Cell-derived microparticles and von Willebrand factor in Brazilian renal transplant recipients.

AIM: This study was aimed at investigating platelet-derived microparticles (PMP), endothelium cell-derived microparticles (EMP) and von Willebrand factor (VWF) according to renal function and time post-transplant. We found this study relevant because unusual biomarkers seem to be a promising tool to evaluate chronic renal disease and post-transplant monitoring. METHODS: Ninety-one renal transplant recipients (RTx) were allocated into groups according to creatinine plasma levels (C1 < 1.4 and C2 ≥ 1.4 mg/dL), estimated glomerular filtration rates (R1 < 60 and R2 ≥ 60 mL/min per 1.73 m2 ) and time post-transplant (T1: 3-24; T2: 25-60; T3: 61-120; and T4 > 120 months). EMP and PMP levels were assessed by flow cytometry and VWF levels were evaluated by enzyme-linked immunosorbent assay. RESULTS: Platelet-derived microparticle levels were higher in C1 group compared with C2 (P = 0.00). According to diameter, small PMP and EMP (≤0.7 µm) were also higher in C1 group, all values of P less than 0.05. T1 and T2 groups have shown high EMP levels and a predominance of big microparticle (>0.7 µm) compared with T4 group, all values of P less than 0.05. Higher VWF levels were observed among RTx with creatinine ≥1.4 mg/dL compared with other RTx, P = 0.01. CONCLUSION: The results showed that PMP, EMP and VWF are promising markers to evaluate endothelial function in RTx. These biomarkers could play a major role in monitoring patients after renal transplant.

Sickle cell disease: Hemostatic and inflammatory changes, and their interrelation.

Sickle cell disease, the most common genetic blood disorder in the world, has high clinical variability, negatively impacts quality of life and contributes to early mortality. Sickled erythrocytes cause blood flow obstruction, hemolysis, and several hemostatic changes that promote coagulation. These events, in turn, induce chronic inflammation, characterized by elevated plasma levels of pro-inflammatory markers, which aggravates the already unfavorable state of the circulatory system. Empirical evidence indicates that the hemostatic and inflammatory systems continuously interact with each other and thereby further propagate the hypercoagulability and inflammatory conditions. In this review article, we discuss the pathophysiological aspects of sickle cell disease and the hemostatic and inflammatory changes that underlie its pathogenesis.

Thrombomodulin and interleukin 6 as potential biomarkers of endothelial dysfunction and inflammation after renal transplant / Trombomodulina e interleucina 6 como potenciais biomarcadores da disfunção endotelial e da inflamação pós-transplante renal

ABSTRACT Introduction: Endothelial dysfunction may contribute to hypercoagulable and inflammation states presents in renal transplant, chronic kidney disease (CKD) and its causes. These disorders can be evaluated by markers, such as thrombomodulin (TM), von Willebrand factor (vWF) and interleukin 6 (IL-6). Objectives: The aim of this study was to assess TM, vWF and IL-6 in renal transplant recipients (RTR) and associate their plasma levels with primary cause of end-stage renal disease (ESRD) and allograft function. Methods: 160 RTR were grouped according to the primary cause of CKD (G1: glomerulopathy; G2: hypertensive nephrosclerosis; G3: diabetic nephropathy; and G4: other causes/unknown etiology); creatinine plasma levels (C1 < 1.4 and C2 ≥ 1.4 mg/dl); and the estimated glomerular filtration rate (eGFR) (R1< 60 and R2 ≥ 60 ml/min/1.73 m2). TM and vWF were determined by the enzyme-linked immunosorbent assay (ELISA) and IL-6 by flow cytometry. The results were presented as median, minimum and maximum; p-value < 0.05 was considered statistically significant. Results: TM levels were significantly higher in the G1 group compared to the others (G1: 8.38; G2: 5.51; G3: 5.88; G4: 6.33 ng/ml, p < 0.0001), and in the R1 group compared to R2 (R1: 6.65; R2: 6.19 ng/ml, p = 0.02). The concentration of IL-6, measured by the mean fluorescence intensity, was higher in C2 group when compared to C1 (C1: 7.9; C2: 13.35, p = 0.03). There was no difference in vWF levels among groups. TM correlated positively with IL-6 and creatinine, and negatively with eGFR. IL-6 also correlated positively with vWF. Conclusion: TM and IL-6 can be identified as potential markers for evaluating renal graft function. TM was more related to the primary cause of CKD compared to vWF and IL-6.

