title: Quantification, identification, and relevance of anti-human leukocyte antigen antibodies formed in association with the berlin heart ventricular assist device in children.
abstract: BACKGROUND
  Ventricular assist devices (VADs) are increasingly being used in pediatric patients to provide long-term cardiac support. One potential complication of VAD therapy is the development of antibodies directed against human leukocyte antigens (HLA). This phenomenon has not been well described with the Berlin Heart EXCOR VAD, the most commonly used VAD in pediatric patients.
  
  
  METHODS
  The records of all pediatric patients undergoing VAD support using the Berlin Heart device at our institution between April 2005 and August 2011 were reviewed retrospectively. Demographic and clinical data regarding the VAD course were collected. Assessment of anti-HLA antibodies was performed using Luminex, and antibodies were quantified using mean fluorescence intensity (MFI). Assessment for anti-HLA antibodies was performed before VAD implantation and in serial fashion after VAD implantation. Clinically significant anti-HLA antibodies (sensitization) were defined by an MFI of more than 1000.
  
  
  RESULTS
  Thirty-six patients were supported with the Berlin Heart VAD; 13 met inclusion criteria. The majority (85%) carried the diagnosis of dilated cardiomyopathy. Evidence of sensitization pre-VAD was found in 69%; new-onset sensitization (the development of new antibodies on VAD) occurred in 69%. All patients survived to transplantation. In two patients, the retrospective crossmatch was positive, but only in one patient was the crossmatch positive for antibodies formed while on VAD.
  
  
  CONCLUSIONS
  Using Luminex and MFI quantification, anti-HLA antibodies are common before VAD implantation in pediatric patients. While on VAD support, new anti-HLA antibodies formed in a majority, but the immediate impact of these antibodies appears to be limited.
authors.affiliation: Department of Pediatrics, University of Arkansas for Medical Sciences/Arkansas Children's Hospital, Little Rock, AR 72202, USA. mjoconnor@uams.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: O'Connor
authors.forename: Terry O
authors.initials: TO
authors.lastname: Harville
authors.forename: Bobbie
authors.initials: B
authors.lastname: Rhodes-Clark
authors.forename: Sherry E
authors.initials: SE
authors.lastname: Pye
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Knecht
authors.forename: Michiaki
authors.initials: M
authors.lastname: Imamura
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Frazier
authors.forename: W Robert
authors.initials: WR
authors.lastname: Morrow
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000276:immunology / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006333:Heart Failure / Q000097:blood / Q000276:immunology / Q000628:therapy*; D006353:Heart-Assist Devices; D006801:Humans; D007223:Infant; D007518:Isoantibodies / Q000276:immunology*; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D006680:HLA Antigens; D007518:Isoantibodies