Case report: Failed platelet transfusion due to HLA, HPA antibodies

Once the patient received platelet transfusions matched for her antibody status, she achieved sustained remission from thrombocytopenia.

A recent case report published in Medicine described a patient who received eight unsuccessful platelet transfusions after experiencing a miscarriage and being diagnosed with acute myeloid leukemia (AML).

“Subsequently, anti-HLA class I and anti-HPAHuman platelet antigen Proteins found on the surface of platelets. Incompatibility between maternal and fetal human platelet antigens can trigger FNAIT.-5b complex antibodies were observed in serum samples of the patient,” the authors wrote.

Such results are relevant in the context of fetal and neonatal alloimmune thrombocytopenia (FNAITFetal and neonatal alloimmune thrombocytopenia A rare condition in which a mother’s immune system attacks fetal platelets, leading to dangerously low platelet levels before and/or after birth.), as individuals with these antibodies may be at higher risk of the disease in future pregnancies.

The patient was a 32-year-old woman with a history of five births, two of which were carried to term. While her doctors were treating her for a miscarriage at 50 days gestation, they diagnosed her with the M2 subtype of AML and low platelet levels.

Read more about FNAIT causes and risk factors

After two weeks of platelet transfusions, the patient’s platelet levels did not improve, leading to a diagnosis of platelet transfusionPlatelet transfusion A treatment for newborns with very low platelet counts that ideally uses HPA-compatible or washed maternal platelets. refractoriness.

The researchers used a variety of laboratory equipment to confirm the presence of anti-HLA and anti-HPA antibodies. Although only 20% of cases of platelet transfusion refractoriness are attributed to immune factors, these two antibodies are the major immune causes of failed transfusions.

“Considering the patient’s history of multiple pregnancies, there may be underlying immune factors at play,” the researchers explained.

The individual then received three more transfusions that were matched to avoid another immune reaction. The first led to a partial response, the second a significant response, and the third resulted in remission.

These findings demonstrate the importance of investigating potential immune causes of platelet transfusion refractoriness. A history of alloimmunizationAlloimmunization The process by which the mother becomes sensitized to fetal platelet antigens and begins producing alloantibodies. This is what causes FNAIT. (due to FNAIT, for example), can increase risk. The authors’ use of multiple methods allowed for a highly thorough analysis of patient samples. This can be used in the future as a reference for diagnosing cases of immune-mediated platelet transfusion refractoriness.

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