| 1. |
- Anderson, Ulrik Dolberg, et al.
(författare)
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Gene expression profiling of first trimester placentas from pregnancies at high risk of developing preeclampsia
- 2013
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Ingår i: Pregnancy Hypertension. - : Elsevier BV. - 2210-7789. ; 3:2, s. 69-69
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Konferensbidrag (refereegranskat)abstract
- INTRODUCTION: Preeclampsia (PE) is an important cause of fetal and maternal morbidity and mortality. It is considered a two-stage disease, the first stage characterized by a defect placentation and the second stage by maternal manifestations. Details of the patho-physiology behind the transition from stage one to stage two remain unclear.OBJECTIVE: Was to study first trimester placental gene expression in patients identified as high risk for PE by either Doppler ultrasound or the biochemical markers cell free fetal hemoglobin (HbF) and alpha-1-microglobulin (A1M).METHODS: Placental samples were obtained from seven women at highrisk of PE as determined by Doppler ultrasound of the uterine arteries and eight women with normal uterine artery resistance who for other reasons terminated their pregnancies surgically. Maternal serum samples were analyzed for HbF and A1M. The patients were risk stratified according to two risk classifications: (I) High vs. low uterine artery resistance and (II) High HbF and A1M vs. low HbF and A1M. Total RNA from the placentas was used for whole genome microarray. The results were analyzed by bioinformatics and genes of interest confirmed with qPCR.RESULTS: A total of 453 and 332 significantly altered genes were identified in the two study groups. Bioinformatics revealed 12 genes of interest in study group I and 7 genes of interest in study group II.CONCLUSIONS: Genes related to vascular tonus regulation and inflammatory response were identified in study group I suggesting that a lack of tonus regulation and increased inflammation might contribute to the high uterine artery resistance seen in this group. Genes related to regulation of hematopoiesis was found in group II suggesting dysfunctional hematopoiesis as a factor explaining the high levels of cell-free HbF seen.
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| 4. |
- Dolberg Anderson, Ulrik, et al.
(författare)
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Fetal hemoglobin and alpha(1)-microglobulin as first- and early second-trimester predictive biomarkers for preeclampsia
- 2011
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Ingår i: American Journal of Obstetrics and Gynecology. - : Elsevier BV. - 1097-6868 .- 0002-9378. ; 204:6
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to evaluate fetal hemoglobin (HbF) and alpha(1)-microglobulin (A1M) in maternal serum as first-trimester biomarkers for preeclampsia (PE). STUDY DESIGN: The design was a case-control study. We included 96 patients in the first trimester of pregnancy (60 with PE and 36 controls). Venous serum samples were analyzed for HbF and total hemoglobin (Hb) by enzyme-linked immunosorbent assay and for A1M by radioimmunoassay. Sensitivity and specificity was calculated by logistic regression and receiver operating characteristic curve analysis. RESULTS: The HbF/Hb ratio and A1M concentration were significantly elevated in serum from women with subsequent development of PE (P < .0001). The optimal sensitivity and specificity was obtained using the biomarkers in combination; 69% sensitivity for a 5% screen positive rate and 90% sensitivity for a 23% screen positive rate. CONCLUSION: The study suggests that HbF/Hb ratio in combination with A1M is predictive biomarkers for PE.
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| 5. |
- DOLBERG ANDERSON, ULRIK, et al.
