Optimal Settings for Double Filtration Plasmapheresis With Targeted Removal Rate of Preexisting Antibody in Antibody-Incompatible Kidney Transplant

Abstract

BackgroundElimination of preexisting donor-reactive antibodies is essential for antibody-incompatible kidney transplantation. Double filtration plasmapheresis (DFPP) using albumin (Alb) replacement fluid (Rf) removes immunoglobulin more selectively than plasma exchange; however, fixed-dose treatment can result in insufficient removal of antibody or excess loss of osmotic pressure and subsequent hypotension. The aim of this study was to determine the optimal setting (volume and concentration of Rf) of DFPP to remove donor-reactive antibodies. Materials and MethodsOne hundred seventeen DFPPs were performed in 41 patients for kidney transplant in an ABO-incompatible or crossmatch-positive setting. A formula for Rf volume was determined based on volume-removal rate (RR) curve of IgG. Another formula for Alb concentration of Rf was also established to keep plasma volume within pre-DFPP plasma volume ± 10% calculated by post- to pre-DFPP hematocrit ratio to avoid hypotensive events. ResultsRR-IgG was obtained based on patient data: Rf (mL) = BW (kg) × eX, [X = (RR-IgG + 10.757)/25.603] (R2 = 0.401, P < .001). Rf Alb concentration was determined by AlbRf ≥ (2.982 − 2.36 × RR-IgG) × Albpre + (2.36 × RR-IgG − 0.236) × pre-DFPP total protein. ConclusionsOptimal volume and concentration of Alb Rf can be calculated using our formulae with targeted RR-IgG.