Antigen-Specific Immunoadsorption With the Glycosorb® ABO Immunoadsorption System as a Novel Treatment Modality in Pure Red Cell Aplasia Following Major and Bidirectional ABO-Incompatible Allogeneic Hematopoietic Stem Cell Transplantation
Ammon Handisurya, Nina Worel, Werner Rabitsch, Marija Bojić, Sahra Pajenda, Roman Reindl‐Schwaighofer, Wolfgang Winnicki, Andreas Vychytil, Hanna A. Knaus, Rainer Oberbauer, Kurt Derfler, Philipp Wohlfarth
Abstract
Pure red cell aplasia (PRCA) after ABO-incompatible allogeneic hematopoietic stem cell transplantation (HSCT) is caused by persisting host-derived isohemagglutinins directed against donor red blood cell (RBC) antigens. ABO antigen-specific immunoadsorption (ABO-IA) with Glycosorb, commonly used for desensitization therapy in ABO-incompatible living donor renal transplantation, specifically eliminates circulating isohemagglutinins and might represent a novel treatment option for post-HSCT PRCA. In this prospective observational (n=3) and retrospective (n=3) analysis of six adult HSCT-recipients with PRCA, ABO-IA was initiated at 159 (range: 104-186) days following HSCT. The median treatment frequency was 4.5 (range: 3.9-5.5) sessions/week. ABO-IA-treatment led to a continuous decrease in isohemagglutinin titers. Reticulocytes increased to ≥30 G/L after 17.5 (range: 4-37) immunoadsorption sessions over 28.5 (range: 6-49) days and continued to rise thereafter. By the end of the three-month follow-up period after discontinuation of ABO-IA, all patients showed a sustained remission of PRCA and were independent from erythropoietin-stimulating agents and transfusions. No case of infection or GVHD was observed. After a median follow-up of 22.03 (range: 6.08-149.00) months after ABO-IA-treatment, all patients were alive and showed a stable RBC engraftment of the donor blood group. Our data provide the first evidence for ABO-IA as an effective treatment for post-HSCT PRCA.