Clinical utilities of simultaneous measurements of reticulated platelets and large platelets in benign thrombocytopenic disorders
Koh, K.Ryang
Journal of the Osaka City Medical Center 48(1-2): 205-212
1999
Accession: 010333153
The automated reticulocyte counter by flowcytometric analysis, the R-300 (Sysmex Inc. Kobe, Japan) has recently been modified to determine reticulated platelets (RPs) and large platelets, (LPs). We measured RP and LP comprehensively for idiopathic thrombocytopenic purpura (ITP, n=21), aplastic anemia (AA, n=20), liver cirrhosis (LC, n=16), as well as hematologically normal subjects (controls, n=67) to examine clinical utilities of these new parameters. The frequency of LP was increased only in ITP, whereas that of RP was increased both in ITP and AA compared with controls (p<0.01). Interestingly, when the frequencies of RP of the subjects from all the study groups was plotted against corresponding total platelet counts, a significant inverse correlation was found, in contrast to the case of LPs plotted against total platelet count. On the other hand, significant positive correlations were observed between the frequencies of RP and LP in controls, ITP, and LC (r=0.76, r=0.79, and r=0.79, respectively) (p<0.0005). However, there was no such correlation in AA, in which bone marrow stem cells are reported to have some qualitative defects. Thus, simultaneous measurements of RP and LP are useful for differential diagnosis of thrombocytopenic disorders. Furthermore, there seemed to be common mechanism in the regulation of the frequencies of RPs, irrespective of the cause of thrombocytopenia. The correlation between RP and LP may be a new indicator to detect qualitatively abnormal platelets.