Extra-high-dose hepatitis B vaccination does not confer longer serological protection in peritoneal dialysis patients: a randomized controlled trial.

Background: The response to recombinant hepatitis B vaccine remains suboptimal among the dialysis population.

Methods: In this multi-centre randomized controlled trial, we studied the factors that modify the response to intramuscular Engerix-B vaccination in patients on peritoneal dialysis. The primary aim was to study if a three-dose schedule of extra-high dose (80 microg) of Engerix-B would offer better primary seroconversion and more persistent serological protection than the conventional 40-microg dose.

Results: Forty-two peritoneal dialysis patients were randomized to receive the conventional 40-microg Engerix-B dose and 45 patients to 80-microg dose. Seroconversion [hepatitis B surface antibody (anti-HBs) level > or =10 IU/l 3 months after completion of the third dose] occurred in 78.6% of patients after 40-microg Engerix-B dosage treatment versus 62.2% for those receiving 80-microg Engerix-B treatment (P = 0.11). After 12 months, the persistence of protective anti-HBs also did not differ between 40- (45.2%) and 80-microg (51.1%) treatment groups (P = 0.67). In contrast, patients with seroconversion 3 months after the third dose of Engerix-B had a higher normalized protein nitrogen appearance (nPNA) than patients without seroconversion (1.16 +/- 0.25 versus 0.96 +/- 0.23 g/kg/day, P = 0.001). Conclusions. We found no evidence of a worthwhile clinical benefit from increasing the three-dose intramuscular Engerix-B vaccine from 40- to 80-microg dose. An unplanned analysis suggested a role of improved protein intake to improve the immune response to hepatitis B vaccine in peritoneal dialysis patients.