Boxplot of cell-free total DNA (cftDNA) in controls and the different subdivisions of PE. Boxplot of cell-free fetal DNA (cffDNA) in controls and the different subdivisions of PE. Circulating cell-free fetal DNA and cell-free total DNA in black South African women with gestational hypertension and preeclampsia.
The objective was to quantify cell-free fetal DNA (cffDNA) and total cell-free DNA (cftDNA) in black South African women with gestational hypertension and preeclampsia. Levels of circulating cffDNA and cftDNA were significantly higher in PE patients compared to levels in controls and in GH patients (p<0.001). There was no difference in the level of cffDNA and cftDNA in GH compared to controls (p > 0.05).
There was a significant increase in the level of cffDNA and cftDNA in SPE in contrast to the concentration in MPE (p<0.05). There was no difference in the level of cffDNA and cftDNA in EOPE compared to LOPE (p > 0.05).
Background
- Prevalence
- Risk factors of hypertension in pregnancy
- Pathogenesis of hypertension in pregnancy
- Classification of pregnancy induced hypertension
- Sub classification of Preeclampsia
Most cases of HDP are seen in low-income countries (Abalos et al., 2013). The end result is disorientation of the fenestrated endothelium, resulting in protein leakage into the urine (Craici et al., 2013). Podocytes are pathologically affected and released into the urine of patients with preeclampsia (Craici et al., 2013).
PIH is classified into the following categories; preeclampsia, gestational hypertension, superimposed preeclampsia and eclampsia (Watanabe et al., 2013). It is responsible for most of the maternal and fetal deaths caused by hypertensive diseases of pregnancy in developing countries (Mol et al., 2016). Development of GH during pregnancy is a warning that a woman may develop essential hypertension in the future (Cruz et al., 2012).
Cell free DNA and Cell free fetal DNA
Origin of cell free DNA and Cell free fetal DNA in maternal circulation
Circulating Cell free fetal DNA and Cell free total DNA (cffDNA) as indicators of
The hypermethylated RASSF1A sequence of fetal origin can then be quantified using real-time quantitative polymerase chain reaction (RT-qPCR) to determine the circulating level of cffDNA. Hypermethylated DNA of fetal origin is not digested because it is resistant to methylation restriction enzymes, unlike the hypomethylated DNA (White et al., 2012). When RASSF1A in maternal plasma is subjected to a methylation-sensitive restriction enzyme such as the BstUI.
Applications of circulating cell free DNA
Problem statement
Hypothesis
Aim
Objectives
Circulating Cell Free Fetal DNA and Cell Free total DNA in Black South African Women with
There was a significant increase in the level of cffDNA and cftDNA in SPE in contrast to that in MPE (p<0.05). Circulating plasma placenta-derived cfDNA can be considered a reliable marker with potential uses in the diagnosis and monitoring of the development of complications during pregnancy, especially since it is released into the maternal circulation in the early stages of pregnancy [11] . There was a significant difference in BMI of controls compared to GH patients (p<0.001).
There was no difference in the level of cftDNA between controls and patients with GH (p>0.05). No difference was seen in cffDNA levels in controls compared to patients with GH (p>0.05). From our results, we observed that the levels of circulating cffDNA and ctfDNA were significantly higher in patients with PE compared with the levels in controls and in patients with GH.
There was a 3.2-fold increase in median cffDNA and cftDNA levels in PE patients compared to control and GH levels. The increase in cfDNA levels in PE is related to the degree of perfusion and the extent of placental injury, which affects circulating cffDNA and cftDNA levels [22-24]. There were no changes in cffDNA and cftDNA levels in GH compared to controls.
In our study, there was a 4.5- and 2.8-fold increase in the level of cftDNA in SPE and MPE compared to the controls, and a 5- and 3.6-fold increase in the concentration of cffDNA in SPE and MPE, respectively. In the EOPE and LOPE group, there was a significant increase in the level of circulating cffDNA and cftDNA compared to the level in the control group, but the level did not vary between EOPE and LOPE. Pregnant women in the gestation period without any history of obstetric complications served as controls.
The limitations of this study are that we did not consider the gender of the fetus. Review: cell-free fetal DNA in the maternal circulation as an indicator of placental health and disease. Cell-free fetal DNA in the plasma of pregnant women with severe fetal growth restriction.
Synthesis
Our results are consistent with previous studies that have also reported increases in circulating cffDNA and cftDNA in the plasma of women with preeclampsia compared to controls (Kim et al., 2015, Salvianti et al., 2015). This explains the reason why these markers are elevated in pregnancy complications affecting the placenta, such as PE (Taglauer et al., 2014). Circulating levels of cffDNA and cftDNA are able to serve as a mirror image of the placenta, as the concentration of these markers in circulation is affected by the rate of release of cellular debris from apoptotic placental cells (Taglauer et al., 2014).
