The bleeding tendency in Glanzmann's thrombasthenia is variable, some individuals having minimal bruising, while others have frequent, severe, potentially fatal hemorrhages. Moreover, platelet αIIbβ3 levels correlate poorly with hemorrhagic severity, as virtually undetectable αIIbβ3 levels can correlate with negligible bleeding symptoms, and 10%–15% levels can correlate with severe hemorrhage. Unidentified factors other than the platelet defect itself may have important roles.
In contrast, glycoprotein Ib receptors are normal with Glanzmann's thrombasthenia. The role of GpIb is to enable platelet activation by contact with the von Willebrand factor-collagen complex that is exposed when the endothelial blood vessel lining is damaged.
^Tholouli E, Hay CR, O'Gorman P, Makris M (2004). "Acquired Glanzmann's thrombasthenia without thrombocytopenia: a severe acquired autoimmune bleeding disorder". Br. J. Haematol.127 (2): 209–13. doi:10.1111/j.1365-2141.2004.05173.x. PMID15461628.
^Glanzmann, WE (1918). "Hereditäre hämorrhagische Thrombasthenie. Ein Beitrag zur Pathologie der Blutplättchen.[Hereditary haemorrhagic thrombasthenia. A contribution to the pathology of platelets] (German)". Jahrbuch für Kinderheilkunde [Yearbook of Pediatrics]88 (1-42): 113–141.
^Kannan, M.; Saxena, R. (2009). "Glanzmann's thrombasthenia: an overview". Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis15 (2): 152–165. doi:10.1177/1076029608326165. PMID18930954.edit