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nbme21/Block 4/Question#14

A 25-year-old woman has a 3-week history of ...

Autoantibodies against platelet glycoproteins

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The patient suffered from Immune Thrombocytopenia. autoantibodies against the glycoproteins GP2B/3A.

On labs, you’ll see: increase in megakaryocytes; on the question stem they’re described as “rare but large.” Megakaryocytes are not suppressed.

ergogenic22  isolated thrombocytopenia (low platelets) should be highly suggestive of ITP https://www.aafp.org/afp/2012/0315/p612.html +1  

She has ITP/immune thrombocytopenia, so she has autoantibodies against her platelets, specifically GPIIb/IIIa. She has the large megakaryocytes because her bone marrow is trying to churn out platelets. She’s a woman of child-bearing age with increased bleeding time but no other neurologic abnormalities/renal issues/fever, so think ITP.

 +1  upvote downvote
submitted by sahusema(31),

I got tricked into picking the "acquired antibodies against P1A1". Human platelet Ag platelet antigen P1-1a, located on integrin β3, is the main target for responsible for neonatal thrombocytopenia.https://www.jimmunol.org/content/194/12/5751

cienfuegos  Same, except in my case I was the person who was tricked and who did the tricking though. Thx for the link. +  

 -4  upvote downvote
submitted by yotsubato(312),

She has Bernard Soulier Disease page 419 of first aid 2019

sympathetikey  That's a genetic deficiency of GP1b -- not antibody related +2  
alexandramda  In Berard Soulierd you have a Defect in adhesion. decreases GpIb and decreased platelet-to-vWF adhesion. Labs: abnormal ristocetin test, large platelets. +