Cardiac manifestations of neonatal lupus erythematosus: guidelines to management, integrating clues from the bench and bedside

Congenital heart block is a serious cardiac manifestation of neonatal lupus erythematosus that is associated with exposure to maternal autoantibodies against components of the SSA/Ro–SSB/La ribonucleoprotein complex. This Review outlines our current hypothesis regarding the pathogenesis of this disease and discusses how basic research can be applied to ensure appropriate prevention and management strategies are followed. One of the strongest clinical associations with autoantibodies against components of the SSA/Ro–SSB/La ribonucleoprotein complex is the development of congenital heart block in an offspring, an alarming prospect facing 2% of primigravid mothers with these reactivities. This risk is increased tenfold in women who have had a previous child with congenital heart block. Accumulated evidence suggests that anti-SSA/Ro and anti-SSB/La antibodies are necessary but insufficient for fetal disease. Basic and clinical research is heavily focused on identifying fetal and environmental factors that convert disease susceptibility to disease development. A disturbing observation that has emerged from current research efforts is the rapidity of disease progression, with advanced heart block and life-threatening cardiomyopathy being observed less than 2 weeks after detection of a normal sinus rhythm. Once third-degree block is unequivocally identified, reversal has never been achieved, despite dexamethasone treatment. Accordingly, strategies aimed at preventing disease before irrevocable scarring ensues assume a high priority. One approach has been the implementation of serial echocardiography to monitor for a prolonged PR interval. Intravenous immunoglobulin is being evaluated as a potential prophylactic approach in mothers who have previously had an affected child. Key Points Mothers with anti-SSA/Ro antibodies face a 2% risk of having a child with congenital heart block if it is a first pregnancy or if previous babies have all been healthy A previous child with congenital heart block raises the risk of having another by almost tenfold Normal sinus rhythm can progress to complete block in 7 days; thus, frequent monitoring of a pregnancy in a mother with anti-SSA/Ro antibodies is appropriate A mechanical PR interval of greater than 150 ms is consistent with first-degree block, and warrants an immediate discussion regarding the use of a fluorinated steroid to potentially reverse the situation Intravenous immunoglobulin is currently being evaluated as a prop