The P1 blood group and the severity of diarrhea-associated hemolytic uremic syndrome.

Thirty-one children with diarrhea-associated hemolytic uremic syndrome were retrospectively studied to determine if expression of the P1 blood type was related to the severity of the acute illness or to the prognosis. No differences were found in the clinical variables studied in the patients who were P1 positive compared to the patients who were P1 negative. The clinical variables studied included the age, hemoglobin, white blood cell count (WBC), and presence of central nervous system involvement at presentation, the duration of elevated WBC, thrombocytopenia, hemorrhagic colitis, and anuria, and the follow-up incidence of proteinuria, hypertension and decreased GFR. Expression of the P1 phenotype does not appear to exert a protective influence in patients with D+ HUS.