title: Relevance of C5b9 immunostaining in the diagnosis of neonatal hemochromatosis.
abstract: BACKGROUND
  Neonatal hemochromatosis caused by a gestational alloimmune mechanism or gestational alloimmune liver disease (GALD) is a rare perinatal disorder characterized by intra- and extrahepatic iron overload. It is believed to result from complement-mediated liver injury, in which the classical complement pathway is activated by maternal antibody/fetal antigen complexes, leading to hepatocyte lysis by the membrane attack complex C5b9. According to some authors, C5b9 expression in more than 75% of liver parenchyma is specific for GALD.
  
  
  METHODS
  We conducted a retrospective multicentric immunohistochemical study with anti-C5b9 in GALD cases (n = 25) and non-GALD cases with iron overload (n = 36) and without iron overload (n = 18).
  
  
  RESULTS
  C5b9 was expressed in 100% of GALD cases but involved more than 75% of the liver parenchyma in only 26% of the cases. C5b9 was detected in 26.75% of the non-GALD cases with more than 75% of positive parenchyma in maternal erythrocytic alloimmunization, herpes and enterovirus hepatitis, bile acid synthetic defect, DGUOK mutation, Gaucher disease, cystic fibrosis, and giant-cell hepatitis with autoimmune hemolytic anemia.
  
  
  CONCLUSIONS
  Diagnosis and therapeutic management of GALD cannot only be based on C5b9 expression in liver samples as it is not specific of this disease.
authors.affiliation: Department of pathology, Hôpital Femme-Mère-Enfant, CHU de Lyon, France.
authors.forename: Estelle
authors.initials: E
authors.lastname: Dubruc
authors.affiliation: Department of pathology, Hôpital Femme-Mère-Enfant, CHU de Lyon, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Nadaud
authors.affiliation: Department of pathology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ruchelli
authors.affiliation: Department of pediatrics, Hôpital Femme-Mère-Enfant, CHU de Lyon, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Heissat
authors.affiliation: Pediatric Hepatology and Inborn Metabolic Diseases Unit, University Children's Hospital, Toulouse, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Baruteau
authors.affiliation: Pediatric Hepatology and Inborn Metabolic Diseases Unit, University Children's Hospital, Toulouse, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Broué
authors.affiliation: Department of Pediatric Surgery, Hepatology, and Transplantation, Necker Enfants Malades Hospital, Paris, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Debray
authors.affiliation: Department of genetics, Hôpital Femme-Mère-Enfant, CHU de Lyon, France.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Cordier
authors.affiliation: Department of immunology, Hôpital Edouard Herriot, CHU de Lyon, France.|Université Claude Bernard Lyon 1, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Miossec
authors.affiliation: Department of pathology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Pierre
authors.initials: P
authors.lastname: Russo
authors.affiliation: Department of pathology, Hôpital Femme-Mère-Enfant, CHU de Lyon, France.|Université Claude Bernard Lyon 1, France.|SOFFOET, Société Française de Foetopathologie, Paris, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Collardeau-Frachon
mesh_terms: D015415:Biomarkers / Q000032:analysis; D015938:Complement Membrane Attack Complex / Q000032:analysis*; D005602:France; D006432:Hemochromatosis / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D008099:Liver / Q000276:immunology* / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D015938:Complement Membrane Attack Complex