Soluble Flt‐1, Placental Growth Factor, and Vascular Endothelial Growth Factor Serum Levels to Differentiate Between Active Lupus Nephritis During Pregnancy and Preeclampsia

Objective To evaluate mean serum levels of vascular endothelial growth factor (VEGF), placental growth factor (PlGF), and soluble Flt‐1 (sFlt‐1) in pregnant patients with systemic lupus erythematosus (SLE) with inactive disease, active lupus nephritis, and preeclampsia for differential diagnosis between these conditions. Methods Pregnant women with SLE, with singleton pregnancies and no other autoimmune diseases, were classified according to disease activity (inactive SLE and active lupus nephritis) and the presence of preeclampsia. Serum samples were collected within 3 weeks of delivery and frozen for subsequent blinded analysis through the enzyme‐linked immunosorbent assay method. Results A total of 71 women were included, with 41 classified as having inactive SLE (group 1; Systemic Lupus Erythematosus Pregnancy Disease Activity Index [SLEPDAI] score