A patient with homozygous factor H deficiency presented with hemolytic urem
ic syndrome (HUS) at the age of 7 months. After a 2-year period of stabilit
y, renal failure and erythrocyte fragmentation recurred between the age of
3 and 4 years. Fresh frozen plasma infusions allowed renal function to be i
mproved and erythrocyte fragmentation to be stopped. Withdrawal of plasma t
herapy led to a relapse of the biological signs of HUS.