Mean cell volume

Keywords: MCV, Erythrocyte mean corpuscular volume

Specimen:

5 mL blood in EDTA tube.

Method:

Part of Full blood count; measured by most automated and semi-automated instruments (some provide red cell size distribution curves).

Arithmetically, MCV is Haematocrit (Hct or PCV) divided by RCC (red cell count).

Reference Interval:

Refer to laboratory – guide only provided below:

Term infant cord blood (mean): 106 fL

Child:         

3 months (mean): 95 fL

1 year: 70-86 fL

3-6 years: 73-89 fL

10-12 years: 77-91 fL

Adult: 80-100 fL.

Application:

Guide to investigation of Anaemia; Blood film should also be requested.

Interpretation:

Macrocytosis (high MCV) is found in megaloblastic, aplastic, dyserythropoietic and sideroblastic anaemias; Myelodysplastic syndromes, myeloma; Liver disease, alcohol excess; chronic hypoxic lung disease; myxoedema; following renal transplant; cytotoxic drug therapy particularly hydroxyurea, therapy with Zidovudine (AZT); and some rare metabolic disorders.

A reticulocytosis may be associated with a mild increase in MCV.

Microcytosis (low MCV) is found in iron deficiency anaemia, some cases of anaemia of chronic disease, haemoglobinopathies (especially the Thalassaemias), lead toxicity, congenital sideroblastosis and rare red cell enzyme deficiencies.

See also Red cell distribution width.

Reference:

Bain et al. Dacie and Lewis Practical Haematology. 11th Ed. 2012.

Bain BJBlood cells: a practical guide. 4th Ed. 2007. Oxford: Blackwell Publishing.