Makindo Medical Notes

Related Subjects: | Systemic Lupus Erythematosus (SLE) | Drug-induced Lupus Erythematosus | Discoid Lupus Erythematosus (DLE) | Neonatal Lupus Erythematosus

Neonatal Lupus Erythematosus (NLE) is a rare autoimmune condition affecting infants born to mothers who have autoantibodies against Ro/SSA and La/SSB antigens. While some mothers may have a known diagnosis of Systemic Lupus Erythematosus (SLE) or other autoimmune diseases, others may be asymptomatic carriers of these antibodies.

Aetiology

• Maternal IgG autoantibodies, specifically Anti-Ro (SSA) and Anti-La (SSB), cross the placenta during pregnancy.
• These antibodies can bind to fetal tissues, leading to inflammation and damage.

Clinical Effects on the Fetus and Neonate

• Cardiac Manifestations:
  • Congenital heart block (first, second, or third degree), which may lead to bradycardia and, in severe cases, congestive heart failure.
  • Cardiomyopathy and endocardial fibroelastosis in some cases.
• Dermatological Manifestations:
  • Circular or elliptical erythematous rash, often with central clearing, typically appearing on the face, scalp, and periorbital areas ("raccoon eyes").
  • Rash may be exacerbated by exposure to ultraviolet light.
• Hematological Manifestations:
  • Haemolytic anaemia.
  • Thrombocytopenia (low platelet count).
  • Neutropenia (low neutrophil count).
• Hepatic Manifestations:
  • Elevated liver enzymes indicating hepatocellular damage.
  • Hepatomegaly (enlarged liver).

Investigations

• Maternal Testing:
  • Serological testing for Anti-Ro (SSA) and Anti-La (SSB) antibodies.
  • Assessment for underlying autoimmune diseases like SLE or Sjögren's syndrome.
• Prenatal Monitoring:
  • Serial fetal echocardiography starting from 16 weeks' gestation to detect early signs of heart block.
  • Monitoring fetal heart rate for bradycardia.
• Neonatal Testing:
  • Electrocardiogram (ECG) and echocardiogram to evaluate cardiac involvement.
  • Complete blood count (CBC) to assess anaemia, thrombocytopenia, and neutropenia.
  • Liver function tests to detect hepatic involvement.
  • Skin biopsy (rarely needed) to confirm diagnosis of skin lesions.

Management

• Prenatal Management:
  • Close monitoring of at-risk pregnancies with serial ultrasounds and fetal echocardiography.
  • Consideration of maternal corticosteroid therapy to reduce antibody levels (use is controversial and should be guided by a specialist).
  • Potential use of hydroxychloroquine in pregnant women with positive antibodies to reduce risk.
• Postnatal Management:
  • Cardiac Management:
    • Insertion of a pacemaker in cases of complete (third-degree) heart block.
    • Treatment of heart failure with medications as needed.
    • Regular cardiology follow-up for ongoing assessment.
  • Dermatological Management:
    • Avoidance of sun exposure; use of protective clothing and sunscreen.
    • Topical corticosteroids may be prescribed for skin lesions.
    • Most skin manifestations resolve spontaneously as maternal antibodies wane.
  • Hematological Management:
    • Monitoring blood counts regularly.
    • Blood transfusions may be necessary for severe anaemia.
    • Management of infections due to neutropenia.
  • Hepatic Management:
    • Supportive care as liver function typically normalizes over time.
• Parental Support and Education:
  • Provide information about the condition, prognosis, and potential complications.
  • Genetic counseling may be offered for future pregnancies.

Prognosis

• Non-cardiac manifestations (skin, liver, hematological) usually resolve by 6 to 8 months of age as maternal antibodies are cleared.
• Congenital heart block is often permanent and may require lifelong pacing and cardiology care.
• With appropriate management, many infants can lead healthy lives.

References

• Neonatal Lupus Erythematosus - StatPearls
• Lupus Foundation of America: Neonatal Lupus
• American College of Rheumatology: Neonatal Lupus