PLT disorders

von Willebrand disease (AD)

-adhesion disorder (PLTs normal, just can’t adhere)

-PLTs unable to adhere to sub endothelium (collagen)

-secondary deficiency of VIII complex activity

-mucocutaneous bleeding

-prolonged aPTT

-abnormal PLT function screen (adhesion)

-normal count

-abnormal aggreg with ristocetin

-treat with: cryoprecipitate or desmopressin acetate

cryoprecipitate

-concentrated blood product with good vWF

-treatment for von Willebrand’s disease in hospital/emergency settings

desmopressin acetate (DDAVP)

-stimulates vWF from endothelial cells

-treatment for von Willebrand’s disease

Bernard Soulier syndrome (AR)

-adhesion disorder

-large PLTs

-GPIb/IX/V deficiency

-mod dec PLT count

GPIb/IX/V

deficiency in Bernard Soulier syndrome

Glanzmann’s Thromboplasthenia (AR)

-aggreg disorder

-GPIIb/IIIa deficiency/lack (altered fibrinogen binding)

-minor bruising to severe hemmorhage

-normal PLT count

-abnormal aggreg

-dec/no clot retraction

GPIIb/IIIa

deficiency in Glanzmann’s thromboplasthenia

disseminated intravascular coagulation (DIC)

-thrombocytopenia

-systemic activation of coagulation → not localized

-stage I: inc thrombin and fibrin → clotting → organ damage and failure

-stage II: factors depleted → thrombocytopenia and bleeding

-caused by sepsis, toxins, trauma, burns, leukemias

-severe bleeding, bruising, organ failure

-prolonged PT, aPTT, TT

-inc schists, FDPs, fibrin monomers

-dec fibrinogen and PLTs

-MAHA with prolonged coag tests

all

prolonged tests in DIC

fibrinogen, PLTs

decreased in DIC

thrombotic thrombocytopenia purpura (TTP)

-ADAMTS13 deficiency

-dec PLTs

-females over 40, preg, drugs, autoimmune disease

-neuro changes and bleeding problems, fever, weakness, MAHA, poik, NRBCs and retics, schists

-MAHA with normal coag tests

-plasmapherisis

hemolytic uremic syndrome (HUS)

-children

-kidneys only organ affected

-MAHA assoc with E. coli and shigella

-fluids, transfusion, dialysis

acute idiopathic thrombocytopenia purpura (ITP)

-autoAb to PLTs 

-splenic destruction

-children 2-5

-after virus and most spont remission

-BM megakaryocytic hyperplasia

-large PLTs, dec lifespan

-PLT-assoc IgG

-PLTs <20

-treat with IVIg and corticosteroids

<20

amount PLTs in acute ITP

chronic ITP

-20-40 yrs

-dec PLTs (<30-80)

-splenic sequestration and lysis

-unknown

-bleeding and bruising

-dec PLT lifespan

-treat: splenectomy, corticosteroids

<30-80

PLTs in chronic ITP

thrombin excess

issue in DIC

endothelial defect

issue in TTP

antiPLT Ab

issue in acute ITP