RESUMO Introdução: A disfunção endotelial pode contribuir para estados de hipercoagulabilidade e inflamação presentes no transplante renal e na doença renal crônica (DRC) e suas causas, podendo ser avaliada por marcadores como trombomodulina (TM), fator de von Willebrand (FvW) e interleucina 6 (IL-6). Objetivos: Avaliar TM, FvW e IL-6 em receptores do transplante renal (RTR) e associar seus níveis com a causa primária de DRC pré-transplante e função do enxerto. Métodos: Foram alocados 160 RTR em grupos de acordo com a causa primária da DRC (G1: glomerulopatias; G2: nefroesclerose hipertensiva; G3: nefropatia diabética; e G4: outras causas/etiologia desconhecida), os níveis plasmáticos de creatinina (C1 < 1.4 e C2 ≥ 1.4 mg/dl) e o ritmo de filtração glomerular estimado (eRFG) (R1< 60 e R2 ≥ 60 ml/min/1.73 m2). A TM e o FvW foram determinados pelo ensaio de imunoabsorção enzimática (ELISA) e a IL-6, por citometria de fluxo. Os resultados foram apresentados como mediana, mínimo e máximo; p < 0,05 foi considerado significativo. Resultados: Níveis de TM foram significativamente maiores no grupo G1 em comparação com os demais (G1: 8,38; G2: 5,51; G3: 5,88; G4: 6,33 ng/ml, p < 0,0001), e no grupo R1 comparado com o R2 (R1: 6,65; R2: 6,19 ng/ml, p = 0,02). A concentração de IL-6, avaliada pela intensidade média de fluorescência, foi maior no grupo C2 quando comparada com o C1 (C1: 7,9; C2: 13,35, p = 0,03). Não houve diferença entre os grupos para o FvW. TM correlacionou-se positivamente com IL-6 e creatinina e negativamente com eRFG. A IL-6 foi positivamente correlacionada com o FvW. Conclusão: TM e IL-6 podem ser apontadas como potenciais marcadores para avaliar a função do enxerto renal. A TM relacionou-se mais com a causa primária da DRC, se comparada com FvW e IL-6.

Aspartate aminotransferase to platelet ratio index (APRI) for differentiation of primary and secondary infection by dengue virus / Aplicação do índice de relação aspartato aminotransferase sobre plaquetas (APRI) na diferenciação de infecção primária e secundária pelo vírus da dengue

ABSTRACT INTRODUCTION: Dengue virus (DENV) infection has been considered a major public health problem in tropical countries. The unavailability of serologic testing in public health centers might adversely impact patients' outcome. OBJECTIVE: This study aimed to evaluate the accuracy of mean platelet volume (MPV) and aspartate aminotransferase (AST) to platelet ratio index (APRI) as laboratory markers of DENV infection that could be used to differentiate primary and secondary infections. METHODS: We assessed laboratory results from 503 patients with positive rapid test for DENV infection. RESULTS: Severe thrombocytopenia and increased liver involvement were observed in patients with DENV heterotypic secondary infection. Our data suggest that APRI was able to distinguish patients with primary and secondary infection (p = 0.006) with a relevant sensitivity (75%), specificity (76%) and a cut-off of 1.06. A total of 80 out of 105 (76%) patients with primary DENV infection had APRI ≤ 1.06, and 12 (75%) with secondary DENV infection had APRI > 1.06. On the other hand, MPV did not show significance in the differentiation of types of infection, coming up with poor area under the receiver operating characteristic (ROC) curve (0.61). CONCLUSION: APRI seems to be a powerful tool for early identification of DENV secondary infection cases in health centers.

