红细胞MCV和RDW对不同方法计数低值血小板的影响

Analysis of the influence of erythrocyte MCV and RDW on the different counting for low platelet counts

目的探讨红细胞平均体积(MCV)和红细胞分布宽度(RDW)对XN-3000血液分析仪电阻抗法(PLT-I)和核酸染色法(PLT-F)低值血小板计数的影响。方法采用Sysmex-XN3000血液分析仪对68例低值血小板患者(分四组:红细胞MCV≥70 f L、MCV<60 f L、60 f LMCV<70 f L而RDW<0.2、60 f LMCV<70 f L而RDW>0.2)EDTA抗凝血分别用PLT-I法和PLT-F法进行血小板计数,同时用Beckman Coulter FC500流式细胞仪(免疫法)计数,以免疫法为参考方法进行比较分析。结果 PLT-F法、PLT-I法与免疫法的相关系数r分别为0.931、0.808,PLT-F法的相关性明显优于PLT-I法;当红细胞MCV≥70 f L、60 f L≤MCV<70 f L而RDW<0.2时,PLT-I法与免疫法比较血小板计数,差异无统计学意义(P>0.05);当红细胞MCV<60 f L、60 f L≤MCV<70 f L而RDW>0.2时,PLT-I法与免疫法比较血小板计数,差异有统计学意义(P<0.05);不同组在PLT-F法与免疫法比较差异均无统计学意义(P>0.05)。结论 PLT-F法与免疫法有良好的相关性,PLT-I法对低值血小板计数的准确性有较大影响,当MCV<60 f L或者60 f L≤MCV<70 f L而RDW>0.2时,血小板应该采用流式细胞仪或PLT-F法检测以获得更为准确的数据。

Objective To investigate the influence of the mean corpuscular volume(MCV) and red cell distribution width(RDW) on the electrical impedance method, and analyze the accuracy of the two platelet counting methods of XN-3000 hematology analyzer. Methods The Sysmex-XN3000 hematology analyzer was used to make the platelet counts for the EDTA anticoagulated blood of 68 low platelet patients(four groups: erythrocyte MCV≥70 f L, MCV<60 f L,60 f L≤MCV<70 f L and RDW<0.2, 60 f L≤MCV<70 f L and RDW>0.2) by the electrical impedance method(PLT-I)and the nucleic acid staining method(PLT-F) respectively; meanwhile, the counting by the Beckman Coulter FC500 flow cytometry(immunoassay) was also taken as a reference method for the analysis. Results The correlation coefficient r of PLT-F method and PLT-I method were 0.931, and the correlation coefficient r of immunoassay was 0.808. The correlation of PLT-F method obviously better than the PLT-I method. The platelet counting results for Group RBC MCV≥70 f L,and Group 60 f L≤MCV<70 f L with RDW<0.2 by the methods of PLT-I and immunoassay had no statistically significant difference(P>0.05). The platelet counting results for Group RBC MCV<60 f L, and Group 60 f L≤MCV<70 f L with RDW>0.2 by the methods of PLT-I and immunoassay had statistically significant differences(P<0.05). The platelet counting results for all Groups by the methods of PLT-F and immunoassay had no statistically significant difference(P>0.05). Conclusion The methods of PLT-F and immunoassay had a good correlation and the PLT-I method had a great influence on the accuracy of the low platelet counts. Thus, for the patients with MCV<60 f L or 60 f L≤MCV<70 f L with RDW>0.2, we recommend that making platelet counts by the flow cytometry or the PLT-F method would be a better choice to obtain more accurate data.