Successful immune response to a recombinant hepatitis B vaccine in children after liver transplantation

Patients who undergo liver transplantation require multifaceted general care, and vaccination has a fundamental role before and after transplantation. The purpose of this study was to provide a prospective evaluation of the immunogenicity of the recombinant vaccine (RV) against Hepatitis B in pediatric patients with liver transplants (TxH) who for different reasons did not receive a pretransplantation vaccine.

From June 1996 to December 1999, 47 pediatric patients with liver transplants were vaccinated with RV. Patients older than 1 year of age, in stable condition, and 6 months post-transplantation were included. The vaccination scheme was 0-1 and 6 months, intramuscular 10 microg in less than 30 kg body weight, and 20 microg in more than 30 kg body weight. The nonresponder patients were vaccinated with a booster dose and a double dose 1 to 6 months after the last dose. Responders to titer HBs Ab enzyme immunoassay (EIA) <10 UI/ml were defined as nonresponders, to titer between 10-100 UI/ml as responders, and to higher titer of 100 UI/ml as high responders.

The following data were obtained from the 47 patients: mean +/- standard deviation (SD) age at vaccination was 10.76 +/- 5.96 years old and the mean +/- SD post-transplant time at the beginning of vaccination was 3.56 +/- 2.19 years. Thirty-three of 47 patients (70%) responded to doses according to body weight, and 14 (30%) did not respond, necessitating a booster dose after which 7 responded (50%). The global seroconversion was 85%. There was not a significant responder cyclosporine concentration dosage (154 vs. 150 ng/ml) difference between responders and nonresponders. Sixty-six percent (8 of 12) of patients receiving a triple immunosuppressive scheme (cyclosporine, steroids, and Azathioprine) had a positive response, while 84% (16 of 19) receiving a double scheme (cyclosporine and steroids) and 100% (16 of 16) receiving monotherapy with cyclosporine had a positive response. By comparing a triple scheme with monotherapy, the Fisher exact test found a P < 0.01. Incidence of adverse effects (local pain) was 2.63%.

Immunization with RV was well-tolerated with acceptable seroconversion and safety in recipients after liver transplantation, particularly in those undergoing cyclosporine monotherapy. The population studied showed better results than did other populations of immunosuppressed patients.