RESUMO INTRODUÇÃO: A infecção pelo vírus da dengue (DENV) é considerada um grande problema de saúde pública nos países tropicais. A indisponibilidade de testes sorológicos em centros de saúde pública pode afetar negativamente o prognóstico do paciente. OBJETIVO: Este estudo teve como objetivo avaliar a precisão do volume médio de plaquetas (MPV) e o índice da relação de aspartato aminotransferase (AST) sobre plaquetas (APRI) como marcadores laboratoriais de infecção por DENV, que poderiam ser utilizados para diferenciar infecções primárias e secundárias. MÉTODOS: Foram avaliados os resultados laboratoriais de 503 pacientes com teste rápido positivo para infecção por DENV. RESULTADOS: Foram observadas trombocitopenia grave e disfunção hepática em pacientes com infecção secundária heterogênea por DENV. Nossos dados sugerem que o APRI foi capaz de distinguir os pacientes com infecção primária e secundária (p = 0, 006), com relevante sensibilidade (75%) e especificidade (76%) e corte de 1, 06. Um total de 80 de 105 (76%) pacientes com infecção primária por DENV tinha APRI ≤ 1, 06; e 12 (75%) com infecção secundária por DENV, APRI > 1, 06. Por outro lado, o MPV não mostrou significância na diferenciação de tipos de infecção, apresentando baixo valor da área sob a curva de característica de operação do receptor (ROC) (0, 61). CONCLUSÃO: APRI parece ser uma ferramenta poderosa para identificação precoce de casos de infecção secundária de DENV em centros de saúde.

Regulatory and pro-inflammatory cytokines in Brazilian living-related renal transplant recipients according to creatinine plasma levels.

AIM: The maintenance of stable graft function in renal transplanted recipients (RTR) is a challenge for healthcare staff. The ideal biomarkers must have significant predictive values to monitor the intricate renal function response triggered after renal transplantation. The main purpose in this study was to evaluate the regulatory and pro-inflammatory cytokines as biomarkers of allograft function in living-related renal transplant patients. METHODS: Regulatory and pro-inflammatory cytokine plasma levels were measured by flow cytometry in 120 living-related renal transplanted patients categorized into three groups according to creatinine plasma levels: creatinine less than 1.4 mg/dL (C1), creatinine within 1.4-2.0 mg/dL (C2) and more than 2.0 mg/dL (C3). Patients were also classified as 'low' or 'high' cytokine producers. Clinical data were obtained from patients' medical record. RESULTS: We have found a peak of regulatory cytokines in RTR with low creatinine levels as well as a peak of IL-6 pro-inflammatory cytokine in patients with high creatinine levels. C1 and C3 groups showed a mixed pro-inflammatory (IL-8, IL-6, IL-1ß, TNF-α, IL-12 and IFN-γ) and regulatory (IL-4, IL-5 and IL-10) cytokine pattern and C2 had a predominant pro-inflammatory profile. C3 group showed a higher frequency of high pro-inflammatory cytokine producers compared to C1. CONCLUSION: Our data suggest that regulatory cytokines IL-4, IL-5 and IL-10 could be good biomarkers associated with stable renal function, while pro-inflammatory cytokines seems to be potential markers in RTR related to high creatinine plasma levels, specially IL-6 despite of its borderline values.

FVIIa-antithrombin levels in early and late preeclampsia.

BACKGROUND: Preeclampsia (PE) is associated with a hypercoagulability state. According to the gestational age (GA) at the onset of the disease, PE has been classified as early (GA<34weeks) and late (GA≥34weeks). It has been admitted that early PE is associated with ischemic placental lesions, while in late PE an adequate or slightly impaired placentation occurs, which suggests that the two clinical forms have distinct etiology. Tissue factor (TF) binds and activates plasma factor VII triggering the coagulation. The inhibitor antithrombin (AT), along with tissue factor pathway inhibitor, acts as an inhibitor of the FVIIa-TF pathway. Once the TF-FVIIa complex is formed, the binding and transfer of FVIIa to AT is facilitated and FVIIa activity is inhibited. OBJECTIVE: We evaluated the FVIIa-AT complex levels in pregnant women with early and late severe PE (sPE), in order to verify if this biomarker can be useful for discriminating the two forms of the disease. METHODS: We evaluated 26 pregnant with severe early PE and 19 pregnant with severe late PE. FVIIa-AT levels were measured by STACLOT® (Diagnostica Stago). Statistical analysis was done by Mann-Whitney test. RESULTS: Increased FVIIa-AT levels were found in early sPE [148.4pM (137.1)] compared to late sPE [95.9pM (66.5)] (P=0.046), which suggests a higher pro-coagulant state when PE onset occurs before 34weeks of gestation. CONCLUSION: These pioneer data allow inferring the relevance of FVIIa-AT as a device for early sPE diagnosis. However, the clinical relevance of FVIIa-AT complex surely needs to be fully clarified.

