ObjectivesThromboembolic events are the major factor affecting the prognosis of patients with chronic kidney disease (CKD). Haemostatic alterations are possible causes of these complications, but their roles remain poorly characterised. In the prospective observational study, we investigated the entire coagulation process in patients with CKD to elucidate the mechanisms of their high thromboembolic risk.MethodsA total of 95 patients with CKD and 20 healthy controls who met the inclusion criteria were consecutively recruited from September 2015 to March 2016. The platelet count, platelet aggregation, von Willebrand factor antigen (vWF:Ag), vWF ristocetin cofactor activity (vWF:RCo), fibrinogen, factor V (FV), FVII, FVIII, antithrombin III, protein C, protein S, D-dimer, standard coagulation tests and thromboelastography were measured in patients with CKD and controls. Associations between the estimated glomerular filtration rate (eGFR) and haemostatic biomarkers were tested using multivariable linear regression.ResultsThe adjusted and unadjusted levels of vWF:Ag, vWF:RCo, fibrinogen, FVII, FVIII and D-dimer were significantly higher in patients with CKD than that in the healthy controls, and were elevated with CKD progression. However, after adjustment for baseline differences, platelet aggregation and thromboelastography parameters showed no significant differences between patients with CKD and healthy controls. In the correlation analysis, vWF:Ag, vWF:RCo and FVIII were inversely associated with eGFR (r=−0.359, p<0.001; r=−0.391, p<0.001; r=−0.327, p<0.001, respectively). During the 1-year of follow-up, one cardiovascular event occurred in patients with CKD 5 stage, whereas no thromboembolic event occurred in the CKD 3 and 4 and control groups.ConclusionsPatients with CKD are characterised by endothelial dysfunction and increased coagulation, especially FVIII activity. The abnormal haemostatic profiles may contribute to the elevated risk of thrombotic events but further longer-term study with large samples is still required to more precisely determine the relationship between the elevation of procoagulant factors and clinical outcomes.

The accumulation of uremic toxins in chronic kidney disease (CKD) induces inflammation, oxidative stress and endothelial dysfunction, which is a key step in atherosclerosis. Accumulating evidence indicates increased mitochondrial fission is a contributing mechanism for impaired endothelial function. Hippurate, a uremic toxin, has been reported to be involved in cardiovascular diseases. Here, we assessed the endothelial toxicity of hippurate and the contribution of altered mitochondrial dynamics to hippurate-induced endothelial dysfunction.Treatment of human aortic endothelial cells with hippurate reduced the expression of endothelial nitric oxide synthase (eNOS) and increased the expression of intercellular cell adhesion molecule-1 (ICAM-1) and von Willebrand factor (vWF). The mechanisms of hippurate-induced endothelial dysfunction in vitro depended on the activation of Dynamin-related protein 1 (Drp1)-mediated mitochondrial fission and overproduction of mitochondrial reactive oxygen species (mitoROS). In a rat model in which CKD was induced by 5/6 nephrectomy (CKD rat), we observed increased oxidative stress, impaired endothelium-dependent vasodilation, and elevated soluble biomarkers of endothelial dysfunction (ICAM-1 and vWF). Similarly, endothelial dysfunction was identified in healthy rats treated with disease-relevant concentrations of hippurate. In aortas of CKD rats and hippurate-treated rats, we observed an increase in Drp1 protein levels and mitochondrial fission. Inhibition of Drp1 improved endothelial function in both rat models.These results indicate that hippurate, by itself, can cause endothelial dysfunction. Increased mitochondrial fission plays an active role in hippurate-induced endothelial dysfunction via an increase in mitoROS.

BackgroundAlbuminuria has been associated with cardiovascular events, but whether such an association can be explained by endothelial dysfunction is not fully understood. In this study, we examined the relationship between the urine albumin-to-creatinine ratio (UACR) and biomarkers of endothelial function in patients with chronic kidney disease (CKD).Material/MethodsThe cross-sectional associations of renal dysfunction and UACR with procoagulant and inflammatory factors were evaluated for 151 consecutive CKD (stage 3–5) patients. Subjects were grouped by UACR (≤300 mg/g or >300 mg/g) and estimated glomerular filtration rate (eGFR) (30≤ eGFR <60, 15≤ eGFR <30, or eGFR <15 ml/min per 1.73 m2).ResultsA higher UACR level was associated with an increase in von Willebrand factor antigen (vWF: Ag) levels, vWF activity, factor VIII, interleukin-2, and log (interleukin-6), even after adjustment for risk factors. Linear regression analysis indicated that for every 88.5 mg/g increase in UACR, the vWF activity and factor VIII were elevated by 8.3% and 6.3%, respectively. The factorial design ANOVA data showed no statistically significant interaction between UACR and CKD stage with procoagulant and inflammatory factors.ConclusionsOur study shows an eGFR-independent association of higher UACR with elevations in markers of endothelial dysfunction and inflammatory factors in CKD patients.

