title: Impact of ABO incompatibility on allogeneic peripheral blood progenitor cell transplantation after reduced intensity conditioning.
abstract: BACKGROUND
  Most studies indicate that ABO incompatibility has no effect on the clinical outcome after allogeneic peripheral blood progenitor cell (PBPC) transplantation (allo-PBPCT). However, it carries additional risks of hemolytic reactions, delayed red blood cell (RBC) engraftment, and pure red cell aplasia (PRCA). Data on these events after reduced intensity conditioning (RIC) regimens are limited, but recent studies have suggested a higher transplant-related mortality (TRM) and morbidity in this setting.
  
  
  METHODS
  We investigated the impact of ABO-matching on the outcome of 77 patients included in a prospective RIC allo-PBPCT protocol, focusing on engraftment, transfusion requirements, graft-versus-host disease, TRM, and survival.
  
  
  RESULTS
  There were 17 (22%) minor and 8 (10%) major ABO-incompatible transplants. No graft failures were observed. After major ABO-incompatible grafts, RBC engraftment was delayed, longer thrombocytopenia periods were documented, and transfusion requirements increased. A transient mild hemolysis occurred in 10 patients, 7 (41%) minor and 3 (37%) major ABO-mismatched. A PRCA was observed in a O+ patient with a pretransplant anti-Jka, grafted from an A + Jka+ donor. Graft-versus-host disease, disease progression, and TRM were not affected by ABO matching.
  
  
  CONCLUSIONS
  ABO incompatibility was not associated with clinically relevant hemolysis after the RIC protocol used and did not impair the clinical outcome. PRCA was only observed in one patient, with a non-ABO RBC allo-antibody.
authors.affiliation: Blood Bank, Hospital de Sant Pau, Barcelona, Spain. ccanals@hsp.santpau.es
authors.forename: Carmen
authors.initials: C
authors.lastname: Canals
authors.forename: Eduardo
authors.initials: E
authors.lastname: Muñiz-Díaz
authors.forename: Clara
authors.initials: C
authors.lastname: Martínez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Martino
authors.forename: Imma
authors.initials: I
authors.lastname: Moreno
authors.forename: Adelaida
authors.initials: A
authors.lastname: Ramos
authors.forename: Marina
authors.initials: M
authors.lastname: Arilla
authors.forename: Neus
authors.initials: N
authors.lastname: Boto
authors.forename: Concepción
authors.initials: C
authors.lastname: Pastoret
authors.forename: Angel
authors.initials: A
authors.lastname: Remacha
authors.forename: Jorge
authors.initials: J
authors.lastname: Sierra
authors.forename: Pedro
authors.initials: P
authors.lastname: Madoz
mesh_terms: D000017:ABO Blood-Group System; D000328:Adult; D000368:Aged; D001787:Blood Group Incompatibility; D017707:Erythrocyte Transfusion; D005260:Female; D006086:Graft vs Host Disease / Q000517:prevention & control; D006461:Hemolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D036102:Peripheral Blood Stem Cell Transplantation; D017713:Platelet Transfusion; D012010:Red-Cell Aplasia, Pure / Q000453:epidemiology; D013921:Thrombocytopenia / Q000453:epidemiology; D018183:Transplantation Chimera; D019172:Transplantation Conditioning / Q000379:methods*; D014184:Transplantation, Homologous; D016896:Treatment Outcome
chemical_list: D000017:ABO Blood-Group System