HEMA 2 - PLATELET DISORDERS Flashcards
platelets are produced predominantly by the ______ as a result of budding of the _____
Bone Marrow Megakaryocytes ; Cytoplasmic Membrane
Megakaryocytes are derived from the _______, which is stimulated to differentiate to mature megakaryocytes under the influence of various cytokines including ___________.
Hemopoietic Stem Cells ; Thrombopoietin
disorders of platelet adhesion - deficiency of glycoprotein Ib/IX
bernard-soulier syndrome
disorders of platelet aggregation - deficiency of glycoprotein IIb/IIIa
glanzmann-thrombasthenia
disorders of platelet secretion
alpha or dense granules deficiency
platelets fail to promote activation of the blood clotting proteins
disorders of platelet procoagulant activity
acquired platelet function disorders, drug like …
drugs like aspirin, non-steroidal anti-inflammatory drugs like indomethacin, ibuprofen.
congenital abnormalities of platelets can be divided into _________ and those of _________
disorders of platelet production ; platelet function
congenital abnormalities all are very _____
rare
In general they cause moderate to severe bleeding problems.
Congenital abnormalities
- an autosomal recessive preleukemic condition which often presents as thrombocytopenia with skeletal or genitourinary abnormalities.
Fanconi’s Anemia
Congenital abnormalities lab features
- Abnormal chromosomal fragility.
- The condition can be cured with bone marrow transplantation (BMT)
rule out pseudotrhombocytopenia
- sequestration
- production
- destruction
look for splenomegaly
sequestration
causes of splenomegaly (sequestration)
- infection
- inflammation
- congestion
- malignancy
- red cell disorders
- storage disorders
bone marrow investigation review meds
production
included in production - bone marrow investigation review meds
- aplasia
- infiltration
- ineffective megakaryopoiesis (e.g MDS)
- selective impairment of platelet production
look for underlying disorders review meds
destruction
included in destruction - bone marrow investigation review meds
- immune auto-immune (ITP, SLE) rugs infection allo-immune
- none-immune seosis DIC, TTP, HUs hypertensive disorders of pregnancy
also included in approach to thrombocytopenia
artefactual (false) or pseudothrombocytopenia and congenital thrombocytopenia
clot in the sample and platelets clumped
artefactual (false) or pseudothrombocytopenia
rare inherited disorders (e.g may hegglin anomaly)
Congenital Thrombocytopenia
platelet count is less than 100,00 cu mm =
thrombocytopenia
Platelet count <50,000
variable risk