LAUSR

OBJECTIVES Cardiac involvement in neonatal lupus (NLE) can present as myocarditis/endocardial fibroelastosis (EFE). It is unknown if high sensitivity troponin T (hs-cTnT) is useful in identifying subclinical myocardial inflammation in infants exposed prenatally to anti-Ro antibodies. This study reports hs-cTnT levels in infants exposed to anti-Ro antibodies with/without cardiac NLE and reports cardiac magnetic resonance imaging (CMR) findings in a subset of these children. METHODS Included were 45 consecutive infants exposed prenatally to anti-Ro antibodies with (n = 7) or without (n = 38) cardiac NLE who were seen at the SickKids NLE Clinic between 2012-2014. Hs-cTnT were measured at least once and those with values ≥ 30 ng/l were offered to undergo CMR. Descriptive statistics were performed. RESULTS Of 38 infants without cardiac NLE, 25 had hs-cTnT ≥ 30 ng/l (including 1 > 113 ng/l) of whom 8 underwent a CMR (all without myocarditis/EFE). All 7 cardiac NLE children had at least one hs-cTnT ≥ 30 ng/l but only 2/7 > 113 ng/l. 4/7 infants with cardiac involvement had CMR (all without myocarditis/EFE). 6/7 cardiac NLE infants had their steroid treatment adjusted based on trend of hs-cTnT levels. CONCLUSION Only 3/45 anti-Ro antibodies exposed infants had hs-cTnT values outside the reference range reported in healthy infants. None of 12 infants who had CMR had subclinical myocarditis/EFE. Routine measurement of hs-cTnT in every anti-Ro antibody exposed infant is not indicated. Further studies are needed to define the role of hs-cTnT as a biomarker for cardiac NLE.