A hypercoagulable state exists in patients with nephrotic syndrome (NS), which more easily leads to venous thromboembolism (VTE). However, whether acute kidney injury (AKI), a common complication of NS, affects the hypercoagulable state and VTE has rarely been elucidated. In this study, we aimed to explore coagulation changes and analyze relevant influencing factors in NS-AKI patients.A total of 269 consecutive NS patients with minimal change disease (MCD) between 2011 and 2016 were included in this observational study. Ninety-one cases were in the AKI group and 178 cases in the non-AKI group. The 1:1 propensity score matching (PSM) method was applied to match the baseline information. The coagulation biomarkers were compared, and the thrombosis events were recorded. Linear correlation was performed to detect any relation between D-dimer and clinical data.The PSM method gave matched pairs of 88 MCD patients with AKI and non-AKI patients, resulting in no differences in baseline information. The D-dimer, fibrinogen, and thromboelastography parameters maximum amplitude (MA), G values of the MCD-AKI patients were significantly higher than the levels of the MCD patients without AKI (D-dimer: 1.8 [1.0, 3.3] vs 1.1 [0.6, 1.7] mg/L, P < 0.001; fibrinogen: 7.0±2.0 vs 6.5 ± 1.4 g/L, P = 0.036; MA: 74.6 ± 5.0 vs 70.5 ± 5.3 mm, P = 0.020; G: 15.7 ± 5.3 vs 12.5 ± 3.3, P = 0.034). For the MCD patients, the serum creatinine, white blood cell count, and interleukin-6 levels in the patients with D-dimers >1 mg/L were significantly higher than those of patients with D-dimers ≤1 mg/L. The correlation analysis showed that the D-dimer level was correlated with serum creatinine, white blood cell count, and interleukin-6 (r = 0.410, P =  < 0.001; r = 0.248, P =  < 0.001; r = 0.306, P =  < 0.001, respectively). Five deep vein thrombosis events occurred in the AKI group and 1 pulmonary embolism event occurred in the non-AKI group after adjusting the propensity score value. AKI appeared to have an association with higher incidence of VTE, but the difference was not statistically significant (RR: 4.9, 95% CI: 0.6–42.7, P = 0.154).The MCD-NS patients complicated with AKI had a more severe hypercoagulable state, which might be associated with the active inflammation of AKI that mediated activation of the coagulation system.

The aims of this study were to evaluate the characteristics of hypercoagulable states in patients with membranous nephropathy (MN) via thromboelastography (TEG) and to identify risk factors. 235 MN patients who had undergone TEG examinations from 2011 to 2014 were included. An abnormality in at least two TEG parameters is considered a hypercoagulable state. Patient data was compared between the hypercoagulable and non-hypercoagulable groups. Potential risk factors for hypercoagulability were analyzed by logistic regression models. Subgroup analysis was performed in hypercoagulable patients. Compared to the non-hypercoagulable MN patients, the hypercoagulable patients showed a significantly higher proportion of female patients, urinary protein, platelet count, triglyceride and fibrinogen level, along with more severe hypoproteinemia and a reduction of serum antithrombin III. Correlation analysis showed that hypoproteinemia was the primary risk factor for hypercoagulability in MN patients. Among the hypercoagulable MN patients, a subgroup TEG parameter analysis showed that glucocorticoids-used subgroup and smoker subgroup had shortened time to initial fibrin formation (R value) and increased coagulation index respectively (P < 0.05), indicating a more serious hypercoagulable state. Meanwhile, the time to initial fibrin formation (R value) and time to clot formation (K value) of the statin-used patients were remarkably higher than those of the non-statin patients. TEG examinations facilitated the detection of hypercoagulable states in MN patients, and hypoproteinemia was the most important risk factor for hypercoagulability in these patients. The use of glucocorticoids and smoking may help to aggravate hypercoagulable states, while statin drugs may alleviate hypercoagulability.