The role of neutrophil extracellular trap formation in kidney transplantation: Implications from donors to the recipient.

Kidney transplantation remains the gold standard for patients with end-stage renal disease, but severe donor organ shortage has led to long waiting lists. The utilization of expanded criteria donor kidneys within the category of deceased donors has enlarged the pool of available kidneys for transplantation; however, these grafts often have an increased risk for delayed graft function or reduced graft survival following transplantation. During brain or circulatory death, neutrophils are recruited to the vascular beds of kidneys where a proinflammatory microenvironment might prime the formation of neutrophil extracellular traps (NETs), web-like structures, containing proteolytic enzymes, DNA, and histones. NETs are known to cause tissue damage and specifically endothelial damage while activating other systems such as coagulation and complement, contributing to tissue injury and an unfavorable prognosis in various diseases. In lung transplantation and kidney transplantation studies, NETs have also been associated with primary graft dysfunction or rejection. In this review, the role that NETs might play across the different phases of transplantation, already initiated in the donor, during preservation, and in the recipient, will be discussed. Based on current knowledge, NETs might be a promising therapeutic target to improve graft outcomes.

Acquired bleeding disorders.

Acquired bleeding disorders can develop in previously healthy people irrespective of age or gender but are particularly common in patients with certain underlying conditions. Here, we review recent advances in the management of acquired haemophilia A (AHA), acquired von Willebrand syndrome (AVWS), and patients with hemostatic abnormalities due to chronic liver disease (CLD). Patients with AHA can now benefit from prophylaxis with emicizumab, a therapeutic antibody that mimics the function of activated coagulation factor VIII. The treatment of AVWS remains challenging in many situations and requires careful consideration of the underlying condition. Haemostatic abnormalities in CLD are often compensated by proportional reduction in pro and anti-haemostatic factors resulting in sustained or even increased thrombin generation. Consequently, bleeding in CLD is rarely caused by haemostatic failure and infusion of plasma or coagulation factor concentrates may not be effective.

Recommendations for the safe use of direct oral anticoagulants in patients with cirrhosis based on a systematic review of pharmacokinetic, pharmacodynamic and safety data.

PURPOSE: The popularity of direct oral anticoagulants (DOACs) is increasing among patients with cirrhosis. Cirrhosis has a major impact on the pharmacokinetics of drugs, potentially increasing adverse events. Safe use of drugs in cirrhosis requires a diligent risk-benefit analysis. The aim of this study is to develop practice recommendations for safe use of DOACs in cirrhosis based on a systematic review of pharmacokinetic, pharmacodynamic and safety data. METHODS: We conducted a systematic literature search to identify studies on pharmacokinetics, pharmacodynamics and safety of DOACs in cirrhosis. Data were collected and presented in summary tables by severity of cirrhosis using the Child-Turcotte-Pugh (CTP) classification. A multidisciplinary expert panel evaluated the results and classified the DOACs according to safety. RESULTS: Fifty four studies were included. All DOACs were classified as 'no additional risks known' for CTP A. For CTP B, apixaban, dabigatran and edoxaban were classified as 'no additional risks known'. Apixaban and edoxaban showed fewer adverse events in patients with cirrhosis, while dabigatran may be less impacted by severity of cirrhosis based on its pharmacokinetic profile. Rivaroxaban was classified as 'unsafe' in CTP B and C based on significant pharmacokinetic alterations. Due to lack of data, apixaban, dabigatran and edoxaban were classified as 'unknown' for CTP C. CONCLUSION: DOACs can be used in patients with CTP A cirrhosis, and apixaban, dabigatran and edoxaban can also be used in CTP B. It is recommended to avoid rivaroxaban in CTP B and C. There is insufficient evidence to support safe use of other DOACs in CTP C cirrhosis.

Prolonged hypothermic machine perfusion enables daytime liver transplantation - an IDEAL stage 2 prospective clinical trial.

