Biological variation estimates of complete blood count parameters in healthy subjects

Background: the complete blood count (CBC) is the test more frequently requested in clinical practice. Therefore, estimating the biological variation (BV) of CBC parameters is essential for assessing the analytical performance of hematological analyzers and for enabling accurate data interpretation and appropriate clinical management. This study was aimed to define BV estimates and reference change value (RCV) of CBC parameters. Methods: the study population consisted of 21 healthy volunteers, who had BV of CBC parameters assessed with Sysmex XN. The study protocol, the analytical measurements and the statistical analysis were carried out according to current recommendations of the European Federation for Clinical Chemistry and Laboratory Medicine (EFLM). Results: Within-subject BV ranged between 0,3% for mean cell hemoglobin (MCH) and 19,7% for immature granulocytes (IG), whilst between-subjects BVs ranged between 0,9% for mean corpuscolar haemoglobin concentration (MCHC) and 66,6% for microcytic red blood cells (Micro-R). The RCV ranged between 2,3% for MCH and 73,5% for IG. Conclusion: This study has allowed the estimation of BV of many CBC parameters, some of which have not been currently explored, thus leading the way to use RCV calculated according to time of monitoring and/or differentiated by sex.