title: Successful renal transplantation in a patient with atypical hemolytic uremic syndrome carrying mutations in both factor I and MCP.
abstract: Kidney transplantation in patients with atypical hemolytic uremic syndrome (aHUS) carrying mutations in the soluble complement regulators factor H (CFH) or factor I (CFI) is associated with elevated risk of disease recurrence and almost certain graft loss. In contrast, recurrence is unusual in patients with mutations in the membrane-associated complement regulator membrane cofactor protein (MCP) (CD46). Therefore, a panel of experts recently recommended the combined liver-kidney transplantation to minimize aHUS recurrence in patients with mutations in CFH or CFI. There was, however, very limited information regarding transplantation in patients carrying mutations in both soluble and membrane-associated complement regulators to support a recommendation. Here, we report the case of an aHUS patient with a heterozygous mutation in both CFI and MCP who received an isolated kidney transplant expressing normal MCP levels. Critically, the patient suffered from a severe antibody-mediated rejection that was successfully treated with plasmapheresis and IvIgG. Most important, despite the complement activation in the allograft, there was no evidence of thrombotic microangiopathy, suggesting that the normal MCP levels in the grafted kidney were sufficient to prevent the aHUS recurrence. Our results suggest that isolated kidney transplantation may be a good first option for care in aHUS patients carrying CFI/MCP combined heterozygous mutations.
authors.affiliation: Servei de Nefrologia, Hospital Universitari de Bellvitge, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain. jmcruzado@bellvitgehospital.cat
authors.forename: J M
authors.initials: JM
authors.lastname: Cruzado
authors.forename: S Rodríguez
authors.initials: SR
authors.lastname: de Córdoba
authors.forename: E
authors.initials: E
authors.lastname: Melilli
authors.forename: O
authors.initials: O
authors.lastname: Bestard
authors.forename: I
authors.initials: I
authors.lastname: Rama
authors.forename: P
authors.initials: P
authors.lastname: Sánchez-Corral
authors.forename: M
authors.initials: M
authors.lastname: López-Trascasa
authors.forename: I
authors.initials: I
authors.lastname: Navarro
authors.forename: J
authors.initials: J
authors.lastname: Torras
authors.forename: M
authors.initials: M
authors.lastname: Gomà
authors.forename: J M
authors.initials: JM
authors.lastname: Grinyó
mesh_terms: D000328:Adult; D017244:Complement Factor I / Q000235:genetics*; D006084:Graft Rejection / Q000188:drug therapy; D006463:Hemolytic-Uremic Syndrome / Q000235:genetics* / Q000601:surgery*; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D051916:Membrane Cofactor Protein / Q000235:genetics*; D009154:Mutation
chemical_list: C497857:CD46 protein, human; D051916:Membrane Cofactor Protein; C493611:CFI protein, human; D017244:Complement Factor I