Evaluation of automated capillary complete blood counts for routine clinical decision making in a large cohort of hematological patients, using Mindray BC-3000 Plus Auto and Sysmex XE-5000 hematology analyzers.

Introduction: Venous blood (VB) sampling for complete blood count (CBC) via venipuncture is the basic method for the daily evaluation of hematological patients. However, several issues during this process, such as venipuncture difficulty and repetitive attempts, may cause pain, phlebitis, hematomas, inadequate sampling, and patient discomfort. Capillary blood (CB) sampling could be an alternative and less painful solution for the patient. The purpose of this study was the comparative evaluation of basic CBC parameters, as counted from venous and capillary blood samples.

Methods: During the period 06/2016-06/2019 in which the study was conducted, 1634 automated counts of VB or CB were performed, derived from 425 hematological hospitalized patients. Bland-Altman plots were performed to show the agreement of VB and CB counts of common hematological parameters (Hb, Hct, WBC, absolute neutrophil count-[ANC], RBC, Plt, MCV, MCH), using two different hematology analyzers (Mindray BC-3000 Plus Auto and Sysmex XE-5000). Clinical significance of CB sampling was assessed by applying specific clinically significant cutoffs for Hb, ANC, and Plt.

Results: All measured parameters revealed a significant correlation (r > .9) between CB and VB samples, irrelatively of the hematology analyzer used. CB measurements of Hb, ANC, and Plt, at different clinically important cutoff levels, showed excellent sensitivity (87%-100%), specificity (95%-100%), positive predictive value, and negative predictive value (87%-100% and 90%-100%, respectively).

Conclusion: Capillary blood and VB counts in hematological patients were equivalent for most basic hematological parameters. Hb, ANC, and Plt CB counts revealed clinically significant performance, indicating that they can reliably substitute VB sampling in the day work.