Comparison of the acute rejection incidence rate in spousal donor transplantation before and after anti-CD20 antibody (rituximab) protocol as desensitization therapy.

Recipients of spousal donor transplantation (SDT) have poorer histocompatibility and higher human leukocyte antigen (HLA) sensitization due to pregnancy than those receiving related donor transplantation (RDT). Thus, SDT carries a higher risk of acute rejection (AR). In our department, patients at a high immunological risk, such as those with ABO incompatibility and HLA sensitization, were considered for desensitization by double filtration plasmapheresis and preoperative administration of rituximab. In this study we compared the AR incidence rates between SDT and RDT according to their immunological risk. We performed RDT in 279 and SDT in 100 patients, a total of 379 cases, between 2000 and 2008; 48.7% of RDT and 67.0% of SDT cases were considered to be at a high immunological risk and underwent preoperative desensitization (P=0.002). Even though the AR incident rate of SDT was higher than RDT in the low immunological risk group, in which the patients had undergone transplantation without desensitization (RDT 24.4%, SDT 37.0%, P=0.012), there was no significant difference between the two donor type groups in the high immunological risk group, in which transplantation with desensitization occurred (RDT 21.3%, SDT 31.3%, P>0.05). Preoperative administration of rituximab significantly reduced AR from 37.4% to 10.6% (P<0.001), especially T-cell mediated rejection (36.4% to 20.2%, P=0.01). SDT no longer carries a high risk when appropriate desensitization, including the use of rituximab, is performed. Overall, the five-year graft survival rates were similar between RDT and SDT.