10b- Intro to Hemostasis- Bleeding Disorders Flashcards
What are 5 defects in primary hemostasis?
- skin and mucosal membrane hemorrhages are common (eg petechiae, epistaxis, menorrhagia)
- Vascular abnormalities (eg Ehlers-Danlos)
- Platelet function disorders
- von Willebrand disease
What are 3 defects in secondary hemostasis?
- bleeds into soft tissues or joint
- clotting factor deficiencies
- hemophilia
- liver disease
- exogenous
- anticoagulants
What is thrombocytopenia? What 4 things are also on the differential diagnosis?
- usually defined as <100,000/uL
- Differential
- decreased bone marrow: aplastic anemia
- increased destruction (immune mediated, non-immune mediated)
- dilutional: decreased platelets bc increased fluid
- sequestration: big spleen harbors platelets
Thrombocytopenia is decreased platelets due to decreased _______
What 7 things cause thrombocytopenia?
Thrombocytopenia is decreased platelet production due to decreased megakaryocytes
- aplastic anemia
- vitamin B12/folate deficiency
- leukemia, lymphoma, MDS
- metastatic carcinoma
- alcohol, toxins
- drugs
- infections
Thrombocytopenia caused by increased destruction can be immune mediated or non-immune mediated? What are 4 examples of immune mediated thrombocytopenia?
immune thrombocytopenia purpura (ITP)
Heparin-induced thrombocytopenia (HIT)
Transfusion/preganncy-associated allo-immune thrombocytopenia
drug (quinine, vancomycin)
What are 4 non-immune mediated causes of thrombocytopenia?
Disseminated intravascular coagulation (DIC)
Thrombotic thrombocytopenic purpura (TTP)
Hemolytic uremic syndrome (HUS)
Drug
WHat is Immunt Thrombocytopenia Purpura (ITP)
Caused by autoantibodies made against PLT antigens (GpIIb/IIIa, GpIb)
destruction of PLTs occurs by phagocytosis, Fc receptor mediated, loction is the spleen
What are the 2 categories of immune thrombocytopenia purpura (ITP)
- Primary: unknown etiologies
- Secondary: diseases we can identify
- lupus
- leukemia/lymphoma (eg CLL/SLL)
- Drugs
- Viruses (eg HIV, Hepatitis)
What are the clinical features of Immune Thrombocytopenia Purpura (ITP)? WHat are the 2 variant/the difference between them?
- skin, mucosal bleeds
- normal size spleen
- variants:
- Acute: self limited (< 6 months, post-viral, children)
- Chronic: adults (females), persistent>6 months
What are the pathologic findings of ITP?
Thrombocytopenia (often quite low), large platelets (circled)
normal to increased megakaryocytes in marrow
white pulp expansion
How do we diagnose ITP?
presumptive
iagnosis of exclusion
no diagnostic test
normal clotting tests
bone marrow not required
How do we treat ITP?
- May not be needed in children with self-limited disease
- immunosuppresant therapy
- steroids, intravenous immunoglobin (IVIG)
- Anti-CD20 antibody
- Thrombopoietin agonist
- Splenectomy
What happens in drug-induced thrombocytopenia?
drug binds to IIa/IIIb to elicit antibody reaction.Phagocytic cells then localize to the antibody and destroy the platelet
What is dilutional thrombocytopenia? Sequestration thrombocytopenia?
Dilution: Massive transfusion of trauma patients
Sequestration: Seen with hypersplenism, increased storage fo Platelelets
What are platelet function disorders? List 5
heterogenous group of inherites and acquired, qulitative disorders with variable clinical presentation
Bernard Soullier
Glanzmann’s thrombasthenia
Storage pool disease
Aspirin
Uremia
What is the pathophysiology of Bernard Soullier?
Inherited vs acquired
Clinically severe or variable?
Gp1b deficiency on platelet memebrane
inherited
severe