Brief report Familial, atypical hemolytic-uremic syndrome in a premature infant Bernard J. Wilson 1 and Joseph T. Flynn 2 1 Section of Neonatal-Perinatal Medicine, Department of Pediatrics and Communicable Diseases, Mott Children’s Hospital, University of Michigan Medical Center, Michigan, USA 2 Section of Pediatric Nephrology, Department of Pediatrics and Communicable Diseases, Mott Children’s Hospital, University of Michigan Medical Center, Michigan, USA &misc:Received December 19, 1997; received in revised form April 13, 1998; accepted April 14, 1998 &p.1:Abstract. The hemolytic-uremic syndrome (HUS) typi- cally presents in toddlers or older children after an epi- sode of bloody diarrhea caused by Escherichia coli 0157:H7. However, numerous ‘‘atypical’’ presentations have been described, including familial cases. Here we describe what we believe to be the first report of famil- ial HUS in a premature infant during the neonatal peri- od. &kwd:Key words: Neonate – Prematurity – Hemolytic-uremic syndrome – Anemia – Thrombocytopenia – Renal fail- ure Introduction The hemolytic-uremic syndrome (HUS) typically presents in toddlers or older children after an episode of bloody diarrhea caused by Escherichia coli 0157:H7 [1]. However, numerous ‘‘atypical’’ presentations have been described, including familial and non-diarrhea-associat- ed cases [2]. In this report, we describe the presentation of HUS in a premature infant who had an older sibling who was also affected by HUS in infancy. We believe this to be the first report of familial HUS in a premature infant during the neonatal period. Case reports Case 1 Patient 1 was a white female, twin B of a dizygotic pair, born at 32 weeks’ estimated gestational age by cesarean section to a 31- year-old gravida 3 para 2 mother, at an outlying hospital. Pregnan- cy was complicated only by premature onset of labor, which failed to respond to terbutaline and magnesium sulfate tocolysis. The mother was also given betamethasone to promote fetal lung matu- rity and ampicillin in the immediate prenatal period. The infant weighed 1,675 g at birth, and was noted to have poor color and respiratory effort immediately after delivery, and was therefore intubated and mechanically ventilated. No umbilical catheters were placed. Initial physical examination was remarkable only for evidence of respiratory distress and decreased tone. Her early course was remarkable for mild respiratory distress syndrome, a negative initial sepsis work-up (ampicillin and cefo- taxime were given for 48 h), apnea of prematurity that was treated with aminophylline, and mild non-hemolytic jaundice. Also, due to hypotonia, dysconjugate eye movements, and a static head cir- cumference noted over the first 2 weeks of life, a neurology con- sultation was requested. The neurologist obtained chromosome analysis, a urine metabolic screen, and an electroencephalogram (EEG). The EEG was read as normal, the metabolic screen was negative, and the chromosome analysis was normal. Cranial ultra- sonography had previously revealed a structurally normal brain without intraventricular hemorrhage. On day of life (DOL) 15 the infant became severely hyperten- sive, for which an evaluation was performed. Urinalysis revealed hematuria and proteinuria. Blood urea nitrogen (BUN) and creati- nine were elevated (Table 1); they had not been previously deter- mined. Renal ultrasonography revealed normal-appearing paren- chyma and normal vasculature. The next day she was noted to be thrombocytopenic. A peripheral blood smear showed burr cells, acanthocytes, and schistocytes. Cultures were obtained and antibi- otics begun. Over the next 4 days she remained thrombocytopenic (Table 1) and became anemic, for which packed red cell transfu- sions were given. Neurologically the baby was lethargic and wors- ening apnea necessitated re-institution of mechanical ventilation. On DOL 17 she experienced a seizure, which was treted with phe- nobarbital. Repeat cranial ultrasonography was unchanged. Through DOL 19 she maintained a brisk urine output, while her BUN and creatinine continued to rise (Table 1). From DOL 19 she experienced progressive oliguria, unrespon- sive to furosemide administration. Worsening hypertension was treated, unsuccessfully, with hydralazine. Concomitant with her decreased urine output was a weight gain of nearly 130 g. Blood cultures were negative. On DOL 20 the infant was transferred to the University of Michigan Medical Center (UMMC) for management of her refrac- tory hypertension and renal failure. Upon arrival at UMMC, her physical examination was normal except for a blood pressure of 140/93 mmHg. The infant was profoundly anemic and thromb- ocytopenic. Fibrinogen level was depressed and prothrombin time as well as fibrinogen split products were modestly elevated. Bio- Correspondence to: J.T. Flynn, F6865 Mott Children’s Hospi- tal/0297, 1505 Simpson Road East, Ann Arbor, MI 48109-0297, USA&/fn-block: Pediatr Nephrol (1998) 12:782–784 © IPNA 1998