TRIM21 and neonatal lupus erythematosus: <h4>Background</h4>Maternal anti-Ro/SSA (Sjögren's syndrome-related antigen A) [± anti-La/SSB (Sjögren's syndrome type B antigen)] antibodies can lead to neonatal lupus, which may present most severely as autoimmune congenital atrioventricular block (CAVB).