Hemolytic uremic syndrome recurrence after renal transplantation.

About 60% of non-Stx-associated aHUS are due to the defect of protection of endothelial cells from complement activation, secondary to mutations in the genes of CFH, MCP, IF, BF, or C3. In addition, 10% of patients have anti-CFH antibodies. While the risk of post-transplant recurrence is less than 1% in Stx-HUS patients, it is approximately 80% in CFH or IF-mutated patients, 20% in MCP-mutated patients, and 30% in patients with no mutation. Patients with anti-CFH antibodies probably also are at risk of recurrence. While MCP-mutated patients can reasonably go to transplantation, recent reports suggest that plasmatherapy started before surgery and maintained life-long may prevent recurrence in CFH-mutated patients. Four successful liver-kidney transplantation utilizing plasmatherapy in CFH-mutated children have been reported recently. In summary, the risk of post-transplant recurrence can now be approached according to genotype. Therefore, aHUS patients should undergo complement determination, screening for anti-CFH antibodies, and genotyping before transplantation. Kidney or kidney + liver transplantation with concomitant plasmatherapy need to be evaluated by prospective trials in patients with hereditary complement abnormalities.