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


METHODS
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.


RESULTS
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%.


CONCLUSIONS
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.
Duca
P
P
Liver Transplant Center, Department of Pediatrics, Hospital Italiano, Buenos Aires, Argentina.
Del Pont
J M
JM
D'Agostino
D
D
D002648:Child; D016572:Cyclosporine; D004334:Drug Administration Schedule; D005260:Female; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000096:biosynthesis* / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007124:Immunoenzyme Techniques; D007166:Immunosuppressive Agents; D007273:Injections, Intramuscular; D016031:Liver Transplantation / Q000276:immunology; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology*
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D007166:Immunosuppressive Agents; D014614:Vaccines, Synthetic; D016572:Cyclosporine