title: Maternal anti-Ro and anti-La antibody-associated endocardial fibroelastosis.
abstract: BACKGROUND
  Maternal anti-Ro and anti-La antibodies are associated with congenital heart block (CHB). Although endocardial fibroelastosis (EFE) has been described in isolated cases of autoantibody-mediated CHB, the natural history and pathogenesis of this disease are poorly understood.
  
  
  RESULTS
  We retrospectively reviewed the clinical history, echocardiography, and pathology of fetuses and children with EFE associated with CHB born to mothers positive for anti-Ro or anti-La antibodies at 5 centers. Thirteen patients were identified, 6 with a prenatal and 7 with a postnatal diagnosis. Six mothers were positive for anti-Ro and anti-La antibodies, and 7 were positive for anti-Ro antibodies only. Only 1 mother had autoimmune disease. Severe ventricular dysfunction was seen in all fetal and postnatal cases. Four fetal and 3 postnatal cases had EFE at initial presentation. However, 2 fetal and 4 postnatal cases developed EFE 6 to 12 weeks and 7 months to 5 years from CHB diagnosis, respectively, even despite ventricular pacing in 6 postnatal cases. Eleven (85%) either died (n=9) or underwent cardiac transplantation (n=2) secondary to the EFE. Pathologic assessment of the explanted heart, available in 10 cases, revealed moderate to severe EFE in 7 and mild EFE in 3 cases, predominantly involving the left ventricle. Immunohistochemistry in 4 cases (including 3 fetuses) demonstrated deposition of IgG in 4 and IgM in 3 and T-cell infiltrates in 3 cases, suggesting an immune response by the affected fetus or child.
  
  
  CONCLUSIONS
  EFE occurs in the presence of autoantibody-mediated CHB despite adequate ventricular pacing. Autoantibody-associated EFE has a very high mortality rate, whether developing in fetal or postnatal life.
authors.affiliation: Department of Paediatrics, Division of Cardiology, The Hospital for Sick Children, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada.
authors.forename: Lynne E
authors.initials: LE
authors.lastname: Nield
authors.forename: Earl D
authors.initials: ED
authors.lastname: Silverman
authors.forename: Glenn P
authors.initials: GP
authors.lastname: Taylor
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Smallhorn
authors.forename: J Brendan M
authors.initials: JB
authors.lastname: Mullen
authors.forename: Norman H
authors.initials: NH
authors.lastname: Silverman
authors.forename: John P
authors.initials: JP
authors.lastname: Finley
authors.forename: Yuk M
authors.initials: YM
authors.lastname: Law
authors.forename: Derek G
authors.initials: DG
authors.lastname: Human
authors.forename: P Gareth
authors.initials: PG
authors.lastname: Seaward
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hamilton
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Hornberger
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D002304:Cardiac Pacing, Artificial; D015331:Cohort Studies; D004452:Echocardiography; D004695:Endocardial Fibroelastosis / Q000150:complications / Q000175:diagnosis / Q000276:immunology* / Q000401:mortality; D005260:Female; D005333:Fetus; D006327:Heart Block / Q000150:complications / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy; D006801:Humans; D015160:Hydrops Fetalis / Q000150:complications / Q000175:diagnosis / Q000401:mortality; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009035:Mothers; D011247:Pregnancy; D020733:RNA, Small Cytoplasmic; D012189:Retrospective Studies; D012261:Ribonucleoproteins / Q000276:immunology*; D016216:Ultrasonography, Prenatal; D018754:Ventricular Dysfunction / Q000150:complications / Q000175:diagnosis / Q000276:immunology*; D000097585:SS-B Antigen; D000099207:SS-A Antigen
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000097585:SS-B Antigen; D000099207:SS-A Antigen; C116006:RO60 protein, human