Mean Cell Hemoglobin Concentration (MCHC)
MCHC is the mean cell hemoglobin concentration, expressed in g/dL.
It can be calculated from the [Hb] and the PCV using the following formula:
MCHC = (Hb ÷ PCV) x 100
The normal value for MCHC is about 33%. Red cell populations with values
below the reference interval can be termed "hypochromic". This can occur
in a strongly regenerative anemia, where an increased population of reticulocytes
with low Hb content "pull" the average value down (an increased MCV would
be expected under this scenario). Low MCHC can also occur in iron deficiency
anemia, where microcytic, hypochromic red cells are produced as a result of
the lack of iron to support hemoglobin synthesis.
Values for MCHC significantly above the reference interval are not physiologically
possible due to limitations on the solubility of Hb. Sample-related problems of
analysis, however, can result in spurious high values. Lipemia or other causes
of turbidity in the lysate can cause falsely high [Hb] values, which raises the
apparent MCHC. In the latter cases we would provide a CHCM which is optically measured directly from the red blood cells by our hematology analyzer. Red cells from animals of the Camillidae family
(camels, llamas, alpacas), however, truly do have higher MCHC(around 40-45 fL) compared
to those of common domestic animals. This is possible due to higher solubility
of the Hb molecule in these species.
Photomicrograph of blood film from|
a normal llama. MCHC=45%.
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