Glycoprotein Ib Explained

Glycoprotein Ib (GPIb), also known as CD42,^[1] is a component of the GPIb-V-IX complex on platelets. The GPIb-V-IX complex binds von Willebrand factor, allowing platelet adhesion and platelet plug formation at sites of vascular injury. Glycoprotein Ibα (GPIbα) is the major ligand-binding subunit of the GPIb-V-IX complex. GPIbα is heavily glycosylated.^[2]

It is deficient in the Bernard–Soulier syndrome. A gain-of-function mutation causes platelet-type von Willebrand disease.^[3]

Autoantibodies against Ib/IX can be produced in immune thrombocytopenic purpura.^[4]

Components include GP1BA and GP1BB.

It complexes with Glycoprotein IX.

Notes and References

1. Bode AP, Read MS, Reddick RL . Activation and adherence of lyophilized human platelets on canine vessel strips in the Baumgartner perfusion chamber . The Journal of Laboratory and Clinical Medicine . 133 . 2 . 200–211 . February 1999 . 9989772 . 10.1016/S0022-2143(99)90013-6 .
2. Hollenhorst MA, Tiemeyer KH, Mahoney KE, Aoki K, Ishihara M, Lowery SC, Rangel-Angarita V, Bertozzi CR, Malaker SA . 6 . Comprehensive analysis of platelet glycoprotein Ibα ectodomain glycosylation . Journal of Thrombosis and Haemostasis . 21 . 4 . 995–1009 . April 2023 . 36740532 . 10065957 . 10.1016/j.jtha.2023.01.009 .
3. Book: McPherson RA, Pincus MR . Henry's Clinical Diagnosis and Management by Laboratory Methods . 2007 . Saunders Elsevier . Philadelphia, Pa . 978-1-4160-0287-1 . 21st . 760–762.
4. McMillan R . The pathogenesis of chronic immune thrombocytopenic purpura . Seminars in Hematology . 44 . 4 Suppl 5 . S3–S11 . October 2007 . 18096470 . 10.1053/j.seminhematol.2007.11.002 .