title: Platelet transfusion refractoriness caused by a mismatch in HLA-C antigens.
abstract: BACKGROUND
  HLA-C antigens have been thought to be of little significance in determining the efficacy of platelet transfusions. However, six alloimmunized patients were encountered who were refractory to platelet transfusions because of anti-HLA-Cw3, -Cw3, -Cw7, or -Cw8.
  
  
  METHODS
  Between 1995 and the present, 88 patients with hematologic malignancies became refractory to random-donor platelet transfusions due to HLA antibodies. HLA-A- and HLA-B-compatible platelet transfusions were successful in boosting platelet levels with 82 of the patients. This study concerns the remaining six HLA-immunized patients who were refractory to HLA-A- and HLA-B-compatible platelet transfusions. The response to the platelet transfusions was assessed by calculating both 1- and 24-hour posttransfusion CCIs for each transfusion.
  
  
  RESULTS
  The average CCI(1 hour) and CCI(24 hours) in all patients were 20.0 and 12.8 for HLA-A-, HLA-B-, and HLA-C-compatible transfusions and were 1.4 and 1.2 for HLA-A- and HLA-B-compatible but HLA-C-incompatible transfusions, respectively (p < 0.001).
  
  
  CONCLUSIONS
  These findings clearly indicate that matching of the HLA-C antigens is also required in some alloimmunized patients to obtain the effectiveness of platelet transfusions.
authors.affiliation: Tissue Typing Laboratory, Nagano Red Cross Blood Center, Japan. stsaito@poplar.ocn.ne.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saito
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ota
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Seshimo
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Setsuo
authors.initials: S
authors.lastname: Nomura
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ito
authors.forename: Jun
authors.initials: J
authors.lastname: Miki
authors.forename: Masao
authors.initials: M
authors.lastname: Ota
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Fukushima
authors.forename: Hiroo
authors.initials: H
authors.lastname: Maeda
mesh_terms: D000293:Adolescent; D001787:Blood Group Incompatibility; D001792:Blood Platelets / Q000276:immunology*; D002675:Child, Preschool; D005260:Female; D015236:HLA-C Antigens / Q000032:analysis / Q000276:immunology*; D019337:Hematologic Neoplasms / Q000097:blood / Q000628:therapy; D006648:Histocompatibility; D006801:Humans; D007518:Isoantibodies / Q000097:blood; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D017713:Platelet Transfusion; D016896:Treatment Outcome
chemical_list: D015236:HLA-C Antigens; D007518:Isoantibodies