Diagnostic accuracy of placental alkaline phosphatase concentrations in
gingival crevicular fluid at early pregnancy in predicting the risk of
preeclampsia: a prospective cohort study
Abstract
Objective: To evaluate the accuracy of concentrations of gingival
crevicular fluid (GCF) placental alkaline phosphatase (PLAP) during
early pregnancy in identifying women at risk of subsequently developing
preeclampsia (PE). Design: Prospective cohort study. Setting: Hospital
Sotero del Río, Santiago, Chile. Population: Pregnant women recruited at
11-14 weeks of gestation. Methods: Maternal obstetric and periodontal
histories were obtained. GCF samples were collected for PLAP
determination by ELISA assay. Multiple logistic regression models
estimated the association between GCF-PLAP concentrations, maternal
variables, and PE development. The accuracy performance of the
prediction model was established. Results: 460 women were recruited into
the study, and 412 completed their pregnancy follow–up visit. 18
(4.3%) women developed PE. GCF-PLAP concentrations and systolic blood
pressure measurements were significantly higher in women who developed
PE (p=0.015 and p<0.001, respectively). An association between
first-trimester systolic blood pressure, GCF-PLAP, and PE were
established. The predictive model had a sensitivity of 83%, specificity
of 72%, a positive predictive value (PPV) of 12%, and a negative
predictive value (NPV) of 99%. The positive and negative likelihood
ratios were 2.9 and 0.3, respectively, thus classifying correctly 72%
of women who subsequently developed PE. The area under the receiver
operating characteristic curve was 0.77 for PE and 0.85 for preterm PE.
Conclusions: An algorithm that includes PLAP concentrations in GCF and
blood pressure during early pregnancy may aid in the identification of
women at risk of developing PE. Funding: FONDEF IDeA: ID16I10452.
NICHD/NIH/DHHS: HHSN275201300006C. Keywords: a cohort study, gestation,
hypertension, placental biomarkers, risk prediction model.