Abstract

BACKGROUND There is a decrease in vaccine-specific antibody to certain vaccine-preventable diseases in children after chemotherapy, but the frequency of non-immune patients is not clear. In the present case-control study, was taken under investigation protection level to Hepatitis B infection in children 6 months after completing chemotherapy. MATERIALS AND METHODS In this study 68 patients with cancer and 68 healthy children were enrolled. Patients were 1.5 -12 years old with completed standard chemotherapy at least for 6 months. All the patients and healthy children were negative for HBsAg and HBeAg and had received Hepatitis B vaccination. IgG antibody concentrations against Hepatitis B Virus (HBV) were determined in the patients receiving chemotrapy and healthy subjects serum by ELISA method. IgG antibody titer > 10 mIU/ml was considered as baseline protective titer for preventing HBV infection. RESULTS Anti-HBs antibody titer in 19.12% of patients was less than 10 mIU/ml and 11.76% of the patients had borderline antibody titer (10-20 mIU/ml). In healthy subjects, 2.94% and 5.88% had antibody titer < 10 mIU/ml and 10-20 mIU/ml, respectively. According to statistical analysis, frequency of non immune subjects in children with cancer was significantly higher than those in healthy children (P-value=0.024). CONCLUSION HBV vaccination post-intensive chemotherapy in the children with cancer is strongly recommended.