Challenges in the management of infantile factor H associated hemolytic uremic syndrome

We describe a 1-year old with four episodes of recurrent hemolytic uremic syndrome (HUS). Family history suggested an autosomal dominant mode of inheritance. Factor H concentrations in the blood were normal in the affected family members. Mutation screening in the human complement factor H gene (HF-1) revealed a novel mutation in exon 23 (c.3546_3581dup36). The HF-1 gene encodes complement factor H and the mutation leads to the insertion of 12 additional amino acids after codon 1176 in factor H. The recurrent HUS responded to plasma infusions and renal function improved from a glomerular filtration rate of 21 to 50 ml/min per 1.73 m(2). The infusions of fresh-frozen plasma were necessary at once-weekly intervals at a dose of 40-45 ml/kg in order to maintain remission and resulted in significant hyperproteinemia. This was addressed by intermittent plasma exchange through an arterio-venous fistula. The prognosis and therapeutic dilemmas are discussed.