Prognostic impact of hyperbilirubinemia in the early phase after allogeneic hematopoietic stem cell transplantation

BACKGROUND: Liver dysfunction occurring after allogeneic hematopoietic stem cell transplantation (HSCT) may have various causes, but since these causes are difficult to identify in the early stages, therapeutic intervention may be delayed. It is, therefore, important to identify unfavorable prognostic factors of liver dysfunction as soon as possible. The objective of this study was to identify the unfavorable prognostic factors of liver dysfunction in the early post-transplant period. METHODS: We defined liver dysfunction as the detection within 30 days of transplantation of elevated liver or biliary enzyme levels corresponding to Grade 2 in the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. We retrospectively investigated 82 patients who had undergone allogeneic HSCT at our institution. RESULTS: Elevated liver or biliary enzyme levels were observed in almost half of the patients studied (n=40, 48.7%). Elevated total bilirubin (T-Bil) level was the most frequently observed unfavorable prognostic factor, having the greatest impact on overall survival (OS), progression-free survival (PFS), and non-relapse mortality (NRM) (probability of unfavorable outcome in patients without elevated T-Bil level versus that in patients with elevated T-Bil level: OS, 58.9% vs. 15.4%, p < 0.001; PFS, 46.4% vs. 15.4%, p < 0.001; NRM, 10.7% vs. 53.8%, p < 0.001). Moreover, the probability of an unfavorable outcome increased in proportion to the degree of T-Bil elevation and the absence of improvements over time in the T-Bil level. CONCLUSION: Our study showed that elevated T-Bil level is a major unfavorable prognostic factor of liver dysfunction after allogeneic HSCT.