Purpose of Study Repeated transfusions in patients with sickle cell disease (SCD) pose a risk for increased exposure to hepatitis B with its subsequent problems of chronic liver disease. These patients are also susceptible to infections caused by encapsulated bacteria, especially pneumococcus. Prevention of these potentially serious infections depends, in large part, on vaccination programs against hepatitis and pneumococcus. Diminished antibody response to hepatitis B immunization has been reported in children with SCD. We wished to assess the immunization status of our population of children with SCD.
Method We conducted a retrospective chart review of seventy-five patients with this disease, ages 2 to 19 years.
Results Seventy patients (93.3%) were vaccinated with pneumococcal vaccine, while one patient (1.3%) did not receive the vaccine. The status in the remaining 4 patients (5.3%) was unknown. Fifty-five (73.3%) were vaccinated with hepatitis B vaccine while two patients (2.3%) did not receive the vaccine and the status of the remaining patients (24.3%) was unknown. Antibody titers for hepatitis were available in 29 of the 55 patients known to have received the vaccine. Nineteen patients (65%) had evidence of seroconversion (titer greater than 10 IU/L); 10 patients (35%), however, despite having been vaccinated against hepatitis, had no antibody present. Genotype seemed to play no role in determining who responded to the vaccine. Analysis of additional patients is under way and concomitant antipneumococcal titer data will be collected.
Conclusion Compliance in patients with SCD remains an issue of concern. Seroconversion against hepatitis B may not occur despite immunization efforts and retesting of antibody titers, and possibly revaccination may be necessary.