Postdiarrhoeal haemolytic uraemic syndrome without thrombocytopenia

Thrombocytopenia is a hallmark of postdiarrhoeal haemolytic uraemic syndrome (D+ HUS), although it can be transient and therefore undetected. There is scarce information regarding the prevalence and the course of the disease in children with D+ HUS without thrombocytopenia.

To determine the prevalence of D+ HUS without thrombocytopenia and to describe the clinical characteristics of a series of children with this condition.

The medical records of patients with D+ HUS hospitalised between 2000 and 2016 were reviewed to identify those without thrombocytopenia (>150,000mm³). Demographic, clinical and laboratory parameters of the selected cases were collected and descriptively analysed.

Nine cases (5.6%) without thrombocytopenia were identified among 161 patients hospitalised during the study period. Median age at diagnosis was 17 months (7-32) and median prodromal symptom duration was 15 days (7-21). Eight patients maintained normal urine output while the remaining one required dialysis. No patient presented with severe extrarenal compromise and/or hypertension.

The prevalence of non-thrombocytopenic D+ HUS was 5.6% and most cases occurred with mild forms of the disease; however, the need for dialysis in one of them indicated that normalisation of platelet count is not always an accurate marker for disease remittance. Our results also confirm that the time of onset of D+ HUS in patients without thrombocytopenia is usually delayed with respect to the initial intestinal symptoms; thus, heightened diagnostic suspicion is necessary.