Background: Liver transplantation is traditionally performed around the clock to minimize organ ischemic time. However, the prospect of prolonging preservation times holds the potential to streamline logistics and transform liver transplantation into a semi-elective procedure, reducing the need for nighttime surgeries. Dual hypothermic oxygenated machine perfusion (DHOPE) of donor livers for 1-2 h mitigates ischemia-reperfusion injury and improves transplant outcomes. Preclinical studies have shown that DHOPE can safely extend the preservation of donor livers for up to 24 h. Methods: We conducted an IDEAL stage 2 prospective clinical trial comparing prolonged (≥4 h) DHOPE to conventional (1-2 h) DHOPE for brain-dead donor livers, enabling transplantation the following morning. Liver allocation to each group was based on donor hepatectomy end times. The primary safety endpoint was a composite of all serious adverse events (SAE) within 30 days after transplantation. The primary feasibility endpoint was defined as the number of patients assigned and successfully receiving a prolonged DHOPE-perfused liver graft. Trial registration at: WHO International Clinical Trial Registry Platform, number NL8740. Findings: Between November 1, 2020 and July 16, 2022, 24 patients were enrolled. The median preservation time was 14.5 h (interquartile range [IQR], 13.9-15.5) for the prolonged group (n = 12) and 7.9 h (IQR, 7.6-8.6) for the control group (n = 12; p = 0.01). In each group, three patients (25%; 95% CI 3.9-46%, p = 1) experienced a SAE. Markers of ischemia-reperfusion injury and oxidative stress in both perfusate and recipients were consistently low and showed no notable discrepancies between the two groups. All patients assigned to either the prolonged group or control group successfully received a liver graft perfused with either prolonged DHOPE or control DHOPE, respectively. Interpretation: This first-in-human clinical trial demonstrates the safety and feasibility of DHOPE in prolonging the preservation time of donor livers to enable daytime transplantation. The ability to extend the preservation window to up to 20 h using hypothermic oxygenated machine preservation at a 10 °C temperature has the potential to reshape the landscape of liver transplantation. Funding: University Medical Center Groningen, the Netherlands.

Anticoagulation in chronic kidney disease: current status and future perspectives.

Chronic kidney disease (CKD) is being diagnosed increasingly worldwide. It is often identified in individuals with comorbidities, which may increase the already heightened risk of thrombosis and hemorrhage associated with CKD. Oral anticoagulation is an effective means of reducing rates of ischemic stroke and systemic embolism in patients with atrial fibrillation and minimizes the morbidity and mortality caused by venous thromboembolic disease. Despite the proven benefits in the majority of patients, these have not been so clearly realized in patients with CKD due to the precarious balance between bleeding and thromboembolic complications. In this review, the current status of anticoagulant utilization in CKD is examined, and some practical recommendations are put forward to assist in the decision-making process of safely anticoagulating patients with CKD diagnosed with atrial fibrillation and venous thromboembolism.

Coagulation factor XIII is a critical driver of liver regeneration after partial hepatectomy.

BACKGROUND: Activation of coagulation and fibrin deposition in the regenerating liver appears to promote adequate liver regeneration in mice. In humans, perioperative hepatic fibrin deposition is reduced in patients who develop liver dysfunction after partial hepatectomy (PHx), but the mechanism underlying reduced fibrin deposition in these patients is unclear. METHODS AND RESULTS: Hepatic deposition of cross-linked (ie, stabilized) fibrin was evident in livers of mice after two-thirds PHx. Interestingly, hepatic fibrin cross-linking was dramatically reduced in mice after 90% PHx, an experimental setting of failed liver regeneration, despite similar activation of coagulation after two-thirds or 90% PHx. Likewise, intraoperative activation of coagulation was not reduced in patients who developed liver dysfunction after PHx. Preoperative fibrinogen plasma concentration was not connected to liver dysfunction after PHx in patients. Rather, preoperative and postoperative plasma activity of the transglutaminase coagulation factor (F)XIII, which cross-links fibrin, was lower in patients who developed liver dysfunction than in those who did not. PHx-induced hepatic fibrin cross-linking and hepatic platelet accumulation were significantly reduced in mice lacking the catalytic subunit of FXIII (FXIII-/- mice) after two-thirds PHx. This was coupled with a reduction in both hepatocyte proliferation and liver-to-body weight ratio as well as an apparent reduction in survival after two-thirds PHx in FXIII-/- mice. CONCLUSION: The results indicate that FXIII is a critical driver of liver regeneration after PHx and suggest that perioperative plasma FXIII activity may predict posthepatectomy liver dysfunction. The results may inform strategies to stabilize proregenerative fibrin during liver resection.

