ADAMTS13 and thrombotic thrombocytopenic purpura: The patient developed meningoencephalitis attributed to Neuro-Behçet syndrome with normal ADAMTS-13 activity.17 The clinical importance of ADAMTS13 activity in TTP was so accepted that recombinant ADAMTS13 was successfully used in a patient with hereditary TTP as a new advancement.18 To our knowledge, this is the first cross-sectional study that has investigated ADAMTS-13 in BD.