[Atypical Hemolytic Uremic Syndrome: experience of a pediatric center]

In the last two years we admitted in our Hospital 38 children with acute renal failure (ARF). Six of them were affected by hemolytic uremic syndrome (HUS) atypical. The aHUS is diagnosed in the presence of thrombotic microangiopathy (MAT), renal insufficiency (GFR 5%). The clinical presentation of our children has been varied and so also its evolution. Patients observed were all male, aged 2 to 12 years, and no one had a family history of kidney disease. In four patients we documented alterations of complement factors (MCP deficiency and factor H and presence of anti factor H). Repeated blood transfusions were required in 4 patients and in 3 patients the platelet count was slightly reduced. In 5 patients we did plasmapheresis and in 3 patients dialysis (hemodialysis and peritoneal dialysis). In three patients in whom the diagnosis was not clear, renal biopsy was performed to confirm the diagnosis. Eculizumab was administered in 3 patients resistant to plasma exchange. We obtain a rapid response on MAT with normalization of platelet count. The effect on renal function was variable (complete remission in a patient, partial improvement in another, and unresponsiveness in the last). The last had on Kidney biopsy signs of severe impairment and we documented the presence of antibodies to eculizumab. HUS is a rare condition, but probably much more common than reported. In children with ARF and microangiopathic anemia is necessary evaluated complement factors as early to obtain an improved clinical response to treatment with eculizumab.