Patrícia Nessralla Alpoim

Preeclampsia: Are platelet count and indices useful for its prognostic?

Abstract Introduction Preeclampsia (PE) is characterized by hypertension and proteinuria after the 20th week gestation. The aim of this study was to investigate whether platelet count (PC) and platelet indices (mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT)) could predict severe form of preeclampsia (sPE). Methods Three groups were evaluated; G1-pregnant with sPE (N = 29); G2-normotensive pregnant (N = 28) and Group 3: non-pregnant women (N = 30). Platelet parameters were obtained using the same automatic blood cells count. Statistical analysis was performed by analysis of variance, t-test, and receiver operating characteristic (ROC) curve. P ≤ 0.05 was considered significant. Results Lower PC and PCT were observed in sPE comparing to normal pregnant (P = 0.031 and 0.035, respectively) and to non-pregnant women (P < 0.001 and 0.004, respectively). PDW was higher in sPE comparing to normotensive pregnant (P = 0.028) and to non-pregnant women (P < 0.001). MPV was higher in sPE comparing to normotensive pregnant and non-pregnant women (P = 0.05 and P < 0.001, respectively). Analysis from the ROC curve and its areas for each variable showed that the parameters have regular diagnostic significance, except for PCT, considered as not good for this purpose. Conclusion PC emerges as a good candidate for sPE diagnosis, since it is a simple and habitually done method, with lower cost and greater accessibility in the clinical laboratory. Further studies evaluating sequential PC and platelet indices throughout pregnancy are necessary to clarify the role of platelet parameters in PE development and severity.

Asymmetric Dimethylarginine (ADMA) in cardiovascular and renal disease

BACKGROUND Asymmetric Dimethylarginine (ADMA) is a modified amino acid formed when intracellular arginine is methylated by methyltransferases that are widely distributed throughout the body. Nitric oxide (NO) is produced from l-arginine in a reaction catalyzed by three distinct isoforms of NO synthase (NOS). NO has emerged as a mediator involved in maintenance of vascular tonus, blood pressure regulation, inhibition of platelet aggregation, leukocyte and endothelial cell interaction and vascular permeability. ADMA is an important inhibitor that competes with NOS and compromises NO synthesis. OBJECTIVE This review aims to compile articles involving renal and cardiovascular diseases in which plasma ADMA was assessed in order to clarify its role in these diseases. CONCLUSION Although current knowledge suggests that ADMA has a role in the onset of cardiovascular and renal diseases, its actions are poorly understood. Clarifying its biochemical mechanisms is essential for improving disease management and promoting better quality of life for these patients.

Soluble endoglin, transforming growth factor-Beta 1 and soluble tumor necrosis factor alpha receptors in different clinical manifestations of preeclampsia.

Background Despite intensive research, the etiopathogenesis of preeclampsia (PE) remains uncertain. Inflammatory and angiogenic factors are thought to play considerable roles in this disease. The objective of this study was to investigate the association between soluble endoglin (sEng), transforming growth factor beta-1 (TGF-β1) and tumor necrosis factor alpha soluble receptors (sTNF-Rs) and the clinical manifestations of PE. Methods Plasma levels of sEng, TGF-β1 and sTNF-Rs were determined by ELISA in 23 non-pregnant, 21 normotensive pregnant and 43 PE women. PE women were stratified into subgroups according to the severity [mild (n = 12) and severe (n = 31)] and onset-time of the disease [early (n = 19) and late (n = 24)]. Results Pregnancy was associated with higher levels of sEng, sTNF-R1 and sTNF-R2 than the non-pregnant state. Moreover, PE women had higher levels of sEng and sTNF-R1 than normotensive pregnant women. No difference was found in TGF-β1 levels, comparing the three study groups. Late PE had higher levels of sTNF-R1 and sTNF-R2 than early PE. No significant differences were found in sEng and TGF-β1 comparing early and late PE. sEng levels were higher in severe PE than in mild PE and no difference was found for TGF-β1, sTNF-R1 and sTNF-R2 levels. There was a positive correlation among sEng, TNF-R1 and sTNF-2 levels. Logistic regression analysis revealed that primiparity and sEng levels are independently associated with the development of PE. Furthermore, sEng levels are independently associated with the disease severity. Conclusions These results suggest that pregnancy is a condition associated with higher levels of anti-angiogenic and pro-inflammatory factors than the non-pregnant state and that PE is associated with an imbalance of these factors in the maternal circulation.

