血管内皮から分泌されたunusually large von Willebrand factor multimer(ULVWFM)は,a disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13(ADAMTS13)によって適当な大きさに切断され,血小板と結合して適切な止血機能を発揮する.しかしADAMTS13に対する抗体が産生され,ADAMTS13活性が10%未満に低下すると,微小血管内で進展したULVWFMに血小板が結合してVWF血小板血栓を生じ,消費性血小板減少と阻血による,脳を含む諸臓器の障害を生じる.
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