title: Severe immune hemolysis after minor ABO-mismatched allogeneic peripheral blood progenitor cell transplantation occurs more frequently after nonmyeloablative than myeloablative conditioning.
abstract: BACKGROUND
  Hemolysis as a result of donor-recipient minor ABO mismatching is a complication of allogeneic peripheral blood progenitor cell (PBPC) transplantation (PBPCT). The increased B-lymphocyte content of PBPC grafts and immunosuppressive regimens without methotrexate (MTX) may increase incidence and severity of this event.
  
  
  METHODS
  A total of 93 patients were analyzed after allogeneic PBPCT. In 25 (27%) cases, minor (n=21) or bidirectional (n=4) ABO mismatching was present. Of these, 15 patients received myeloablative and 10 received nonmyeloablative conditioning regimens. For GVHD, prophylaxis cyclosporin A (CsA) alone (n=2) or CsA with MTX (n=13) was given after myeloablative conditioning and CsA with mycophenolate mofetil (MMF) after nonmyeloablative conditioning (n=10).
  
  
  RESULTS
  Hemolysis occurred in 4 out of 25 (16%) patients with minor or bidirectional ABO mismatching only. Three patients underwent nonmyeloablative conditioning and were given CsA with MMF, and one patient underwent myeloablative conditioning and was given CsA alone for GVHD prophylaxis. Hemolysis began 7 to 10 days after transplantation, and donor type alloantibodies were detectable concomitantly with recipients type RBCs.
  
  
  CONCLUSIONS
  Patients receiving minor or bidirectional ABO-mismatched PBPC grafts and GVHD prophylaxis without MTX are at risk of hemolysis. Prophylactic interventions in patients before minor ABO-mismatched PBPCT not receiving MTX should be taken into consideration. Careful monitoring of hemolysis parameters during the first 15 days after PBPCT transplantation is mandatory.
authors.affiliation: Department for Blood Group Serology and Transfusion Medicine, Bone Marrow Transplantation, University Hospital of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
authors.forename: Nina
authors.initials: N
authors.lastname: Worel
authors.forename: Hildegard T
authors.initials: HT
authors.lastname: Greinix
authors.forename: Felix
authors.initials: F
authors.lastname: Keil
authors.forename: Margit
authors.initials: M
authors.lastname: Mitterbauer
authors.forename: Klaus
authors.initials: K
authors.lastname: Lechner
authors.forename: Gottfried
authors.initials: G
authors.lastname: Fischer
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Mayr
authors.forename: Paul
authors.initials: P
authors.lastname: Höcker
authors.forename: Peter
authors.initials: P
authors.lastname: Kalhs
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000743:Anemia, Hemolytic / Q000209:etiology* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology / Q000637:transplantation; D001787:Blood Group Incompatibility / Q000097:blood*; D002292:Carcinoma, Renal Cell / Q000628:therapy; D017707:Erythrocyte Transfusion; D005260:Female; D006086:Graft vs Host Disease / Q000209:etiology / Q000401:mortality; D019337:Hematologic Neoplasms / Q000628:therapy; D006461:Hemolysis; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007680:Kidney Neoplasms / Q000628:therapy; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000628:therapy; D009196:Myeloproliferative Disorders / Q000628:therapy; D036102:Peripheral Blood Stem Cell Transplantation / Q000009:adverse effects* / Q000401:mortality; D015995:Prevalence; D012204:Rh-Hr Blood-Group System / Q000235:genetics / Q000276:immunology; D016019:Survival Analysis; D018183:Transplantation Chimera; D019172:Transplantation Conditioning / Q000379:methods* / Q000401:mortality; D014184:Transplantation, Homologous / Q000009:adverse effects* / Q000276:immunology
chemical_list: D000017:ABO Blood-Group System; D007166:Immunosuppressive Agents; D012204:Rh-Hr Blood-Group System; D008727:Methotrexate