Red blood cell indices
Red blood cell indices are blood tests that provide information about the hemoglobin content and size of red blood cells. Abnormal values indicate the presence of anemia and which type of anemia it is.[1]
Red blood cell indices | |
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Purpose | information about the hemoglobin content and size of red blood cells |
Mean corpuscular volume
Mean corpuscular volume (MCV) is the average volume of a red blood cell and is calculated by dividing the hematocrit (Hct) by the concentration of red blood cell count.
- Normal range: 80–100 fL (femtoliter)
Mean corpuscular hemoglobin
Mean corpuscular hemoglobin (MCH) is the average amount of hemoglobin (Hb) per red blood cell and is calculated by dividing the hemoglobin by the red blood cell count.
- Normal range: 27-31 pg/cell
Mean corpuscular hemoglobin concentration
Mean corpuscular hemoglobin concentration (MCHC) is the average concentration of hemoglobin per unit volume of red blood cells and is calculated by dividing the hemoglobin by the hematocrit.
- Normal range: 32-36 g/dL
Red blood cell distribution width
Red blood cell distribution width (RDW or RDW-CV or RCDW and RDW-SD) is a measure of the range of variation of red blood cell (RBC) volume, yielding clues about morphology.
Erythropoietic precursor indices
The reticulocyte production index (RPI) or corrected reticulocyte count (CRC) represents the true significance of the absolute reticulocyte count to provide some reflection of erythropoietic demand and supply. The immature reticulocyte fraction (IRF) goes a step further to cast more light on the same question.
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/100) / 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 = Hb / (Hct/100) | 250 grams/liter | 25 grams/deciliter | (deci is 10−1) |