Decreased platelet glycoprotein IIb-IIIa The glycoprotein IIb-IIIa is an integrin complex found on platelets that acts a receptor for fibrinogen and aids in platelet activation. Reduced level of platelet glycoprotein IIb/IIIa complex HP:0001975 UMLS:C0040015 UMLS:C4021767 SNOMEDCT_US:32942005 Decreased cell membrane concentration of glycoprotein IIb-IIIa. Glanzmann thrombasthenia Abnormal platelet membrane protein expression