Differences in maternal soluble ST2 levels in the third trimester of normal pregnancy versus preeclampsia

BACKGROUND: Preeclampsia is associated with intense inflammatory response in pregnancy, and soluble ST2 (sST2) is pathologically increased in this condition. No data exist regarding maternal sST2 levels in normal pregnancy versus preeclampsia in areas of southeast Asia with an ethnic Malay predominance. MATERIALS AND METHODS: Patients were sorted into normal pregnancy or preeclampsia. Patients with a history of allergic, inflammatory, or malignant disease were excluded. One sample was taken per patient; all samples were taken during the third trimester of pregnancy. Thirty samples from each group were enrolled in the study, totaling 60 samples. Soluble ST2 levels in maternal plasma were measured using the Presage® ST2 Assay according to manufacturer instructions, and data was analyzed using SPSS 23. RESULTS: Patients in the preeclampsia group were significantly older than those in the normal pregnancy group (p = 0.01). Most patients with preeclampsia presented as early-onset (n = 23). Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly higher (p < 0.001) in the preeclampsia group. Mean sST2 level in the preeclampsia group (85.89 ng/ml) was significantly higher than the normal pregnancy group mean (38.3 ng/ml) during the third trimester (p < 0.001). This study also found a correlation between sST2 and preeclampsia (p < 0.001, r = 0.480), SBP (p < 0.001, r = 0.407), and DBP (p = 0.007, r = 0.342), while preeclampsia was found to be the best explanatory variable of sST2 levels (r = 0.468, p < 0.001). sST2 level> 63.66 ng/ml has sensitivity 50% and specificity 93.3%, with AUC of 0.78 [95% CI 0.66 – 0.90], p < 0.001. The sST2 > 63.66 ng/ml has an OR of 14.0 [95% CI 2.82 – 69.6], p < 0.001 for preeclampsia. The dose-response relationship between sST2 level and preeclampsia was linear. CONCLUSION: Soluble ST2 levels were increased in both normal pregnancy and preeclampsia but were significantly higher in patients with preeclampsia. Preeclampsia was also found to be the best explanatory variable for the increase of sST2 levels in ethnic Malay predominance.