Immune Thrombocytopenic Purpura, as the name implies, it is an autoimmune disease.
The type of hypersensitivity in which the autoantibodies such as IgG
may then attack the glycoproteins on a platelet.
So what does that mean to you?
You are not attacking the glycoproteins way back in the bone marrow.
Keep it separate now.
So as I had referred to earlier,
you wanna keep the two compartments separate because of diagnostic purposes.
If it was aplastic anemia or if it was myelophthisic anemia due to infiltration,
then the bone marrow has been compromised, correct?
So the megakaryocyte itself is not developing properly
resulting in thrombocytopenia or in this case, in peripheral circulation,
not in the bone marrow, we have these autoantibodies that are then attacking the glycoproteins,
could be either Ib. Picture that.
What was that binding to?
Von Willebrand factor, or IIb/IIIa, that was binding to your fibrinogen or fibrin.
If then, you had this autoantibodies that are attacking these glycoproteins, then guess what?
You don't have proper functioning platelets.
Welcome to Immune Thrombocytopenic Purpura.
You may then consume your platelets resulting in purpura
and you also have the spleen which will get involved.
So these new, well, these abnormal platelets will then be taken to the spleen
for destruction resulting in thrombocytopenia.
Welcome to ITP.
Now, as simple as it may seem in terms of pathogenesis,
the symptoms could be quite difficult,
so this often times ends up being a diagnosis of exclusion, as we shall see.
Let's take a look at the clinical presentation of immune thrombocytopenic purpura.
As we get older, each one of us can look forward to bruise easily.
In a patient's ITP or who may suffer from ITP, patient may also suffer from bruising easily.
However, more symptoms will be given.
Superficial bleeding may be taking place in the skin.
Look for pinpoint petechia and also purpura that might be taking place in lower extremities.
We are going to be dividing ITP into acute and chronic.
Acute will occur more commonly in children.
Self-limited as we shall see.
Whereas because this is immune, then the gender in an adult
would be more commonly found in woman.
So therefore, not only would that be prolong bleeding from the cuts,
we talk about increase in bleeding time, spontaneous bleeding from the gums,
bleeding in to the urine or stool, and if it's a lady,
when she's then having her menses, she may have increase menstrual flow.
So now you should be thinking about two situations
in which there would be an increase in menstrual flow.
One would be von Willebrand disease but that's completely different.
We talk about how there might be an increase in bleeding time
but then also an increase in PTT because of the lack of let's say von Willebrand factor.
That's the one that you definitely wanna know as being more common.
In ITP though, remember, these are autoantibodies attacking glycoprotein.
And profuse bleeding taking place during surgery,
difficult, difficult to know that your patient may have ITP prior.
So that will be, a rather unfortunate situation.
But acute ITP is seen more commonly in children often following viral
and luckily within 6 months is self-limited.
If its chronic ITP, then in terms of adults, it would be woman affected more
so remember, in general, immune diseases affect women more commonly than men.
Gradual onset of petechia, ecchymoses.
So it started out small and the bleeding gets larger.
Diagnosed by thrombocytopenia and in your bone marrow,
you're gonna find normal megakaryocyte. Why?
Because once again, these autoantibodies are attacking the glycoproteins
on the surface of the platelet membrane, not the bone marrow.
Treatment maybe IVIg and if counts are less than 50,000.
Remember, normal, lower limit, is at least 150,000, so that's pretty significant drop.
And you may have the spleen which may undergo splenomegaly
and so therefore, splenectomy may at times be recommended.