Antibody to cardiolipin, lupus anticoagulant, and fetal death

Area of Science:

• Obstetrics and Gynecology
• Rheumatology
• Hematology

Background:

• Systemic lupus erythematosus (SLE) and lupus anticoagulant are associated with adverse pregnancy outcomes, including fetal death.
• Predictive markers for fetal death in these high-risk pregnancies are crucial for clinical management.

Purpose of the Study:

• To compare the concordance and predictive accuracy of activated partial thromboplastin time (APTT) and cardiolipin antibodies (aCL) for fetal death in pregnant women with SLE.
• To determine which assay, APTT or aCL, is a superior predictor of fetal demise.

Main Methods:

• A cohort of 50 pregnant women with SLE and/or lupus anticoagulant was studied.
• APTT and IgG/IgM aCL levels were assessed during pregnancy.
• The association between abnormal test results and fetal death was analyzed, calculating sensitivity and specificity.

Main Results:

• Overall concordance between abnormal aCL and abnormal APTT was 76% (p<0.10).
• Fetal death occurred in 50% of patients with high APTT versus 16% with low APTT.
• Fetal death occurred in 77% of patients with abnormal aCL versus 5% with normal aCL.
• Sensitivity for predicting fetal death was 0.55 for APTT and 0.85 for aCL.
• Specificity was 0.81 for APTT and 0.92 for aCL.

Conclusions:

• APTT and aCL assays are frequently discordant, precluding their interchangeable use.
• Cardiolipin antibodies (aCL) demonstrate superior predictive power for fetal death compared to APTT in pregnant women with SLE.
• aCL is the recommended assay for predicting fetal death in this patient population.