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A case of neonatal lupus. Lorna Miller CBMS Immunology. Neonatal lupus. Rare disorder Mum has SLE Transplacental passage of Mum’s IgG autoantibodies Cardiac, skin and liver symptoms. Systemic Lupus Erythematosus. Arthritis Fatigue Skin rash Pericarditis Neuropathy Nephritis
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A case of neonatal lupus Lorna Miller CBMS Immunology
Neonatal lupus Rare disorder Mum has SLE Transplacental passage of Mum’s IgG autoantibodies Cardiac, skin and liver symptoms
Systemic Lupus Erythematosus Arthritis Fatigue Skin rash Pericarditis Neuropathy Nephritis Recurrent miscarriage Thrombosis
Pathogenesis Autoantibody production: Dysregulated self tolerance Defective apoptosis leading to antigen presentation of DNA & nuclear proteins Immune complex deposition - skin, kidneys Complement activation
Laboratory investigation Diagnosis: ANA (anti-nuclear antibodies) DNA antibody ENA antibodies (extractable nuclear antigens) Monitoring: C3 C4 DNA antibody level if positive at diagnosis
Case study Baby boy Mum has SLE Normal birth & weight Tachycardia, raised respiratory rate & low O2 sats since birth Cardiology referral – no abnormality
1 week after birth developed macular, erythematous rash on head, neck and trunk Not pyrexial, no signs of infection Referred to Dermatology
CRP <1 mg/L Normal renal function ANA medium positive with speckled staining pattern
Negative ANA Speckled ANA
ENA antibodies Baby Anti Ro Positive Anti La Positive Anti RNP Negative Anti Sm Negative
ENA antibodies Baby Anti Ro Positive Anti La Positive Anti RNP Negative Anti Sm Negative Mum Anti Ro Positive Anti La Positive Anti RNP Negative Anti Sm Negative
Baby Anti Ro Anti La Mum Anti Ro Anti La Neonatal lupus – rash, no cardiac defect Placental transfer
Monitor antibody levels Hydrocortisone cream for rash Suggest screen future pregnancies for fetal heart block
4 months later Mum Anti Ro Positive Anti La Positive Baby Anti Ro Negative Anti La Negative No rash Normal development
Neonatal lupus Only 1% of babies with positive maternal antibodies develop neonatal lupus. If anti Ro positive mother has 1 child with neonatal lupus, incidence in subsequent pregnancies is 25%.
Skin symptoms are transient and disappear by age 6 months when cleared from the neonatal circulation. Transient haemolytic anaemia, neutropenia or thrombocytopenia may occur within first 2 weeks and usually disappear by 2 months old.
Fetal heart block Anti Ro & La can cause cardiac conduction defects in utero leading to complete heart block. Autoantibodies bind to cardiocytes stimulating destruction by macrophages and fibrosis Neonatal mortality rate is 20-30 %