| Background: Despite improvement in the safety of blood products, sickle
cell disease (SCD) and thalassemic patients are at greater risk than the
general population for hepatitis B infection and chronic liver disease,
making hepatitis B immunization especially important for this population.
This study was conducted to evaluate and follow up the antibody response to
hepatitis B vaccination, in patients with SCD, after 1-15 years of
vaccination. Methods: participants were 30 SCD and 30 thalassemic
patients attending the Hematology Department, Children’s Hospital, Cairo
University as well as 30 ages and sex matched normal controls. They were
subjected to clinical evaluation, complete blood count, and measurement of
liver transaminases, serum bilirubin, and serum ferritin levels as well as
estimation of anti-HBs titer by enzymatic immunoassay. Results: Anti-HBs
titers in SCD patients ranged between 5.6 and 381 IU/L (54.83 ± 15.30),
while the levels of thalassemic patients ranged between 16 and 343 IU/L
(93.4 ± 30) and those of the control group ranged from 10 to 523 IU/L (83.4
± 28.1) which revealed statistically significant decrease in SCD patients
compared to thalassemic and healthy controls (p =0.0317). Out of the 30
SCD patients, 40% showed anti-HBs titer below 10 IU/L (non-protective
titer), while none of the thalassemic patients or the control group revealed
the same. Achievement of a protective titer had no correlation with sex,
consanguinity, or any of the clinical or laboratory data tested. Conclusion:
Immune dysfunction in thalassemia is not playing a major role in response
to hepatitis B vaccination. However, SCD children should have their anti-
HBs titer measured after routine hepatitis B immunization to ensure that
they achieved protective titer, then after 1 year of vaccination and repeated
every 5 years and those who do not seroconvert should receive additional
doses. Booster HBV vaccination of unprotected SCD patients seems
mandatory. |