with acute hepatitis B liver failure (hepatitis B surface antibody [HBsAb], n = 4), and those with hepatitis B core antibody positive grafts (n = 5). A fixed dose of hepatitis B immune globulin (HBIG) was administrated during the study based on the monoprophylaxis approach, and the increase in the hepatitis B surface antibody titer was measured to evaluate the efficacy of the vaccination.

RESULTS

The vaccination protocol was initiated a mean of 54 months (range, 13-124) after liver transplantation, and all patients tolerated the vaccination well without adverse effects. The overall hepatitis B virus (HBV) recurrence rate was 5% (2/39) based on hepatitis B surface antigen positivity, and 2% (1/39) based on HBV DNA detectability. Six (15%) patients showed a good response to vaccination with an increase in the HBsAb titer greater than 100 IU/L at the end of vaccination, but only three (8%) maintained an adequate HBsAb level to spare HBIG during the 2-year observation period.

CONCLUSION

While a few patients demonstrated an adequate response to vaccination, the clinical indication for the HBV vaccination for liver transplant recipients is currently minimal.

[Liver transplantation for chronic hepatitis B]

Liver transplantation for hepatitis B represents 5-10 % of all liver transplantations performed in Europe. The prognosis after liver transplantation is related to the efficacy of prophylaxis of HBV graft reinfection. The risk of HBV reinfection is directly related to the HBV viral load at transplantation. HBV prophylaxis after transplantation with long-term administration of anti-HBS immune globulins (HBIG) or with monoprophylaxis with lamivudine can reduce significantly the risk of HBV recurrence mainly in patients without active HBV replication. Antivirals such as lamivudine, adefovir, entecavir or tenofovir can control HBV replication in patients with decompensated HBV cirrhosis waiting for transplantation. However, there is a risk of HBV viral breakthrough during nucleo (t) side antiviral treatment. The use of an antiviral alone or in combination should take into account the antiviral efficacy and the risk of viral resistance. The post-transplant combination of antiviral therapy and HBIG prophylaxis is very effective in reducing the rate of HBV reinfection to less than 10 % even in patients with HBV replication at transplantation. In the absence of active viral replication at transplantation, the possibilty to discontinue HBIG prophylaxis at long-term after transplantation with maintenance of antiviral treatment or HBV vaccination is in evaluation. The use of new antiviral therapies (nucleos(t)ide analogues) has dramatically improved the prognosis of patients with HBV reinfection of the graft. The current 5-year survival after liver transplantation for HBV related liver disease is 85 %. In conclusion, the prophylaxis of HBV reinfection combining antiviral therapy prior to transplantation, and combination of HBIG and antiviral therapy post-transplantation is effective in reducing the rate of HBV reinfection to less than 10 %.

Prevention of hepatitis B recurrence after living donor liver transplantation: primary high-dose hepatitis B immunoglobulin monotherapy and rescue antiviral therapy

The prevention of hepatitis B virus (HBV) recurrence is essential after liver transplantation in patients infected with HBV. We evaluated the efficacy of primary high-dose hepatitis B immunoglobulin (HBIG) monotherapy and rescue antiviral therapy in 639 HBV-infected adult patients who underwent living donor liver transplantation (LDLT) between February 1997 and December 2004. The overall 5-year survival rate was 80.7%, and recurrence of hepatocellular carcinoma was the most common cause of late mortality. Pretransplant HBV replication was observed in 392 (61.3%) patients. The interval of 10,000-IU HBIG administration to maintain antibody to hepatitis B surface antigen > 500 IU/L was 30 days in 11.4% patients, 40 to 50 days in 72.1%, and 60 days in 16.5%. At the last follow-up, 3.9% of the patients without HBV recurrence were receiving combination therapy. Overall 1-year, 3-year, 5-year, and 10-year HBV recurrence rates were 1.4%, 5.5%, 7.3%, and 8.5%, respectively. HBV recurrence occurred after a mean of 25.7 +/- 16.4 months after LDLT. After HBV recurrence, 5 of 9 patients died from rapidly progressive liver failure before treatment with adefovir, and only 1 of 29 patients died after treatment with adefovir. Need for frequent HBIG infusions (< or =30 days), active pretransplant HBV replication, and hepatocellular carcinoma recurrence were significant risk factors for HBV recurrence and indications for combination therapy. Our posttransplant HBV prophylaxis regimen resulted in a 5-year HBV recurrence rate of 7.3% and a mortality rate of 13.2% after HBV recurrence, showing the effectiveness of high-dose HBIG monotherapy and rescue antiviral therapy.

Update on immunizations in solid organ transplant recipients: what clinicians need to know

Vaccine-preventable diseases remain a major source of morbidity and mortality in transplant recipients. Since the publication of the American Society of Transplantation's guidelines for vaccination of solid organ transplant recipients in 2004 (1), several new vaccines have been licensed. Transplant clinicians have been inundated by questions from patients and colleagues regarding the utility and safety of these vaccines in transplant candidates and recipients. In addition, new data has appeared regarding utility of some established vaccines, lack of rejection after vaccination and newer adjuvant strategies. Literature published between 2004 and 2007 was reviewed in a Medline search. Guidelines from the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices are reviewed and summarized, with particular attention to vaccines for human papillomavirus, varicella and varicella-zoster, tetanus-reduced diphtheria-acellular pertussis (Tdap) and hepatitis B, as well as conjugated meningococcal and conjugated pneumococcal vaccines. Although randomized controlled trials in transplant recipients have not been performed for most new licensed vaccines, preliminary recommendations can be formulated based on current data and guidelines. Further studies will be important to determine the indications and optimal timing of newer immunizations and immunization strategies.

Adherence to Lamivudine after an early withdrawal of hepatitis B immune globulin plays an important role in the long-term prevention of hepatitis B virus recurrence

Lamivudine combined with hepatitis B immune globulin (HBIg) is the standard of care for preventing the recurrence hepatitis B virus after liver transplant. To determine the risk of hepatitis B virus (HBV) recurrence after early withdrawal of HBIg in patients receiving lamivudine maintenance therapy, 20 patients receiving a course of HBIg and lamivudine after transplantation and long-term maintenance therapy with lamivudine and 9 patients receiving HBIg and lamivudine indefinitely were analyzed. The survival rate was 90% after a mean follow-up of 83 months. The HBV recurrence rate was 14% with a mean period of 91 months free from HBV recurrence. Both groups had similar HBV recurrence rates, 15% for the combination and 11% for lamivudine alone. Four patients, 3 of whom were noncompliant with therapy, experienced posttransplant HBV recurrence. Patients who adhere to long-term prophylaxis with lamivudine after early withdrawal of HBIg have a low risk of HBV recurrence, similar to those who receive combination prophylaxis.