Thrombotic microangiopathy after ABO-incompatible living donor liver transplantation: a case report

Thrombotic microangiopathy (TMA) has rarely been reported in the setting of liver transplantation. Herein we have reported a successful case of TMA after ABO-incompatible living donor liver transplantation (LDLT) treated with plasma exchange and high-dose intravenous gamma-globulin infusion. A 50-year-old woman was diagnosed with hepatitis C virus-related cirrhosis. We performed an ABO-incompatible LDLT (group B to O) with preoperative plasma exchange to reduce the anti-B hemagglutinin titers to 1:8. The immunosuppressants consisted of tacrolimus, mycophenolate mofetil, and steroid. On postoperative day (POD) 8, her anti-B hemagglutinin titer suddenly increased to 1:64. The serum lactate dehydrogenase (LDH) level was grossly elevated (1518 IU/L). On POD 13, we suspected infection of an intra-abdominal hematoma (Serratia marcescens) which was drained surgically. On day 5 after the reoperation, thrombocytopenia developed with a platelet count of 3 x 10(4)/mm3. A peripheral blood film showed severe red blood cell (RBC) fragmentation. Thus, we made a clinical diagnosis of TMA and reduced the tacrolimus dose. We started intensive daily plasma exchange (4 L/d) with fresh frozen plasma and high-dose intravenous gamma-globulin infusions. One week thereafter, thrombocytopenia improved with reduced transfusion requirements. The peripheral blood film showed normal RBC morphology. The serum LDH returned to baseline levels. Four factors were considered to have caused TMA in this case: the prescription of tacrolimus, ABO-incompatible liver transplantation, bacterial infection, and surgical stress. These factors may have all contributed by causing significant endothelial injury and TMA.