(författare)
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Fetal hemoglobin, α1-microglobulin and hemopexin are potential predictive first trimester biomarkers for preeclampsia
- 2016
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Ingår i: Pregnancy Hypertension. - 2210-7789. ; 6:2, s. 103-109
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Tidskriftsartikel (refereegranskat)abstract
- Objective Overproduction of cell-free fetal hemoglobin (HbF) in the preeclamptic placenta has been recently implicated as a new etiological factor of preeclampsia. In this study, maternal serum levels of HbF and the endogenous hemoglobin/heme scavenging systems were evaluated as predictive biomarkers for preeclampsia in combination with uterine artery Doppler ultrasound. Study design Case-control study including 433 women in early pregnancy (mean 13.7 weeks of gestation) of which 86 subsequently developed preeclampsia. The serum concentrations of HbF, total cell-free hemoglobin, hemopexin, haptoglobin and α1-microglobulin were measured in maternal serum. All patients were examined with uterine artery Doppler ultrasound. Logistic regression models were developed, which included the biomarkers, ultrasound indices, and maternal risk factors. Results There were significantly higher serum concentrations of HbF and α1-microglobulin and significantly lower serum concentrations of hemopexin in patients who later developed preeclampsia. The uterine artery Doppler ultrasound results showed significantly higher pulsatility index values in the preeclampsia group. The optimal prediction model was obtained by combining HbF, α1-microglobulin and hemopexin in combination with the maternal characteristics parity, diabetes and pre-pregnancy hypertension. The optimal sensitivity for all preeclampsia was 60% at 95% specificity. Conclusions Overproduction of placentally derived HbF and depletion of hemoglobin/heme scavenging mechanisms are involved in the pathogenesis of preeclampsia. The combination of HbF and α1-microglobulin and/or hemopexin may serve as a prediction model for preeclampsia in combination with maternal risk factors and/or uterine artery Doppler ultrasound.
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| 6. |
- Dolberg Anderson, Ulrik, et al.
(författare)
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First Trimester Prediction of Preeclampsia.
- 2015
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Ingår i: Current Hypertension Reports. - : Springer Science and Business Media LLC. - 1534-3111 .- 1522-6417. ; 17:9, s. 74-74
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Forskningsöversikt (refereegranskat)abstract
- Preeclampsia (PE) is a serious pregnancy-related condition that causes severe maternal and fetal morbidity and mortality. Within the recent years, there has been an increasing focus in predicting PE at the end of the first trimester of pregnancy. In this review, literature published between 2011 and 2015 was evaluated. In a total of six biomarker algorithms, for first and early second trimester, the prediction of preeclampsia is discussed. In addition, one randomized clinical trial was included. Several algorithms were based on placental biomarkers such as pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PLGF), and soluble FMS-like tyrosine kinase 1 (s-FLT-1). The algorithms containing these biomarkers showed a high prediction rate (PR) for early onset PE, ranging from 44 to 92 % at 5 % false positive rate (FPR). New biomarkers suggest an alternative model based on free HbF and the heme scavenger alpha-1-microglobulin (A1M) with a prediction rate of 69 % at an FPR of 5 %. Interestingly, this model performs well without uterine artery Doppler pulsatility index (UtAD-PI), which is an advantage particularly if the screening method were to be implemented in developing countries. The randomized clinical trial showed a clear reduction in early onset PE as well as reducing preterm PE if identified high-risk pregnancies were treated with low-dose aspirin. In conclusion, PE prediction is now possible through several prediction algorithms and prophylaxis is beneficial in high-risk cases.
