Importance of red cell serology in optimizing transfusion strategy for patients undergoing allogeneic hematopoietic stem cell transplant

Abstract

In ABO-incompatible allogeneic hematopoietic stem cell transplant (HSCT) monitoring for the appearance of donor-derived ABO antigens on red blood cells (RBCs) is a valuable tool for deciding the transfusion strategy. It was a retrospective study (6 months) where the patients undergoing ABO-incompatible (major/minor/bidirectional) allogenic HSCT were followed up for blood grouping, direct antiglobulin test (DAT), and antibody screen (ABS). Blood grouping (ABO and RhD) and ABO antibody titers were done by tube technique; DAT and ABS were done using gel technique (Bio-Rad, Switzerland). A total of six patients underwent ABO-incompatible transplant including three major (1 case AB→B; 2 cases B→O), two minor (A→AB; O→B), and one bidirectional (A→B) transplants. ABS and DAT were negative. In major ABO-incompatible transplants, the recipient anti-A/anti-B titers varied from 2 to 16 (immunoglobulin M [IgM]: 2–8; immunoglobulin G [IgG]: 2–16), and in minor ABO-incompatible transplants, the donor anti-B titer ranged from 8 to 32 (IgM: 8–16; IgG: 8–32). In the bidirectional case, the recipient anti-A titer was 32 (IgM = IgG). No plasma/red cell reduction was done in the product before the transplant. A mixed-field agglutination (MFA) was observed with anti-B on posttransplant day 44 in one major ABO-incompatible transplant, with anti-B on posttransplant day 31 in one minor ABO-incompatible transplant, and with anti-A as well as anti-B on posttransplant day 36 in the bidirectional ABO-incompatible transplant, which indicated RBC engraftment. A total of 30 (median: 4.5) packed RBC units were transfused in the posttransplant phase. In conclusion, pretransplant immunohematology work-up and the monitoring of blood group for MFA are important tools for optimizing the transfusion strategy of patients undergoing ABO-incompatible allogeneic HSCT.