Abstract: Objective To investigate the correction performance of platelet optical detection technology of Mindray BC6800 blood analyzer for EDTA-dependent pseudothrombocytopenia（EDTA-PTCP）. Methods Totally 53 patients with EDTA-PTCP were assigned into the experimental group and 25 without platelet aggregation into the control group. Within 20 minutes after the specimens were collected,the blood of EDTA-K₂ anticoagulant was detected by CDR mode with Mindray BC6800,and the count values of PLT-I and PLT-O were obtained. Meanwhile,non anticoagulated venous blood was counted by artificial microscope and recorded as PLT-M. The three groups of data were compared and analyzed. In addition, according to the number of platelet aggregation particles under microscope,the experimental group was divided into 5 groups：PLT<6,PLT 6~10,PLT 11~15,PLT 16~20 and PLT>20. Taking PLT-M as the target value and CV≤12.5% as the judgment standard, we counted the qualification rate of PLT-O correction counting in each group and analyzed the unqualified specimens. Additionally,10 specimens with successful correction were randomly selected and placed for 40 minutes and 60 minutes respectively,and then the number of qualified correction of the instrument was counted, with the smear simultaneously examined by microscope.Results There was significant difference between PLT-I and PLT-M in the experimental group（P<0.05）,while PLT-O and PLT-M did not differ significantly（P=0.317）. No significant difference was observed between PLT-M and PLT-O or PLT-I in the control group. The qualification rates of PLT-O correction counting in 5 groups of specimens with different aggregate particle numbers were 88.7%,88.7%,81.8%,80% and 22.2%, respectively. Compared with the blood smears of corrected and qualified specimens,the aggregation of platelets in corrected but failed specimens was more dense and clumpy,and the boundary of platelets was blurred. After being placed for 40 and 60 minutes, the qualification rate of correction was 70% and 50%. The number of platelet aggregation particles in the newly added specimens with unqualified correction was >20.Conclusion The optical detection technology of BC6800 blood analyzer can be used to correct the specimen counting in patients with EDTA-PTCP, but the accuracy of corrected counting results should be determined by combining the approximate particle number of platelet aggregation under blood smear and the density of adhesion between platelets.

Key words: Blood analyzer, Optical detection technology, EDTA-dependent pseudo thrombocy-topenia, Corrective performance