Maternal anti-Ro and anti-La antibody-associated endocardial fibroelastosis.
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.
Nield
Lynne E
LE
Department of Paediatrics, Division of Cardiology, The Hospital for Sick Children, University of Toronto Faculty of Medicine, Toronto, Ontario, Canada.
Silverman
Earl D
ED
Taylor
Glenn P
GP
Smallhorn
Jeffrey F
JF
Mullen
J Brendan M
JB
Silverman
Norman H
NH
Finley
John P
JP
Law
Yuk M
YM
Human
Derek G
DG
Seaward
P Gareth
PG
Hamilton
Robert M
RM
Hornberger
Lisa K
LK
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
D001323:Autoantibodies; D001324:Autoantigens; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000097585:SS-B Antigen; D000099207:SS-A Antigen; C116006:RO60 protein, human