Hemolytic uremic syndrome in Kuwaiti Arab children.

Twenty-five children with hemolytic uremic syndrome (HUS) were diagnosed between January 1985 and January 2000 in the Pediatric Nephrology Unit at Mubarak Al-Kabeer Hospital. Fourteen patients (56%) had typical (D+) HUS whereas 11 (44%) had atypical (D-) HUS. No bacterial or viral pathogens could be isolated in the majority of cases. The atypical HUS group had more severe anemia (P=0.03), which was significantly more prolonged than in the typical HUS group (P=0.0028). There was no significant difference between the two groups in the mean maximum serum creatinine (P=0.1), blood urea nitrogen values (P=0.8) and severity of leukocytosis (P=0.4). Anuria and the need for dialysis were not significantly different between the two groups (P=0.1 and 0.05, respectively). Mortality was significantly higher in the D- HUS patients (P<0.0001). Recurrence of HUS was documented in 63.3% of the D- HUS group compared to 14.2% of the D+ HUS group (P=0.0053). Family history of HUS was reported in 72.7% of the atypical HUS group and 14.2% of the typical HUS group. There were no significant differences in chronic renal sequelae between the two groups. In conclusion, the pathogenesis of HUS in Kuwaiti children appears to be influenced by genetic factors rather than certain environmental pathogens. Atypical HUS has a higher mortality rate, a definite familial tendency and a high relapse rate.