Platelet adhesion assessed by PFA-100 is not linked to progression of ACLD.

Background & Aims: Increased aggregation of individual platelets upon activation, as assessed by whole blood aggregometry standardised to platelet count (PLT), has recently been linked to progression of advanced chronic liver disease (ACLD). Moreover, changes in primary haemostasis have been implicated in bleeding and thrombosis in patients with ACLD.We aimed (i) to identify the determinants of the primary haemostatic capacity - as assessed by Platelet Function Analyzer 100 (PFA-100) ('in vitro bleeding time') - in patients with ACLD and (ii) to investigate its potential association with clinical outcomes. Methods: PFA-100 was performed in 688 patients with ACLD undergoing hepatic venous pressure gradient measurement. Hepatic decompensation and liver-related death as well as bleeding and thrombosis were the outcomes of interest. Results: Sixty-three percent of patients had a PFA-100 collagen/epinephrine closure time (CT) of >150 s (i.e. prolonged). PLT and haematocrit were the main determinants of CT, whereas it was not impacted by von Willebrand factor antigen. Mirroring the increasing prevalence/severity of thrombocytopaenia and anaemia, we observed a progressive prolongation of CT (i.e. decreased primary haemostatic capacity) with more advanced disease, as indicated by clinical stage, Child-Turcotte-Pugh score, United Network for Organ Sharing model for end-stage liver disease (2016) score, and hepatic venous pressure gradient. Although increased CT (i.e. decreased primary haemostatic capacity) was associated with an increased risk of hepatic decompensation/liver-related death, these associations were less consistent after adjusting/correcting for PLT/haematocrit and established prognostic indicators. Finally, CT was not associated with the incidence of major bleedings or thromboses. Conclusions: These findings do not support the hypothesis that increased platelet adhesion - assessed in vitro under shear stress by PFA-100 - promotes ACLD progression. Impact and implications: The potential of platelets to aggregate in the bloodstream may be increased in patients with advanced chronic liver disease. Platelet Function Analyzer 100 (PFA-100), a blood test reflecting in vitro bleeding time, might be suggestive of an impaired primary clot forming capacity. In our study, we could show that PFA-100 results were not linked to bleeding/thrombotic events. Our findings do not support the hypothesis that an increased adhesion of platelets (assessed by PFA-100) might lead to a disease progression in patients with advanced chronic liver disease.

Patients with metabolic dysfunction-associated steatotic liver disease have preserved in vitro responses to antiplatelet drugs.

Background: Patients with metabolic dysfunction-associated steatotic liver disease (MASLD) are at a risk of developing cardiovascular disease. Antiplatelet therapy not only prevents cardiovascular disease in these patients, but may also lower the risk of progression into advanced stages of fibrosis. However, patients with MASLD-associated cirrhosis often have complex changes in the hemostatic system and have been excluded from randomized trials. Objectives: The aim of this study was to assess the potency of antiplatelet drugs in these patients with MASLD-associated cirrhosis. Methods: We included patients with MASLD-associated cirrhosis (n = 19), patients with type 2 diabetes (DM2) and steatosis (n = 22), patients with steatosis only (n = 15), and healthy controls (n = 20). We measured basal platelet aggregation and activation using light transmission aggregometry and flow cytometry. We subsequently measured platelet aggregation and activation after in vitro addition of aspirin, cangrelor, and ticagrelor and compared the antiplatelet response in patients and healthy controls. Results: Rates of aspirin resistance as measured by light transmission aggregometry were similar between patients with MASLD-associated cirrhosis and healthy controls (21% vs 16%), but were significantly higher in patients with DM2 and steatosis (50% [P = .02] vs controls) and patients with steatosis only (53% [P = .05] vs controls). In patients with DM2 and steatosis, but not with MASLD-associated cirrhosis, the potency of cangrelor was significantly lower than that in healthy controls (P = .028). Conclusion: The in vitro potency of aspirin, cangrelor, and ticagrelor in samples of patients with MASLD-associated cirrhosis is similar to that of healthy controls. In contrast, the potency of commonly used antiplatelet drugs may be altered in patients with DM2 and steatosis and in patients with steatosis only.