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| 7. |
- Dolberg Anderson, Ulrik
(författare)
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New predictive and diagnostic biomarkers for preeclampsia
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Abstract Preeclampsia is a serious pregnancy complication that affects 3-8% of all pregnancies leading to maternal- and fetal morbidity and mortality. The etiology is still not known in detail. Previous findings have shown an up regulation of the genes coding for fetal hemoglobin (HbF) in preeclamptic placentas. The cell-free HbF protein was shown to be accumulating in the vascular lumen, to induce oxidative stress, which damages the blood-placenta-barrier, causing a leak into the maternal blood circulation. Unbound cell-free HbF is highly reactive and toxic and therefore normally being scavenged by haptoglobin, hemopexin (Hpx) and α1-microglobulin (A1M). In the maternal circulation cell-free HbF causes general endothelial- and organ damage. This thesis describes the role of placentally derived HbF in the etiology of preeclampsia and how it can be used as a biomarker for PE. The five articles also describe the role of hemoglobin- and heme scavenging proteins in prediction and diagnosis of preeclampsia and HbF as a causal factor for renal injury in preeclampsia. The results in paper I and II show that the maternal HbF plasma concentration is increased as early as the first trimester in women who subsequently develop preeclampsia. Furthermore increased circulating concentrations of A1M and decreased levels of hemopexin were found. The results indicate that HbF, A1M and Hpx can be used as predictive biomarkers as early as the first trimester with 60% prediction rate at 5% false positive rate. The results in paper III and IV indicate that the constant increased level of HbF strain the scavenging proteins and gradually deplete them. The HbF plasma levels were four fold increased in patients diagnosed with PE compared to controls. Furthermore, the A1M levels were increased and the levels of Hpx, Hpx enzymatic activity and Haptoglobin were significantly lower in patients with preeclampsia. In both paper III and IV HbF, heme and scavenging proteins were evaluated as biomarkers that support the diagnosis of PE. The results showed that the combination of these biomarkers could detect up to 84% of the PE patients at a false positive rate of 10% in term pregnancy. It was further concluded that HbF and hemoglobin- and heme scavengers potentially can be used to support the diagnosis of PE. In addition, both HO-1 and Hpx activity correlated with the maternal blood pressure and hence the severity of PE. It is known that excessive amounts of cell-free Hb lead to endotheliosis and kidney injuries. In paper IV it was shown that there was increased urinary concentrations of podocyte specific extracellular vesicles (EVs) in women diagnosed with PE. The excessive circulating concentrations of HbF in women with PE was correlated to the concentration of urinary podocyte specific EVs and proteinuria. It was concluded that increased circulating concentrations of HbF in combination with low scavenging capacity might cause significant damage to the renal podocytes. In conclusion the thesis present free HbF and its’ scavenging proteins as new important players in the PE etiology. Furthermore, it was shown that HbF and the heme scavenging proteins could be used as predictive- and diagnostic biomarkers for PE as early as the first trimester of pregnancy.
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| 8. |
- Dolberg Anderson, Ulrik, et al.
(författare)
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Review: Biochemical markers to predict preeclampsia.
- 2012
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Ingår i: Placenta. - : Elsevier BV. - 1532-3102 .- 0143-4004. ; 33, s. 42-47
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Tidskriftsartikel (refereegranskat)abstract
- Worldwide the prevalence of preeclampsia (PE) ranges from 3 to 8% of pregnancies. 8.5 million cases are reported yearly, but this is probably an underestimate due to the lack of proper diagnosis. PE is the most common cause of fetal and maternal death and yet no specific treatment is available. Reliable biochemical markers for prediction and diagnosis of PE would have a great impact on maternal health and several have been suggested. This review describes PE biochemical markers in general and first trimester PE biochemical markers specifically. The main categories described are angiogenic/anti-angiogenic factors, placental proteins, free fetal hemoglobin (HbF), kidney markers, ultrasound and maternal risk factors. The specific biochemical markers discussed are: PAPP-A, s-Flt-1/PlGF, s-Endoglin, PP13, cystatin-C, HbF, and α(1)-microglobulin (A1M). PAPP-A and HbF both show potential as predictive biochemical markers in the first trimester with 70% sensitivity at 95% specificity. However, PAPP-A is not PE-specific and needs to be combined with Doppler ultrasound to obtain the same sensitivity as HbF/A1M. Soluble Flt -1 and PlGF are promising biochemical markers that together show high sensitivity from the mid-second trimester. PlGF is somewhat useful from the end of the first trimester. Screening pregnant women with biochemical markers for PE can reduce unnecessary suffering and health care costs by early detection of mothers at increased risk for PE, thus avoiding unnecessary hospitalization of pregnant women with suspect or mild PE and enabling monitoring of the progression of the disease thereby optimizing time for delivery and hopefully reducing the number of premature births.
