KIR2DL1 Gene Expression in Women with Preeclampsia: A Case Control Study

Abstract

Background: Preeclampsia is a major cause of hypertension in pregnancy and is a leading cause of
maternal and perinatal morbidity worldwide. Abnormal regulation of killer cell immunoglobulin-like
receptor 2DL1 (KIR2DL1) has been linked to defective placentation caused by impaired uterine natural
killer cell function at the fetal–maternal interface.
Objective: To quantify KIR2DL1 expression in the peripheral blood of preeclamptic patients and assess
its potential as a diagnostic marker.
Materials and Methods: The study design was hospital-based, and sixty pregnant women were included
in the study. The participants were randomly assigned to either the preeclampsia group or the health
control group, consisting of thirty participants in each group. The RNA was extracted from the blood, and
RT-qPCR was used to determine KIR2DL1 expression using GAPDH as an endogenous control. The
2⁻ΔΔCt formula was used for data analysis. The Mann-Whitney test, Spearman correlation, and ROC
curve were used.
Results: The expression of KIR2DL1 was significantly higher in the preeclampsia group compared to the
controls (median fold change: 1.950 vs. 1.005; p = 0.0001). The ROC curve showed perfect discriminative
power of the marker for preeclampsia, with an area under the ROC curve of c1.00 and sensitivity and
specificity of 100% at a cut-off of 1.240. The expression of KIR2DL1 correlated positively with maternal
age in the preeclampsia group (rho = 0.462; p = 0.030).
Conclusion: High expression of KIR2DL1 in peripheral blood cells is strongly and significantly related
to preeclampsia, suggesting that there is excessive inhibitory receptor activity at the maternal-fetal
interface. KIR2DL1 holds great potential to become a molecular diagnostic biomarker for preeclampsia.