Moderate and severe thalassemias
are often diagnosed in childhood
because these symptoms usually
appear in the first two years of life.
So what do we do to diagnose
a patient? Well you do a CBC.
This includes a measure of hemoglobin
and the quantity and size of the red blood cells
Patients with thalassemia have fewer healthy red
blood cells and less hemoglobin than normal patients
and those with alpha and beta thalassemia trait may have
smaller than normal red blood cells and these are microcytic.
A reticulocyte count is a measure of
the young red blood cells in circulation
and this can indicate that your bone marrow is not
producing an adequate number of red blood cells.
The RDW may assist in differentiating iron
deficiency and sideroblastic anemia from thalassemia.
The RDW is going to be elevated in more
than 90% of patients with iron deficiency anemia
but this is only seen in about
50% of patients with thalassemia.
An iron panel is next and this is key,
this is where you find your difference.
An iron panel's gonna be performed because this will
differentiate iron deficiency anemia from thalassemia.
These are different conditions and
on a CBC, they can look the same.
The management of the
two conditions is very different.
Next you can do hemoglobin electrophoresis and
this can be used to help diagnose beta thalassemia.
And finally there are genetic test available.
Here we see a CBC, this includes components of
a red blood cell count, the white blood cell count
and you'll also see a differential, this is the
percentage of each type of white blood cell.
You'll get a platelet count, the reticulocyte distribution
width which again is the size of the red blood cells,
hematocrit and this is the red blood cell percentage
for blood volume, and also the hemoglobin.
These are the red blood cell indices that can be
used to describe the red blood cells size and color.
the MCV is the cell size.
We also get the MCHC and this is a ratio.
And next we have the mean cell hemoglobin
and this is the amount of hemoglobin on the cell.
Here we see our indices and
at the bottom you'll see the MCV.
Remember, this is the red blood cell size
and you can describe this in three different ways.
The cell can be microcytic where it's
too small, normocytic is a normal size and
macrocytic, you have this
abnormally large red blood cells.
Next on the top left, you'll see the MCH, remember this is
the amount of hemoglobin in the cell, this provides the color.
If it's hypochromic, means low
color, there is not enough hemoglobin.
If it's normochromic, there's a
normal amount of hemoglobin.
And there's no such thing as hyperchromic, we don't
worry about a cell having too much hemoglobin.
Next we're gonna do an iron panel and remember this is key
in differentiating iron deficiency anemia from thalassemia.
First we'll do the iron level, this is just
the amount of iron carried by transferrin.
We also have the transferrin level and this is a
transport protein used to move iron through the body.
It's produced by the liver and in patients with liver dysfunction,
they're going to have a decreased transferrin production.
Next we have ferritin and this is
the amount of stored iron in the body.
Patients will have an artificially
high ferritin in the settings of infection,
late stage cancer, severe
inflammation and alcoholism.
Now we have the TIBC or total iron binding
capacity, and this is a tricky one to conceptualize.
This is a measure of the open spots for iron to bind,
it's not a measure of the amount of iron that is bound.
So if a patient has a low iron level, they're
going to have a lot of available binding sites
available from where iron's attached.
Here we can compare the differences between
the lab findings of a patient with thalassemia
and a patient with iron deficiency anemia.
remember on a CBC, the two
conditions can initially mimic each other
so the clinician needs to
delve deeper with an iron panel.
In both conditions, the anemia
can range from minor to severe,
In both conditions, a microcytic anemia will be
noted with the cells having a slightly lower MCV
or volume in thalassemia when
compared to iron deficiency anemia
The MCH, both conditions will
reveal a hypochromic cell or a pale cell
Here is the major difference - the serum iron.
In thalassemia, it is increased.
So you want to be sure that you differentiate
this condition from iron deficiency anemia
because the treatment of iron deficiency
anemia is to give your patient iron.
But in a patient with thalassemia, you do not want to add in
any extra iron because that's gonna cause lots of problems.
In iron deficiency anemia, the serum
level is low requiring supplementation.
TIBC, this is also normal
in patients with thalassemia
but it's going to be increased in your
patients with iron deficiency anemia.
Remember this refers to the
open spots available for iron to bind
and a person who is deficient in
iron has a lot of room for more to bind
so this level's going to be increased
in patients with iron deficiency anemia.
The patient with thalassemia already has enough
iron, they don't need anymore open binding spots.
The marrow iron stores, now this has to do a
lot with how much iron is stored in the marrow.
This level is increased in patients with
thalassemia and of course these stores are absent
in patients who are iron deficient because
they don't have any extra iron to stash away.
The serum ferritin, it's gonna be much
higher in a patient with thalassemia.
This is the iron stored in the blood
and this is an easy distinguisher
between the two conditions
when comparing the lab values.
The bilirubin, this level's going to be
increased in patients with thalassemia
as there is increased hemolysis or
the breakdown of the red blood cells.
Bilirubin is a byproduct of this and there's gonna be a normal
level of bilirubin in patients with iron deficiency anemia
because this process is not as destructive.
The RDW, this is short for red blood cell distribution width
and this is a distribution of the sizes of the red blood cells.
This is gonna be normal in
the setting of thalassemia.
In patient with iron dificiency anemia, their
red blood cell sizes are going to vary greatly
so an elevated RDW is the
hallmark of iron deficiency anemia.