Coagulation profiles during and after anabolic androgenic steroid use: data from the HAARLEM study.

Background: Anabolic androgenic steroids (AAS) are thought to increase venous thromboembolism (VTE) risk. Objectives: We investigated whether AAS influence coagulation parameters associated with VTE by assessing their changes during and after AAS use. Methods: The HAARLEM study enrolled 100 male amateur athletes voluntarily starting an AAS cycle between 2015 and 2018. We measured procoagulant and anticoagulant protein levels, D-dimer levels, endogenous thrombin potential (ETP), and clot lysis time (CLT) at baseline and during 2 years of follow-up. Changes in coagulation during AAS cycle, 3 months after its discontinuation, and 1 year after its inclusion compared with baseline were estimated using linear mixed models. The associations between AAS dose and duration of use with these outcomes were studied through adjusted multivariable linear regression. Results: Participants used AAS for a median of 13 weeks (IQR: 10-23) with a median weekly dose of 901 mg (IQR: 634-1345 mg). Mean levels of multiple coagulation factors (F) increased during use compared with baseline, whereas FVIII and von Willebrand factor levels remained unchanged. Protein S and D-dimer showed the biggest increase (22% [95% CI: 15-29] and 1.3-fold [95% CI: 1.2-1.5], respectively). CLT was 8 minutes longer (95% CI: 5-10) and ETP was 165 nM∗min (95% CI: -205 to -124) lower during the AAS cycle. A high weekly AAS dose and short cycle duration were associated with changes in protein S and ETP during use. All parameters returned to baseline values 3 months after discontinuation and remained similar after. Conclusion: During AAS use, procoagulant and anticoagulant protein levels increased in a reversible manner. The overall balance did not suggest a clear procoagulant state.

How to assess hemostasis in patients with severe liver disease.

Patients with advanced liver diseases frequently acquire profound alterations in their hemostatic system. Simultaneous changes in procoagulant and anticoagulant systems result in a reset in the hemostatic balance with a relatively neutral net effect, although there are notable hypocoagulable and hypercoagulable features in the hemostatic system in patients with liver disease. Laboratory and clinical studies have demonstrated that patients have a relatively well-preserved hemostatic system even though routine diagnostic tests of hemostasis (prothrombin time, platelet count) suggest a bleeding tendency. Routine diagnostic tests of hemostasis are unsuitable to assess the hemostatic status of patients with liver disease, as these tests are insensitive for the concurrent prohemostatic and antihemostatic changes in these patients. These tests are, however, frequently requested in patients with liver disease, as they are well established indicators of severity of liver disease. This paper will discuss commonly used diagnostic and research-type hemostatic tests and will outline how test results should be interpreted in patients with liver disease.

Bile proteome reveals biliary regeneration during normothermic preservation of human donor livers.

Normothermic machine perfusion (NMP) after static cold storage is increasingly used for preservation and assessment of human donor livers prior to transplantation. Biliary viability assessment during NMP reduces the risk of post-transplant biliary complications. However, understanding of molecular changes in the biliary system during NMP remains incomplete. We performed an in-depth, unbiased proteomics analysis of bile collected during sequential hypothermic machine perfusion, rewarming and NMP of 55 human donor livers. Longitudinal analysis during NMP reveals proteins reflective of cellular damage at early stages, followed by upregulation of secretory and immune response processes. Livers with bile chemistry acceptable for transplantation reveal protein patterns implicated in regenerative processes, including cellular proliferation, compared to livers with inadequate bile chemistry. These findings are reinforced by detection of regenerative gene transcripts in liver tissue before machine perfusion. Our comprehensive bile proteomics and liver transcriptomics data sets provide the potential to further evaluate molecular mechanisms during NMP and refine viability assessment criteria.

