On the relationship between platelet volumes and platelet kinetics in idiopathic thrombocytopenic purpura (ITP)

This is the authors' abstract. We don't add key points for this paper.

The platelet volume distribution and the appearance rate of megathrombocytes were measured with Coulter counter Model-B in 20 patients with ITP during platelet kinetic studies.Normal range of platelet volumes in EDTA-blood is as follows: mode; 5.2±0.3μm3 (mean±1 S. D.), median; 7.1±0.7μm3 and mean volume; 9.0±0.8μm3.In 13 patients with ITP platelets were increased in mean volume, 6 patients showed normal size and one patient decreased in mean volume. Increased percentage of megathrombocytes (volume more than 14μm3) was noted in 13 cases. Remaining 7 cases showed normal rate appearance (13±3.8%).In 5 patients, highest peak was deviated to the smaller elements although the mean volume was remained in normal range or increased. This finding suggests that at least two population of platelets are present in the blood in these cases.No close correlation was noted between platelet counts, platelet mean survival time or platelet turnover and platelet volume. The appearance rate of megathrombocytes had also no correlation with the results of platelet kinetics.From above results, it could be concluded that young platelets could be of variable size in ITP. And, in ITP it might be impossible to suspect the amounts of effective platelet production in the bone marrow from the data of platelet volume or the appearance rate of megathrombocytes.