[The study of platelet kinetics with 51Cr labeled platelets (author's transl)].

After infusion of 51Cr--labeled isologous platelets into one patient with no hematological disease and into four patients with thrombocytopenia, radioactivity was measured from 1 to 8 days. Normal platelets survival was determined as 7 to 8 days in the first patient, whereas the thrombocytopenic patients showed a reduced survival, between 1 to 2 days. The percentage of maximum recovery of transfused platelets was severely reduced in those patients with thrombocytopenia, ranging from 13 to 18%, as compared with the normal 50% found in the first patient. Surface scanning of the spleen, liver and precordium, served as an index for selective platelet sequestration, and it was positive only in case of chronic idiopathic thrombocytopenic purpura (ITP). Despite the low incorporation to the platelets, 51Cr seems to be a suitable label as well as the method described. The pathological aspects of the platelets survival are discussed.