RT Journal Article
SR Electronic
T1 Anti–Factor H Autoantibodies Associated with Atypical Hemolytic Uremic Syndrome
JF Journal of the American Society of Nephrology
JO J. Am. Soc. Nephrol.
FD American Society of Nephrology
SP 555
OP 563
DO 10.1681/ASN.2004050380
VO 16
IS 2
A1 Dragon-Durey, Marie-Agnès
A1 Loirat, Chantal
A1 Cloarec, Sylvie
A1 Macher, Marie-Alice
A1 Blouin, Jacques
A1 Nivet, Hubert
A1 Weiss, Laurence
A1 Fridman, Wolf Herman
A1 Frémeaux-Bacchi, Véronique
YR 2005
UL http://jasn.asnjournals.org/content/16/2/555.abstract
AB Several studies have demonstrated genetic predisposition in non–shigatoxin-associated hemolytic uremic syndrome (HUS), involving regulatory proteins of the complement alternative pathway: Factor H (FH) and membrane co-factor protein (CD46). Regarding the observations of thrombotic thrombocytopenic purpura patients, in whom a von Willebrand factor protease (ADAMST-13) deficiency may be inherited or acquired secondary to IgG antibodies, it was speculated that HUS might occur in a context of an autoimmune disease with the development of anti-FH antibodies leading to an acquired FH deficiency. The presence of FH autoantibodies was investigated by an ELISA method using coated purified human FH in a series of 48 children who presented with atypical HUS and were recruited from French university hospitals. Anti-FH IgG antibodies were detected in the plasma of three children who presented with recurrent HUS. The anti-FH specificity was conserved by the Fab′2 fraction. The plasma FH activity was found to be decreased, whereas plasma FH antigenic levels and FH gene analysis were normal, indicating that the presence of anti-FH antibodies led to an acquired functional FH deficiency. This report supports for the first time that HUS may occur in a context of an autoimmune disease with the development of anti-FH–specific antibody leading to an acquired FH deficiency. This new mechanism of functional FH deficiency may lead to the design of new approaches of diagnosis and treatment with a particular interest in plasma exchanges or immunosuppressive therapies.