Detection of verocytotoxin bound to circulating polymorphonuclear leukocytes of patients with hemolytic uremic syndrome

The epidemic form of hemolytic uremic syndrome (HUS) is the most common cau se of acute renal failure in children and is characterized by a prodromal p hase of sometimes bloody diarrhea. The role of verocytotoxin (VT)-producing Escherichia coli has been strongly implicated. Although antibodies against VT have been detected in the serum of patients with HUS, VT itself has nev er been detected in circulating blood. In this study, VT-2 was detected in the systemic circulation in 9 of 10 patients with the epidemic form of HUS. In those cases, VT-2 was bound exclusively to polymorphonuclear leukocytes (PMN). The detection of VT-2 bound to PMN was associated with the presence of diarrhea at the time the blood samples were obtained. The one patient f or whom VT was not detected presented with atypical HUS, For 5 of the 10 pa tients with HUS who were studied, the time course of VT binding was analyze d; binding decreased in four patients. The finding of VT bound to PMN in th e systemic circulation of patients with HUS is important for a clearer unde rstanding of the pathogenesis of HUS and suggests new approaches for treatm ent in the future.