The Platelet Function of the Thrombopathy on the Åland Islands

Abstract

SummaryIn the summer of 1962 we checked a total of 20 bleeders from Åland in order to elucidate the pathogenesis of the haemorrhagic diathesis on the Åland Islands/Finland (“hereditary pseudohaemophilia” – “constitutional thrombopathy” – “v. Willebrand’s disease”). They partly belong to the same families described in 1933 by v. Willebrand and R. Jürgens. We came to the following results :1. On the determination of the volumetric retraction under consideration of the heamatocrit value 17 of 19 patients presented a hyporetractility of the coagulum.2. The thrombelastogram showed in 14 out of 18 patients a completely normal blood coagulation and only in 4 cases a very slight prolongation of the clotting time (increase of r and k).3. The clot retraction disturbance could not be normalized by adding tissue thromboplastin to the venous blood of the 4 patients with mild hypocoagu-laemia mentioned under no. 2. The hyporetractility of the coagulum can therefore not be due to the hypocoagulaemia or a lack of the intrinsic system of thromboplastin generation.4. In 18 out of 19 patients there was a partially extremely decreased platelet adhesiveness on glass surfaces.5. In 17 out of 19 patients a disorder of the platelet agglomeration in citrated plasma released by the effect of glass surfaces was established.6. 14 out of 16 patients showed a pathologic rotation thrombelastogram.7. It is possible, but not yet proved that all these phenomenons are caused by the decreased platelet adhesiveness on glass. In any case, however, the decreased platelet adhesiveness on glass speaks in favor of a disturbed platelet function which could possibly play a part in the development of the haemostatic defect in this disease. Whether we are dealing with an endothrombocytic defect, or whether the decreased adhesiveness on glass presents a secondary disorder of the platelet function due to the lack of an antibleeding factor, is another question which could not yet be definitely settled. Investigations concerning this question are continued.