Transient liver function abnormality following treatment with rabbit antithymocyte globulin for nonmyeloablative hematopoetic stem cell transplant: two case reports.

Rabbit antithymocyte globulin (rATG) is increasingly used in nonmyeloablative hematopoetic stem cell transplant (HSCT). Elevated liver function tests (LFTs) have been reported for antithymocyte globulin in the treatment of aplastic anemia, but not when used in a conditioning regimen for HSCT. We describe two cases of patients receiving a conditioning regimen for HSCT containing rATG who developed a transient, severe transaminase elevation. In the first case, a 66-year-old woman with a history of acute myeloid leukemia received the first dose of rATG and the patient's transaminases were found to be extremely elevated within a few hours. The aspartate transaminase (AST) peaked at 1286 U/L and alanine transaminase (ALT) peaked at 991 U/L and both resolved within a week. In the second case, a 72-year-old woman with a history of non-Hodgkin lymphoma received the first dose of rATG and the AST and ALT were found to be 1212 U/L and 689 U/L, respectively, 1 h after finishing the infusion. Like the previous case, the transaminase elevation resolved within a week. LFT abnormalities induced by rATG during conditioning therapy for HSCT may be transient and have a rapid onset after the first dose, but quickly subside without any complications or sequelae. It is important to follow the LFTs closely, as well as monitor for any signs and symptoms of acute liver failure.