Management of coagulation abnormalities in liver disease

Coagulation Abnormalities in Chronic Liver Disease

Chronic liver disease is a frequently encountered disorder and a major concern worldwide with a complex pathophysiology, which often affects the hemostatic system. Such alterations, which affect both primary and secondary hemostasis, are heterogenous, including prohemorrhagic (i.e., decreased coagulation factors, increased fibrinolysis, thrombocytopenia, and platelet dysfunction) and prothrombotic (i.e., decreased natural anticoagulants) changes. As a consequence of this unstable balance, patients with liver cirrhosis may experience both hemorrhagic complications and venous thromboembolic events, which are often unpredictable and whose management is particularly challenging for clinicians. This narrative review will address the most recent advances in the pathophysiology of key derangements of hemostasis in patients with chronic liver disease, focusing on their clinical implications and management.

Thrombotic complications post liver transplantation: Etiology and management

Liver transplantation (LT) is the life saving therapeutic option for patients with acute and chronic end stage liver disease. This is a routine procedure with excellent outcomes in terms of patient survival and quality of life post LT. Orthotopic LT (OLT) patients require a critical care as they are prone to variety of post-operative vascular, cardiovascular, biliary, pulmonary and abdominal complications. Thrombotic complications (both arterial and venous) are not uncommon post liver transplant surgery. Such vascular problems lead to increased morbidity and mortality in both donor and graft recipient. Although thromboprophylaxis is recommended in general surgery patients, no such standards exist for liver transplant patients. Drastic advancements of surgical and anesthetic procedures have improvised survival rates of patients post OLT. Despite these, haemostatic imbalance leading to thrombotic events post OLT cause significant graft loss and morbidity and even lead to patient's death. Thus it is extremely important to understand pathophysiology of thrombosis in LT patients and shorten the timing of its diagnosis to avoid morbidity and mortality in both donor and graft recipient. Present review summarizes the current knowledge of vascular complications associated with LT to highlight their impact on short and long-term morbidity and mortality post LT. Also, present report discusses the lacunae existing in the literature regarding the risk factors leading to arterial and venous thrombosis in LT patients.

Fibrin clot properties and thrombus composition in cirrhosis

Patients with cirrhosis frequently acquire profound hemostatic alterations, which may affect thrombus quality and composition-factors that determine the susceptibility to embolization and fibrinolysis. In this narrative review, we describe in vitro studies on fibrin clot formation and quantitative and qualitative changes in fibrinogen in patients with cirrhosis, and describe recent findings on the composition of portal vein thrombi in patients with cirrhosis. Patients with mild cirrhosis have increased thrombin generation capacity and plasma fibrinogen levels, which may be balanced by delayed fibrin polymerization and decreased factor XIII levels. With progressing illness, plasma fibrinogen levels decrease, but thrombin generation capacity remains elevated. Fibrinogen is susceptible to posttranslational protein modifications and is, for example, hypersialylated and carbonylated in patients with cirrhosis. Despite changes in thrombin generation, factor XIII levels and the fibrinogen molecule, fibrin fiber thickness, and density are normal in patients with cirrhosis. Paradoxically, fibrin clot permeability in patients with cirrhosis is decreased, possibly because of posttranslational protein modifications. Most patients have normal fibrinolytic potential. We have recently demonstrated that portal vein thrombosis is likely a misnomer as the material that may obstruct the cirrhotic portal vein frequently consists of a thickened portal vein wall, rather than a true thrombus. Patients with cirrhosis often have thrombocytopenia and anemia, which may also affect clot stability and composition, but the role of cellular components in clot quality in cirrhosis has not been extensively studied. Finally, we summarize abstracts on fibrin formation and clot quality that were presented at the ISTH 2022 meeting in London.

