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.

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.

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

I got stuck on the no organomegaly...I had thought that immune thrombocytopenia would have splenomegaly since it is the destruction of platelet in the spleen, like many extravascular anemias that present with splenomegaly due to the overworking of this organ. But I learned my lesson, splenomegaly would NOT be present when destructing platelet.

She has Bernard Soulier Disease page 419 of first aid 2019