Ristocetin test

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MudPhud20XX

Full Member
10+ Year Member
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Alright so I just know that Ristocetin test is negative whicm means no agglutination for both vWF and BS syndrome.

My understanding of Ristocetin test is that you get no agglutination if your GpIb is absent or dysfunction (as in BS syndrome), so why would you get negative (no agglutination) Ristocetin test result for vWF?

Many thanks inadvance.
 
To my understanding to differentiate the two, you would then need to add normal Serum (vWF), if it then adheres it was a vWF problem. If no adhesion you then add platelets, and if it then adheres it was BS.
 
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To my understanding to differentiate the two, you would then need to add normal Serum (vWF), if it then adheres it was a vWF problem. If no adhesion you then add platelets, and if it then adheres it was BS.


Addition to that .


To confirm diagnosis of vw disease.. Check for vw antigen level. Also in BS, you will see big platelets whereas that is not the case in vw disease.
 
For a side note, there are three types of VMD (I have "VMD" written in my notes, not sure if this is right or not):

Type 1 (AD): decreased VWF production
Type 2 (AD): decreased VWF activity (+Ristocetin aggregation test)
Type 3 (AR): No VWF
 
risorectin is what binds vwf and gp1b...if either of the 2 are absent, risorectin assay will be abnormal, hence, vwf disease or bernard soulier syndrome.

risorectin assay is normal in gp2b/3a deficiency aka glanzmann thrombasthenia cuz the gp1b binding (adhesion process) already occurs.