38 women with SLE (according to American College of Rheumatology classification criteria) followed at a high risk prenatal care were included. They had no other autoimmune disease diagnosed and were divided according to disease activity and presence of PE. Blood collection was performed at third trimester of pregnancy, within 3 weeks of delivery, and frozen for subsequent blinded analysis through ELISA method.
According to according to SLEPDAI (Systemic Lupus Erythematosus Pregnancy Disease Activity Index), 23 patients had inactive SLE (group 1),8 had active lupus nephritis (group2) and 7 had PE (group3). The mean gestational age of blood collection was 36.4 weeks for group 1, 35.5 for group 2 and 35.8 for group 3, without statistical difference between groups. The mean values of VEGF, PlGF and sFlt-1 of all groups are described on Table 1. Considering VEGF and PlGF, patients with SLE and PE had significantly lower mean serum levels than SLE patients without PE, while sFlt-1 was significantly higher in patients with PE compared to inactive SLE and SLE nephritis. The ratio sFlt-1/PlGF was also significantly higher in patients of group 3(PE) compared to other patients with SLE (groups1 and 2). There was no difference between all three studied cytocines or sFlt-1/PlGF ratio when the results were compared between inactive and active SLE.
In this pilot study, pregnant patients with SLE and PE had lower mean serum levels of VEGF and PlGF and higher mean serum levels of sFlt-1 and sFlt-1/PlGF ratio than pregnant patients with inactive SLE and active SLE nephritis. The results suggest that SLE patients with PE have the same angiogenic and antiangiogenic profile of patients with PE without lupus. Further studies with more patients are needed to confirm the use of angiogenic and antiangiogenic factors as potential tools to differentiate PE from SLE nephritis in clinical practice.