Double-filtration plasmapheresis for ABO-incompatible living-donor kidney transplantation

INTRODUCTION: ABO-incompatible (ABOi) kidney transplantation (KT) is now an established form of renal replacement therapy. However, it is important to note that ABO antibody clearance affects the procedure's success. As demonstrated in prior studies, both double filtration plasmapheresis (DFPP) and plasma exchange (PE) can eliminate IgM and IgG isoagglutinins. However, relatively few studies have examined the long-term prognosis of patients with both. The present study aimed to compare the efficacy and long-term prognosis of DFPP with those of PE in patients with ABOi-KT. METHODS: From September 2014 to April 2024, 230 consecutive ABO-incompatible living donor KTs were performed. The participants were divided into DFPP and PE groups. Following propensity score matching (PSM), the primary outcomes included acute rejection (AR), infection, graft loss, patient death, and the effects of the two modalities on isoagglutinin titers (IgG and IgM). RESULTS: After 1:4 PSM, a total of 24 patients in the PE group and 63 patients in the DFPP group were included in the final analysis. Compared with PE, DFPP was associated with a significantly lower incidence of six-month AR (6.3% vs. 33.3%, P = 0.003) and six-month patient mortality (0% vs. 12.5%, P = 0.019), along with shorter hospital stays (22 [18-29] vs 42 [36-48] days, P < 0.001). Multifactorial analysis revealed that the risk of AR in ABOi KTs with antibody rebound was 6.43 times greater than that in ABOi KTs without antibody rebound (OR = 6.43, 95% CI: 1.21-34.1, P = 0.029), whereas the risk of AR in ABOi KTs pretreated with DFPP was 85.8% lower than that in ABOi KTs pretreated with PE (OR = 0.142, 95% CI: 0.04-0.57, P = 0.006). However, no statistically significant differences were observed between the two groups in six-month creatinine levels or six-month graft loss. No significant differences were observed between the two groups in the reduction of IgG and IgM isoagglutinins. A single PE session led to a reduction in the IgM isoagglutinin titer by approximately 3-fold, in comparison to a 2-fold reduction that was observed with a single session of DFPP. Similarly, a single PE session led to a 2-fold reduction in IgG isoagglutinin titer. DFPP sessions resulted in a reduction that was marginally less than 2-fold. It is noteworthy that DFPP exhibited a more pronounced depletion of albumin (10.6 ± 6.7 vs 4.8 ± 5.5 g/L, P < 0.001), globulin (10.4 ± 6.5 vs 5.5 ± 5.7 g/L, P = 0.002), and fibrinogen (1.5 [1.2-2.2] vs 1.1 [0.1-1.9] g/L, P = 0.024).