Determination of HB Antibody Serum Titer in Vaccinated Major Thalassemia Children in Kerman, Iran

Viral hepatitis is an important causative agent resulting in acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma. Because of frequent transfusions, thalassemic patients are at a greater risk of developing this disease. Therefore, knowledge on the HB immune status of these patients is impotents. The aim of this study was to determine the immune status of HB-vaccinated Major -thalassemic children by measuring the serum anti-HBS antibody level. This study carried out on 215 thalassemic children who received three standard intramuscular recombinant HBV vaccine. Their age range was 1 - 4.5 years (mean 3.37 years). Serum anti-HB antibodies measurements were recorded on three occasions and based on the time lapsed since the last injection. The results were categorized into three groups: good, low responders and non responders.The mean of anti-HBS level in the above three groups were as 205.34, 128.8 and 54.25 Iu/lit respectively (p<0.001). In the girls the mean of antibody level was 104.2 and in boys it was 95.8 Iu/Lit (p>0.05). The distribution of immune response in these three groups was as following: the first group: good responders 29, low responders 6, non responders 1, the second group: good responders 31, low responders 16and non responders 13; the third group: good responders 15, low responders 43 and non responders 61 (p<0.001). In other words the anti-HBS Ab level had declined by time of last vaccination. Overall from 215 selected individuals 75 had good response, 65 low response and 75 non responses. The results from this study suggest that standard HBV vaccination in thalassemic children results in 65% immune responses. In order to maintain the immune status among these patients, it is recommended that anti-HBS Ab level be measured after 45 months of last HBV and a booster dose of the vaccine be administered when necessary.