Thrombocytoasthenia is a well defined disease, due to defective pseudopod formation and lack of spreading of platelets, i.e., defective adhesivity in contact with wettable surfaces. This defect persists in pathologic or normal plasma, serum, heated serum and barium adsorbed serum. The platelets behave normally, however, in saline or plasma substitutes. There is a manifest or latent defect of clot retraction, which can be revealed by thrombelastography. This disturbance seems to be in relation with the primary platelet disorder, and can not be corrected by addition of serotonin. Coagulation factors are normal.
Under the name of thrombocytopathia, possibly heterogenous diseases have been provisionally classified into three groups. In some patients a diminution of thromboplastic activity of platelets is ascertained. The platelets may also show marked morphologic anomalies. This group has been designated as "thrombocytopathia." In the majority of patients a deficiency of thromboplastic activity of platelets is only found temporarily or the results are only moderately pathologic. This group has been designated as "probable thrombocytopathia." The third group includes patients with a normal thromboplastic activity of platelets. As indicated with existing methods; more sensitive tests, still on trial, may give positive results. This group has been designated as "possible thrombocytopathia."
Capillary microscopy gave normal results in patients of all three groups. The relation to "vascular pseudohemophilia" is briefly discussed.