Mean Corpuscular Volume (MCV), Mean Cell Volume

Sample

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

Indication

1. This is one of the blood indices.
2. This is done to diagnose anemia.

Pathophysiology

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

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

NORMAL

Source 1

Age	fL
Fetal blood
18 to 20 weeks	133.9 ± 8.8
21 to 22 weeks	130.1 ± 6.2
23 to 25 weeks	126.2 ± 6.2
26 to 30 weeks	118.2 ± 5.8
Infants and Child
Cord blood	98 to 118
0.5 month	88 to 140
0ne month	91 to 112
2 month	84 to 106
4 month	76 to 97
6 month	68 to 85
9 month	70 to 85
12 month	71 to 84
0.5 to 2 year	70 to 84
2 to 5 year	73 to 85
5 to 9 year	75 to 87
9 to 12 year	76 to 90
	Male	Female
12 to 14 year	77 to 94	73 to 95
15 to 17 year	79 to 95	78 to 98
18 to 44 year	80 to 99	81 to 100
45 to 64 year	81 to 101	81 to 101
65 to 74 year	81to 103	81 to 102

Source 2

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

Macrocytic anemias are seen in:

1. B12 or folic acid deficiency :
   1. Decreased ingestion.
      1. lake 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.

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.

MCV increased in:

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

MCV decreased in:

1. Thalassemia.

2. Iron deficiency anemia.
   

   Iron deficiency anemia picture

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