Ro/SSA and La/SSB are proteins found inside cells. Anti-Ro/SSA and anti-La/SSB are antibodies that form against these proteins. These antibodies can be seen in autoimmune diseases, the most common being<unk>  and Sjögren’s. Mothers can have these antibodies circulating in their blood without having any signs or symptoms of an autoimmune disease. Babies born to mothers with these antibodies have a chance of developing<unk> . This occurs when maternal anti-Ro/SSA and anti-La/SSB antibodies enter fetal circulation and affect neonatal organs by crossing the placenta using FcRn receptors. The mechanism in which the antibodies affect organs is not yet completely understood. For the heart, it is thought that these antibodies bind to cells in the heart that go through physiologic cell death during embryogenesis. This leads to heart cell injury which causes secondary fibrosis in the conduction system, ultimately causing heart block. These antibodies can also affect calcium channels which are needed to initiate action potentials. Disruption to action potential propagation can affect the AV and SA nodes which are part of the conduction system of the heart. Fetal susceptibility and environmental factors could also play a role in pathogenesis since not all infants develop congenital heart block even when exposed to antibodies.
Neonatal lupus erythematosus
Transient bullous dermolysis of the newborn
Neonatal tetanus
Neonatal herpes simplex
Neonatal hepatitis
Neonatal toxic shock-like exanthematous disease
Michelin tire baby syndrome
Congenital syphilis