Recurrent hemolytic uremic syndrome
Recurrent hemolytic uremic syndrome. Siegler RL, Pavia AT, Sherbotie JR. Clincal Pediatrics 2002;41:705-709.
Hemolytic uremic syndrome (HUS) in children follows a diarrheal prodrome (D+) approximately 90% of the time, and recurrence due to enteric reinfection with Shiga toxin-producing E. coli (STEC) can occur but is rare. It is not well recognized that nondiarrheal (D-) recurrences can also follow an episode of D+ HUS. This paper reports on two unrelated cases of multiple D- episodes following an initial episode of D+ HUS. The first case was a seven-month old female who developed HUS following four days of nonbloody diarrhea. She experienced nine days of oligoanuria and seizures but no hypertension. She had a recurrence four years later that was preceded by a week of lethargy and vomiting but no diarrhea. She had high blood pressure on admission, and although she recovered from acute renal failure severe hypertension persisted. A renal biopsy showed changes consistent with atypical HUS. Severe hypertension persisted and renal function slowly declined over the following decade. Two weeks following a renal transplant at age 17, she experienced a recurrence of HUS in her renal graft that resulted in renal failure and she returned to dialysis. After 15 years of chronic hemodialysis she received a second graft and at three months posttransplant was doing well. Similarly, a second female infant was hospitalized due to seizures after two days of nonbloody diarrhea and vomiting. Renal function returned to normal after a period of prolonged oliguric renal failure. Her first recurrence at age 5 was preceded by an upper respiratory infection and vomiting. Renal function slowly deteriorated and she became dialysis dependent four years later. She received a renal graft at 13 years of age, and three weeks later experienced a mild HUS recurrence in her graft. She recovered but two weeks later presented with thrombocytopenia, hemolytic anemia, and multiple brain and retinal infarcts, signs consistent with thrombotic thrombocytopenic purpura (TTP), but no renal failure. Daily plasma exchange was started and her central nervous system (CNS) disease slowly improved. Six years later she had had no additional recurrences and was free of any significant CNS sequelae, but she had severe visual impairment. These cases account for only 0.5% of the postdiarrheal cases in this particular registry. Since the initial illnesses occurred before HUS was linked to STEC, stool culture verification was not available, although their clinical presentations were consistent with Shiga toxin (Stx)-mediated disease. Both patients experienced recurrent HUS in their renal grafts, which is consistent with reports that HUS recurrence is renal grafts is more likely to occur in those with atypical HUS than in classic Stx HUS. Renal transplantation should be performed with circumspection in this group. An HUS classification system that includes recurrence risk is also presented in this paper.