Disseminated Intravascular Coagulation in Sepsis and Associated Factors

Background: sepsis is a life-threatening organ dysfunction caused by an excessive host immunological response to infection. The incidence of sepsis is increasing every year, and sepsis is the primary cause of mortality in intensive care units (ICUs). DIC is a coagulopathy syndrome that causes microvascular and macrovascular thrombosis and increases the risk of bleeding due to consumptive coagulopathy. The pathophysiology of DIC in sepsis is complex, and further research is required to investigate the involved mechanisms and risk factors. Method: this study is a prognostic analysis of a retrospective cohort. Samples were patients diagnosed with sepsis and admitted to Cipto Mangunkusumo National General Hospital from January 2016 to October 2022. Research subjects were followed until occurrence of DIC during sepsis or recovery from sepsis. The research subjects were selected from medical records using a consecutive total sampling approach. The inclusion criteria were patients aged ≥18 years old and diagnosed with sepsis according to qSOFA criteria with a score of 2. The exclusion criterion was an incomplete medical record. Bivariate and multivariate logistic regression analyses were performed to determine which independent variables contributed to the incidence of DIC and obtain the odds ratios (ORs). p < 0.05 was considered to indicate a statistically significant difference. Results: a total of 248 patients were included after considering the inclusion and exclusion criteria. Of these, 50 (20.2%) septic patients developed DIC. In the multivariate analysis, albumin ≤2.5 g/dL (OR: 2.363; 95% CI: 1.201−4.649), respiratory infection (OR: 2.414; 95% CI: 1.046−5.571), and antibiotic treatment ≥1 h (OR: 2.181; 95% CI: 1.014−4.689) were associated with DIC development. On the basis of the ROC curve, the area under the curve (AUC) was determined to be 0.705 with 95% CI = (0.631−0.778). Conclusion: in our study, the prevalence of DIC in septic patients was 20.2%. Low albumin, respiratory infection, and antibiotic treatment ≥1 h were found to be risk factors for development of DIC in septic patients.

Primary Nonfunction of the Liver Allograft

Severe allograft dysfunction, as opposed to the expected immediate function, following liver transplantation is a major complication, and the clinical manifestations of such that lead to either immediate retransplant or death are the catastrophic end of the spectrum. Primary nonfunction (PNF) has declined in incidence over the years, yet the impact on patient and healthcare teams, and the burden on the organ pool in case of the need for retransplant should not be underestimated. There is no universal test to define the diagnosis of PNF, and current criteria are based on various biochemical parameters surrogate of liver function; moreover, a disparity remains within different healthcare systems on selecting candidates eligible for urgent retransplantation. The impact on PNF from traditionally accepted risk factors has changed somewhat, mainly driven by the rising demand for organs, combined with the concerted approach by clinicians on the in-depth understanding of PNF, optimal graft recipient selection, mitigation of the clinical environment in which a marginal graft is reperfused, and postoperative management. Regardless of the mode, available data suggest machine perfusion strategies help reduce the incidence further but do not completely avert the risk of PNF. The mainstay of management relies on identifying severe allograft dysfunction at a very early stage and aggressive management, while excluding other identifiable causes that mimic severe organ dysfunction. This approach may help salvage some grafts by preventing total graft failure and also maintaining a patient in an optimal physiological state if retransplantation is considered the ultimate patient salvage strategy.

Donor genetic variants as risk factors for thrombosis after liver transplantation: A genome-wide association study

Thrombosis after liver transplantation substantially impairs graft- and patient survival. Inevitably, heritable disorders of coagulation originating in the donor liver are transmitted by transplantation. We hypothesized that genetic variants in donor thrombophilia genes are associated with increased risk of posttransplant thrombosis. We genotyped 775 donors for adult recipients and 310 donors for pediatric recipients transplanted between 1993 and 2018. We determined the association between known donor thrombophilia gene variants and recipient posttransplant thrombosis. In addition, we performed a genome-wide association study (GWAS) and meta-analyzed 1085 liver transplantations. In our donor cohort, known thrombosis risk loci were not associated with posttransplant thrombosis, suggesting that it is unnecessary to exclude liver donors based on thrombosis-susceptible polymorphisms. By performing a meta-GWAS from children and adults, we identified 280 variants in 55 loci at suggestive genetic significance threshold. Downstream prioritization strategies identified biologically plausible candidate genes, among which were AK4 (rs11208611-T, p = 4.22 × 10^-05 ) which encodes a protein that regulates cellular ATP levels and concurrent activation of AMPK and mTOR, and RGS5 (rs10917696-C, p = 2.62 × 10^-05 ) which is involved in vascular development. We provide evidence that common genetic variants in the donor, but not previously known thrombophilia-related variants, are associated with increased risk of thrombosis after liver transplantation.

