Comparison of Complete Blood Count Results Between K3-EDTA- and MgSO₄-Anticoagulated Samples Using a DxH800 Analyzer

Area of Science:

• Hematology
• Clinical Pathology
• Laboratory Medicine

Background:

• EDTA-induced pseudothrombocytopenia (PTCP) necessitates alternative anticoagulants for accurate platelet counting.
• Magnesium sulfate (MgSO4)-anticoagulated tubes are a potential alternative, but their comparability to K3-EDTA requires validation.
• Assessing the stability of complete blood count (CBC) parameters in MgSO4 tubes is crucial for clinical utility.

Purpose of the Study:

• To compare CBC and differential counts obtained from MgSO4- and K3-EDTA-anticoagulated blood samples.
• To evaluate the stability of CBC parameters in MgSO4 tubes over a 24-hour period.
• To determine if MgSO4 tubes are a reliable alternative for patients with PTCP.

Main Methods:

• Comparison of CBC results from 355 patients using K3-EDTA and MgSO4 anticoagulants on DxH800 analyzers.
• Analysis of differential counts in 33 cases and sample stability in 10 patients over 24 hours.
• Statistical analysis including correlation and mean relative bias (MRB) assessment against established criteria.

Main Results:

• CBC parameters like WBC count, hematocrit, and MCV showed slight differences between MgSO4 and K3-EDTA tubes, with MCHC being slightly higher in MgSO4.
• Mean platelet volume (MPV) was significantly lower in MgSO4 tubes, with MRBs exceeding recommendations.
• Neutrophil counts were significantly lower in MgSO4 tubes, but within optimal bias limits; WBC morphology remained similar. Stability analysis showed less pronounced MCV and RDW increase in MgSO4 tubes compared to K3-EDTA.

Conclusions:

• CBC and differential results from MgSO4-anticoagulated samples are largely comparable to K3-EDTA, with notable exceptions for MPV.
• MgSO4 tubes demonstrate acceptable stability for CBC parameters over 24 hours at room temperature.
• The findings suggest MgSO4 tubes are a viable alternative for CBC analysis, particularly in managing PTCP, provided MPV results are interpreted with caution.