Abstract:

Objective　To investigate the accuracy of platelet（PLT） counting which was influenced by erythrocyte fragments（FRC）， red blood cell volume（MCV）， PLT parameters [platelet distribution width（PDW）， platelet-larger cell ratio（P-LCR） and platelet hematocrit（PCT）] and immature platelets（IPF） by SYSMEX XE-5000 hematology analyzer（XE-5000）. Methods　The 200 samples with no FRC were analyzed by XE-5000， and were classified into 4 groups and each group of 50 cases: A1 group（MCV＜60 fL）， B1 group（60 fL≤MCV＜70 fL）， C1 group（70 fL≤MCV＜80 fL） and D1 group（MCV ≥ 80 fL）， respectively. The samples with FRC of different concentrations and MCV ≥70 fL were classified into 2 groups and each group of 40 cases: A2 group（0.1%≤FRC≤0.99%） and B2 group（FRC≥1.0%）， respectively. The samples of 50 cases with no FRC， MCV≥70 fL and PLT parameters（PDW， PCT and P-LCR） showed "-"（C2 group） were chosen. PLT counting was performed in the 330 cases and determined for microscopy by electrical impedance analysis， optics and manual method. One case of naive patients with thrombocythemia was continuously observed for 5 d by electrical impedance analysis， optics and manual method. Results　There were significant differences between electrical impedance analysis and manual method from A1， A2， B1， B2 and C2 groups（P＜0.05）. It showed no statistical significance between electrical impedance analysis and manual method from C1 and D1 groups（P＞0.05）. It showed no statistical significance between optics and manual method from A1， B1， C1， D1， A2， B2 and C2 groups（P＞0.05）. One case of naive patients with thrombocythemia was continuously observed for 5 d by the 3 methods， respectively. The results of electrical impedance analysis were less than those of optics and manual method. The results of manual method were relatively stable， and the results of electrical impedance analysis and optics increased with the mature of PLT. There existed giant PLT by microscopy. Conclusions　When the samples of MCV ＜70 fL， FRC and PLT parameters shows "-" by XE-5000， and it should be measured by optics and smear microscopy. While the specimens with high IPF and many giant PLT under microscopy， they should be detected by manual method.

Key words: Red blood cell volume, Erythrocyte fragment, Platelet parameter, Immature platelet, Platelet counting