Liver transplantation of a patient with extreme thrombocytopenia - A case report

BACKGROUND

Patients with chronic liver disease (CLD) planned for liver transplantation (LT) often show severe thrombocytopenia, but there is a lack of evidence in deciding the threshold for prophylactic platelet transfusion.

CASE

A 47-year-old female with acute liver failure was referred for LT. Despite daily transfusion of platelets, platelet counts remained under 10,000/µl. During LT, 2 units of single donor platelets (SDP) were transfused. Although platelet counts remained extremely low (3,000-4,000/µl) no diffuse oozing was observed and the blood loss was 860 ml. Postoperatively, there was no sign of active bleeding or oozing, and the patient received only 1 unit SDP transfusion.

CONCLUSIONS

CLD patients may have severe thrombocytopenia. However, primary hemostasis may not be significantly hindered due to the existence of rebalanced hemostasis. Prophylactic platelet transfusion in these patients should not be decided based on platelet counts only, but also take other coagulation tests and clinical signs into consideration.

Guidelines on the use of liver biopsy in clinical practice from the British Society of Gastroenterology, the Royal College of Radiologists and the Royal College of Pathology

Liver biopsy is required when clinically important information about the diagnosis, prognosis or management of a patient cannot be obtained by safer means, or for research purposes. There are several approaches to liver biopsy but predominantly percutaneous or transvenous approaches are used. A wide choice of needles is available and the approach and type of needle used will depend on the clinical state of the patient and local expertise but, for non-lesional biopsies, a 16-gauge needle is recommended. Many patients with liver disease will have abnormal laboratory coagulation tests or receive anticoagulation or antiplatelet medication. A greater understanding of the changes in haemostasis in liver disease allows for a more rational, evidence-based approach to peri-biopsy management. Overall, liver biopsy is safe but there is a small morbidity and a very small mortality so patients must be fully counselled. The specimen must be of sufficient size for histopathological interpretation. Communication with the histopathologist, with access to relevant clinical information and the results of other investigations, is essential for the generation of a clinically useful report.

Manifestations of blood coagulation and its relation to clinical outcomes in severe COVID-19 patients: Retrospective analysis

Introduction

Characteristics of blood coagulation and its relation to clinical outcomes in COVID‐19 patients are still rarely reported. We aimed to investigate the blood coagulation function and its influences on clinical outcomes of patients with syndrome coronavirus 2 (SARS‐CoV‐2) infection.

Methods

A total of 71 severe patients with confirmed SARS‐CoV‐2 infection who were treated in Wuhan First Hospital from February 12 to March 20, 2020, were enrolled. The blood coagulation data in these patients and in 61 healthy controls were collected. The patients with COVID‐19 were divided into two groups: the aggravated group and the nonaggravated group, respectively, basing on whether the patients' conditions turned to critically ill or not after admission.

Results

Compared with healthy controls, patients with COVID‐19 had significant performances with coagulation dysfunction, including dramatically elevated values of FIB, PT, APTT, INR, FDP, and D‐Dimers but markedly reduced AT value (P < .05). Importantly, more noteworthy coagulation disorders similar to the differences between patients and controls were found in the aggravated patients with conditions deterioration after admission than those in the nonaggravated patients without conditions deterioration (P < .05). Moreover, the aggravated patients possessed a longer hospital stay and a higher mortality compared with the nonaggravated patients (P < .001). The coagulation parameters of COVID‐19 patients were widely and closely related to the indexes of liver function and inflammation (P < .05), indicating the coagulation dysfunction of these patients may be caused by liver injury and inflammatory storm.

Conclusion

Severe patients with SARS‐CoV‐2 infection often possess coagulation dysfunction on admission. A certain correlation exists in coagulation disorder and adverse clinical outcome among severe COVID‐19 patients.

