A severe case of neonatal thrombocytopenia with a fatal outcome, implicating HPA‐12bw fetomaternal platelet alloimmunization

Abstract

She agreed that outside laboratory results are not acceptable, unless certain conditions are met. She cited many standards (5.15.2.2, 5.13.5, 1.11, 4.1, 4.2.2, and 4.3 2 ) that apply to the computer crossmatch in our situation. She stated that in terms of a historic record the results would have had to have been confirmed at the time of collection using two independent identifiers. Also in terms of the outside laboratory, the testing shall be performed in a laboratory certified by CMS and registered with the FDA, if indicated, by 21CFR. Testing or services required by these blood banking and transfusion services standards shall be performed in a laboratory accredited by the AABB or equivalent accrediting body. Also the outside facility must have a medical director who is a licensed physician. This director will provide consultative and support services that relate to the care and safety of donor and/or transfusion recipients.We interpreted the FDA response as all but prohibiting the practice of accepting ABO Rh results performed at outside institutions and manually entering them into the hospital database and the AABB response as a shade more nuanced, but essentially shedding significant doubt as to the acceptability of the practice. We recommend that historical information from outside laboratories not be utilized as part of compatibility testing and that two separate ABO Rh determinations be performed at the transfusing institution for crossmatch testing by any method, including, but not limited to, the computer crossmatch. This will ensure compliance with accrediting and regulating bodies and reduce the consequences of WBIT.

Cab4b, the first human platelet antigen carried by glycoprotein IX discovered in a context of severe neonatal thrombocytopenia

“…). Like Cab4b, anti‐HPA‐2 and anti‐HPA‐12bw alloantibodies can also lead to major thrombocytopenias and ICH . ICH in FNAIT is mainly associated with anti‐HPA‐1a alloimmunization, where antibodies against the β 3 integrin subunit react with the α v β 3 vitronectin receptor expressed by fetal endothelial cells (ECs).…”

How do we treat fetal and neonatal alloimmune thrombocytopenia?

“…In our experience, HPA-6bw, HPA-9bw, HPA-12bw, and HPA-13bw are not restricted to single families. [12][13][14] Consequently, in the absence of fetomaternal incompatibility for the most frequent antigens according to the ethnicity, genotyping of these low-frequency antigens is recommended.…”

Genetic polymorphisms of human platelet antigens in the Asian population: implications in the establishment of platelet donor registries

“…However, both these alleles are highly prevalent among Africans, reaching up to 40% in Central Africa . HPA‐21bw has garnered some recent interest, as it appears to be more prevalent in Asians with an allelic frequency of 0·56%, while absent among Whites .…”