[The Bernard-Soulier syndrome. A hereditary functional and structural disorder of blood platelets]

The authors submit a clinical and laboratory description of a patient with Bernard-Soulier syndrome diagnosed in this country for the first time. The investigation comprises an analysis of haemostatic functions, selected structural indicators and the detailed morphology of thrombocytes. The analysis of defined inborn functional disorders of thrombocytes is a method for studying haemostatic mechanisms.

In addition to standard haemostatic methods flow cytometry in used to assess the size of platelets, and using monoclonal antibodies against glycoproteins, their presence on the surface membrane is assessed. Thrombocytic glycoproteins are further analyzed using diagonal electrophoresis on sodium dodecyl sulphate polyacrylamide gel (SDS-PAGE). The authors found medium thrombocytopaenia with the presence of giant thrombocytes which on elecronmicroscopic examination, with the occasional exception of endoplasmic membrane proliferation, do not display structural deviations. The assessed deviation of thrombocyte aggregation after ristocetin, suggesting a defect of the adhesive capacity of thrombocytes, is apparently due to reduction of the surface glycoprotein GPIb, proved by flow cytometry and SDS-PAGE. The drop of glycoprotein GPIb to 20% of normal values suggests a heterozygote type of disorder with a medium grade of haemorrhagic manifestations.

This is the first case of Bernard-Soulier syndrome in the Czech literature. Its analysis provides evidence of the relationship of the adhesive function to the surface glycoprotein GPIb and confirm the effectiveness of the elaborated diagnostic methods.