Plasma from patients with HUS increases platelet retention.

Plasma from patients with HUS taken during the acute phase of disease (n = 17; median platelet retention, 30%) showed increased platelet retention compared to plasma from the same patients after recovery (n = 14; median, 18%, P = .0001), patients with non-STEC–associated bloody diarrhea (n = 4; median, 16%;P < .001), and pediatric controls (n = 10; median, 20%; P < .01).