Breaking Free From MCHC Interferences? French-Speaking Cellular Haematology Group (GFHC) Review of Causes, Rising Trends and Practical Solutions.

Mean corpuscular haemoglobin concentration (MCHC) is determined by the ratio of haemoglobin concentration to haematocrit. Managing increased MCHC presents significant challenges, mainly due to variations in analytical methods and pathophysiological conditions. Depending on the haematological analyser (HA), MCHC can be measured directly or calculated. It is important that all people involved in hematocytometry must identify and correct artefacts to ensure accurate erythrocyte parameters. In order to harmonise and standardise haematology practices in all laboratories, the French-speaking Cellular Haematology Group (GFHC) has reviewed the interferences and pathophysiological situations that could increase MCHC, and the advice on how to manage cases of elevated MCHC. We will review current techniques, such as impedance and optical methods, for accurate determination of MCHC. We will also examine the interferences that can artificially increase MCHC; and the pathophysiological conditions responsible for such increases. Finally, we will present guidelines for the management of elevated MCHC, including strategies to bypass interferences and determine which erythrocyte parameters can be reliably reported, as well as the acceptable MCHC values for various pathophysiological variations.