ADAMTS13 and Thrombocytopenia: Among all recorded parameters, platelet count was the only baseline marker that significantly differed between the two study groups: TMA patients with severe ADAMTS13 deficiency had lower platelet counts (median difference − 27 × 109/l, 95% CI − 37 to − 3), most of them presenting with severe thrombocytopenia (i.e., < 30 × 109/l).