title: Does histocompatibility affect homograft valve function after the Ross procedure?
abstract: BACKGROUND
  Homograft valves have been shown to be immunogenic, but it is unknown whether this affects valve function. Therefore, we prospectively studied the degree of histoincompatibility (defined as the number of human leukocyte antigen [HLA] mismatches between valve donor and recipient) and the response of the recipient (measured by antibodies against HLA) in relation to echocardiographic parameters of homograft valve function after the Ross procedure.
  
  
  RESULTS
  Twenty-six patients (mean age 41+/-14 years; 20 males, 6 females) and the cryopreserved pulmonary homograft valves that were implanted during a Ross procedure were typed for HLA-A, HLA-B, and HLA-DR. After a mean follow-up of 15+/-6 months, 14 (54%) of the patients were anti-HLA class I antibody positive. In all but 1 patient, these antibodies were shown to be donor specific. During follow-up, there was a significant increase of the maximal (+6.2+/-7.1 mm Hg) and mean (+3.2+/-4.3 mm Hg) transhomograft pressure gradients but not of homograft regurgitation. Neither the number of HLA mismatches nor antibody status was found to have significant impact on homograft valve function. In a multivariate analysis, smaller homograft size (P=0.001) and younger recipient age (P=0.044) were shown to be significantly associated with increased transhomograft pressure gradients.
  
  
  CONCLUSIONS
  Implantation of a cryopreserved pulmonary homograft during the Ross procedure can induce a specific humoral response. We observed a significant increase of the transhomograft pressure gradients within 15+/-6 months after surgery. For this period, we were unable to demonstrate a relationship between this increase and the degree of histoincompatibility.
authors.affiliation: Clinic for Cardiac Surgery, Institute for Immunology and Transfusion Medicine, Medical University of Luebeck, Luebeck, Germany.
authors.forename: J F
authors.initials: JF
authors.lastname: Bechtel
authors.forename: C
authors.initials: C
authors.lastname: Bartels
authors.forename: C
authors.initials: C
authors.lastname: Schmidtke
authors.forename: W
authors.initials: W
authors.lastname: Skibba
authors.forename: M
authors.initials: M
authors.lastname: Müller-Steinhardt
authors.forename: H
authors.initials: H
authors.lastname: Klüter
authors.forename: H H
authors.initials: HH
authors.lastname: Sievers
mesh_terms: D000328:Adult; D001021:Aortic Valve / Q000503:physiopathology* / Q000601:surgery; D001323:Autoantibodies / Q000097:blood; D001794:Blood Pressure; D006348:Cardiac Surgical Procedures; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D015234:HLA-A Antigens / Q000276:immunology; D015235:HLA-B Antigens / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D006349:Heart Valve Diseases / Q000097:blood / Q000276:immunology* / Q000601:surgery; D019918:Heart Valve Prosthesis Implantation; D006648:Histocompatibility / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011664:Pulmonary Valve / Q000276:immunology* / Q000637:transplantation*; D014184:Transplantation, Homologous / Q000276:immunology
chemical_list: D001323:Autoantibodies; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D015395:Histocompatibility Antigens Class I