title: Association of the Number of HLA-DR Mismatches With Early Post-transplant Acute Cellular Rejection Among Heart Transplantation Recipients: A Cohort Study in Japanese Population.
abstract: BACKGROUND
  Although many risk factors are reported about graft rejection after heart transplantation (HTx), the effect of HLA mismatch (MM) still remains unknown, especially in the Japanese population. The aim of the present study was to investigate the influence of HLA MM on graft rejection among HTx recipients in Japan.
  
  
  METHODS
  We retrospectively investigated the association of the number of HLA MM including class I (A, B) and class II (DR) (for each locus MM: 0 to 2, total MM: 0 to 6) and the incidence of moderate to severe acute cellular rejection (ACR) confirmed by endomyocardial biopsy (International Society for Heart and Lung Transplantation grade ≥ 3A/2R) within 1 year after HTx.
  
  
  RESULTS
  Between 2007 and 2014, we had 49 HTx cases in our institute. After excluding those with insufficient data and positive donor-specific antigen, finally 35 patients were enrolled. Moderate to severe ACR was observed in 16 (45.7%) patients. The number of HLA-DR MM was significantly associated with the development of ACR (ACR+: 1.50 ± 0.63, ACR-: 1.11 ± 0.46, P = .029). From univariate analysis, DR MM = 2 was the only independent risk factor for ACR episodes (P = .017). The frequency of ACR within 1 year was significantly higher in those with DR MM = 2 (DR MM = 0 to 1: 0.3 ± 0.47, DR MM = 2: 1.17 ± 1.34 times, P = .007).
  
  
  CONCLUSIONS
  The number of HLA-DR MMs was associated with the development and recurrence of ACR episodes among HTx recipients within 1 year after transplantation in Japanese population.
authors.affiliation: Department of Cardiovascular Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Nitta
authors.affiliation: Department of Internal Medicine 2, The University of Toyama, Toyama, Japan. Electronic address: kinugawa-tky@umin.ac.jp.
authors.forename: K
authors.initials: K
authors.lastname: Kinugawa
authors.affiliation: Department of Cardiovascular Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Imamura
authors.affiliation: Department of Blood Transfusion, The University of Tokyo, Tokyo, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Iino
authors.affiliation: Department of Organ Transplantation, The University of Tokyo, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Endo
authors.affiliation: Department of Cardiovascular Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Amiya
authors.affiliation: Department of Therapeutic Strategy for Heart Failure, The University of Tokyo, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hatano
authors.affiliation: Department of Cardiac Surgery, The University of Tokyo, Tokyo, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Kinoshita
authors.affiliation: Department of Cardiac Surgery, The University of Tokyo, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nawata
authors.affiliation: Department of Cardiac Surgery, The University of Tokyo, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ono
authors.affiliation: Department of Cardiovascular Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Komuro
mesh_terms: D000208:Acute Disease; D000328:Adult; D001706:Biopsy; D015331:Cohort Studies; D005260:Female; D006084:Graft Rejection / Q000276:immunology*; D006684:HLA-DR Antigens / Q000276:immunology*; D016027:Heart Transplantation; D006650:Histocompatibility Testing; D006801:Humans; D015994:Incidence; D007564:Japan; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D014019:Tissue Donors
chemical_list: D006684:HLA-DR Antigens