A favorable 3-year outcome of kidney transplantation in atypical hemolytic uremic syndrome associated with a factor H mutation: case report.

Complement factor H (CFH)-associated hemolytic uremic syndrome (HUS) is a genetic form of atypical HUS characterized by deficient CFH levels or activity, which cause a disorder of the regulation of the alternative pathway, leading to uncontrolled complement activation. This genetic disorder, which frequently leads to end-stage renal failure, often recurs in kidney transplants, resulting in the poorest graft outcomes among all atypical HUS forms, due to a mutation in genes encoding complement components and regulatory proteins. Herein we have report our experience with a 40-year-old woman, suffering from a clearly defined sporadic form of genetic atypical HUS, consisting of a heterozygous missense mutation in factor H gene. She underwent cadaveric kidney transplantation. At the moment of surgery she displayed positive hemolysis indices and C3 consumption. A calcineurin inhibitor (CNI)-free immunosuppressive regimen was based on sirolimus, mycophenolic acid and steroids after basiliximab induction. An early and intense prophylactic course of plasma exchange (PE), and fresh frozen plasma (40 mL/kg) was prescribed, starting before surgery and continuing daily for the first week. The frequency of PE slowly reduced over the following 2 weeks. After that, just plasma infusion at the same dose was performed once a week until 12 weeks after transplantation. There was prompt graft function and in third week there were no signs of hemolysis or of C3 consumption. More than 3 years after transplantation, the graft is still functioning well and there was no recurrence. In our opinion, this case indicates that, although evidence is lacking, avoidance of CNI and intensive prophylactic plasma therapy are essential to achieve good results in this peculiar type of kidney transplantation. Nevertheless, controlled, prospective studies are necessary to establish the actual role of these two therapeutic procedures in renal transplantation of patients with CFH-associated HUS.