Mentzer index more than 13 suggests a

diagnosis of

a) Iron deficiency anemia

b) Thalassemia

c) Hereditary Spherocytosis

d) Autoimmune Hemolytic Anemia

Correct Answer - A

Ans. is ‘a’ i.e., Iron deficiency Anemia

Mentzer index more than 13 suggests a diagnosis of Iron-deficiency

anemia.

Mentzer index

The Mentzer index is used to help in differentiating iron deficiency

anemia from beta thalassemia.

The index is calculated as the quotient of the mean corpuscular

volume (MCV, in fL) divided by the red blood cell count (RBC, in

millions per microleter).

If the Mentzer index is less than 13, thallassemia is said to be more

likely.

If the Mentzer Index is greater than 13, Then iron-deficiency anemia

is said to be more likely.

Principle

In iron deficiency, the marrow cannot produce as many RBCs and

they are small (imcrocytic), so the RBC count and the MCV will both

be low, and as a result, the index will be greater than 13.

Conversely, in thalassemia, which is a disorder of globin synthesis,

the number of RBCs produced is normal, but the cells are smaller

and more fragile. Therefore, the RBC count is normal, but the MCV

is low, so the index will be less than 13.

n practice, the Mentzer index is not a reliable indicator and should

not, by itself be used to differentiate the two conditions.

Index Formula

Value for

iron

deficiency

anemia

Value for

iron

thalassemia

Mentzer

index

MC V/RBC

count > 13 < 13

Shine and

Lal index

MCV2 x

MCH x 0.01 > 1530 < 1530

England and

Fraser index

MCV – RBC

- (5 x Hb)

5.19

0 < 0

Srivastava

index MCH/RBC > 3.8 < 3.8

Green and

king index

MCV2 x

RDW x

Hb/100

65 < 65

Red cell

distribution

width index

MCV x

RDW/RBC > 220 < 220