Assessment efficacy of neutrophil-lymphocyte ratio and monocyte-lymphocyte ratio in preeclampsia

Abnormal changes in immune-mediated inflammation contribute to the pathogenesis of preeclampsia (PE). We aim to investigate the value of systemic immune inflammation indices-neutrophil-lymphocyte ratio (NLR) and monocyte-lymphocyte ratio (MLR)-to identify and evaluate the prognosis of patients with PE.

This study reviewed clinical records of 367 PE patients (162 with mild PE and 205 with severe PE), in addition to a control group of 172 normal pregnancies. Blood cell counts were performed at the first diagnosis of PE, and NLR and MLR were calculated by absolute cell count.

Absolute neutrophil, lymphocyte, and monocyte counts and NLR and MLR values in PE were significantly different from controls, although monocyte counts did not significantly differ between mild and severe PE. Receiver operating characteristics curve (ROC) analysis showed NLR and MLR had better diagnostic accuracy in distinguishing PE from controls [NLR area under the curve (AUC) = 0.70; MLR AUC = 0.78]. Further, NLR was the best predictor of disease severity (AUC = 0.71). Cutoff values of NLR > 4.198 or MLR > 0.325 for control and PE groups or a cutoff value of NLR > 4.182 for PE groups indicated that patients were more likely to encounter preterm delivery, have shorter admission-to-delivery interval, and develop maternal and neonatal complications.

Secondary analyses of white blood cell differential count parameters effectively evaluate the systemic inflammatory/immune state. Compared with absolute cell counts, NLR and MLR offer more effective indicators of clinical assessment, disease severity evaluation, and prognosis evaluation of PE.