Disseminated intravascular coagulation in liver cirrhosis: fact or fiction?

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.

Hemostatic Alterations in Patients With Cirrhosis: From Primary Hemostasis to Fibrinolysis

In the setting of liver cirrhosis (LC), profound hemostatic changes occur, which affect primary hemostasis, coagulation, and fibrinolysis. They involve prohemorrhagic and prothrombotic alterations at each of these steps. Patients with cirrhosis exhibit multifactorial thrombocytopenia and in vitro thrombocytopathy, counterbalanced by increased von Willebrand factor. The resultant shift is difficult to assess, but overall these changes probably result in a rebalanced primary hemostasis. Concerning coagulation, the reduced activity of coagulation factors is counterbalanced by an increase in factor VIII (produced by liver sinusoidal endothelial cells), a decrease of the natural anticoagulants, and complex changes, including changes in circulating microparticles, cell-free DNA, and neutrophil extracellular traps. Overall, these alterations result in a procoagulant state. As for fibrinolysis, increased tissue-type and urokinase-type plasminogen activators, a relatively decreased plasminogen activator inhibitor 1, and decreased levels of thrombin-activatable fibrinolysis inhibitor and α2-antiplasmin are counterbalanced by decreased plasminogen and a decreased fibrin clot permeability. Whether and how these changes shift fibrinolysis remains to be determined. Overall, the current consensus is that in patients with cirrhosis, the hemostasis is shifted toward a procoagulant state. We review the published evidence for the concept of LC as a prothrombotic state, discuss discordant data, and highlight the impact of the underlying cause of LC on the resultant imbalance.

A Review on Clinical, Pathophysiological, and Diagnostic Hematological Features in Children With Liver Cirrhosis

Appropriate diagnostic and therapeutic measures for liver cirrhosis is critical, particularly in children. In the present review, a comprehensive approach was provided toward hematological parameters in pediatric liver cirrhosis. The literature search included MeSH terms "liver cirrhosis" and "hepatic cirrhosis" and databases such as PubMed, Web of Science, Scopus, and Google Scholar were searched up until December 2017. Hematologic changes in the liver cirrhosis mainly encompassed anemia and coagulopathies. In addition, bleeding diathesis was considered as the most clinical complication in these patients. In addition to reduced coagulation factors, hyperfibrinolysis is a common feature in childhood cirrhosis and may be an important contributor to the risk of bleeding. Based on the results, children with liver cirrhosis also demonstrated a procoagulant state at laboratory and clinical levels. This may be partly due to a reduction in coagulation inhibitors such as anti-thrombin, C1 inhibitor, and α1-antitrypsin in children with cirrhosis. The portal vein thrombosis and portal hypertension are considered as the most clinical presentations of the hypercoagulable state. Further, children with liver cirrhosis complicated with portal hypertension usually show leukopenia, anemia, and thrombocytopenia due to hypersplenism. Although the etiology of childhood and adult cirrhosis may be different, their hematological compilations and clinicopathological features are somehow similar.

How I treat disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a condition characterized by systemic activation of coagulation, potentially leading to thrombotic obstruction of small and midsize vessels, thereby contributing to organ dysfunction. At the same time, ongoing consumption of platelets and coagulation proteins results in thrombocytopenia and low concentrations of clotting factors, which may cause profuse hemorrhagic complications. DIC is always secondary to an underlying condition, such as severe infections, solid or hematologic malignancies, trauma, or obstetric calamities. A reliable diagnosis of DIC can be made through simple scoring algorithms based on readily available routine hemostatic parameters. The cornerstone of supportive treatment of this coagulopathy is management of the underlying condition. Additionally, administration of heparin may be useful, and restoration of physiological anticoagulants has been suggested, but has not been proven successful in improving clinically relevant outcomes so far. In patients with major bleeding or at risk for hemorrhagic complications, administration of platelet concentrates, plasma, or coagulation factor concentrates should be considered.

Coagulation parameters and major bleeding in critically ill patients with cirrhosis

Disturbances of coagulation and hemostasis are common in patients with liver cirrhosis. The typical laboratory pattern mimics disseminated intravascular coagulation (DIC). The aim of this study was to assess the impact of routine coagulation parameters in critically ill cirrhosis patients with regard to new onset of major bleeding and outcome. A total of 1,493 critically ill patients were studied prospectively. Routine coagulation parameters were assessed, and the DIC score was calculated based on platelets, fibrinogen, d-dimer, and prothrombin index. New onset of major bleeding during the stay at the intensive care unit and mortality were assessed. Patients were followed for 1 year. Two hundred eleven patients of the cohort had liver cirrhosis. Platelets, fibrinogen, prothrombin index, activated partial thromboplastin time, and d-dimer as well as the DIC score differed significantly between patients with and without cirrhosis (P < 0.001 for all). Moreover, fibrinogen, platelets, and activated partial thromboplastin time (but not prothrombin index) differed significantly between cirrhosis patients with and without major bleeding (P < 0.01 for all). Bleeding on admission, platelet count <30 < 10(9) /L, fibrinogen level <60 mg/dL, and activated partial thromboplastin time values >100 seconds were the strongest independent predictors for new onset of major bleeding in multivariate regression analysis. One-year mortality in cirrhosis patients with and without major bleeding was 89% and 68%, respectively (P < 0.05 between groups).

