Neonatal Lupus Erythematosis, NLE  (SLE, Congenital Heart Block)

• a rare disease caused by placental transfer of maternal immunoglobulin G autoantibodies.
• all symptoms (rash, low platelets, liver dz) except that of heart block should clear once the antibodies clear in about 6-12 months.
• Note: Mom can have the antibodies without having SLE. As many as 80% of mothers of infants who have NLE are asymptomatic; the remainder have been diagnosed as having systemic lupus erythematosus or another rheumatic disease. 25% of infants with heart block are born to undiagnosed mothers.
• Associated with Anti-Rho and Anti-La antibodies.
• Maternal autoantibodies in infants who have NLE cause tissue damage that may affect the newborn's heart, skin, and liver.
• The major cause of morbidity and mortality is complete (third-degree) congenital heart block (CHB).

Cardiac involvement

• CHB in NLE results from immune damage to the fetal cardiac conduction system and is associated with transplacental passage of maternal anti-Ro (SSA) and, occasionally, anti-LA (SSB) antibodies.
• CHB occurs in approximately 50% of infants who have NLE and, unlike other manifestations that resolve as maternal antibodies disappear, usually is permanent and complete.
• It may be:
  • asymptomatic
  • fetal bradycardia
  • intrauterine congestive heart failure
  • hydrops fetalis / fetal death
  • neonatal death.
• The infant who has CHB may require pacemaker insertion, although death rates as high as 15% have been reported despite this intervention.
• If newborn has complete heart block, should evaluate mom for subclinical SLE)

Liver, skin, hematologic, neuro, renal

• Transient skin rash, IUGR

• Approximately 15% of infants who have NLE have hepatic involvement either alone or in association with cardiac, skin, or hematologic abnormalities.

• Typically, affected infants exhibit hepatomegaly, biochemical evidence of cholestasis, and possibly elevation of transaminases.

• Despite this, there do not appear to be long-term consequences of neonatal liver disease.

• Thrombocytopenia, occasionally accompanied by anemia or neutropenia, occurs in as many as 10% of affected infants. Platelet numbers generally normalize over the first few weeks of life, and treatment with high-dose corticosteroids only occasionally is required. An unusual complication caused by thrombocytopenia is intracerebral hemorrhage.

• Glomerulonephritis only rarely has been associated with NLE and is transient.

Treatment: Usually observe; can try short course of steroids/ or exchange transfusion

References:
McCauliffe DP. Neonatal lupus erythematosus. In: Harper J, Oranje A,
Prose N, eds. Textbook of Pediatric Dermatology. Malden, Mass:
Blackwell Science, Ltd; 2000:111-116
Rennebohm RM. Inflammatory "noninfectious" cardiovascular diseases.
In: Emmanouilides GC, Riemenschneider TA, Allen HD, Gutgesell HP, eds.
Moss and Adams' Heart Disease in Infants, Children, and Adolescents:
Including the Fetus and Young Adult. 5th ed. Baltimore, Md: Williams &
Wilkins; 1995:1441-1453
Silverman ED, Laxer RM. Neonatal lupus erythematosus. Rheum Dis Clin
North Am. 1997;23:599-618