platelettype

Platelettype is a term used to describe the specific set of inherited platelet surface antigens expressed by an individual. These antigens are determined by genes that code for proteins embedded in the platelet membrane. The most well-known and clinically significant platelet antigens are part of the Human Platelet Antigen (HPA) system, which comprises a variety of biallelic polymorphisms. These polymorphisms lead to different versions, or alleles, of specific platelet antigens.

The genetic makeup of an individual regarding these platelet antigens constitutes their platelettype. For example, an individual might have a specific combination of HPA alleles that results in the expression of certain HPA types on their platelets. This platelettype is unique to each person, inherited from their parents.

Understanding an individual's platelettype is crucial in certain medical contexts, particularly in transfusion medicine and obstetrics. For instance, in cases of neonatal alloimmune thrombocytopenia (NAIT), a condition where a newborn's platelets are destroyed by maternal antibodies, the incompatibility often arises because the mother lacks an antigen that is present on the father's platelets and inherited by the baby. Identifying the platelettype of both parents and the infant is essential for managing this condition and preventing future occurrences. Similarly, in patients who develop alloimmune refractoriness to platelet transfusions, determining their platelettype and matching donor platelets accordingly can improve transfusion efficacy.