The sFlt-1 to PlGF ratio in pregnant women with rheumatoid arthritis: impact of disease activity and sulfasalazine use.

OBJECTIVES:An elevated sFlt-1/PlGF ratio has been validated as a significant predictor of preeclampsia, but has not been established in women with RA. We explored whether the sFlt-1/PlGFratio could be altered due to disease activity in RA, and could be applied in this population to predict preeclampsia. Since SSZ has been suggested to improve the angiogenic imbalance in preeclampsia, we also aimed to examine whether SSZ could affect sFlt-1 or PlGF levels. METHODS:Making use of a nationwide, observational, prospective cohort study on pregnant women with RA, sFlt-1 and PlGF were measured in the third trimester. A total of 221 women, aged 21-42 years, were included, with a median gestational age of 30 + 3 weeks. RESULTS:No differences in sFlt-1 or PlGF were observed between women with high, intermediate or low disease activity (P = 0.07 and P = 0.41), whereas sFlt-1 and PlGF did not correlate with DAS28-CRP score (r = -0.01 and r = -0.05, respectively). Four (2%) women with a sFlt-1/PlGF ratio ≤38 developed preeclampsia in comparison to three (43%) women with a ratio > 38, corresponding to a negative predictive value of 98.1%. SSZ users (n = 57) did not show altered levels of sFlt-1 or PlGF in comparison to non-SSZ users (n = 164, P = 0.91 and P = 0.11). CONCLUSION:Our study shows that in pregnant women with RA, the sFlt-1/PlGF ratio is not altered due to disease activity and a cut-off ≤38 can be used to exclude preeclampsia. Additionally, SSZ use did not affect sFlt-1 or PlGF levels in this population.