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hemoglobin

The mean corpuscular hemoglobin concentration, a measure of the concentration of hemoglobin in a given volume of packed red blood cells. It is reported as part of a standard complete blood count.

It is calculated by dividing the hemoglobin by the hematocrit. Reference ranges for blood tests are 32 to 36 g/dL,^[1] or between 19.9 ^[2] and 22.3^[2] mmol/L. It is thus a mass or molar concentration. Still, many instances^[3]^[4] measure MCHC in percentage (%), as if it were a mass fraction (m_Hb / m_RBC). Numerically, however, the MCHC in g/dL and the mass fraction of hemoglobin in red blood cells in % are identical, assuming a RBC density of 1g/mL and negligible hemoglobin in plasma.

Interpretation

MCHC is diminished ("hypochromic") in microcytic anemias, and normal ("normochromic") in macrocytic anemias (due to larger cell size, though the hemoglobin amount or MCH is high, the concentration remains normal). MCHC is elevated ("hyperchromic") in hereditary spherocytosis, sickle cell disease and homozygous hemoglobin C disease.^[5]

This count is used to give a rough guide to what shade of red erythrocytes will be (i.e., the paler the color the lower the MCHC will be than the standard).

Complications with cold agglutinin

Because of the way automated analysers count blood cells, a very high MCHC (greater than about 370 g/L) may indicate the blood is from someone with a cold agglutinin. This means that when their blood gets colder than 37°C it starts to clump together. As a result, the analyzer may incorrectly report a low number of very dense red blood cells for blood samples in which agglutination has occurred.

This problem is usually picked up by the laboratory before the result is reported. The blood is warmed until the cells separate from each other, and quickly put through the machine while still warm. This is the most sensitive test for iron deficiency anemia.

There are four steps to perform when an increase 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 and Auto-immune antibodies—if the MCHC corrects, report corrected results and comment on Lipemia
Check the slide for spherocytosis (e.g. in hereditary spherocytosis, among other causes)

Worked example

Measure	Units	Conventional units	Conversion
Hct	40%
Hb	100 grams/liter	10 grams/deciliter	(deci- is 10⁻¹)
RBC	5E+12 cells/liter	5E+6 cells/μL	(micro is 10⁻⁶)
MCV = Hct / RBC	8E-14 liters/cell	80 femtoliters/cell	(femto- is 10⁻¹⁵)
MCH = Hb / RBC	2E-11 grams/cell	20 picograms/cell	(pico- is 10⁻¹²)
MCHC = MCH / MCV	250 grams/liter	25 grams/deciliter	(deci is 10⁻¹)

References

^ MedlinePlus Encyclopedia RBC indices
^ ^a ^b Converted with conversion factor from (Wallach, Jacques Burton (2007). Interpretation of Diagnostic Tests. Lippincott Williams & Wilkins. ). 1 g/dL = 0.6206 mmol/L
^ Blood Test Results - Normal Ranges Bloodbook.Com. Retrieved on Jan 7, 2009
^ MedicineNet > Definition of MCHC Last Editorial Review: 7/21/1999
^ Rifkind, David; Cohen, Alan S. (2002). The Pediatric Abacus. Informa Healthcare. p. 54. ISBN 1-84214-147-3.

External links

FP Notebook
Cornell

UpToDate Contents

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1. 貧血を有する成人患者に対するアプローチ approach to the adult patient with anemia
2. 成人における鉄欠乏性貧血の原因および診断 causes and diagnosis of iron deficiency anemia in the adult
3. αサラセミアの病態生理 pathophysiology of alpha thalassemia
4. 健常者および患者における胎児性ヘモグロビン（ヘモグロビンF） fetal hemoglobin hemoglobin f in health and disease
5. 乳幼児における鉄欠乏：スクリーニング、予防、臨床症状、および診断 iron deficiency in infants and young children screening prevention clinical manifestations and diagnosis

English Journal

Effects of Acute Exposure to Endosulfan (Organochlorine Pesticides) on Hematology of African Mud Catfish, Clarias gariepinus (Burchell, 1822).

Ndimele PE1, Jenyo-Oni A, Kumolu-Johnson CA, Chukwuka KS, Onuoha S.
Bulletin of environmental contamination and toxicology.Bull Environ Contam Toxicol.2015 Aug;95(2):164-70. doi: 10.1007/s00128-015-1504-x. Epub 2015 Mar 1.
Changes in the blood parameters of fingerlings of Clarias gariepinus were investigated after 24 and 96-h of exposures to endosulfan. 180 fingerlings of C. gariepinus [mean weight (10.5 ± 1.3 g); total length (11.2 ± 1.2 cm)] were exposed to five different concentrations (1.00, 2.20, 4.80, 11
PMID 25726008

Effect of fishmeal replacement by soy protein concentrate with taurine supplementation on growth performance, hematological and biochemical status, and liver histology of totoaba juveniles (Totoaba macdonaldi).

López LM1, Flores-Ibarra M, Bañuelos-Vargas I, Galaviz MA, True CD.
Fish physiology and biochemistry.Fish Physiol Biochem.2015 Aug;41(4):921-36. doi: 10.1007/s10695-015-0058-5. Epub 2015 Apr 22.
The effect of dietary inclusion of soy protein concentrate (SPC) and simultaneous supplementation with taurine on the growth, hematology, blood biochemistry, and liver histology of totoaba (Totoaba macdonaldi) juveniles was assessed. Four isoproteic and isolipidic diets were formulated containing ei
PMID 25899616

A novel (A)γδβ(0)-thalassemia caused by DNA deletion-inversion-insertion of the β-globin gene cluster and five olfactory receptor genes: Genetic interactions, hematological phenotypes and molecular characterization.

Singha K1, Fucharoen G2, Hama A3, Fucharoen S4.
Clinical biochemistry.Clin Biochem.2015 Jul;48(10-11):703-8. doi: 10.1016/j.clinbiochem.2015.03.023. Epub 2015 Apr 9.
OBJECTIVE: To report the phenotypes and genetic basis of a novel (A)γδβ(0)-thalassemia found in Thai individuals with several forms of thalassemia.DESIGNS AND METHODS: An initial study was done in an adult Thai woman who had hypochromic microcytic red cells with unusually 100% Hb F. Extended stud
PMID 25866400

Japanese Journal

P19 アゾピリジニウム塩色素/ポリアクリル酸水溶液の吸収スペクトルへの超音波効果(Poster Session)

祝懐瑞,周衛民,多賀谷基博,小林高臣
ソノケミストリー討論会講演要旨集 (21), 59-60, 2012-11-09
… Hypochromic effect indicated that external stimuli of US influenced the aggregation of superstructures of amphiphilic azopyridinium salt in aqueous PAA environment. …
NAID 110009710737

外部刺激に応答する金属錯体の自己集合とそのダイナミックな構造制御

黒岩敬太
高分子論文集 69(8), 485-492, 2012-08-25
NAID 10031009572

Physiological Responses of Erythrocytes of Goats to Transportation and the Mondulatory Role of Ascorbic Acid

Minka Ndazo Salka,Ayo Joseph Olusegun
Journal of Veterinary Medical Science 72(7), 875-881, 2010
… The obtained results showed that handling, loading and transportation of the control goats induced significant (P<0.05) increases in RBC, Hb, EOF and hypochromic erythrocytes and a decrease (P<0.05) in the volume and average Hb content in RBCs. …
NAID 130000264285