Optimal dosage regimen for rituximab in ABO-incompatible living donor liver transplantation.

Abstract

Rituximab has greatly improved the outcomes of ABO-incompatible living donor liver transplantation (ABO-I LDLT). To clarify the optimal regimen for rituximab in adult ABO-I LDLT, a multicenter study was conducted in Japan. Clinical data of 33 adult patients undergoing ABO-I LDLT at 15 centers in 2013 were retrospectively corrected. The targeted blood type was A1 in 18, B in 14, and AB in one patient. Rituximab was administered at 7 to 48 days before LT, at a dose of 375 mg/m2 in 12 patients, 500 mg in 15 patients, 300 mg in five patients, and 100 mg in one patient. Adverse effects of rituximab were tolerable. Overall 1-year patient survival was 81%; antibody-mediated rejection (AMR) occurred in three patients (9%), two of whom died. Rituximab dose was significantly lower in patients with AMR (P < 0.001, 137 ± 61 vs. 307 ± 66 mg/m2 ). Among rituximab dose (n = 28), local infusion (n = 11), splenectomy (n = 23), prophylactic intravenous immunoglobulins (n = 12), preoperative tacrolimus (n = 9), preoperative antimetabolites (n = 21), and plasmapheresis (n = 23), only rituximab dose was a significantly favorable factor for AMR (P < 0.001). The use of rituximab at sufficient doses is recommended in adult ABO-I LDLT.