title: Safe transplantation of blood type A2 livers to blood type O recipients.
abstract: BACKGROUND
  Transplantation of blood type A subgroup 2 (A2) livers into non-A recipients has not been reported previously. A2 to O renal transplantation has been reported, with early results including some accelerated rejections and graft losses. This has led some to selectively offer A2 renal transplantation only for patients with low anti-A titers. Given the different clinical behavior of liver allografts to preformed antibody, we felt that such restriction was unnecessary.
  
  
  METHODS
  We performed six cases of A2 to O liver transplantation with no augmented immunomodulation or restriction with regard to antibody titers. Clinical courses, anti-A titers, rejection rates, and graft and patient survival were evaluated.
  
  
  RESULTS
  All six patients had high pretransplant anti-A titers (>1:8), and all six grafts functioned normally. There were nine rejections in the six patients, of which three were severe (steroid-resistant) and five were late (>90 days). No rejection was vascular, and no grafts were lost, with mean follow-up of 665 days. In one patient who had anti-A antibody measured at the time of rejection IGM titers increased from baseline. Currently all patients are home with normal function.
  
  
  CONCLUSIONS
  We found that transplantation of blood group A2 livers into blood group O recipients is safe and can be performed without graft loss and without regard to anti-A titer level. The rate of acute cellular rejection is high in this small series, and a significant proportion of these events were late or required OKT-3. We did not rely on plasmapheresis or anti-A titer determinations. However, the potential for late rejection prompts us to consider the addition of a third immunosuppressive agent. The transplantation of A2 livers into O recipients can partially compensate for the more frequent use of O livers in recipients from other blood groups.
authors.affiliation: Recanati/Miller Transplantation Institute, Mount Sinai Medical Center, New York, New York 10029, USA. Thomas_Fishbein@smtplink.mssm.edu
authors.forename: T M
authors.initials: TM
authors.lastname: Fishbein
authors.forename: S
authors.initials: S
authors.lastname: Emre
authors.forename: S R
authors.initials: SR
authors.lastname: Guy
authors.forename: P A
authors.initials: PA
authors.lastname: Sheiner
authors.forename: L H
authors.initials: LH
authors.lastname: Kim
authors.forename: M E
authors.initials: ME
authors.lastname: Schwartz
authors.forename: C M
authors.initials: CM
authors.lastname: Miller
mesh_terms: D000017:ABO Blood-Group System; D006084:Graft Rejection / Q000453:epidemiology; D006085:Graft Survival / Q000502:physiology; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis; D015994:Incidence; D007518:Isoantibodies / Q000032:analysis; D016031:Liver Transplantation / Q000276:immunology*; D012086:Reoperation; D012449:Safety; D016019:Survival Analysis; D014019:Tissue Donors
chemical_list: D000017:ABO Blood-Group System; D007075:Immunoglobulin M; D007518:Isoantibodies