Human platelet antigens (HPA) are polymorphisms in platelet antigens. These can stimulate production of alloantibodies (that is, antibodies against other people's antigens) in recipients of transfused platelets from donors with different HPAs.

Fetal neonatal alloimmune thrombocytopenia (FNAIT) is caused by maternal alloantibodies directed against the human platelet antigens (mostly HPA‐1a or HPA‐5b) of the (unborn) child and can lead to severe bleeding. Anti‐HPA‐1a‐mediated FNAIT shows a severe clinical outcome more often than anti‐HPA‐5b‐mediated FNAIT.

Approximately 80% of these antibodies form in neonatal alloimmune thrombocytopenia anti-HPA-1a (PL A1). This same antibody is implicated in cases of post-transfusion purpura, in which the recipient of a platelet-containing blood product develops antiplatelet antigens that destroy not only the transfused platelet, but native platelets as well.

2023年6月27日 · 大多数患者可检测出IgG型抗HPA-1a抗体，一般持续存在12～15个月。 因此，输血后紫癜应进行血小板抗体检测，可以明确诊断。 研究发现，抗GPIb抗体阳性的ITP患者对糖皮质激素的疗效显著差于抗GPIb抗体阴性的ITP患者，提示抗GPIb/Ⅸ抗体与ITP疾病的严重性和难治性有关。 同时，IVIG对于抗GPIb抗体阳性的ITP患者仅部分有效或无效，潜在原因可能在于抗GPIb抗体为Fc非依赖性抗体，而IVIG的主要作用在于封闭Fc受体，因而不能有效减少抗GPIb抗体引 …

2023年7月6日 · Human platelet antigen-1a (HPA-1a) negative platelets are used to treat neonatal alloimmune thrombocytopenia (NAIT), a bleeding disorder in newborns.

研究表明，血小板抗体是影响血小板输注效果的主要免疫因素之一。目前发现与ptr相关的hpa主要是hpa-1b、5a和5b[7]。若患者输注与其本身hpa不相合的血小板，就可能产生hpa抗体，引起病理性同种免疫反应，导致血小板破坏。

2015年6月15日 · Human platelet Ag (HPA)-1a, located on integrin β3, is the main target for alloantibodies responsible for fetal and neonatal alloimmune thrombocytopenia (FNAIT) in the white population. There are ongoing efforts to develop an Ab prophylaxis and therapy to …

2017年4月21日 · We found that human anti-HPA-1a mAb 26.4 partially inhibits adhesion and migratory capacity of HTR8/SVneo cells. Our findings suggest that anti-HPA-1a antibodies may affect trophoblast functions crucial for normal placental development.

2017年4月21日 · Results: We found that human anti-HPA-1a mAb 26.4 partially inhibits adhesion and migratory capacity of HTR8/SVneo cells. Conclusions: Our findings suggest that anti-HPA-1a antibodies may affect trophoblast functions crucial for normal placental development.

2022年4月1日 · HPA-1a is a high frequency allele in most ethnic groups (98% Caucasians, 90% Africans, 100% Asians) [2]. HPA-1bb individuals are able to make antibodies to HPA-1a if exposed to this alloantigen. In Caucasians, 85% of FNAIT cases are indeed caused by passage of HPA-1a antibodies through the placenta during pregnancy [7]. FNAIT is usually ...