title: LVAD implant as a bridge to heart transplantation is associated with allosensitization as measured by single antigen bead assay.
abstract: BACKGROUND
  Left ventricular assist devices (LVAD) as a bridge (BTT) to heart transplantation (HTX) may be limited by the formation of anti-human leukocyte antigen antibodies. Whether sensitization occurs with continuous axial flow LVAD implant as assessed by single antigen bead (SAB) assay is unknown.
  
  
  METHODS
  Cytotoxic panel-reactive antibody (PRA) and SAB assays were analyzed in HTX recipients undergoing LVAD implant as a BTT. Sensitization was defined as peak anti-human leukocyte antigen antibody values of more than 2000 mean fluorescence intensity because these values have been found to correlate with flow cytometric crossmatch results.
  
  
  RESULTS
  LVADs were implanted as BTT in 30 patients. There were 7% (2 of 30) of patients before LVAD implant and no patients after LVAD implant with PRA more than 10%. However, 20% (6 of 30) of patients before LVAD and 53% (16 of 30) after LVAD were sensitized as measured by SAB (P=0.024). At HTX, 47% (14 of 30) of patients remained sensitized. A positive virtual crossmatch was observed in 28% (4 of 14) of the sensitized patients at HTX. There was no difference between the sensitized and nonsensitized groups (P>0.4 for all) in usage of blood products (6411 vs. 6339 units) and time to HTX (28,663 vs. 25,748 days), and 1 year after HTX, there were no differences in rejection (total rejection score 0.30 vs. 0.37) and survival (93% vs. 88%).
  
  
  CONCLUSIONS
  Allosensitization after LVAD is common despite cytotoxic PRA being negative. One year after HTX, this sensitization does not translate into increased acute cellular or antibody-mediated rejection or reduced survival.
authors.affiliation: University of Connecticut Health Center, Farmington, CT, USA.
authors.forename: Nisha
authors.initials: N
authors.lastname: Shankar
authors.forename: Richard
authors.initials: R
authors.lastname: Daly
authors.forename: Jennifer
authors.initials: J
authors.lastname: Geske
authors.forename: Sudhir K
authors.initials: SK
authors.lastname: Kushwaha
authors.forename: Michael
authors.initials: M
authors.lastname: Timmons
authors.forename: Lyle
authors.initials: L
authors.lastname: Joyce
authors.forename: John
authors.initials: J
authors.lastname: Stulak
authors.forename: Manish
authors.initials: M
authors.lastname: Gandhi
authors.forename: Walter
authors.initials: W
authors.lastname: Kremers
authors.forename: Soon
authors.initials: S
authors.lastname: Park
authors.forename: Naveen L
authors.initials: NL
authors.lastname: Pereira
mesh_terms: D000328:Adult; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D016027:Heart Transplantation; D006353:Heart-Assist Devices; D006650:Histocompatibility Testing; D006801:Humans; D007518:Isoantibodies / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged
chemical_list: D006680:HLA Antigens; D007518:Isoantibodies