Haemolytic uraemic syndrome associated with non shiga toxin-producing Escherichia coli bacteraemia: a case report.

backgroundHaemolytic uraemic syndrome (HUS) is a thrombotic microangiopathy (TMA) characterized by predominant renal involvement. Several types of HUS can be distinguished: the most frequent « typical » HUS, due to shiga toxin producing Escherichia coli (STEC), "atypical" HUS due to complement alternative pathway dysregulation and "secondary" HUS associated with various diseases/conditions, the classification of which is still subject to debate. CASE PRESENTATION: We report a case of HUS following E.coli prostatitis and bacteraemia in an adult male. He presented with severe renal and neurological involvement. Initially considered as a "typical" HUS, the condition was treated by antibiotics. No other specific treatment for HUS was administered. The outcome was favorable. We eventually identified a non shiga toxin producing E.coli. Genetic testing of the complement alternative pathway revealed a rare - potentially pathogenic - variant of factor H. This constitutes a possible factor of susceptibility for atypical HUS, suggesting that E.coli infection may be the trigger.

conclusionThis case raises the question of complement exploration for HUS associated with infections, in order to classify such cases of HUS in accordance with their underlying pathophysiological mechanisms.