Fibrin fragment E potentiates TGF-β-induced myofibroblast activation and recruitment

Fibrin is an essential constituent of the coagulation cascade, and the formation of hemostatic fibrin clots is central to wound healing. Fibrin clots are over time degraded into fibrin degradation products as the injured tissue is replaced by granulation tissue. Our goal was to study the role of the fibrin degradation product fragment E (FnE) in fibroblast activation and migration. We present evidence that FnE is a chemoattractant for fibroblasts and that FnE can potentiate TGF-β-induced myofibroblast formation. FnE forms a stable complex with α_Vβ₃ integrin, and the integrin β₃ subunit is required both for FnE-induced fibroblast migration and for potentiation of TGF-β-induced myofibroblast formation. Finally, subcutaneous infusion of FnE in mice results in a fibrotic response in the hypodermis. These results support a model where FnE released from clots in wounded tissue promote wound healing and fibrosis by both recruitment and activation of fibroblasts. Fibrin fragment E could thus represent a therapeutic target for treatment of pathological fibrosis.

Assessment of bleeding in chronic liver disease and coagulopathy using the IMPROVE bleeding criteria

BACKGROUND

In this study, the authors utilized the IMPROVE (International Medical Prevention Registry on Venous Thromboembolism) bleeding definition to explore the safety profile of pharmacologic venous thromboembolism (VTE) prophylaxis in patients with chronic liver disease (CLD) and concurrent coagulopathy (INR ≥1.5).

METHODS

A retrospective study was conducted on 193 adult patient admissions with a diagnosis of CLD and INR ≥1.5 not due to therapeutic anticoagulation. Patients were stratified based on their receipt of pharmacological thromboprophylaxis or not during hospitalization. The rates of overall bleeding, defined as the composite of major bleeding and clinically relevant non-major bleeding; major bleeding; and clinically relevant non-major bleeding, within 14 days of admission were evaluated. Secondary endpoints included the rates of thrombosis and mortality.

RESULTS

The composite of overall bleeding occurred in 17.6% of the admissions. More patients in the group not receiving pharmacological thromboprophylaxis had overall bleeding (18.5% vs 10%), major bleeding (13.3% vs 10%), and clinically relevant non-major bleeding (14.5% vs 5%), with overlapping 95% CI. When stratified per pharmacological thromboprophylaxis status, IMPROVE bleeding risk score (BRS) ≥ 7 was associated with higher rates of overall bleeding, major bleeding, and clinically relevant non-major bleeding as compared to IMPROVE BRS <7, whether patients received or did not receive pharmacological thromboprophylaxis. The overall incidence of in-hospital mortality among our study population was 15.5%. Receiving pharmacological thromboprophylaxis was markedly associated with higher in-hospital mortality (OR = 16.58, 95% CI = 4.47-61.45).

CONCLUSION

This study shows that the IMPROVE BRS calculated on admission may serve as a guide for omission of thromboprophylaxis in advanced CLD.

Infusion of DDAVP does not improve primary hemostasis in patients with cirrhosis

BACKGROUND & AIMS

Cirrhosis frequently affects multiple components of hemostasis. Reversal of the coagulopathy of these patients is frequently required in case of bleeding episodes, or as prophylaxis before invasive procedures. Although 1-deamino-8-D-arginine vasopressin (DDAVP) is widely used as a pro-hemostatic agent in patients with cirrhosis, it is unclear whether DDAVP truly enhances hemostasis in these patients. Here we investigated the hemostatic effects of a single bolus of DDAVP in patients with cirrhosis.

METHODS

Ten patients with cirrhosis (child B or C) and ten patients with mild haemophilia A received an intravenous single bolus of 0.3 microgram/kg DDAVP. Plasma was collected prior to and at 1, 3, 6, and 24 h after DDAVP administration. Levels of Von Willebrand factor (VWF), VWF propeptide, factor VIII (FVIII), and ADAMTS13 were measured in all plasma samples, whereas VWF multimers and functional VWF-dependent platelet adhesion were determined in the samples pre- and 1 h after DDAVP administration.

RESULTS

Following DDAVP administration, VWF, FVIII, and VWF propeptide levels increased in patients with haemophilia, while patients with cirrhosis only showed an increase in VWF propeptide and FVIII levels. High molecular weight VWF multimers and VWF-dependent platelet adhesion increased in patients with haemophilia one hour after DDAVP administration, but did not change in the patients with cirrhosis. Levels of ADAMTS13 were unaffected in both patient groups after DDAVP.

CONCLUSION

The lack of relevant effects of DDAVP on laboratory indices of primary hemostasis in patients with cirrhosis is in line with previous clinical study results in these patients.