PE patients and Healthy pregnant groups

The Baquba Teaching Hospital's Obstetrics and Gynecology Department conducted this cross-sectional, case-control study from Sep. 2022 to Dec 2023. The Diyala Sciences College's Ethical Committee granted its permission for this study's ethical conduct. The research included 22 third-trimester pregnant women with severe PE and 38 with moderate PE at admission (MPE group) (SPE group). 30 healthy and expecting.

• Proteinuria was < 2+  on urine dipstick on at least two random specimens collected more than 4 hours apart after the 24th week of pregnancy, and MPE was SBP 140 mmHg or DBP 90 mmHg validated by 6 or more hours apart.
• SPE was identified by having SBP of at least 160 mmHg, DBP of at least 110 mmHg, proteinuria > 2+ on a urine dipstick, as well as headache, visual disturbances, upper abdominal pain, and oliguria. The SPE group's whole female population experienced both proteinuria and hypertension.
• Healthy pregnant : Normotensive pregnant women with gestational ages of  more than 24 weeks, no chronic medical conditions, and no signs of labor. They had healthy blood pressure and were not hypertensive during pregnancy. Patients having a history of diabetes, kidney illness, hypertension, other cardiovascular issues, or infectious infections with symptoms were not allowed to participate.

Criteria for inclusion

Absence of labor contractions, an early membrane rupture, or clinical chorioamnionitis were the criteria for the PE group. None of the patients included had any of the following conditions, which were ruled out through regular consultations, clinical examinations, and laboratory tests: underlying diabetes, renal illnesses, chronic hypertension, or symptomatic infectious diseases. Before being enrolled in the trial, for a minimum of seven days, the pregnant women did not get corticosteroids.

Sample collection

Blood samples were taken from the patients' antecubital veins while they were lying supine after a minimum of eight hours of fasting and one hour of rest. The serum was then collected and stored at -20 C until use; whereas the urine that was still in the sterile container was examined with a Dipstick.

Urine sample : First morning urine sample was taken in a clean container free from any detergent. A mid-stream sample was taken, and it was put in a sterile container. The sample was then moved to an all-purpose container, and the pee still present in the sterile container was analyzed using a Dipstick. The qualitative dip-stick technique was used to assess the protein content of urine.

Anthropometries Measurements

Age, weight, and height were established using anthropometric measurements. Calculating one's body mass index involves employing a method that is based on the fundamental formula of weight divided by height squared (BMI).

Measurements of blood pressure 

Using a stethoscope, sphygmomanometer, which consists of a blood pressure cuff and a mercury column pressure gauge, and auscultation, which involves listening to sounds, blood pressure was indirectly measured by 1902 by Russian physician N.S. Korotkoff. Systolic and diastolic blood pressure were both measured in millimeters of mercury, and for each individual, the average of the previous two readings was taken.

Urine analysis

A mid-stream sample was taken, and it was put in a sterile container. The sample was then moved to an all-purpose container, and the pee still present in the sterile container was analyzed using a Dipstick. The qualitative dip-stick technique was used to assess the amount of urine protein (CYBOWTM DFI Co Ltd, Republic of Korea). It was determined in accordance with the manufacturer's description. The test's underlying principle is the protein "error of indicators." The presence of protein causes indicator dyes to release H⁺ ions, which cause them to turn green from yellow to blue green whenever a buffer keeps the pH stable. A visual inspection is an assay. A new strip was briefly dipped into urine that had been gathered early in the morning and stored in clean, dry plastic containers. In less than two seconds, the Up to the test region, the strip was inserted. To eliminate extra urine, the strip's edge was drawn around the brim of the vessel, making sure the test area did not contact it. Since too much pee on the strip might produce chemical interactions between neighboring pads that would lead to inaccurate findings, to get rid of any remaining pee, the strip was turned over and tapped against a piece of absorbent paper. In well-lit situations, both the test result that was displayed on the strip that was held horizontally and the color scheme that was included on the bottle label were contrasted.

Study of groups in clinical laboratories

The concentrations of sEng were measured using an ELISA plate reader (ca Inc., San Diego, CA, USA). An automated enzymatic technique was used to evaluate the serum lipid profile testing.

Statistical analysis

Using SPSS, the statistical analysis was completed (version 25). For numerical variables having normally distributed data, the data were converted into the average and the variation from the mean, respectively, and for categorical variables, into frequency/percentage. While a t-test performed independently, and an ANOVA test were employed to see whether there was a significant difference between the typically numerical variables. P 0.05 was used as the significant level The Pearson correlation and t-test were used to calculate the correlation's significance for the relationship between the two quantitative variables. Using the receiver operating characteristic (ROC) curve approach, it was possible to evaluate the utility of sEng as a diagnostic marker or disease-screening tool. Additionally, it was possible to determine the value range of the cut-off of the serum sEng concentration that has the maximum specificity and sensitivity for diagnostics.

PE patient groups and healthy persons' anthropometric and biochemical features

The mean ages of the normal participant group (43.6 4.7) and the PE patients (43.5 10.7) are shown in Table 1 with p 0.05, respectively. Between the healthy subject group's (29.2 3.7 kg/m2) and PE  patients' (28.7 3.76 kg/m2) mean BMIs, there was no significant difference (p > 0.05). The findings from the subgroups, which included 30 patients with newly diagnosed PE and 30 individuals with continued diabetes, are given in table 2.

