Treatment of preeclampsia at extremely preterm gestation with therapeutic plasma exchange

Different forms of apheresis have been proposed as potential therapeutic approaches to remove soluble Fms-like tyrosine kinase-1 (sFlt-1) and allow safe pregnancy prolongation in cases of extremely preterm preeclampsia. This is a follow-up study presenting our experiences with therapeutic plasma exchange (TPE) in 5 women with preeclampsia at < 28 weeks of gestational age.

All women received standard treatment for preeclampsia and 2 - 3 TPE treatments per week. Blood samples for sFlt-1 and placental growth factor (PlGF) measurements were collected before and after each TPE.

Seventeen TPE procedures were performed, 2 - 5 per patient. TPE significantly reduced sFlt-1 (by 35 ± 6%), sFlt-1/PlGF ratio (by 24 ± 13%), and to a lesser degree also PlGF (by 12 ± 16%), with a rebound observed on day 1 post procedure. TPE procedures were well tolerated by pregnant women and fetuses. Stabilization of sFlt-1 allowed pregnancy prolongation for a median of 8 (range 2 - 14) days from first TPE and for a median of 10 (range 4 - 17) days from hospital admission. There were no signs of increased risks of adverse neonatal outcome associated with TPE. One neonate died due to extreme prematurity 3 days after delivery, 2 had bronchopulmonary dysplasia, and 1 had retinopathy of prematurity.

This study provides new evidence of effective reduction in sFlt-1 and sFlt-1/PlGF ratio with TPE treatment, which seems to allow a clinically meaningful prolongation of pregnancy. Controlled studies are necessary to convincingly show the potential benefit of apheresis treatment in preeclampsia at extremely preterm gestation.