Evaluation of immune status against hepatitis B in children with thalassemia major in Egypt: A single center study

Objectives: Thalassemic children with repeated blood transfusion are at higher risk of suffering transfusion relatedinfections including hepatitis B virus (HBV). HBV vaccine immunogenicity in several studies showed variable responserates. The aim of this study is to evaluate the immunogenic effect of hepatitis B vaccine in thalassemic children at differentage groups.Materials and methods: After ethical approval and informed parent consent, 125 diagnosed thalassemic patients wererecruited from the Hematology/Oncology Unit, Pediatric Department, Tanta University Hospital. Patient’s transfusion,and vaccination history, clinical data, and blood samples were obtained. Patient’s sera were stored at -20°C till tested forAnti-hepatitis B surface (anti-HBs) by ELISA. Patients with titers <10 IU were tested for HBs-Ag.Results: Although none of our cases had hepatitis B virus infection, only 20.8% had a protective anti-HBs titer (>10IU/L). Significantly higher percentage of protected patients (40.1%) were younger than 3 years of age, while age groupsabove 3years showed a significant trend towards having non protective titers (p=0.003). Anti-HBs titers weren’t correlatedto age, ferritin, liver enzymes, and duration of transfusion or number of transfused packs.Conclusion: Protective Anti-HBs titer was reduced after age of 3 years in our patients. So, we recommend screeningof thalassemic patients at age of 3 years to evaluate the need of a booster dose. J Microbiol Infect Dis 2012; 2(2): 44-49Key words: Thalassemia, HBV, vaccination, immunogenicity