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

hemoglobin Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobin ...

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 nor ...

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 chemis ...

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 the number of moles of solute per liter of solution. Specifically, It is a measure of the concentration of a chemical species, in particular, of a so ...

. Still, many instances measure MCHC in

percentage In mathematics, a percentage () is a number or ratio expressed as a fraction (mathematics), fraction of 100. It is often Denotation, denoted using the ''percent sign'' (%), although the abbreviations ''pct.'', ''pct'', and sometimes ''pc'' are ...

(%), 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 ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

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 ("hyperchromic") in

hereditary spherocytosis Hereditary spherocytosis (HS) is a congenital hemolytic disorder wherein a genetic genetic mutation, mutation coding for a structural membrane protein phenotype causes the red blood cells to be sphere-shaped (spherocytosis), rather than the norma ...

sickle cell disease Sickle cell disease (SCD), also simply called sickle cell, is a group of inherited Hemoglobinopathy, haemoglobin-related blood disorders. The most common type is known as sickle cell anemia. Sickle cell anemia results in an abnormality in the ...

and

homozygous hemoglobin C disease Hemoglobin C (abbreviated as HbC) is an abnormal hemoglobin in which glutamic acid residue at the 6th position of the HBB, β-globin chain is replaced with a glycine residue due to a point mutation in the ''Human β-globin locus, HBB'' gene. Peopl ...

, 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 count) or when there is opacification of the plasma (falsely increasing the measured hemoglobin). Causes of plasma opacification that can falsely increase the MCHC include hyperbilirubinemia, hypertriglyceridemia, 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 various substances 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 37.0 g/dL) 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 is com ...

is from someone with a cold agglutinin, 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 cold agglutinin # Saline replacement: Replace plasma with same amount of saline to exclude interference e.g.

Lipemia Hyperlipidemia is abnormally high levels of any or all lipids (e.g. fats, triglycerides, cholesterol, phospholipids) or lipoproteins in the blood. citing: and The term ''hyperlipidemia'' refers to the laboratory finding itself and is also use ...

and Auto-immune antibodies—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