RÉSUMÉ
【Objective】 To investigate the frequency of platelet antibodies in voluntary blood donors and patients in Zhongshan, Guangdong Province, and to study the specificity and cross-matching of platelet antibodies. 【Methods】 Platelet antibodies of blood donors and patients were screened by solid-phase immunoadsorption (SPIA), rechecked by flow cytometry (FCM), and antibody specificity was identified by PakPlus enzyme immunoassay, and platelet cross-matching was simulated by SPIA. 【Results】 A total of 1 049 blood donor samples and 598 patient samples were tested, with 6 (0.57%) and 49 (8.19%) samples positive for SPIA,respectively(P<0.05); In SPIA positive samples, the positive concordance rate of FCM in blood donors and patients was 100% vs 95%, and that of enzyme immunoassay was 100% vs 88%. Among the initial screening positive samples of blood donors, 5 were anti-HLA Ⅰ antibodies, accounting for 83%, and 1 was anti CD36 antibody, accounting for 17%, with an incidence rate of 0.10%. Among the 14 samples of enzyme immunoassay positive patients, 2 were anti-GP Ⅱb/Ⅲa, 1 was anti-GP Ⅱa/Ⅱa, 8 were anti HLA Ⅰ, and 3 were mixed antibodies (HLA Ⅰ, GP Ⅱb/Ⅲa, GP Ⅰa/Ⅱa). According to the types of antibodies, HLA Ⅰ antibodies were the most common, accounting for 65% (11/17), followed by HPA related anti GP, accounting for 35% (6/17). The majority of patients had a platelet antibody positive typing rate below 30%, accounting for 71.4% (10/14). 【Conclusions】 The positive rate of platelet antibody of patients in Zhongshan area is significantly higher than that of voluntary blood donors, and most of them are anti-HLA Ⅰ and anti-GP, and the incidence of anti-CD36 is extremely low. Therefore, it is necessary to establish a known platelet antigen donor bank, and at the same time, carry out platelet antibody testing and matching of patients, which is helpful to solve the issue of platelet transfusion refractoriness.
RÉSUMÉ
【Objective】 To find the HLA-matched platelets from platelet donor registry and track the transfusion effect for aplastic anemia patients in pregnancy with platelet transfusion refractory (PTR) caused by anti-HLA, so as to support the childbirth and follow-up treatment of the patients. 【Methods】 Antibodies to HPA and HLA were detected by ELISA kit and Luminex, respectively. DNA of the patient and 523 platelet donors from the donor registry were extracted for high-resolution HLA genotyping. The Risk Factors Evaluation Software of PTR was used to select the ABO-compatible and HLA-matched donors, without HLA Eplets specific to the patient. After MASPAT cross matching, the patient was transfused with 1 U of platelets, and the 24h post-transfusion effect was recorded. 【Results】 Only anti-HLAⅠantibody was found in the patient serum, and the specificity Eplet was 65QIA, including HLA-B*27∶08, B*27∶05, B*07∶02, B*55∶01, B*67∶01 and B*54∶01; anti-HLA Ⅱ antibody was negative. The HLA genotypes of both the patient and donor were HLA-A*02∶07, A*11∶01, B*46∶01, B*46∶01, C*01∶02, 01∶03, DRB1*04∶05, DRB1*0901, DQB1*03∶03 and DQB1*04∶01. The results of MASPAT matching were negative. HLA-matched platelets transfusion provided a satisfactory posttransfusion platelet responses in patients(1 before vs 33 ×109/L after). A baby boy was delivered by cesarean section 4 weeks later, and the same donor was recruited due to the mother′s low Plt and bleeding trend. The 24h posttransfusion Plt (×109 / L) rose from 5 to 37 after the secondary transfusion of 1U platelet. The vital signs of the mother and her baby were normal during the two-day follow up. 【Conclusion】 The establishment of blood donor registry and screening of HLA-matched donors is an effective approach to treat PTR caused by HLA antibodies in pregnancy complicated with aplastic anemia.