Human platelet antigens - 2013

Area of Science:

• Immunology
• Hematology
• Genetics

Background:

• 33 human platelet alloantigens (HPAs) identified on six platelet glycoprotein (GP) complexes.
• HPAs are implicated in alloimmune platelet disorders such as fetal and neonatal alloimmune thrombocytopenia (FNAIT), posttransfusion purpura (PTP), and multitransfusion platelet refractoriness (MPR).

Purpose of the Study:

• To review the current understanding of human platelet alloantigens (HPAs).
• To highlight the significance of HPAs in various alloimmune platelet disorders.

Main Methods:

• Review of existing literature on human platelet alloantigens.
• Analysis of HPA distribution on platelet glycoprotein complexes.

Main Results:

• 20 of 33 HPAs are located on the GPIIb/IIIa complex, crucial for hemostasis and inflammation.
• HPA-1a is the most frequent HPA in FNAIT and PTP among Caucasians.
• 12 HPAs form six biallelic systems, while 21 are low-frequency or rare.

Conclusions:

• HPAs, particularly those on GPIIb/IIIa, play a significant role in alloimmune platelet disorders.
• Understanding HPA systems and rare antigens is vital for managing FNAIT, PTP, and MPR.
• Platelet antigens like ABO and HLA also contribute to alloimmune conditions.