Are only pre-transplant rituximab and plasma exchange sufficient for desensitization protocol of ABO incompatible LDLT?

Abstract

Introduction: ABO incompatible living donor liver transplantation (ABOi LDLT) has become a feasible option because of improved outcomes by various desensitization strategies. However, the protocol of ABOi LDLT has not been established worldwide. Nevertheless, the results after transplantation are homogenous. The reports for the results of ABOi LDLT using only rituximab and plasma exchange are scarce. We present the outcomes of our desensitization protocol for ABOi LDLT. Method: From January 2015 to August 2018, we performed 117 LDLTs. Of them, 29 patients (25%) received ABOi LDLT. We used only a single dose of rituximab(300 mg/m2) and several plasma exchanges for pre-transplant desensitization in ABOi LDLT and post-transplant immunosuppression consisted of basiliximab, tacrolimus, mycophenolate mofetil and steroid. The target iso-agglutinin IgG titer before transplantation and during post-transplant period were 1:32 and 1:64. Result: The mean initial iso-agglutinin IgG titer was 131 (range, 4∼512) and initial iso-agglutinin IgG titer in recipient blood type O was higher than in another blood types. Pre-transplant plasma exchanges were performed in all recipients with more than target titer (mean number of sessions, 2.32 (range, 1∼5)). Post-transplant plasma exchanges were performed in 3 patients because of higher target isoaaglutinin titer (> 1:64), but none had antibody mediated rejection. Biliary complications were identified in 8 patients, but all was anastomotic site stricture. Acute cellular rejection was confirmed in one patient and resolved by steroid pulse therapy. Conclusion: Both rituximab and plasma exchange along are one of desensitization strategies to eliminate the risk of antibody mediated rejection and our results were also comparable to ABO-identical or compatible LDLT. Hence, we believe that complex protocols including splenectomy, intravenous immunoglobulin, and local infusion therapy are not necessary in most ABOi LDLT.