Assessment of L-arginine asymmetric 1 dimethyl (ADMA) in early-onset and late-onset (severe) preeclampsia.

Preeclampsia (PE) is characterized by hypertension and proteinuria. It has been classified in early or late according to gestational age at the onset of disease. Endothelial dysfunction plays a crucial part in its pathogenesis. NO is a potent vasodilator and ADMA is its endogenous inhibitor. We have assessed maternal ADMA levels. ADMA were increased in early [0.66 μmol/L] versus late sPE [0.47 μmol/L] (P=0.001) and versus normotensive pregnant [0.48 μmol/L] (P=0.001). Our findings suggest that high ADMA levels in early sPE could compromise NO synthesis contributing to endothelial dysfunction, leading to impaired placentation and the onset of this disease.

Preeclampsia and ABO blood groups: a systematic review and meta-analysis

Preeclampsia (PE) is a multifactorial pregnancy-specific syndrome which represents one of the leading causes of maternal mortality worldwide. Inherited thrombophilia have been investigated as risk factor for the development of PE and it is currently known that ABO blood group may impact haemostatic balance, having the non-O blood groups (A, B or AB) subjects increased risk for thrombus formation, as compared to those of group O. We performed a systematic review of the literature for published studies investigating whether ABO blood groups could influence PE developing. A sensitive search of four databases identified 45 unique titles. The retrieved papers were assessed independently by authors and a rigorous process of selection and data extract was conduct. Methodological quality of the included studies was also evaluated. Two studies met eligibility criteria. As a main finding of our systematic review, an association between the AB blood group and the occurrence of PE was detected based on two original studies. Considering the role of ABO blood groups on the hemostatic process and thrombus formation, special attention should be given to pregnant patients carrying the AB blood group in order to prevent the syndrome and improve prognosis.

Polymorphisms in endothelial nitric oxide synthase gene in early and late severe preeclampsia.

Preeclampsia (PE) is characterized by hypertension and proteinuria, occurring after the 20th week of pregnancy in women who have had no previous symptoms. The disease progresses with generalized vasoconstriction and endothelial dysfunction. Clinically, it is important to diagnose the severe form of the disease (sPE), in which blood pressure and proteinuria are much higher. Recently, the gestational age (GA) of the onset of PE has led to the classification of this disease as early (GA <34 weeks) and late (GA ≥34 weeks). Several genetic polymorphisms affecting endothelial nitric oxide synthase (eNOS) levels or function were described, including G894T (Glu298Asp), VNTR b/a (variable-number 27-bp tandem repeat) and T-786C (promoter) polymorphisms. Thus, the aim of this study was to compare the distribution of G894T, VNTR b/a and T-786C polymorphisms and their haplotypes in Brazilian early and late sPE, as well as in normotensive pregnant. A total of 201 women were evaluated, 53 with early sPE, 45 with late sPE and 103 as normotensive pregnant women. The frequency of 894T allele was higher in late sPE vs normotensive pregnant, and 894TT genotype was higher in late sPE vs early sPE and normotensive pregnant. For VNTR b/a polymorphism, higher frequencies of aa genotype and a allele were observed in early sPE vs late sPE and normotensive pregnant. Besides, the frequency of haplotype T-b-C was higher in late sPE vs early sPE and normotensive pregnant. Considering the results found for eNOS polymorphisms, it is possible to suggest that the functional alterations induced by these two polymorphisms may influence the time of severe PE onset, although both alterations are putatively associated with low NO bioavailability. However, other studies are necessary to validate these findings and clarify this issue.

Severe preeclampsia: are hemostatic and inflammatory parameters associated?

BACKGROUND Preeclampsia (PE) is characterized by hypertension and proteinuria. A predisposition to endothelial dysfunction, which may trigger abnormal activation of the hemostatic and/or inflammatory systems, is thought to play a crucial part in pathogenesis of PE. We investigated the relationship between hemostatic and inflammatory parameters in women with severe PE. METHODS D-Dimer, PAI-1, IL-8, IL-6, TNF-α, and IFN-γ concentrations were measured in 59 pregnant women with severe PE (sPE), 49 normotensive pregnant and 48 non-pregnant women. RESULTS D-Dimer and PAI-1 were higher in women with sPE compared to normotensive pregnant and non-pregnant women. IL-8, IL-6, and IFN-γ also were higher in women with sPE compared to normotensive pregnant women. However, only IL-6 and IFN-γ were higher in women with sPE compared to non-pregnant women. Moreover, D-Dimer and PAI-1 showed an elevated area under ROC curve proving to be excellent for discriminating sPE. Correlation analysis showed a weak correlation between D-Dimer and IL-8 and between PAI-1 and IFN-γ in sPE. CONCLUSION D-Di and PAI-1 concentrations showed to be an important tool for monitoring sPE.

