Platelet Dysfunction

**103**

**1. Introduction**

**Chapter 5**

**Abstract**

Bleeding Disorders Associated

Glanzmann Thrombasthenia and

Platelets, the smallest cells in the blood, are associated with hemostasis, bowel formation, tissue remodeling, and wound healing. Although the prevalence of inherited platelet disorders is not fully known, it is a rare disease group and is encountered in approximately between 10000 and 1000000. Glanzmann thrombasthenia (GT) and Bernard-Soulier syndrome (BSS) are more frequently observed in inherited platelet disorders. In GT, the platelet aggregation stage due to deficiency or dysfunction of the platelet GPIIb/IIIa complex cannot take place. BSS is a platelet adhesion disorder due to the absence or abnormality of GPIb/IX complex on the platelet surface. If there is bleeding after easy bruising, mucous and oral cavities, menorrhagia, tooth extraction, tonsillectomy, or other surgical interventions, inherited platelet dysfunction should be considered if the platelet count is normal while the bleeding time is long. Firstly, other causes should be investigated by making differential diagnosis of GT and BSS. In this chapter, the definition, etiology, historical process, epidemiology, genetic basis, pathophysiology, clinical findings, diagnosis, differential diagnosis, and the follow-up and treatment approach of GT

with Abnormal Platelets:

Bernard-Soulier Syndrome

and BSS will be reviewed according to the current medical literature.

**Keywords:** Glanzmann thrombasthenia, Bernard-Soulier syndrome, thrombocyte function disorder, thrombocyte transfusion, rFVIIa

Platelets, the smallest cells in the blood, are associated with hemostasis, bowel formation, tissue remodeling, and wound healing. Platelets perform their tasks in ensuring hemostasis in four stages: platelet adhesion, activation of platelet, platelet aggregation, and platelet procoagulant activity. When a damage occurs on the vascular endothelial surface, platelets bind to the collagen, fibronectin, von Willebrand factor, thrombospondin, and fibrinogen in the endothelial substrate with the glycoprotein receptors they carry on their surface. In this way, platelet adhesion takes place. Binding of platelet receptors to their respective ligands causes activation of the platelet. This activation occurs as a result of the change in the cytoskeleton system due to intracellular calcium. By importing the impulse from outside the cell, platelet α-granules secrete their contents. The released ADP causes structural

*Muhammet Mesut Nezir Engin*

## **Chapter 5**
