Neonatal Lupus Flashcards
Anti-Ro60/Trove2
60-kD polypeptide
- Ro60 protects the cell from damage from UV
- play a role in RNA quality control
- May protect against the development of autoabs by sequestering defective RNPs
- Can appear on the cell surface during stress or apoptosis and therefore be a direct target for autoantibodies
Anti La/48
Can appear on the cell surface during stress or apoptosis and therefore be a direct target for autoantibodies
- Not a good screening tool alone
Anti Ro 52/Trim 21
Catalyzes the ubiquitination of
several proteins including Ro 52 itself
- Regulates of proinflammatory cytokine production
- The production of type I ifn and cytokine via its ubiquitination of IRF
- Regulation of innate immune response to dsDNA
- Modulation of follicular b cell homeostasis and IG production
- Less sensitive but more specific (found in 70-100 percent of mothers of children with CHB
Autoantibodies to test for in NLE
- Anti Ro60
- Anti Ro52
- Anti La 48
- Anti U1RNP
Most common autoimmune diseases present in a mother of a child with NLE
SS
SLE
UCTD
Genes important for the production of anti-Ro and anti-La antibodies
HLA DR
HLA DQ
Genes associated with anti Ro52 and anti La48
HLA DR3
Risk factors for CHB
Mother with high anti-Ro Titers who already had a child with CHB (risk rises from 1 to 5% to 18-25%)
Characteristic pathological finding
Absence of degeneration of the AV node with or without the bundle of HIS with replacement by fibrosis and calcification
Risk factors associated with perinatal mortality
- Earlier gestational age at CHB diagnosis
- fetal hydrops
- myocarditis
- EFE
- CHB with a heart rate less than 50 bpm
Treatments for NLE (mother)
- Dexamethasone for second or third degree heart block without EFE, EFE, or EFE with any degree of heart block
- Maternal IVIG if there is evidence of myocarditis, EFE or incomplete AV block
- High dose maternal beta 1 adrenergic stimulation is used when fetal heart rates are below 50 bpm or when there is significantly reduced cardiac contractility
Treatments for NLE (Baby)
- Pulse for neonates with myocarditis/EFE
- A trial of red for neonates with second degree heart block, those who were in CHB in utero and showed signs of improvement and or those who had evidence of myocarditis/EFE on pre or post natal cardiac US
Why is the rash of NLE more common in females?
Estrogen increases surface expression of Ro an LA on keratinocytes
Rash associated with NLE
- Resembles lesions of SCLE, less malar , less indurated\
- Face and scalp are the most commonly involved areas but it can be anywhere including palms and soles
- Can see raccoon eye distribution
- Can be present at birth but more commonly develops within the first few weeks of life
- rarely develop after 6 months