Anti-hav seroconversion in autologous hematopoietic stem cell transplantation recipients

It is well known that preformed antibodies against certain bacterial and especially viral infections are lost after hematopoietic stem cell transplantation. There is some literature reporting that Hepatitis A antibodies also disappear after transplantation.The aim of this study was to determine the seroprevalance of anti-HAV antibodies after stem cell transplantation and the possible risk factors (age, sex, diagnosis, preparation protocol, mean follow up period) that may play a role in antibody loss in stem cell transplant patients.One hundred and fifty three patients were analyzed retrospectively, 98% of which were determined to be anti-HAV positive. A total of 125 patients were included into the ?anti-HAV loss?study. Seven of these patients (5.6%) lost their anti-HAV antibodies after stem cell transplantation.About 30% of the patients were under 40 years of age. Loss of antibodies was more frequent in this group of patients. There was a significant relationship between loss of anti-HAV antibodies and younger age (p: 0.015).No statistically significant relationship was determined between anti-HAV antibody loss and sex, diagnosis, stem cell source or preparation protocol.The follow up time versus antibody titers were analyzed and it was found that with increasing follow up time, the rate of anti-HAV antibody loss decreases.Following stem cell transplantation, it is crucial to monitor the immunity against certain infectious agents. The possibility that hepatitis A infection may be more severe in older individuals and that it can be prevented by immunization renders the antibody monitoring necessary. Future studies are indicated to define other risk factors that may have a role in antibody loss and the possible mechanisms of antibody loss. The loss of HAV antibodies imply that other infectious agents that can be prevented by immunization should also be scrutinized for antibody loss after stem cell transplantation.Key words: Anti-HAV, autologous, risk factors