Soluble Flt-1 as a diagnostic marker of pre-eclampsia.
BACKGROUND
Serum levels of soluble fms-like tyrosine kinase (sFlt-1) increase in pre-eclampsia (PE).


OBJECTIVE
To determine whether concentrations of serum sFlt-1 can differentiate PE or superimposed PE (SPE) from gestational hypertension (GH) or chronic hypertension (CH).


METHODS
Blood was collected from pregnant women being investigated for hypertension (blood pressure of > 140 and/or 90 mmHg). Normotensive (NP) and pre-eclamptic (PE-C) control ranges were measured.


RESULTS
Patients with evolving hypertension in pregnancy eventually fell into four groups: GH (n = 14), PE (n = 7), CH (n = 9) and SPE (n = 9). Patients who later developed pre-eclampsia had a higher sFlt-1 (PE: 2.61 ng/mL and SPE: 2.77 ng/mL, respectively) than GH (P < 0.001) or CH (1.05 ng/mL, P = 0.11). Women with established PE at recruitment (PE-C; (n = 18) (3.13 ng/mL; interquartile range (IQR): 2.14-4.17 ng/mL) had a median sFlt-1 higher than NP (n = 18) (0.47 ng/mL; IQR: 0.11-0.89) (P < 0.0008). Patients with GH compared to NP had a slight increase (1.33 ng/mL, P < 0.003). Using a sFlt-1 cut-off of > or = 1.9 ng/mL yielded a sensitivity of 94% (95% confidence interval (CI) 73-100%) and specificity of 78% (95% CI 64-82%).


CONCLUSIONS
sFlt-1 was elevated in women with PE compared to NP. The sFlt-1 also differentiated women destined to develop PE among those who presented with a diagnostic rise in maternal blood pressure. The sFlt-1 test is a useful diagnostic test for PE.
Woolcock
Jane
J
Department of Obstetrics and Gynecology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
Hennessy
Annemarie
A
Xu
Bei
B
Thornton
Charlene
C
Tooher
Jane
J
Makris
Angela
A
Ogle
Robert
R
D000328:Adult; D015415:Biomarkers / Q000097:blood*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis; D046110:Hypertension, Pregnancy-Induced / Q000175:diagnosis; D011225:Pre-Eclampsia / Q000175:diagnosis*; D011247:Pregnancy; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000097:blood*
D015415:Biomarkers; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1