ABSTRACT
【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.
ABSTRACT
Objective To detect and determine the specificity of platelet-reactive antibodies in patients who were refractory to platelet transfusions.Methods Serum samples from 48 patients who were refractory to platelet transfusions were screened with MACE for platelet-reactive antibodies.Specificity of platelet alloantibodies was determined with PAK12 and MAIPA.Results Platelet-reactive antibodies were detected in the serum of 50% PTR patients(24/48).The incidence of HLA antibodies was 39.6%(19/48),accounting for 79.2% of serum with platelete alloantibodies.The HPA alloantibodies were found in 29.2%(14/48)serum,of which,64.3%(9/14)occurred together with anti-HLA.The following platelet-specific antibodies were identified:anti-HPA-3a(n=2),anti-HPA-5b(n=1),anti-HPA-5a(n=1),anti-HPA-2b(n=1),anti-HPA-4b(n=1).Of the 14 serum with HPA antibodies,78.6%(11/14)contained panreactive anibodies against platelet glycoprotein(GP)Ⅱb/Ⅲa,GPⅠa/Ⅱa,and/or GPⅠb/Ⅸ.Platelet-reactive antibodies were detected more in female(16/29)than in male(8/19)with a frequency of 55.2%,42.1%,respectively,but there was no statistical significant difference.Conclusion The platelet-specific antibody in PTR patients are not as rare as previous thought although alloantibodies are predominantly anti-HLA.Antibody specificities in Chinese PTR patients are different from those observed in Caucasians,in whom anti-HPA-5b and-1b are the most prevalent specificity.The most prevalent platelet-specific antibodies are anti-HPA-3 and anti-HPA-5 while anti-HPA-4b and anti-HPA-2b are also detected.
