抄録
The simultaneous platelet survival study by isotopic (51Cr-labeling) and non-isotopic (Aspirin-loading) methods was performed in 7 patients with thrombocythemia, one with polycythemia vera and 6 with essential thrombocythemia. Three of them were males and 4 females, and their ages ranged from 33 to 69, 3 of them having a history of thrombosis or hemorrhage. The results are as follows;
1) The mean values of platelet half-life (mean±SD) are 3.8±0.7 days by 51Cr method and 4.1±0.9 by Aspirin method, and the platelet half-life in patients with thrombocythemia seemed to be slightly shortened compared with that of normal subjects (4.9±0.1).
2) The values of platelet half-life determined simultaneously by both methods were quite similar in each patient except for 2 patients in whom abrupt decrease in % radioactivity of 51Cr was seen in the first 24 hours. In each of these 2 patients, however, the survival curves after the second day showed linear decrease of radioactivity and the half-life times calculated from these curves were quite similar to those of Aspirin method. This abrupt decrease in % radioactivity is probably due to some mechanical injury to labeled platelets in the course of labeling, resuspension and injection of the platelets.
3) The non-isotopic method is simple and clinically useful for the determination of platelet survival in vivo.
