ALTERED RENOVASCULAR RESISTANCE AFTER SPONTANEOUS-RECOVERY FROM HEMOLYTIC-UREMIC SYNDROME

Twenty-three patients were evaluated from 1-15 (mean 6) years after re covering from an episode of diarrhea-associated childhood hemolytic ur emic syndrome (DA-HUS). All patients had received only conservative tr eatment; none had been given experimental, anti-coagulant, or immunolo gical therapies. Follow-up studies included morphologic and duplex Dop pler sonograms. Doppler sonography was used to determine the resistive index, a measure of renovascular resistance. Histories and physical e xaminiations revealed no abnormalities. Results of laboratory studies, which included calculated glomerular filtration rates, were all withi n normal limits, except for one patient with minor urinary abnormaliti es. Renal sonograms showed no significant abnormalities of kidney leng th or parenchymal appearance. However, Doppler sonographic examination s revealed that the DA-HUS patients demonstrated less of a decrease in renovascular resistance with age than did the control group (p<0.0002 ). After recovery, patients treated exclusively with conservative mana gement during an acute episode of DA-HUS appeared to have an excellent long-term prognosis. Comparison of our results with those from other studies in which investigational therapies have been used during the a cute phase of DA-HUS suggests that latent toxicities which cause long term sequelae may not have been appreciated previously. The clinical s ignificance of the altered renal vascular resistance remains to be del ineated.