LONG-TERM OUTCOMES OF POSTNATAL IMMUNOSUPPRESSIVE THERAPY IN CHILDREN WITH CARDIAC NEONATAL LUPUS ERYTHEMATOSUS

PV154 / #267

Poster Topic: AS17 - Miscellaneous

Background/Purpose Neonatal lupus erythematosus (NLE) is a passively acquired autoimmune condition. The antibody-mediated neonatal heart disease of NLE is associated with a high risk of mortality and adverse health outcomes. Prenatal treatment can slow progression from incomplete to complete heart block and improve neonatal survival. However, the impacts of postnatal immunosuppressant treatment have not been described. This study aimed to describe the outcomes of children with antibody-mediated cardiac NLE treated with postnatal therapy.

Methods We reviewed patients consented from the NLE clinic in a tertiary pediatric center, born between January 1, 1997 – June 10, 2024. We identified patients with cardiac manifestations who received postnatal immunosuppressants. The protocol typically included 1 dose of intravenous immunoglobulin (IVIG) 2g/kg, pulse corticosteroid of 30 mg/kg/day for 3 days, followed by 2 mg/kg/day for 4 weeks with tapering guided by troponin levels. We reviewed medical records with long-term outcomes supplemented by patient/parent questionnaires. We report the prevalence of features and outcomes using summary statistics.

Results We reviewed 33 patients with cardiac manifestations of NLE and postnatal therapy. Of the total cohort, 28 (85%) mothers received prenatal immunosuppressive therapy with dexamethasone, IVIG and/or a beta agonist. The median duration of follow-up was 6.04 years (IQR: 2.47 – 11.36 years). The majority (70%) of patients presented with heart block at birth (first-degree/second-degree atrioventricular block [n=7], complete heart block [n=16]). The remaining 10 patients had extranodal manifestations of cardiac inflammation, including echogenic endocardium and valvular regurgitation. All the patients received corticosteroids, 17 with pulse and 28 received IVIG. Of the 7 patients with first or second-degree block at birth, 4 progressed to complete heart block within an average of 11 months. One patient with first-degree block had complete reversal to normal sinus rhythm. Of the 18 (70%) patients that required a permanent pacemaker, 83% were paced within the first year of life. Of all patients that developed complete heart block in their lifetime, 2 never required pacing (age at last follow-up 17.38 and 19.25 years). None of the patients required a heart transplant. Three patients developed device-associated or sternal wound infections an average of 1.1 months after birth. Mortality in the cohort was 9% with cause of death attributed to circulatory shock due to sepsis and an unrelated genetic syndrome.

Conclusions We report on the outcomes of a large series of children with cardiac NLE who received postnatal immunosuppressive therapy. The vast majority of patients had good outcomes. The 9% mortality is improved upon historical reports ranging from 13-30%. Postnatal immunosuppressive therapy may be responsible for improved cardiovascular outcomes in children with antibody-mediated neonatal heart disease.