Comparison of Blood Cell Count Results Between MgSO4 and K2EDTA. Stability and Accuracy of Platelet Counting With MgSO4.

INTRODUCTION

We investigated the stability and accuracy of platelets with MgSO4 and compared the results of blood counts between MgSO4 and K2EDTA.

METHODS

Platelet stability as a function of time was assessed on the XN Sysmex analyzer by comparing the percentage deviation to the desirable bias of the EFLM. Accuracy was determined by calculating the LoQ of platelets corresponding to a CV of 10%. Results from 250 patients were compared between K2EDTA and MgSO4.

RESULTS

At 20°C, platelets were stable for 24 h in impedance, 10 h in fluorescence and at 4°C for 4 h in impedance, 2 h in fluorescence. This decrease is related to the formation of platelet aggregates. For platelets in fluorescence, LoQ is 4 × 109/L using MgSO4. The results of the complete blood count did not differ between K2EDTA and MgSO4 except for the MCV, for which the median relative bias (MRB) with respect to K2EDTA was -5.6%. For MgSO4 platelets, the MRB is 2.9% in fluorescence and 11.9% in impedance.

CONCLUSION

The use of MgSO4 with the XN produces results comparable to those obtained with K2EDTA, except for those related to MCV and for impedance platelets.