Hepatitis viruses and hematopoietic cell transplantation: A guide to patient and donor management.

HEMATOPOIETIC CELL transplantation (HCT) is performed annually in over 30,000 patients worldwide for a range of underlying disorders including hematologic malignancy, severe aplastic anemia, solid tumors, and genetic diseases.1 While the risk of acquiring hepatitis virus infection from transfusion of blood products is now extremely low, it is not uncommon for patients to come to transplantation already infected with hepatitis viruses from past exposure. Particularly in endemic areas, potential hematopoietic cell donors may also have evidence of hepatitis virus infection. Furthermore, there is a large group of long-term HCT survivors with chronic hepatitis B and/or hepatitis C infection, many of whom are unaware they are infected. Clinical manifestation of hepatitis B and C infection are determined by host-virus interactions. In both infections, hepatocellular damage appears to be mediated primarily by host cellular immune responses. Inflammatory and fibrogenic cytokines, released by infiltrating T cells, potentiate inflammation, hepatocyte damage, and progression to fibrosis. The marked immunosuppression and subsequent immune reconstitution associated with HCT have the potential to significantly impact the pathobiology of hepatitis virus infection. So that appropriate management decisions can be made, it is important to understand the impact of recipient and donor hepatitis virus infection, on the short-term and long-term outcome of HCT.