title: Organ-specific cardiac autoantibodies in dilated cardiomyopathy--an update.
abstract: Autoimmune disease is characterized by the presence of organ- and disease-specific autoantibodies in patients and first degree relatives; antibody detection may precede disease onset by several years. We investigated potential involvement of organ-specific autoimmunity in dilated cardiomyopathy (DCM). Using indirect immunofluorescence and absorption studies, organ- and disease-specific IgG cardiac antibodies were found in one-third of DCM patients. Antibody status at diagnosis was associated with better exercise capacity; at 1-year follow-up two-thirds of antibody-positive patients became negative. These findings suggest that antibodies are early markers; their absence in the majority of patients at diagnosis may relate to long-standing pre-clinical DCM. Antibody screening was performed in asymptomatic DCM relatives, 177 from 33 families with > 1 affected individual (familial DCM) and 165 from 31 pedigrees with non-familial DCM. Antibodies were detected in 37 (58%) pedigrees and were more common among relatives than in normals (20% vs 3.5%, P = 0.0001). Antibody-positive relatives were younger, had larger left ventricular end-systolic dimension and reduced % fractional shortening compared to antibody-negative relatives. These findings provide evidence for autoimmunity in a subset (58%) including both familial and non-familial DCM; cardiac-specific antibodies may identify relatives at risk of developing DCM.
authors.affiliation: Department of Cardiology, University of Padua, Italy.
authors.forename: A L
authors.initials: AL
authors.lastname: Caforio
authors.forename: J H
authors.initials: JH
authors.lastname: Goldman
authors.forename: M K
authors.initials: MK
authors.lastname: Baig
authors.forename: P J
authors.initials: PJ
authors.lastname: Keeling
authors.forename: G F
authors.initials: GF
authors.lastname: Bottazzo
authors.forename: W J
authors.initials: WJ
authors.lastname: McKenna
mesh_terms: D000328:Adult; D000368:Aged; D000918:Antibody Specificity / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000235:genetics / Q000276:immunology*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000276:immunology*; D009928:Organ Specificity / Q000276:immunology
chemical_list: D001323:Autoantibodies