Glycoprotein IIb/IIIa

In medicine, glycoprotein IIb/IIIa (gpIIb/IIIa, also known as integrin αIIbβ3) is an integrin complex found on platelets. It is a receptor for fibrinogen and aids in platelet activation. The complex is formed via calcium-dependent association of gpIIb and gpIIIa, a required step in normal platelet aggregation and endothelial adherence. Platelet activation by ADP (blocked by clopidogrel) leads to a conformational change in platelet gpIIb/IIIa receptors that induces binding to fibrinogen. The gpIIb/IIIa receptor is a target of several drugs including abciximab, eptifibatide, tirofiban.

Pathology
Defects in glycoprotein IIb/IIIa cause Glanzmann's thrombasthenia.

Autoantibodies against IIb/IIIa can be produced in immune thrombocytopenic purpura.

Medicine
Glycoprotein IIb/IIIa inhibitors can be used to prevent blood clots in an effort to decrease the risk of heart attack or stroke.