白血球除去フィルター使用輸血における同種免疫感作の頻度と危険因子 プロスペクティブ研究

Abstract

Seventy-eight patients multitransfused using leukocyte-reduction filters at bedside were prospectively studied to determine the rate of post-transfusion alloimmunization and its risk to platelet transfusion. HLA- and HPA-antibodies were detected by standard lymphocytotoxicity test (LCT), antihuman globulin-lymphocytotoxicity test (AHG-LCT) and mixed passive haemagglutination method (MPHA).Of these 78 patients, all of whom had a negative antibody screening on admission, 11 (14%) developed HLA antibodies but only one (1%) developed an HPA antibody. HLA antibodies were detected in 9 (24%) of 38 patients with previous transfusion, pregnancy or both but in only 2 (5%) of 40 patients with no presensitization (p<0.02). Among children (<20 years), one (3%) of 35 patients developed HLA antibodies whereas 10 (23%) of 43 adult patients (≥20 years) developed HLA antibodies (p<0.01). An HPA antibody (anti-HPA-2b) was detected with multireactive HLA antibodies in a woman with previous pregnancy.We conclude that WBC-reduced transfusions decrease primary immunization for HLA and HPA antigens. In presensitized adults, however, these transfusions may provide sufficient antigenic stimulation to boost or sustain a secondary alloimmune response. Women with previous pregnancy were identified as a high-responder group with regard to alloimmunization.