Systemic Lupus Erythematosus, Part I: Diagnosis and Risks

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Reading: SMFM Consult Series #64: SLE in Pregnancy

What is systemic lupus erythematosus?

  • Definition

    • Chronic, multisystem, inflammatory autoimmune disease characterized by relapses and remission

    • Many organs can be involved and manifestations are variable between individuals

  • Why do we care about SLE in pregnancy?

    • The prevalence of SLE is about 28-150/100,000 individuals

    • More prevalent in females than males; often affects young adults, so it is a condition that can be encountered in pregnant individuals – currently 3300 deliveries per year are in people with SLE

How do we diagnose lupus?

  • Lupus = a syndrome and diagnosis requires presence of characteristic clinical features + confirmatory laboratory studies

    • Unfortunately, there are broad clinical manifestations, lack of pathognomic features or lab tests

    • Usually, you won’t have to diagnose lupus and someone will come into pregnancy already with the diagnosis

    • However, knowing the diagnostic criteria can be helpful in recognizing individuals who may have lupus

    • Can help the patient have faster recognition + referral to rheumatology

  • Diagnostic criteria – will include 2

    • From The European Alliance of Associations for Rheumatology (EULAR) – sensitivity of 96%, specificity is 93%

    • From the Systemic Lupus International Collaborating Clinics (SLICC) – sensitivity is 97%, specificity is 84%

smfm sTATEMENT ON sle; eular cRITERIA FOR sle

smfm; slicc criteria for sle

smfm; aplas criteria

Pregnancy and lupus

  • Increased maternal morbidity and mortality

    • Complications include nephritis, hematologic complications, neurologic abnormalities

    • Several fold increased risk of thrombosis, thrombocytopenia, infection, multiorgan disease

    • Pregnancy can also increase risk of disease flare, and 15-30% of flares are severe, and some can be life-threatening  

  • Lupus nephritis

    • Active renal disease is defined as >1g/day of proteinuria or GFR <60 in non-pregnant state

    • There is increased risk of permanent renal damage if GFR going into pregnancy is <40 or creatinine is >/= 1.5 mg/dL

    • One issue: difficult to differentiate lupus nephritis from preeclampsia

      • We discussed this in our episode “Imitators of Pre-eclampsia”

      • Features more common with lupus flare and less likely to be preeclampsia: increased anti-dsDNA ab, decreased levels of complements, usually will not have thrombocytopenia or elevated LFTs

      • Also, kidney biopsy that showed glomerulendotheliosis can yield a definitive diagnosis

      • Important to differentiate because the treatment for lupus nephritis can be medical, while severe preeclampsia may require delivery à if we don’t differentiate, could deliver extremely premature infant with no need

  • Hematologic Complications

  • Central Nervous System and Neurologic Complications

    • Can include headache, seizures, neuropathy, chorea, cerebritis, and even psychosis

    • CNS vasculitis is the most serious CNS disorder  

  • Other organ manifestation:

    • Cutaneous lupus erythematousus

    • Can also affect bones, joints, lungs, heart

  • So… how does all this affect pregnancy?

    • Obstetric outcomes:

      • 3x increased risk of pregnancy loss; however, if well controlled, risk ranges from 8-32%, which may not be substantially different from rates reported in the general obstetrical population for early pregnancy loss

      • Increased risk of preeclampsia: 15-35%

        • Risk is highest in those with active disease at time of conception, renal disease, chronic hypertension, those on high-dose prednisone, or those with APLS antibodies  

        • Prevention: low dose aspirin beginning at 12 weeks of gestation until delivery to decrease risk of preeclampsia

    • Fetal outcomes:

      • Risk of fetal growth restriction is 6-35% depending on the study

      • Increased risk of preterm birth, ranging from 19%-49%

        • The risk of preterm birth is associated with increased disease activity at time of conception, nephritis, chronic hypertension, and APLS antibodies

    • Neonatal complications 

      • Occurs in 1/20,000 live births, so it is rare but it is a serious complication

      • Caused by antibodies that can cross the placenta, usually anti-SSA, though anti-SSB antibodies can also cause this

      • Manifestations include skin lesions, congenital heart block, anemia, hepatitis, and thrombocytopenia

        • Skin lesions occur in approximately 50% of affected infants

      • Recurrence risk in patients with history of neonatal lupus and positive antibodies is 15-20% 

      • Because it is due to antibodies, skin, hematologic manifestations, and hepatitis usually resolves 3-6 months after birth; however, congenital heart block will not resolve as SSA antibodies lead to fibrosis of myocardial tissue and conduction system