Clinical Outcome of Thrombotic Microangiopathy after Living-Donor Liver Transplantation Treated with Plasma Exchange Therapy

Abstract

Thrombotic microangiopathy (TMA) is a well-documented but severe complication that occurs after solid-organ transplant. Administration of calcineurin inhibitors is considered a major cause of this fatal complication; prompt initiation of plasma exchange therapy after reduction or conversion of calcineurin inhibitors has been recommended. Nevertheless, little is known about clinical evidence of this strategy against TMA after solid-organ, especially non-renal-organ, transplantation. Medical records of 63 patients who were hospitalized at Artificial Organ and Transplantation Division in Tokyo University Hospital and underwent blood purification therapy between January 1999 and May 2005 were reviewed. Twenty-eight living-donor liver transplantation (LDLT) recipients who received plasma exchange therapy were identified, and 18 of them were found retrospectively to receive a diagnosis of having TMA. Of the 18 patients, 10 (56%) responded to this therapy and survived after the treatment was stopped, whereas eight (44%) patients died before improvement. Subsequent follow-up of patients clarified that 1-yr survival rate of post-LDLT TMA was approximately 30%. Multivariate Cox proportional-hazards regression analysis demonstrated that the interval between transplant surgery and onset of TMA (hazard ratio 1.35 per 30 d; 95% confidence interval 1.07 to 1.71; P = 0.021) and pretreatment blood urea nitrogen level (hazard ratio 1.39 per 10 mg/dl; 95% confidence interval 1.02 to 1.90; P = 0.037) predicted mortality. Analyses identified post-LDLT recipients with TMA as being at high risk for poor prognosis. Effective strategies are needed for late-onset TMA after LDLT to improve treatment response and survival.