Letícia Gonçalves Freitas

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.

Severe preeclampsia: Association of genes polymorphisms and maternal cytokines production in Brazilian population

INTRODUCTION Preeclampsia (PE) is a multi-system disorder of pregnancy characterized by hypertension and proteinuria. Healthy pregnancy is associated with a controlled inflammatory process, which is exacerbated in PE in response to excessive placental stimuli. Gene expression levels can affect inflammation and immune regulation. It is known that differences in cytokine allele frequencies amongst populations may contribute to difference in the incidence of several diseases. OBJECTIVE The aim of this study was to investigate the frequency of TNF-α, IL-6, IFN-γ and IL-10 genes polymorphisms and their relationship with the cytokines plasma levels in PE. METHODS A total of 281 women were included in this study; 116 with severe PE, 107 normotensive pregnant and 58 non-pregnant women. Cytokine genotyping was carried out by the polymerase chain reaction. The analyzed polymorphisms were: TNF-α (-308 G→A), IL-10 (-1082 G→A), IL-6 (-174 G→C), and IFN-γ (+874 A→T). Cytokine plasma levels were measured by Cytometric Bead Array method. RESULTS A higher frequency of the IFN-γ (+874) T/T genotype in severe PE comparing to normotensive pregnant women was found (P<0.001). TNF-α, IL-6 and IFN-γ plasma levels were higher in PE women compared to non-pregnant women (P<0.001; P<0.001; P=0.004). IL-6 and IFN-γ levels were also higher in PE women compared to normotensive pregnant (P<0.001; P=0.010). IL-10 levels were higher in normotensive pregnant women compared to PE (P<0.001). IFN-γ and IL-6 genes polymorphisms influenced the genic expression in PE and normotensive pregnant women, respectively. CONCLUSIONS These results suggest that IFN-γ seems to play a role in PE occurrence.

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.

D-dimer in preeclampsia: Systematic review and meta-analysis

Preeclampsia is a multifactorial disease characterized by high blood pressure and proteinuria after the 20th week of pregnancy. Preeclampsia is associated with microvasculature fibrin deposition and maternal organ dysfunction. D-dimer (D-Di) has been used as a marker of production/degradation of fibrin in vivo. D-Di has emerged as a useful diagnostic tool for thrombotic conditions because its plasma concentration has a high negative predictive value for venous thromboembolism. The aim of this study was to evaluate publications that assessed plasma D-Di in preeclampsia and normotensive pregnant subjects to define its diagnostic value. A total of 194 publications were identified. Following the exclusion process, seven studies were in accordance with the pre-defined eligibility criteria. This systematic review was performed with methodologic accuracy, including a careful definition of preeclampsia and a high sensitivity literature search strategy. Quality of the included studies was assessed in accordance with widely accepted literature recommendations. Our meta-analysis indicates that increased plasma D-Di is associated with preeclampsia in the third trimester of gestation vs normotensive pregnant subjects. These preliminary findings in this select group of patients clearly highlight the need for additional comprehensive studies throughout pregnancy, including the establishment of an appropriate cut-off, in order to fully elucidate the diagnostic/prognostic role of D-Di in preeclampsia.

Clinical applicability of reticulated platelets.

BACKGROUND Reticulated platelets (RPs), immature platelets newly released from the bone marrow into the circulation, have a high content of ribonucleic acid and are larger and more active in thrombus formation. OBJECTIVE This review compiles articles that evaluated RP in order to establish their clinical significance. DISCUSSION RPs increase when platelet production rises and decrease when production falls. As such, the measurement of circulating RPs allows the assessment of thrombocytopenia, i.e., bone marrow production or peripheral destruction. CONCLUSION RPs are a promising laboratory tool for evaluation of idiopathic thrombocytopenia (differentiating hypoproduction from accelerated platelet destruction), chemotherapy and after stem cell transplantation (predicting platelet recovery) and thrombocytosis (estimating platelet turnover). Additional randomized and well controlled clinical studies are required to clearly establish the significance of circulating RPs in other clinical conditions.

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.

Antiphospholipid syndrome: a clinical and laboratorial challenge

Antiphospholipid syndrome (APS) is an acquired autoimmune thrombophilia characterized by the presence of a heterogeneous family of antibodies that bind to plasma proteins with affinity for phospholipid surfaces. The two major protein targets of antiphospholipid antibodies are prothrombin and β2-glycoprotein I (β2GPI). APS leads to aprothrombotic state, and it is characterized by the occurrence of arterial, venous or microvascular thrombosis or recurrent fetal loss. The diagnosis of APS is based on a set of clinical criteria and the detection of lupus anticoagulant (LA), anticardiolipin antibodies (ACA) or anti-β2GPI in plasma. Although laboratory tests are essential for APS diagnosis, these tests have limitations associated with the robustness, reproducibility and standardization. The standardization of diagnostic tests for detection of APLAs has been a challenge and a variety of results have been obtained using different commercial kits and in-house techniques. An increased sensitivity of the ELISA kits for detection of ACA effectively has contributed to APS diagnosis. However, the lack of specificity associated with a high number of false-positive results is a clinical and laboratorial challenge, since such results may lead to mistaken clinical decisions, such as prescription of oral anticoagulant, leading to the risk of hemorrhaging. Furthermore, clinicians are often unfamiliar with these tests and have difficulty interpreting them, requiring interaction between clinical and laboratory professionals in order to ensure their correct interpretation.

Preeclampsia: Integrated network model of platelet biomarkers interaction as a tool to evaluate the hemostatic/immunological interface

BACKGROUND Preeclampsia (PE) is associated with platelet activation, which may be involved in its pathogenesis promoting coagulation and mediating inflammation. We investigated whether the platelet activation status together with the frequency of platelet-leukocyte aggregates/PLA and monocyte tissue factor/TF expression could be used as laboratorial biomarkers for PE diagnosis and prognosis. METHODS Ninety-seven women were evaluated including severe PE/sPE (N=15), mild PE/mPE (N=20), normotensive pregnant/NP (N=31) and non-pregnant women/nonP (N=31). Platelet markers were analyzed by flow cytometry. RESULTS Platelet counts and CD41a expression by platelets were lower in NP and sPE vs nonP. The expression of CD61 was lower during pregnancy. Altered balance of platelet marker expression was also observed in NP and sPE vs nonP. No significant differences in the PLA and TF expression by monocytes were observed among the groups. There are several correlations between platelet activation markers, especially in sPE, which suggest a relevant role of the hemostatic/immunological cross-talk in this disease. CONCLUSIONS PE is not associated with increased platelet activation markers. It cannot rule out a role of platelet activation in the PE pathophysiology. Despite those correlations, we did not find a putative laboratorial biomarker that could be useful by itself for PE diagnosis and prognosis.