From the Guidelines
Bernard-Soulier Syndrome (BSS) is characterized by a reduced platelet count with giant platelets, whereas Glanzmann Thrombasthenia (GT) typically presents with a normal platelet count but impaired platelet aggregation. The distinction between these two conditions is crucial for diagnosis and management, as BSS affects platelet adhesion and production, while GT affects platelet aggregation without impacting count. In BSS, patients usually have platelet counts ranging from 20,000-100,000/μL, with characteristically large platelets visible on blood smear 1. This thrombocytopenia occurs because BSS involves a defect in the GPIb-IX-V complex, which is crucial for platelet adhesion to von Willebrand factor and normal platelet production.
In contrast, GT patients have quantitatively normal platelets (150,000-450,000/μL) but with dysfunctional platelets due to defects in the GPIIb/IIIa receptor complex, which is essential for platelet aggregation. The fundamental difference between BSS and GT helps in differential diagnosis, with BSS showing reduced platelet count with giant platelets, while GT shows normal count with impaired aggregation. Both conditions present with mucocutaneous bleeding, but the underlying mechanisms differ. Yearly complete blood counts will facilitate monitoring platelets over time, and caution is required to differentiate a normal decrease from conditions requiring treatment to ensure unnecessary investigations and therapies are avoided 1.
Key differences between BSS and GT include:
- Platelet count: BSS typically has a reduced platelet count, while GT has a normal platelet count
- Platelet size: BSS is characterized by giant platelets, while GT has normal-sized platelets
- Platelet function: BSS affects platelet adhesion and production, while GT affects platelet aggregation
- Clinical presentation: Both conditions present with mucocutaneous bleeding, but the underlying mechanisms differ. The most recent and highest quality study on this topic is from 1, which discusses the management of major bleeding and coagulopathy following trauma, but does not specifically address the difference in platelet count between BSS and GT. However, it highlights the importance of platelet transfusion in patients with thrombocytopenia, which is relevant to BSS patients with low platelet counts.
From the Research
Comparison of Bernard-Soulier Syndrome (BSS) and Glanzmann Thrombasthenia (GT)
- Both BSS and GT are inherited platelet disorders that can lead to severe bleeding events, often requiring platelet transfusions or other treatments 2, 3, 4, 5.
- Patients with BSS and GT may experience frequent and severe bleeding events, which can result in secondary iron deficiency anemia (IDA) 3.
- The management of BSS and GT focuses on treating bleeding events and preventing complications, rather than prophylactic treatment 5.
- Platelet transfusions are often necessary for patients with BSS and GT, but they carry a risk of alloimmunization, which can render future transfusions ineffective 2, 4.
Impact on Platelet Count
- BSS is characterized by a deficiency of the GPIb-IX-V complex, which can lead to thrombocytopenia and large platelets 4, 6.
- GT is characterized by a deficiency of the GPIIb/IIIa complex, which can also lead to thrombocytopenia and impaired platelet function 4, 6.
- Patients with BSS and GT may require regular monitoring of their platelet count and bleeding events to manage their condition effectively 3, 5.
Treatment Options
- Treatment options for BSS and GT include platelet transfusions, recombinant activated factor VII (rFVIIa), and antifibrinolytic agents 2, 3, 4.
- Female hormones, such as oestrogen and progesterone, may be used to manage menorrhagia and pregnancy in women with BSS and GT 2, 5.
- Desmopressin may be used to increase plasma levels of von Willebrand factor and factor VIII, which can help to reduce bleeding events 2.