Genetics of HUS: the impact of MCP, CFH, and IF mutations on clinical presentation, response to treatment, and outcome.
Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy with manifestations of hemolytic anemia, thrombocytopenia, and renal impairment. Genetic studies have shown that mutations in complement regulatory proteins predispose to non-Shiga toxin-associated HUS (non-Stx-HUS). We undertook genetic analysis on membrane cofactor protein (MCP), complement factor H (CFH), and factor I (IF) in 156 patients with non-Stx-HUS. Fourteen, 11, and 5 new mutational events were found in MCP, CFH, and IF, respectively. Mutation frequencies were 12.8%, 30.1%, and 4.5% for MCP, CFH, and IF, respectively. MCP mutations resulted in either reduced protein expression or impaired C3b binding capability. MCP-mutated patients had a better prognosis than CFH-mutated and nonmutated patients. In MCP-mutated patients, plasma treatment did not impact the outcome significantly: remission was achieved in around 90% of both plasma-treated and plasma-untreated acute episodes. Kidney transplantation outcome was favorable in patients with MCP mutations, whereas the outcome was poor in patients with CFH and IF mutations due to disease recurrence. This study documents that the presentation, the response to therapy, and the outcome of the disease are influenced by the genotype. Hopefully this will translate into improved management and therapy of patients and will provide the way to design tailored treatments.
Caprioli
Jessica
J
Mario Negri Institute for Pharmacologic Research, Clinical Research Center for Rare Diseases, Aldo e Cele Daccò, Bergamo, Italy.
Noris
Marina
M
Brioschi
Simona
S
Pianetti
Gaia
G
Castelletti
Federica
F
Bettinaglio
Paola
P
Mele
Caterina
C
Bresin
Elena
E
Cassis
Linda
L
Gamba
Sara
S
Porrati
Francesca
F
Bucchioni
Sara
S
Monteferrante
Giuseppe
G
Fang
Celia J
CJ
Liszewski
M K
MK
Kavanagh
David
D
Atkinson
John P
JP
Remuzzi
Giuseppe
G
D016913:Blood Component Transfusion; D003179:Complement C3b / Q000235:genetics / Q000378:metabolism; D017242:Complement Factor H / Q000096:biosynthesis / Q000235:genetics*; D017244:Complement Factor I / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006463:Hemolytic-Uremic Syndrome / Q000235:genetics* / Q000378:metabolism / Q000628:therapy; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D051916:Membrane Cofactor Protein / Q000096:biosynthesis / Q000235:genetics*; D009154:Mutation; D010949:Plasma; D011485:Protein Binding / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics; D012008:Recurrence; D022621:Shiga Toxin; D016896:Treatment Outcome
D051916:Membrane Cofactor Protein; D022621:Shiga Toxin; D003179:Complement C3b; D017242:Complement Factor H; D017244:Complement Factor I