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-ß1) and tumor necrosis factor alpha soluble receptors (sTNF-Rs) and the clinical manifestations of PE. METHODS: Plasma levels of sEng, TGF-ß1 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-ß1 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-ß1 comparing early and late PE. sEng levels were higher in severe PE than in mild PE and no difference was found for TGF-ß1, 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.

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.

Severe preeclampsia goes along with a cytokine network disturbance towards a systemic inflammatory state.

Although preeclampsia causes high maternal/fetal morbidity and mortality, the etiology of this multi-system disorder still remains to be elucidated. Herein, we have characterized the cytokine plasma levels in severe preeclamptic women compared to normotensive pregnant and non-pregnant women, aiming to better understand the immunological network and its clinical significance for the pathogenesis and severity of preeclampsia. A total of 219 women were selected. The study population was composed of three groups referred as severe preeclamptic, normotensive pregnant and non-pregnant women. Cytokine plasma levels were determined using commercially available kits, Cytometric Beads Array - CBA to quantify TNF-α, IFN-γ, IL-4, IL-5, IL-10, IL-1ß, IL-6, IL-8 and IL-12. Our findings demonstrated that severe preeclamptic state is associated with high levels of pro-inflammatory cytokines IL-8, IL-6, and IFN-γ (P < 0.05 for all) whereas normotensive pregnancy evolves high levels of regulatory cytokine IL-10 (P < 0.05). Moreover, an outstanding pro-inflammatory "cytokine signature" could be observed in severe preeclamptic women display, while an overall regulatory state is the hallmark for normotensive pregnancy. In summary, our data showed that elevated levels of pro-inflammatory cytokines in the maternal circulation with a deviation in the "IL-8 × IL-6" axis towards IFN-γ might drive the cytokine network in preeclamptic women towards an excessive systemic inflammatory state.

ADAMTS13, FVIII, von Willebrand factor, ABO blood group assessment in preeclampsia.

INTRODUCTION: Preeclampsia (PE) is a multifactorial disease characterized by high blood pressure and proteinuria after the 20th week of pregnancy. PE is associated with fibrin deposition in placental microcirculation and intrauterine fetal growth retardation. We evaluated FVIII activity, VWF and ADAMTS13 plasma levels, according to O and "non O" blood groups, in women with severe PE (sPE). METHODS: This case-control study included 140 women; 55 pregnant with sPE, 35 normotensive pregnant and 50 non-pregnant women. VWF and ADAMTS13 antigen levels were assessed by ELISA (American Diagnostica). FVIII activity was measured by automated coagulometric method (Dade Behring) and ABO blood groups phenotyping was performed by indirect technique. RESULTS: FVIII activity and VWF levels were significantly higher comparing either sPE to normotensive pregnant (P=0.01; P=0.05) and to non-pregnant women (P=0.00 in both cases) or normotensive pregnant and non-pregnant women (P=0.00 in both cases). A significant decrease in ADAMTS13 levels was observed comparing either sPE to normotensive pregnant (P=0.02) and non-pregnant women (P=0.00) or normotensive pregnant and non-pregnant women (P=0.00). FVIII activity and VWF levels were associated to O and "non O" blood groups only in non-pregnant women. CONCLUSIONS: The increase of FVIII activity and VWF levels and the decrease of ADAMTS13 in sPE are not associated to O and "non O" blood groups. These alterations in hemostatic markers in sPE largely surpass those physiologically determined by ABO blood groups influence and may have masked the effect of O and "non O" groups in this disease. A concomitant analysis of VWF levels and ADAMTS13 activity and antigenic levels will be important to clarify the imbalance between these parameters found in sPE in the present study.