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| 9. |
- Gilani, Sarwat I, et al.
(författare)
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Urinary Extracellular Vesicles of Podocyte Origin and Renal Injury in Preeclampsia
- 2017
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Ingår i: Journal of the American Society of Nephrology: JASN. - 1533-3450. ; 28:11, s. 3363-3372
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Tidskriftsartikel (refereegranskat)abstract
- Renal histologic expression of the podocyte-specific protein, nephrin, but not podocin, is reduced in preeclamptic compared with normotensive pregnancies. We hypothesized that renal expression of podocyte-specific proteins would be reflected in urinary extracellular vesicles (EVs) of podocyte origin and accompanied by increased urinary soluble nephrin levels (nephrinuria) in preeclampsia. We further postulated that podocyte injury and attendant formation of EVs are related mechanistically to cellfree fetal hemoglobin (HbF) in maternal plasma. Our study population included preeclamptic (n=49) and normotensive (n=42) pregnant women recruited at delivery. Plasma measurements included HbF concentrations and concentrations of the endogenous chelators haptoglobin, hemopexin, and α1- microglobulin. We assessed concentrations of urinary EVs containing immunologically detectable podocyte-specific proteins by digital flow cytometry and measured nephrinuria by ELISA. The mechanistic role of HbF in podocyte injury was studied in pregnant rabbits. Compared with urine from women with normotensive pregnancies, urine from women with preeclamptic pregnancies contained a high ratio of podocin-positive to nephrin-positive urinary EVs (podocin(+) EVs-to-nephrin(+) EVs ratio) and increased nephrinuria, both of which correlated with proteinuria. Plasma levels of hemopexin, which were decreased in women with preeclampsia, negatively correlated with proteinuria, urinary podocin(+) EVs-to-nephrin(+) EVs ratio, and nephrinuria. Administration of HbF to pregnant rabbits increased the number of urinary EVs of podocyte origin. These findings provide evidence that urinary EVs are reflective of preeclampsia-related altered podocyte protein expression. Furthermore, renal injury in preeclampsia associated with an elevated urinary podocin(+) EVs-to-nephrin(+) EVs ratio and may be mediated by prolonged exposure to cellfree HbF.
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| 10. |
- Gram, Magnus, et al.
(författare)
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The Human Endogenous Protection System against Cell-Free Hemoglobin and Heme Is Overwhelmed in Preeclampsia and Provides Potential Biomarkers and Clinical Indicators.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Preeclampsia (PE) complicates 3-8% of all pregnancies and manifests clinically as hypertension and proteinuria in the second half of gestation. The pathogenesis of PE is not fully understood but recent studies have described the involvement of cell-free fetal hemoglobin (HbF). Hypothesizing that PE is associated with prolonged hemolysis we have studied the response of the cell-free Hb- and heme defense network. Thus, we have investigated the levels of cell-free HbF (both free, denoted HbF, and in complex with Hp, denoted Hp-HbF) as well as the major human endogenous Hb- and heme-scavenging systems: haptoglobin (Hp), hemopexin (Hpx), α1-microglobulin (A1M) and CD163 in plasma of PE women (n = 98) and women with normal pregnancies (n = 47) at term. A significant increase of the mean plasma HbF concentration was observed in women with PE. Plasma levels of Hp and Hpx were statistically significantly reduced, whereas the level of the extravascular heme- and radical scavenger A1M was significantly increased in plasma of women with PE. The Hpx levels significantly correlated with maternal blood pressure. Furthermore, HbF and the related scavenger proteins displayed a potential to be used as clinical biomarkers for more precise diagnosis of PE and are candidates as predictors of identifying pregnancies with increased risk of obstetrical complications. The results support that PE pathophysiology is associated with increased HbF-concentrations and an activation of the physiological Hb-heme defense systems.
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