A healthy pregnant woman's serum sEng in PE groups

The level of serum sEng was significantly higher in pregnant patients with PE(58.31) ng/ml compared to the healthy pregnant group (82.53±13.16 ng/ml) (p < 0.05),  and it was also significantly higher in severe PE patients (51.26 ± 7.05) ng/ml compared to the moderate PE patients group (67.08±6.59] ng/ml). These findings are depicted in Figure 1 (A, B).

A correlation between the severity of the illness and the serum sEng level

As shown in Table 3, there was a significant positive association between the serum sEng concentration and proteinuria in the moderate PE group (R = 0.47, p< 0.05) as well as SBP (R = 0.36, p< 0.05). Additionally, In the group with severe PE, Serum sEng concentration correlated substantially with proteinuria (R = 0.74, p <0.001) and SBP (R = 0.54, p 0.001). A significant inverse association between the serum sEng levels and the weeks of pregnancy at the time of sampling, however, also exists. Serum sEng did not significantly correlate with any biochemical variable, including the lipid profile (p > 0.05).

ROC curve analysis test

Utilizing ROC curve analysis (Table 4; Fig. 2(A)), it was determined how well the blood sEng concentration could discriminate mild PE patients from healthy pregnant women. Compared to the PE diagnostic test, the ROC curve showed significantly higher reliability (high sensitivity and high specificity). Accuracy in predicting proteinuria was maximized at an AUC of 0.70 (p = 0.001), as shown by the ROC curve for the diagnosis of mild PE patients (Table 4; Fig. 2(A)). Serum sEng concentration was evaluated using ROC curve analysis to see if it could distinguish severe PE patients from healthy pregnant women (Table 5; Fig. 2(B)). The ROC curve showed more validity than the diagnostic test for PE, which was significantly higher (high sensitivity and high specificity). A fair level (high likelihood) of correctly predicting proteinuria was shown by the occurrence of a PE diagnosis, which was indicated by the ROC curve's AUC of 0.703 (p< 0.001).

Figures & Tables

Discussion

This study evaluated sEng levels in women with mild and severe PE and healthy pregnant women. Angiogenic imbalance may be implicated in PE pathophysiology [17]. Eng, a pro-angiogenic drug, inhibits hypoxia endothelial cell death and regulates vascular tone via nitric oxide [18,19]. An anti-angiogenic protein called soluble Eng prevents TGF-b1 from attaching to its receptors and suppresses downstream signaling, which includes eNOS activation and vasodilation [20].

Preeclampsia patients have greater serum sEng levels than typical pregnant women. We also found that sEng levels rose with preeclampsia severity, suggesting that they accurately signify the deterioration of the systemic vascular endothelium. Worse preeclampsia symptoms were associated with higher blood sEng levels, including proteinuria exceeding 2g/day. Our findings support the idea that this particular antiangiogenic factor is altered in women with preeclampsia and that these biochemical abnormalities become more prominent as the condition progresses, especially when preterm. [21,22].

Additionally, we found that the serum sEng levels and the number of weeks pregnant had a substantial negative correlation. A significant inverse relationship between the blood sEng levels and gestational age at sampling has been shown by prior studies1[23,24].

Troisi et al. (2008) linked sEng to pregnancy-related elevated blood pressure [23]. In one PE animal model, sEng-encoding adenovirus induced hypertension, proteinuria, and endothelial dysfunction, which were exacerbated by sEng and sFlt1 coadministration and brought about the help syndrome and prenatal growth restriction [26]. Our experimental results are supported by the positive correlation between systolic blood pressure and PE sEng levels.

Since glomeruli separate the blood and urine compartments, angiogenesis is crucial to renal homeostasis. Genetic studies in mice show that VEGF and PlGF are crucial to renal development and vascular health [27]. sFlt-1 and sEng, anti-angiogenic factors, are linked to glomerular injury and proteinuria. Venkatesha et al. [26] discovered nephrotic-range proteinuria in sEng-treated rats and severe proteinuria in sFlt-1-treated rats. Masuyama et al. [28] found higher proteinuria in high-sEng patients.

Serum sEng has a high AUC of 0.95 and more than 90% sensitivity and specificity for PE diagnosis in normal pregnant women. Based on our findings, sEng is a serum marker with excellent accuracy in identifying PE. Its higher sensitivity and specificity in severe and early-onset PE patients makes it more accurate. De Vivo et al. [29] found that sEng may predict PE early with over 80% sensitivity and specificity in blood samples from 24–28 weeks of gestation. Lim et al.[30] found sEng’s PE prediction AUC to be 0.83. Baumann et al. [31] found an AUC of 0.62 for sEng in predicting late-onset PE in first trimester serum. Our ROC curve study shows that sEng is better at diagnosing PE in normal pregnant women than severe and early-onset cases.

Our study's strengths include a well-defined, standardized medical regimen for preeclampsia patients and the fact that all samples were taken early in PE, avoiding selection bias. Our study only included PE patients as the case group, and we lost individuals from early pregnancy before PE onset. Thus, longitudinal studies should evaluate sEng, a potential marker, in a larger sample size and follow patients from early pregnancy.

Conflict of Interest

The authors declare that there is no conflict of interest regarding the publication of this paper.

Author Contributions

Ekhlas Abdallah Hassan: conceptualization, analysis, visualization, curation of data, study, writing, original draft. 

Shaima Sh.  Al-Kilan: Resources, Visualization, editing writing

The final paper was read and authorized by all writers.

References