The mean corpuscular hemoglobin concentration (MCHC) is a measure of the concentration of

hemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyte ...

in a given volume of packed red blood cell. It is calculated by dividing the hemoglobin by the

hematocrit The hematocrit () (Ht or HCT), also known by several other names, is the volume percentage (vol%) of red blood cells (RBCs) in blood, measured as part of a blood test. The measurement depends on the number and size of red blood cells. It is norm ...

Reference ranges for blood tests Reference ranges (reference intervals) for blood tests are sets of values used by a health professional to interpret a set of medical test results from blood samples. Reference ranges for blood tests are studied within the field of clinical chem ...

are 32 to 36 g/dL (320 to 360g/L), or between 4.81 and 5.58 mmol/L. It is thus a mass or

molar concentration Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solut ...

. Still, many instances measure MCHC in

percentage In mathematics, a percentage (from la, per centum, "by a hundred") is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%", although the abbreviations "pct.", "pct" and sometimes "pc" are also us ...

(%), as if it were a mass fraction (m_Hb / m_RBC).Blood Test Results - Normal Ranges
Bloodbook.Com. Retrieved on Jan 7, 2009MedicineNet > Definition of MCHC
Last Editorial Review: 7/21/1999 Numerically, however, the MCHC in g/dL and the mass fraction of hemoglobin in red blood cells in % are identical, assuming an RBC

density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...

of 1g/mL and negligible hemoglobin in plasma.

Interpretation

A low MCHC can be interpreted as identifying decreased production of hemoglobin. MCHC can be normal even when hemoglobin production is decreased (such as in iron deficiency) due to a calculation artifact. MCHC can be elevated ("polychromatic") in

hereditary spherocytosis Hereditary spherocytosis (HS) is a congenital hemolytic disorder, wherein a genetic mutation coding for a structural membrane protein phenotype leads to a spherical shaping of erythrocytic cellular morphology. As erythrocytes are sphere-shaped (sp ...

sickle cell disease Sickle cell disease (SCD) is a group of blood disorders typically inherited from a person's parents. The most common type is known as sickle cell anaemia. It results in an abnormality in the oxygen-carrying protein haemoglobin found in red blo ...

and homozygous hemoglobin C disease, depending upon the hemocytometer. MCHC can be elevated in some megaloblastic anemias. MCHC can be falsely elevated when there is agglutination of red cells (falsely lowering the measured RBC) or when there is opacifaction of the plasma (falsely increasing the measured hemoglobin). Causes of plasma opacification that can falsely increase the MCHC include hyperbilirubinemia, hypertryglyceridemia, and free hemoglobin in the plasma (due to hemolysis).

Complicating conditions

Because of the way

automated analyser An automated analyser is a medical laboratory instrument designed to measure different chemicals and other characteristics in a number of biological samples quickly, with minimal human assistance. These measured properties of blood and other fluids ...

s count blood cells, a very high MCHC (greater than about 370 g/L) may indicate the

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...

is from someone with a

cold agglutinin Cold sensitive antibodies (CSA) are antibodies sensitive to cold temperature. Some cold sensitive antibodies are pathological and can lead to blood disorder. These pathological cold sensitive antibodies include cold agglutinins, Donath–Landstei ...

, or there may be some other problem resulting in one or more artifactual results affecting the MCHC. For example, for some patients with cold agglutinins, when their blood gets colder than 37 °C, the red cells will clump together. As a result, the analyzer may incorrectly report a low number of very dense red blood cells. This will result in an impossibly high number when the analyzer calculates the MCHC. This problem is usually picked up by the laboratory before the result is reported. The blood can be warmed until the cells separate from each other, and quickly put through the machine while still warm. There are four steps to perform when a suspect increased MCHC (>370 g/L or >37.0 g/dL) is received from the analyzer: # Remix the EDTA tube—if the MCHC corrects, report corrected results # Incubation at 37 °C—if the MCHC corrects, report corrected results and comment on possible

# Saline replacement: Replace plasma with same amount of saline to exclude interference e.g.

Lipemia Hyperlipidemia is abnormally elevated levels of any or all lipids (fats, cholesterol, or triglycerides) or lipoproteins in the blood. citing: and The term ''hyperlipidemia'' refers to the laboratory finding itself and is also used as an umbre ...

and

Auto-immune antibodies In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an "autoimmune disease". P ...

—if the MCHC corrects, report corrected results and comment on Lipemia # Check the slide for spherocytosis (e.g. in

Interpretation

Complicating conditions

Worked example

See also

References

External links