Öz
The aim of this study was to determine the rates of hepatitis b virus (HBV) and varicella zooster virus (VZV) serology assesment before and after chemotherapy, antibody response changes after therapy, and factors affecting this situation. In our study we evaluated the files of patients who were followed up with malignancy in the pediatric oncology department between March 2016 and April 2019 retrospectively. Twenty four (32%) of the 75 patients followed for childhood cancer other than leukemia were girls. Anti Hbs antibody was evaluated in 70 patients and 44 (58.6%) were positive, anti VZV antibody was evaluted in 62 patients and 48 (64%) was positive. Of the 44 patients who had anti Hbs seropositivity before chemotherapy, 8 (18.1%) were seronegative after therapy. Anti VZV was negative after therapy in 4 (8.3%) of 48 patients who had anti VZV seropositivity before chemotherapy. The rate of disappearance of vaccine response after a single dose varicella vaccine was found to be higher than the rate of negative response of naturally developed varicella antibody response. Since there were no studies comparing these two situations before, this data may be a guide. There was no correlation between purine analogue, cyclophosphamide, steroid use, disease stage and disappearance of anti Hbs and VZV antibodies. Further studies are needed to evaluate the pre-and post-treatment immune status of oncology patients, and guidelines should be developed for these patients.