Impact of the baseline anti-A/B antibody titer on the clinical outcome in ABO-incompatible kidney transplantation.

BACKGROUND/AIMS We investigated the impact of the baseline anti-A/B antibody titer on the clinical outcome in ABO-incompatible kidney transplantation (IKT). METHODS We included 183 patients who had undergone KT (40 ABO IKT and 143 ABO-compatible KT). Eight patients with a baseline titer of ≥1:512 were assigned to the high-titer group and 32 patients with a baseline titer of ≤1:256 were assigned to the low-titer group. Patients who underwent ABO-compatible KT were used as the control group. We compared the clinical outcomes of the three groups. RESULTS Before transplantation, the high-titer group displayed more frequent antibody rebound, as shown in a lower titer reduction rate, and more difficulty reaching the target titer (1:16) than the low-titer group. During the postoperative period and out-clinic follow-up, antibody rebound was more frequent, and the rate of acute rejection and infection were significantly higher and allograft function was lower in the high-titer group than in the low-titer and control groups. Multivariate analysis showed that high baseline antibody titer was an independent risk factor for acute rejection. CONCLUSION ABO IKT in the high-titer group (baseline titer ≥1:512) required greater caution compared to the low-titer group because of the higher tendency of antibody rebound and the risk for acute rejection.