Immune Thrombocytopenia vs Thrombotic Thrombocytopenic Purpura Flashcards
What is the epidemiology of ITP?
Mostly self-limiting in children but is chronic relapsing in adults
What is the pathogenesis of ITP?
Destruction of platelets by autoantibodies
What are the clinical presentations of ITP?
Small red/purple spots on mucosal membranes, skin, retina, conjunctiva, mucocutaneous bleeding from gums, nose (epistaxis), females have heavy periods
What does a peripheral blood film show in ITP?
Abnormal platelets and all other cells normal
What does a bone marrow biopsy show in ITP?
High number of megakaryocytes
What does FBC show in ITP?
Thrombocytopenia
What are the results of lab coagulation screens in ITP?
PT, APTT, TT are within normal range
What is the epidemiology of TTP?
Usually affects 20-50 yr olds and is more common in women, life-threatening disease in children and adults
What is the pathogenesis of TTP?
Congenital/acquired absence/decrease of the von Willebrand factor-cleaving protease ADAMTS13: Microthrombi formation
What is the classic pentad of symptoms in TTP?
- Fever
- Anaemic symptoms (due to Microangiopathic Haemolytic Anaemia (MAHA))
- Renal impairment
- Fluctuating neurological signs
- Bleeding/bruising easily (due to thrombocytopenia)
What does a blood film show in TTP?
Schistocytes, poikilocytes (occur in MAHA)
What does FBC show in TTP?
Thrombocytopenia, elevated unconjugated bilirubin, elevated LDH, elevated reticulocyte count, decreased haptoglobin concentration
What are the results of lab coagulation screens in TTP?
- PT normal/increased
- APTT normal/increased
- Fibrinogen and antithrombin levels normal
- FDP/D-Dimer level elevated
What is Evan’s syndrome?
ITP occurs with warm AIHA.
What is the treatment for ITP?
Corticosteroids with/without IV immunoglobulins.
What are the diagnostic methods for TTP?
Pentad of symptoms and blood film findings.
Can also do ADAMTS13 activity, functional inhibitor, and anti-ADAMTS13 antibody assays.
What is the treatment for TTP?
Plasma exchange with high-dose corticosteroid therapy.
Why is TTP considered a haematological emergency?
Due to infarction in the microcirculation in the brain, heart, and kidney, which can be fatal.
What is thrombocytopenia?
Platelet count below normal range
What causes underproduction of platelets?
Drugs affecting haematopoietic stem cell, liver damage reducing TPO synthesis, part of pancytopenia due to failed stem cell or unhealthy microenvironment
What conditions can lead to reduced survival of platelets?
Conditions affecting peripheral circulation
What autoimmune condition causes Immune Thrombocytopenia (ITP)?
Autoimmune conditions
What is hypersplenism?
An overactive spleen that causes most of the platelet mass to be kept in the spleen
What drugs can affect platelet survival?
NSAIDs, penicillin, furosemide
