Usefulness of fully automated measurement of reticulated platelet using the whole blood

Abstract number: P1803

Sakakura^* M., Wada^* H. W., Nobori^* T. N., Abe^* A. Y., Nishioka^* J. N., Oguni† S. O., Hamaguchi† Y. H.

^*Mie University School of Medicine, Japan; †Sysmex Corporation, Japan

The percentage of reticulated platelet (RP%), which is reflected with production of thrombocyte in bone marrow, was measured by the automated hematology analyzer. We investigated the basic performance such as frequencies of RP% in healthy control and the clinical significance in thrombocytopenic patients. Peripheral blood with K2EDTA of normal healthy controls and patients were measured by modified R-2000 (Sysmex, Kobe, Japan). In this instrument, reticulated platelets were stained by Auramin-O and RP% was analyzed with a special software. Among healthy normal controls, the RP% are 0.48 ± 0.26 in men and 0.48 ± 0.32% (mean ± SD) in women. No significant differences in the RP% values due to sex or age (21–60) were observed. Furthermore, the reverse correlations were observed between PLT counts and RP%. The RP% in patients with idiopathic thrombocytopenic purpura (ITP) (N = 58) was higher than that of the normal population. The RP% were 1.99 ± 0.85% in ITP (active, N= 26), 0.89 ± 0.56% in ITP (PR, N= 19), 0.41 ± 0.26% in ITP (CR, N= 13), 0.51 ± 0.20% in aplastic anemia (AA) (active, N= 9), 1.36 ± 0.94% in AA (PR, N= 7), 0.25 ± 0.10% in AA (CR, N= 7) and 0.94 ± 0.51% (mean ± 1SD) systemic lupus erythematosus (SLE) (N = 7). The RP% in ITP showed a decreasing tendency, ITP (active) to ITP (PR) to ITP (CR). By contrast, in patient with AA (N = 26), while the RP% in AA (PR) was higher than in the healthy control group, the RP% in AA (active), AA (CR) was same as in the control group. These results show that RP% reflects the pathology of the thrombocytopenic disorders. Moreover, this automated RP count was suitable for routine clinical test because this method was simple and complicated operation was not required. We believe that the measurement of RP% is useful for the differential diagnoses of thrombocytopenia and the analysis of platelet kinetics.