Ann Lab Med.  2024 Nov;44(6):478-486. 10.3343/alm.2023.0460.

Integration of an MC-80 Digital Image Analyzer With an Automated BC-6800Plus Hematology Analyzer Enables Accurate Platelet Counting in Samples With EDTA-Induced Pseudothrombocytopenia

• So MK
• Huh J
• Kim S
• Park S

• KMID: 2560794
• DOI: http://doi.org/10.3343/alm.2023.0460

Abstract

Background
EDTA-induced pseudothrombocytopenia (PTCP) during whole blood collection requires significant laboratory resources to obtain accurate results. We evaluated platelet-deaggregation function in EDTA-induced PTCP and platelet-clump flagging by the BC-6800Plus hematology analyzer using integrated digital image analysis.
Methods
We prospectively collected 132 whole blood samples suspected of platelet clumping (102 in EDTA and 30 in sodium citrate) from 88 individuals. We compared platelet counts determined using the platelet count by impedance (PLT-I) function of the DxH 900 hematology analyzer and the PLT-I or optical platelet count (PLT-O) function of the BC-6800Plus. Platelet clumping was verified through manual inspection and the MC-80 digital image analyzer.
Results
Among the 132 whole blood samples, 43 EDTA samples showed platelet clumping. The DxH 900 PLT-I and BC-6800Plus PLT-I results demonstrated a strong correlation (r = 0.711) for the EDTA samples but only a moderate correlation with the BC-6800Plus PLT-O results (r = 0.506 and 0.545, respectively). The BC-6800Plus PLT-O results were consistent with the sodium citrate platelet counts, with a median dissociation rate of 102.5% (range, 74.9%–123.1%). The DxH 900 and BC-6800Plus analyzers had sensitivity values of 0.79 and 0.72, respectively, for platelet-clump flagging. When integrating the MC-80 digital image analysis results, the sensitivity of BC-6800Plus improved to 0.89 (standard mode) or 1.0 (PLT-Pro mode).
Conclusions
BC-6800Plus PLT-O measurement results are close to the actual values obtained by platelet deaggregation with PTCP samples. Integrating the BC-6800Plus with a digital imaging analyzer effectively improved the diagnosis of PTCP and reduced the requirement for additional laboratory procedures.

Keyword

Analyzer; Anticoagulant; Complete blood count; Digital image; EDTA; Pseudothrombocytopenia

Figure

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  Fig. 1 True platelet clumps detected using different automated hematology analyzers. (A) DxH 900 NRBC channel. (B–E) BC-6800Plus. (B) Platelet-distribution histogram. (C) WNB channel. (D) DIFF channel. (E) RET channel. Panel (E) confirms the lack of RBC interference. Arrows indicate platelet clumps. Abbreviations: NRBC, nucleated red blood cell; DIFF, differential; RET, reticulocyte.

• 

  Fig. 2 Comparison of platelet counts measured using the DxH 900 PLT-I, BC-6800Plus PLT-I, and BC-6800Plus PLT-O method with EDTA tubes from patients with pseudothrombocytopenia (N=43). Abbreviations: PLT-I, platelet count by impedance; PLT-O, optical platelet count.

• 

  Fig. 3 Comparison of platelet counts measured using the BC-6800Plus PLT-O method with EDTA tubes and the DxH 900 PLT-I method with sodium citrate tubes from patients with pseudothrombocytopenia (N=30). Abbreviations: PLT-O, optical platelet count; PLT-I, platelet count by impedance.

• 

  Fig. 4 Presence of giant and large platelets confirmed by MC-80 image analysis of PLT clumps flagged by the DxH 900 analyzer. (A) BC-6800Plus platelet-distribution histogram. (B and C) MC-80 standard mode. (D) MC-80 PLT-Pro mode. Abbreviation: PLT, platelet.

• 

  Fig. 5 Presence of heavy platelets confirmed by MC-80 image analysis of PLT clumps flagged by the D×H 900 analyzer. (A) BC-6800Plus platelet-distribution histogram. (B and C) MC-80 standard mode. (D) MC-80 PLT-Pro mode. In panel (B), the platelet clumps are classified as artifacts. Abbreviation: PLT, platelet.

Reference

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