Marked platelet transfusion refractoriness caused by anti-HLA-I and anti-HPA-5b antibodies: A case report

Platelet transfusions are the key treatment for patients with severely low platelet counts and significant bleeding symptoms. Platelet transfusion refractorines (PTR) is defined as unsatisfactory transfusion of platelets with at least 2 ABO blood groups matched and stored for <72 hours.

A 37-year-old woman presented for medical evaluation due to the cessation of fetal heart activity after 50 days of gestation.

AML-M2, PTR.

To explore potential immune-mediated causes of platelet refractoriness, the following diagnostic evaluations were conducted: Platelet antibody screening using the PAK-Lx assay (Immucor) to detect anti-HLA class I and HPA antibodies. Anti-HLA class I specificity determination via LIFECODES LSA Single Antigen bead assays (Luminex). Molecular typing of HLA class I and HPA alleles using PCR-sequence based typing (PCR-SBT), as well as CD36 phenotyping via flow cytometry. Confirmation testing for anti-HPA-5b antibodies using chloroquine-treated platelet solid-phase assays.

The patient had high-fluorescence-intensity HLA antibodies along with HPA antibodies, resulting in severe refractoriness to platelet transfusion.

Various methods were used to comprehensively analyze the specificity of anti-platelet antibodies in the samples of patients with ineffective platelet transfusion, thus providing a reference for the clinical diagnosis and treatment of PTR.