Expression of prealbumin in maternal serum and placenta tissue of pregnant women and its relation with severity of hypertensive disorder complicating pregnancy

Abstract

Objective To investigate the expressions of prealbumin (PBA) in maternal serum and placenta tissue of pregnant women with hypertensive disorder complicating pregnancy, preeclampsia (PE) and PE with fetal growth restriction (FGR) and its clinical significance. Methods A total of 98 cases of singleton pregnancy women with different degrees of hypertensive disorder complicating pregnancy who had routine prenatal examination and delivered by cesarean section in Beijing Luhe Hospital, Capital Medical University from January 2014 to January 2016 were selected as research subjects. Among them, 31 pregnant women with hypertensive disorder complicating pregnancy, 33 cases with PE, and 34 cases with PE and FGR were divided into hypertensive disorder complicating pregnancy group, simple PE group and PE with FGR group, respectively. There were 30 cases of early-onset PE and 37 cases of late-onset PE among 67 pregnant women in simple PE group and PE with FGR group. Another 36 cases of normal full-term singleton pregnancy women who had routine prenatal examination and delivered by cesarean section in the same hospital during the same period were included into control group. Enzyme linked immunosorbent assay and immunohistochemical method were applied to detect the serum PBA levels and the expressions of PBA in placenta tissues of pregnant women before delivery. The serum PBA levels of 4 groups were compared by one-way ANOVA method, and further pairwise comparison was conducted by least-significant difference (LSD) method. Rates of negative, weakly positive, moderately positive, less strongly positive and strongly positive PBA expressions in placenta tissues of pregnant women in 4 groups were compared by Kruskal-Wallis H rank sum test, and Mann-Whitney U test was used for further pairwise comparison by adjusting size of test with Bonferroni method (α′=0.05/6=0.008). The procedures followed in this study were in accordance with the standards established by the Committee of Investigation in Human Beings Beijing Luhe Hospital, Capital Medical University, and this study was approved by the committee (Approval No. 2018LH-KS-025). All the subjects signed the informed consents for clinical trials. Results ①There were no statistical differences among 4 groups in the general clinical data, such as age, gravidity, parity, and body mass index (BMI) before pregnancy and so on (P>0.05). ②There were statistical differences among 4 groups in the mean arterial pressure, 24 h urine protein quantitation, gestational age, neonatal birth weight and serum PBA level (F=233.773, 222.081, 113.597, 214.420, 90.147; P<0.001). The results of further pairwise comparison of serum PBA levels among 4 groups showed that the serum PBA levels in hypertensive disorder complicating pregnancy group, simple PE group and PE with FGR group were significantly lower than that in the control group, serum PBA levels in simple PE group and PE with FGR group were significantly lower than that in hypertensive disorder complicating pregnancy group, serum PBA level in PE with FGR group was significantly lower than that in simple PE group, and all the differences were statistically significant (P<0.05). ③PBA was expressed in cytoplasm of placental villus trophoblast cells and represented as coarse brown particles. In maternal placental tissues of pregnant women in control group, PBA was less strongly positively and/ or strongly positively expressed in maternal placental tissues of pregnant women in simple PE group and PE with FGR group, PBA was negatively or weakly positively expressed; and PBA was moderately positively expressed in maternal placental tissues of pregnant women in hypertensive disorder complicating pregnancy group. ④There were statistical differences among 4 groups in the rates of negative, weakly positive, moderately positive, less strongly positive and strongly positive expression of PBA in maternal placental tissues (χ2=39.405, P=0.013). The results of further pairwise comparison showed that PBA expression in maternal placental tissues of pregnant women in simple PE group and PE with FGR group both were lower than that in the control group, and both the differences were statistically significant (Z=3.416, 4.846; P<0.001). Compared with hypertensive disorder complicating pregnancy group, PBA expression in maternal placental tissues of pregnant women in PE with FGR group decreased, and the difference was statistically significant (Z=2.829, P=0.004). ⑤Serum PBA level and PBA expression in maternal placental tissues of pregnant women with early-onset PE were lower than those with late-onset PE, and the differences were statistically significant (t=3.160, P=0.002; χ2=8.201, P<0.001). Conclusions PBA is lowly expressed in serum and placental tissues of pregnant women with hypertensive disorder complicating pregnancy, PE, and PE combined with FGR, especially in pregnant women with early-onset PE. And the expression level of PBA decreases as the severity of hypertensive disorder complicating pregnancy increases. Key words: Hypertension, pregnancy-induced; Pre-eclampsia; Fetal growth retardation; Prealbumin; Pregnant women