Circulating levels of fetal and total cfDNA may reflect placental status, as the concentration of these markers is influenced by the rate of release of cellular debris from apoptotic placental cells ( Taglauer et al., 2014 ). These authors showed that the level of cffDNA and cftDNA remained consistently low in patients with GH in a case-control study (Kim et al., 2015). It has also been stated that the imbalance in the level of pro- and anti-angiogenic molecules and endothelial dysfunction is a unique and peculiar feature of PE (Noori et al., 2010).
Therefore, identifying women with preeclampsia who are at risk of developing severe pulmonary embolism will aid in patient management and prevention of complications associated with SPE (Fong et al., 2014). Abdelhalim et al (2016) reported an increase in the level of cffDNA and cftDNA in patients with SPE compared to those with MPE. Although these authors used different markers (HBB gene for estimation of cftDNA and the TSPY1 gene for quantification of cffDNA) for the quantification of fetal and total cfDNA (AbdelHalim et al., 2016).
Kim et al., (2015) also reported similar findings of an increase in the level of cfDNA with the severity of the preeclampsia. They also stated that increase in cffDNA seen in cases of SPE results from an increase in the release of syncytiotrophoblasts from ischemic lesions (Jakobsen et al., 2013). Studies have shown that EOPE and LOPE are different entities with different pathologies (Von Dadelszen et al., 2003, Walker, 2000).
These authors have also stated that the increased level of circulating cfDNA in the early stages of pregnancy is associated with altered placentation, which is an initiating factor of PE (Papantoniou et al., 2013).
Conclusions
EOPE is more associated with altered cardiovascular function due to placental disturbance while LOPE is more related to maternal factors (Valensise et al., 2008). The finding of this present study shows a significant increase in the level of circulating cffDNA and cftDNA in EOPE and LOPE groups compared to the level in the control group, but the level did not differ between EOPE and LOPE. This finding is in agreement with the study conducted by Papantoniou et al., who noted that the level of cffDNA in EOPE did not differ from the level in LOPE, although the number of EOPE to LOPE in their study was only 2 out of a total of 24 were preeclamptic women (Papantoniou et al., 2013).
Although the results obtained in this study showed no difference in the level of circulating cffDNA and cftDNA during EOPE compared to LOPE, Papantoniou et al. (2013) showed that circulating levels of these markers can be used to identify women likely to develop preeclampsia at an early stage, as circulating fetal and total DNA concentrations are elevated in these women during the early stages of pregnancy. This finding supports the hypothesis that the elevation of cfDNA in PE is due to impaired trophoblastic invasion of the uterine spiral arteries, leading to ischemia and placental damage, with the consequent release of apoptotic syncytiotrophoblast fragments containing fetal DNA.
Recommendations
These entities differ in pathological features and in maternal and fetal outcomes (Raymond and Peterson, 2011). Free fetal DNA in maternal plasma in anembryonic pregnancies: confirmation that the origin is the trophoblast. Quantification of cell-free fetal DNA in maternal plasma in normal pregnancies and in pregnancies with placental dysfunction.
EDTA-mediated inhibition of DNases protects circulating cell-free DNA from ex vivo degradation in blood samples. Identification of mild and severe preeclampsia in asymptomatic pregnant women by levels of cell-free fetal DNA. Quantification and application of potential epigenetic markers in maternal plasma from pregnancies with hypertensive disorders.
Relationship of circulating cell-free DNA levels to cell-free fetal DNA levels, clinical characteristics and laboratory parameters in preeclampsia. Predominant hematopoietic origin of cell-free DNA in plasma and serum after sex-mismatched bone marrow transplantation. Quantification of cell-free DNA in normal and complicated pregnancies: overcoming biological and technical issues.
Fetal RHD genotyping using real-time polymerase chain reaction analysis of cell-free fetal DNA during pregnancy of RhD-negative women in southern Iran. The effect of labor and placental separation on the secretion of syncytiotrophoblast microparticles, cell-free DNA and mRNA in normal pregnancy and pre-eclampsia. Early and late preeclampsia are two different hemodynamic conditions of the mother in the latent phase of the disease.
Feasibility of quantification of fetal-derived hypermethylated RASSF1A sequence in maternal plasma - The next step towards reliable non-invasive prenatal diagnosis. DATASHEET: Characterizing cell-free DNA in normal pregnancy and hypertensive disorders of pregnancy in black South African women. If you do not want to be in the study, you will not be treated differently from other patients.
