Mentzer index more than 13 suggests a
a) Iron deficiency anemia
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
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
If the Mentzer Index is greater than 13, Then iron-deficiency anemia
is said to be more likely.
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.
count > 13 < 13
MCH x 0.01 > 1530 < 1530
MCV – RBC
- (5 x Hb)
0 < 0
index MCH/RBC > 3.8 < 3.8
65 < 65
RDW/RBC > 220 < 220