Revisiting HELLP syndrome.

HELLP syndrome was first described in 1982 by Weinstein et al. and the term HELLP refers to an acronym used to describe the clinical condition that leads to hemolysis, elevated liver enzymes and low platelets. The syndrome frequency varies from 0.5 to 0.9% pregnancies and manifests preferentially between the 27th and 37th week of gestation. Approximately 30% of cases occur after delivery. Although the etiopathogenesis of this syndrome remains unclear, histopathologic findings in the liver include intravascular fibrin deposits that presumably may lead to hepatic sinusoidal obstruction, intrahepatic vascular congestion, and increased intrahepatic pressure with ensuing hepatic necrosis, intraparenchymal and subcapsular hemorrhage, and eventually capsular rupture. Typical clinical symptoms of HELLP syndrome are pain in the right upper quadrant abdomen or epigastric pain, nausea and vomiting. However, this syndrome can present nonspecific symptoms and the diagnosis may be difficult to be established. Laboratory tests and imaging exams are essential for differential diagnosis with other clinical conditions. Treatment of HELLP syndrome with corticosteroids, targeting both lung maturation of the fetus is still an uncertain clinical value. In conclusion, three decades after the tireless efforts of Dr. Weinstein to characterize HELLP syndrome, it remains a challenge to the scientific community and several questions need to be answered for the benefit of pregnant women.

Is there a link between endothelial dysfunction, coagulation activation and nitric oxide synthesis in preeclampsia?

BACKGROUND There may be a relationship between endothelial dysfunction, coagulation activation and nitric oxide (NO) synthesis in women with mild and severe preeclampsia (PE). METHODS Plasma thrombomodulin (TM), D-Dimer (D-Di), cyclic guanosine monophosphate (cGMP) and placental nitric oxide synthase activity (NOS) were investigated in 21 normotensive pregnant women (G1), 22 pregnant women with mild PE (G2) and 20 pregnant women with severe PE (G3). RESULTS TM and D-Di were significantly increased in G3 compared to G1 (P=0.001 and P=0.006, respectively) and G2 (P=0.001, in both cases). However, there was no significant difference when G1 was compared to G2. For total NOS, calcium independent NOS, calcium dependent NOS no significant difference was observed among the groups studied. CONCLUSIONS TM and D-Di levels are raised in women with severe PE compared to normotensive pregnant women and women with mild PE. While increased TM levels may reflect endothelial dysfunction, raised D-Di levels indicate a hypercoagulable state. NO assessed by 2 indirect methods did not show any significant difference among the groups studied. Due to current limitations with in vitro NO measurements and interferences associated with NO bioavailability, particularly in PE, such findings should not be over-interpreted.

Sources of Thrombomodulin in Pre-Eclampsia: Renal Dysfunction or Endothelial Damage?

A plethora of evidence exists to show that endothelial perturbations underlie many of the clinical features of pre-eclampsia (P-EC), and consequently the markers signifying endothelial disturbance exhibit a rise in plasma. Among others, plasma thrombomodulin (TM) level rises significantly. TM is a transmembrane glycoprotein expressed abundantly on the endothelium of the microvasculature. It neutralizes the thrombotic potential of thrombin, mediating this anticoagulant effect through activation of protein C. Endothelial injury results in a localized loss of TM with a focal impairment of protein C activation and resultant thrombotic tendency. Mainly expressed on the endothelial cells, a small amount of TM is found in plasma with levels rising in certain pathological conditions. Although elevation in levels of TM can be due to endothelial TM proteolysis secondary to endothelial insult, ineffective clearance may account for this in renal and hepatic dysfunction. In P-EC not only is there ongoing endothelial injury, but renal function is also affected. To establish the cause of elevated TM level in P-EC, three groups of pregnant women were investigated. It appears that the elevation in plasma TM is not related to renal or hepatic dysfunction in P-EC. It is more likely that plasma TM is derived from placental or vascular endothelial cells subsequent to activation or damage, confirming the hypothesis that damage to vascular endothelial cells is the primary underlying cause of P-EC.