title: Umbilical cord blood levels of maternal antibodies reactive with p200 and full-length Ro 52 in the assessment of risk for cardiac manifestations of neonatal lupus.
abstract: OBJECTIVE
  Maternal anti-Ro autoantibodies are associated with cardiac manifestations of neonatal lupus (cardiac NL), yet only 2% of women with this reactivity have an affected child. Identification of a more specific marker would channel intense monitoring to fetuses at greater risk. This study aimed to determine whether autoantibodies against Ro 52 amino acids 200-239 (p200) confer added risk over autoantibodies to full-length Ro 52, Ro 60, or La.
  
  
  METHODS
  Anti-Ro-exposed pregnancies resulting in cardiac NL or no cardiac manifestations were identified from the Research Registry for Neonatal Lupus and the PR Interval and Dexamethasone Evaluation study. Umbilical cord (n = 123) and maternal (n = 115) samples were evaluated by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The frequencies of p200, Ro 52, Ro 60, and La autoantibodies were not significantly different between affected and unaffected children. However, neonatal anti-Ro 52 and Ro 60 titers were highest in cardiac NL and their unaffected siblings compared to unaffected neonates without a cardiac NL sibling. Although both maternal anti-Ro 52 and p200 autoantibodies were less than 50% specific for cardiac NL, anti-p200 was the least likely of the Ro autoantibodies to be false-positive in mothers who have never had an affected child. Titers of anti-Ro 52 and p200 did not differ during a cardiac NL or unaffected pregnancy from the same mother.
  
  
  CONCLUSIONS
  Maternal reactivity to p200 does not confer an added risk to fetal conduction defects over full-length Ro 52 or Ro 60 autoantibodies. Mothers who may never be at risk for having an affected child have lower anti-Ro 60 titers and may require less stringent echocardiographic monitoring compared to women with high-titer autoantibodies.
authors.affiliation: New York University School of Medicine, New York, USA. joanne.reed@nyumc.org
authors.forename: Joanne H
authors.initials: JH
authors.lastname: Reed
authors.forename: Robert M
authors.initials: RM
authors.lastname: Clancy
authors.forename: Kristen H
authors.initials: KH
authors.lastname: Lee
authors.forename: Amit
authors.initials: A
authors.lastname: Saxena
authors.forename: Peter M
authors.initials: PM
authors.lastname: Izmirly
authors.forename: Jill P
authors.initials: JP
authors.lastname: Buyon
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005312:Fetal Blood / Q000276:immunology*; D006327:Heart Block / Q000097:blood / Q000209:etiology* / Q000276:immunology; D006801:Humans; D016056:Immunodominant Epitopes; D016014:Linear Models; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000151:congenital* / Q000209:etiology / Q000276:immunology; D008297:Male; D010446:Peptide Fragments / Q000276:immunology*; D011247:Pregnancy; D012042:Registries; D012261:Ribonucleoproteins / Q000276:immunology*; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States; D000099207:SS-A Antigen
chemical_list: D000974:Antibodies, Antinuclear; D015415:Biomarkers; D016056:Immunodominant Epitopes; D010446:Peptide Fragments; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C035356:SS-A antibodies