Mean Corpuscular Volume (MCV)

Sample for Mean Corpuscular Volume (MCV)

1. The best sample is EDTA blood.
2. Stable for 6 hours at 25 °C  and 24 hours at 4 °C.
3. Fetal blood is collected percutaneous from the umbilical area.

Indications for Mean Corpuscular Volume (MCV)

1. This is one of the blood indices.
2. This is done to classify and diagnose anemia.
3. It is a useful screening test for occult alcoholism.

Definition of Mean Corpuscular Volume (MCV)

• It represents an average measurement of RBC volume varying from 82 to 98 fL.
• Mean Corpuscular Volume (MCV) is manually calculated as hematocrit divided by RBC count.
• It can be measured directly by the automated instrument.

Mean Corpuscular Volume (MCV) facts

1. Mean Corpuscular Volume (MCV) measures the average volume or size of a single RBC.
2. MCV indicates the volume occupied by a single RBC and is measured in a cubic micrometer of the mean volume.
   1. Cubic micrometer = femtoliter ( fL ).
3. MCV helps to classify various anemias.

• Macrocytic RBC:
  • When the RBC size is larger than normal, more than 100 fL.
• Microcytic RBC:
  • When the RBC size is small than normal, less than 82 fL.

NORMAL Mean Corpuscular Volume (MCV)

Source 1

Source 2

• Adult = 80 to 95 fL.
• Newborn = 96 to 108 fL

Increased Mean Corpuscular Volume (MCV):

Macrocytic anemia:

1. B12 or folic acid deficiency :
   1. Decreased ingestion.
      1. Laking animal protein.
      2. Vegetarians.
   2. Impaired absorption.
      1. Intrinsic factor deficiency.
      2. Abnormal intrinsic factor molecule.
      3. Patient with partial or total gastrectomy.
      4. Ileal resection.
      5. Sprue.
      6. Celiac disease.
      7. Intestinal lymphoma.
      8. Drug-induced malabsorption.
2. Parasitic infestation.
   1. Diphyllobothrium latum.
   2. Infected diverticula.
   3. Blind loop.
3. Increased requirement.
   1. Pregnancy.
   2. Malignancies.
   3. Hyperthyroidism.
   4. Chronic pancreatic disease.

Mean corpuscular volume (MCV): Macrocytic RBCs and hypersegmented polys.

Decreased Mean Corpuscular Volume (MCV):

Microcytic anemias are seen in:

1. Iron metabolism-related.
   1. Iron deficiency anemia.
   2. Decreased dietary intake.
   3. Malabsorption.
   4. Increased iron loss.
   5. Increased body requirements for iron.
   6. Congenital hypochromic microcytic anemia.
   7. Anemias of chronic diseases.
2. A defect in heme synthesis.
   1. Idiopathic refractory sideroblastic anemia.
   2. Acquired sideroblastic anemia.
   3. Hereditary sideroblastic anemia.
   4. Autosomal anemia ( X chromosome-linked ).
3. Disorder of globin synthesis.
   1. Thalassemia.
   2. Hemoglobinopathies.

Mean Corpuscular Volume (MCV) increased in:

1. Pernicious anemia (vit.B12 deficiency).
2. Folic acid deficiency.
3. Liver diseases.
4. Alcoholism.
5. Antimetabolic therapy.

Mean Corpuscular Volume (MCV) decreased in:

1. Thalassemia.

2. Iron deficiency anemia.