Immune thrombocytopenia

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Introduction0:00–0:19

Immune thrombocytopenic purpura or ITP is an autoimmune condition in which the body produces antibodies against its own thrombocytes or platelets, which are destroyed.
And this result in purpura, or small bleeding spots beneath the skin. Normally, when there’s any kind of damage to the blood vessel, hemostasis occurs, which is the process that stops the bleeding and plugs the damaged vessel to limit the blood loss.

Physiology0:19–1:10

And there are two steps: primary and secondary hemostasis. During primary hemostasis, platelets aggregate to form a plug at the site of an injured blood vessel.
Platelet aggregation is mediated by surface proteins found on platelets, called GP2B3A receptors. While these platelets are aggregating, secondary hemostasis kicks in.
Secondary hemostasis is also called coagulation, because that’s when clotting factors come into play one after another, with a view to cleaving fibrinogen into fibrin.
Then, fibrin forms a protein mesh, kinda like a giant net that covers the platelet plug and stabilizes it. Now, in ITP, the spleen produces certain IgG autoantibodies which bind to the platelet receptor Gp2B3A, and target the platelet-antibody complexes for destruction in the spleen.

Pathology1:10–2:01

This leads to lowering of platelet counts in the blood, which makes it harder for bleeding to stop. Now, ITP can be acute or chronic.
Acute ITP usually affects children, a couple of weeks after a viral infection, and resolves spontaneously within two months.
Chronic ITP usually affect females of reproductive age, and persist more than six months. Chronic ITP can also be primary, when it occurs without an underlying trigger, or secondary, when it’s triggered by another condition like hepatitis C, HIV, or lupus.
Most of the time, ITP is asymptomatic. In some cases, it can cause purpura, which are red or purple spots on the skin, measuring 0.3 to 1 cm in diameter.

Symptoms2:01–2:25

In severe cases of ITP, when platelet levels get very low, there may be frequent mucosal bleeding, which most commonly presents as epistaxis, meaning nose bleeds.ITP is a diagnosis of exclusion, so there’s no specific test that confirms the diagnosis.
Interestingly, the CBC usually shows isolated thrombocytopenia, with a normal hematocrit and leukocyte count. Now, in some cases, if there’s significant bleeding, that can lead to anemia.

Diagnosis2:25–2:56

An abdominal ultrasound is often done to rule out splenomegaly, and hepatitis C virus and HIV testing are done to rule out secondary ITP.
Individuals with secondary ITP are treated for their underlying condition, while treatment of primary ITP depends on the platelet count and symptoms.
Asymptomatic patients with a platelet count over 30,000 can be observed, and often recover on their own. Patients with an active bleed or those with a platelet count below 30,000 are usually started either on corticosteroids or on intravenous immunoglobulin, or IVIG for short.

Treatment2:56–3:47

Corticosteroids act as immunosuppressants, and IVIG has an immunomodulatory effect - both of them help stop the formation of new autoantibodies.
In individuals who don’t respond to steroids; a splenectomy can be done to get rid of the splenic macrophages that are destroying the platelets.
Finally, transfusing platelets can be done when platelet count is less than 10,000.All right, as a quick recap, ITP is a condition where the spleen produces IgG antibodies against platelet receptor Gp2B3A, which leads to destruction of platelets.
Acute ITP lasts for less than 2 months, and usually affects children. Chronic ITP lasts more than 6 months, and usually affects females of reproductive age.

Review3:47–4:28

Most of the time there are no symptoms, but sometimes individuals with ITP can have purpura, or even nosebleeds in some severe cases.
In general, asymptomatic ITP resolves on its own, but severe cases are treated with corticosteroids or intravenous immunoglobulin.
the time there are no symptoms but sometimes individuals with ITP can have purpura or even nosebleeds In some severe cases In general asymptomatic ITP resolves on its own But severe cases are