Optimal dose of rituximab in ABO-incompatible kidney transplantation in patients with low anti-A/B antibody titers: A single-center retrospective cohort study

BackgroundThe clinical outcomes of ABO-incompatible (ABOi) kidney transplantation have improved with the introduction of desensitization therapy with rituximab. However, rituximab prevents not only antibody-mediated rejection (AMR) but also increases the risk of adverse events, such as infection. For ABOi kidney transplantation in patients with low anti-A/B antibody titers, we previously used a rituximab-free desensitization protocol and then initiated a single dose of 100 mg rituximab in 2016. We retrospectively compared the outcomes of ABOi kidney transplantation in patients with low anti-A/B antibody titers before and after the introduction of rituximab. MethodsABOi kidney transplantations (n = 142) in patients with low anti-A/B antibody titers between 2007 and 2021 were included. Patients were divided into two groups (with and without rituximab) for desensitization. The primary outcomes were the incidence of acute AMR and infection. ResultsSixty-six patients were desensitized without rituximab (rituximab-free group), and 76 were pretreated with 100 mg rituximab (rituximab group) before transplantation. The incidence of acute AMR was significantly lower in the rituximab group than in the rituximab-free group (.0% [0/76] vs. 7.6% [5/66], respectively; p = .047). Post-transplantation anti-A/B antibody titers were also lower in the rituximab group than in the rituximab-free group. There was no significant difference in the incidence of adverse events, including infections, between the two groups. ConclusionIn ABOi kidney transplantation patients with low anti-A/B antibody titers, the desensitization protocol with a single dose of 100 mg rituximab was effective in preventing acute AMR without increasing the risk of other adverse events.