Hepatitis-associated aplastic anemia.

Hepatitis-associated aplastic anemia (HAAA) is a rare illness, characterized by onset of pancytopenia with a hypoplastic bone marrow that traditionally occurs within 6 months of an increase in serum aminotransferases. HAAA is observed in 1% to 5% of all newly diagnosed cases of acquired aplastic anemia. Several hepatitis viruses have been linked to the disease, but in many cases no specific virus is detected. The exact pathophysiology is unknown; however, immune destruction of hematopoietic stem cells is believed to be the underlying mechanism. HAAA is a potentially lethal disease if left untreated. Management includes immunosuppression with antithymocyte globulin and cyclosporine and allogeneic hematopoietic stem cell transplantation.