Von Willebrand factor is an independent predictor of short-term mortality in acutely ill patients with cirrhosis.

BACKGROUND AND AIMS: Levels of von Willebrand factor (VWF) are elevated in patients with cirrhosis, and correlate well with disease severity. In patients with decompensated cirrhosis (DC), plasma VWF is associated with mortality. The value of VWF in predicting short-term mortality risk in patients with acute-on-chronic liver failure (ACLF) is, however, unclear. METHODS: We included patients with DC (n = 111) and ACLF (n = 105). We measured VWF levels and correlated these with other laboratory parameters and prediction models for mortality. Also, we assessed the predictive value of VWF in the prediction of 90- and 30-day mortality in patients with DC and ACLF, respectively, and compared this to the predictive value of clinically used prediction models. Finally, we determined the optimal cut-off value for VWF in patients with ACLF. RESULTS: Sixteen of 111 (14%) patients with DC and 35 of 105 (33%) with ACLF died within 90 and 30 days, respectively. VWF was associated with mortality and correlated closely with other prediction models. In patients with ACLF, VWF levels had a discrimination for 30-day mortality comparable with these models and accurately identified ACLF patients with high 30-day mortality risk. CONCLUSIONS: Levels of VWF associate closely with risk of mortality in patients with DC and ACLF, and may have predictive utility as a laboratory marker of prognosis. Further research is warranted to assess the additional value of VWF in the prediction of mortality and associated complications in chronic liver failure syndromes.

Von Willebrand factor processing in patients with advanced chronic liver disease and its relation to portal hypertension and clinical outcome.

BACKGROUND AND AIMS: Endothelial dysfunction and portal hypertension (PH) are reflected by increased von Willebrand factor antigen (VWF-Ag) levels in advanced chronic liver disease (ACLD). This study investigated VWF release and cleavage and their association with PH and clinical outcomes. METHODS: Levels of VWF-Ag, VWF-N (VWF-propeptide), and VWF-A (VWF processed by the main VWF-cleaving protease ADAMTS13) were assessed in 229 patients with clinically stable ACLD (hepatic venous pressure gradient [HVPG] ≥ 6 mmHg; absence of bacterial infections or acute decompensation) undergoing HVPG-measurement. Liver-healthy individuals served as controls (n = 24). RESULTS: VWF-Ag and VWF-N were similarly accurate for the identification of clinically significant PH (CSPH; HVPG ≥ 10 mmHg) in compensated ACLD (AUROC: VWF-Ag 0.748; VWF-N 0.728). ADAMTS13 activity was similar between patients with ACLD and controls and did not correlate with PH and disease severity, whereas VWF cleavage decreased in patients with CSPH (i.e., VWF-Ag/-A-ratio increased). In vitro VWF activity strongly reflected VWF-Ag levels (Spearman's r = 0.874, p < 0.001), but decreased (vs. controls) in patients with CSPH when normalized to VWF-Ag levels (VWF-activity/-Ag-ratio). VWF-Act/-Ag ratio correlated negatively with ADAMTS13 activity (r =- 0.256, p < 0.001). ADAMTS13 activity was independently predictive for (i) portal vein thrombosis (PVT) and (ii) hepatic decompensation or liver-related death. CONCLUSIONS: VWF-Ag levels and its propeptide are similarly suitable surrogates of PH in patients with compensated ACLD. ADAMTS13-Act was not linked to disease and PH severity, however, when normalized to VWF-Ag, both VWF cleavage and VWF activity were decreased in patients with CSPH, as compared to liver-healthy individuals. Low ADAMTS13-Act was associated with presumably more procoagulant VWF and adverse outcomes. CLINICAL TRIAL NUMBER: NCT03267615.