Description

Glanzmann’s thrombasthenia (GT) is a hemorrhagic syndrome, affecting the megakaryocytic line and characterized by the loss of platelet aggregation. The syndrome is rare, but its prevalence is unknown. The clinical picture is variable: some patients have only minimal bleeding, while others show frequent, severe and potentially fatal bleeding. The sites of the haemorrhage are well defined: purpura, epistaxis, gingival haemorrhage and menorrhagia are almost constant; gastrointestinal bleeding and hematuria are less common. In most cases, bleeding symptoms appear soon after birth, although GT is occasionally diagnosed later. The syndrome is transmitted as an autosomal recessive trait. The molecular defect consists of a quantitative and / or qualitative anomaly of the integrin alfa2b beta3. This receptor mediates the binding of adhesion proteins, which ensure the formation of platelet aggregates and the formation of thrombus in damaged sites of blood vessels. The diagnosis is based on mucocutaneous hemorrhage, on the absence of platelet aggregation in response to physiological stimuli, with normal morphology and number of platelets. Platelet deficiency in alpha2b beta3 or its failure should be confirmed, for example by flow cytometry. To avoid platelet alloimmunization, therapeutic management should include, if possible, local haemostatic treatments and / or the administration of dDAVP (desmopressin). When these methods are ineffective, or in anticipation of surgery, management is based on the transfusion of HLA-compatible platelet concentrates. Administration of recombinant factor VIIa is a new therapeutic alternative, which must be considered. GT can be a severe bleeding disorder, but the prognosis is excellent with careful supportive care.

External Information

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