Bernard Soulier syndrome

Discussion in 'Step I' started by medstu2006, May 18, 2008.

  1. medstu2006

    medstu2006 Senior Member
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    According to FA, the platelet count in Bernard Soulier syndrome is decreased. Does anyone know why?
     
  2. obiwan

    obiwan Junior Member
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    I always thought that bernard syndrome would have normal platelet counts, its just the bleeding time that would be abnormal b/c of the impaired binding to the endothelium.
     
  3. ROBINHO

    ROBINHO Junior Member
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    Decreased Life Span due to Qualitative defect?
     
  4. medstu2006

    medstu2006 Senior Member
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    In Glanzmann and Bernard Soulier the bleeding time is increased, but only in Bernard Soulier is the platelet count dec. So im not sure if it's due to a qualitative defect. I dont think Goljan even mentioned about the dec platelet count in Bernard Soulier.
     
  5. DOCTORSAIB

    DOCTORSAIB Ophtho or bust!
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    The thrombocytopenia in BS syndrome is generally mild.

    They haven't really figured out why though.

    And you see abnormally LARGE platelets on peripheral smear.
     
  6. LUBDUBB

    LUBDUBB Freakaholic
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    DOCTORSAIB, you are right.

    Bernard-Soulier is a defect in platlet adhesion glycoprotein, the one that can bind to vWB, therefore BS and vWD both giive you a failed ristocetin assay. However, in BS, the ristocetin is not corrigible with addition of normal FVIII/vWB.

    The variable thrombocytopenia has been hypothesized to be either an inherent decrease in platelet lifecycle or ineffective thrombopoiesis.

    Clinically, BS shows heterogeneity; variants include an antibody-mediated (against the glycoprotein receptor), called pseudo-bernard soulier. And even a case associated with Gaucher's Dz, which presented with a BS-like picture, including abnormal ristocetin. It was found patient had intact GPIb receptor and no antibodies detected. This was termed pseudo-pseudo-Bernard-Soulier.

    Glanzmann's dz is a defect in platlet GP IIb/IIIa, for aggregation. Variants have also included an antibody-mediated type.
     

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