Background. The purpose of this study was to evaluate the impact of hepatit
is B prophylaxis in preventing hepatitis B infection in children with malig
nancy. Procedure, Between May, 1993, and September, 1998, a total of 151 ch
ildren (95 boys, 56 girls), 29 (19%) with lymphoma, 58 (39%) with leukemia,
and 64 (42%) with solid tumor, were screened for hepatitis B Virus (HBV).
The mean age was 7.5 +/- 2.5 years. Children with negative serology; receiv
ed active and/or passive immunization. HBsAg and anti-HBs were positive pri
or to vaccination in 16 (10%) and 17 (11%) children, respectively. One hund
red eighteen children (78%) of one hundred fifty-one with negative serology
were included in the vaccination program. The vaccine dose was 40 mu g. Ch
ildren With solid tumor and lymphoma received recombinant hepatitis B vacci
ne at diagnosis, repeated at months 1, 2, and 12. Hyperimmunglobulin was ad
ministered monthly in children with leukemia during the intensive chemother
apy period. They were then vaccinated following the third month of maintena
nce therapy with the schedule described above. Anti-HBs titers were measure
d every 3 months, and titers above 10 mlU/ml were accepted as protective. R
esults. Anti-HBs positivity after the first three doses was 77% in solid tu
mors, 88% in acute leukemia, and 48% in lymphomas. Anti-HBs positivity with
respect to diagnosis in children completing the vaccination schedule was 9
4% in solid tumor, 90% in leukemia, and 74% in lymphoma (P > 0.05). Thirty-
three percent of children have not received the fourth dose as yet. In tota
l 78% of the children developed protective antibody titers with or without
the fourth dose, and none was infected with HBV during 3 years of follow-up
. Ten (39%) of twenty-six children who remained unresponsive to immunizatio
n were infected with HBV. Conclusions. These data reveal that HBV prophylax
is is necessary and that our vaccination schedule is effective in preventin
g HBV infection in these children. (C) 2000 Wiley-Liss, Inc.