Q. I’m having some difficulty grasping the MCHC, MCV and RDW in hereditary spherocytosis. Wouldn’t the MCHC, MCV, and RDW be elevated in all anemias? What makes hereditary spherocytosis special?
A. MCHC, MCV and RDW aren’t elevated in all anemias…they are different in different anemias.
The mean cell volume (MCV) tells you whether cells are small (microcytic), normal (normocytic) or big (macrocytic). The mean cell hemoglobin concentration (MCHC) tells you how much hemoglobin there is on average in a red cell. If the MCHC is low, the cells are called hypochromic. If the MCHC is normal, the red cells are called normochromic. The MCHC doesn’t ever go above normal (so there isn’t such a thing as a macrochromic cell!).
The red cell distribution width (RDW) tells you how much the red cells vary in size from one to another. If the red cells are all pretty much the same size, the RDW is within the normal range. If there some small red cells and some large red cells, the RDW is increased (the word for this variation in red cell size is anisocytosis).
In hereditary spherocytosis, the MCV is generally normal. The anemias in which the MCV is low include iron-deficiency anemia and thalassemia. Anemias in which the MCV is elevated include megaloblastic anemia and a few other types of anemias including alcohol-related anemia. Most other anemias are just normocytic.
some of the hs cases have a slightly hi mchc in our practice .
Prhaps this is related to the sphere’s geometry .
we use a coulter counter .
What a thorough explanation! It makes me actually think about what those parameters ate as opposed to just memorizing what is elevated/normal/decreased.
Very useful lesson thank you very much,easily undrrstand
The other useful red cell parameter is the Mean Cell Haemoglobin (MCH). This usually correlates with the MCV. That is, it is low in microcytic anaemias and normal in normocytic anaemias and high in macrocytic anaemias.
The MCHC may be raised in hereditary spherocytosis and autoimuune causes of spherocytosis. A raised MCHC in cold haemagglutinin disease (CHAD) is due to the analyser giving a falsely low RBC. The MCHC may be falsely raised in lipaemic samples because the analyser is detecting a falsely high Hb.
thanks for explaining it so clearly…thanks a lot
great info, and yes MCHC/MCH/MCV increased widely with Cold Agglutinin
Awesome! Is there a “like” button or “heart” icon where I can click on somewhere?