CONCLUSION

Abnormal coagulation parameters and high DIC scores (primarily due to fibrinogen and platelets) correspond to increased bleeding risk in patients with liver cirrhosis in the intensive care unit, and fibrinogen and platelet count were identified as the best routine coagulation parameters for prediction of new onset of major bleeding; however, further studies are required to evaluate the potential therapeutic implications of these findings. (Hepatology 2016;64:556-568).

Spontaneous bleeding or thrombosis in cirrhosis: What should be feared the most?

The more modern and accurate concept of a rebalanced hemostatic status in cirrhosis is slowly replacing the traditional belief of patients with cirrhosis being “auto-anticoagulated”, prone only to bleeding complications, and protected from thrombotic events. With greater attention to clinical thrombotic events, their impact on the natural history of cirrhosis, and with the emergence and increased use of point-of-care and global assays, it is now understood that cirrhosis results in profound hemostatic alterations that can lead to thrombosis as well as to bleeding complications. Although many clinical decisions are still based on traditional coagulation parameters such as prothrombin (PT), PT, and international normalized ratio, it is increasingly recognized that these tests do not adequately predict the risk of bleeding, nor they should guide pre-emptive interventions. Moreover, altered coagulation tests should not be considered as a contraindication to the use of anticoagulation, although this therapeutic or prophylactic approach is not at present routinely undertaken. Gastroesophageal variceal bleeding continues to be one of the most feared and deadly complications of cirrhosis and portal hypertension, but great progresses have been made in prevention and treatment strategies. Other bleeding sites that are frequently part of end-stage liver disease are similar to clinical manifestations of thrombocytopenia, with gum bleeding and epistaxis being very common but fortunately only rarely a cause of life-threatening bleeding. On the contrary, manifestations of coagulation factor deficiencies like soft tissue bleeding and hemartrosis are rare in patients with cirrhosis. As far as thrombotic complications are concerned, portal vein thrombosis is the most common event in patients with cirrhosis, but venous thromboembolism is not infrequent, and results in important morbidity and mortality in patients with cirrhosis, especially those with decompensated disease. Future studies and the more widespread use of point-of-care tests in evaluating hemostasis will aid the clinician in decision making when facing the patient with bleeding or with thrombotic complications, with both ends of a continuum being potentially fatal.

Safety, efficacy, and response predictors of anticoagulation for the treatment of nonmalignant portal-vein thrombosis in patients with cirrhosis: a propensity score matching analysis

BACKGROUND/AIMS

Portal-vein thrombosis (PVT) develops in 10-25% of cirrhotic patients and may aggravate portal hypertension. There are few data regarding the effects of anticoagulation on nonmalignant PVT in liver cirrhosis. The aim of this study was to elucidate the safety, efficacy, and predictors of response to anticoagulation therapy in cirrhotic patients.

METHODS

Patients with liver cirrhosis and nonmalignant PVT were identified by a hospital electronic medical record system (called BESTCARE). Patients with malignant PVT, Budd-Chiari syndrome, underlying primary hematologic disorders, or preexisting extrahepatic thrombosis were excluded from the analysis. Patients were divided into two groups (treatment and nontreatment), and propensity score matching analysis was performed to identify control patients. The sizes of the thrombus and spleen were evaluated using multidetector computed tomography.

RESULTS

Twenty-eight patients were enrolled in this study between 2003 and 2014: 14 patients who received warfarin for nonmalignant PVT and 14 patients who received no anticoagulation. After 112 days of treatment, 11 patients exhibited significantly higher response rates (complete in 6 and partial in 5) compared to the control patients, with decreases in thrombus size of >30%. Compared to nonresponders, the 11 responders were older, and had a thinner spleen and fewer episodes of previous endoscopic variceal ligations, whereas pretreatment liver function and changes in prothrombin time after anticoagulation did not differ significantly between the two groups. Two patients died after warfarin therapy, but the causes of death were not related to anticoagulation.

CONCLUSIONS

Warfarin can be safely administered to cirrhotic patients with nonmalignant PVT. The presence of preexisting portal hypertension is a predictor of nonresponse to anticoagulation.

Comprehensive review of post-liver resection surgical complications and a new universal classification and grading system

Liver resection is the gold standard treatment for certain liver tumors such as hepatocellular carcinoma and metastatic liver tumors. Some patients with such tumors already have reduced liver function due to chronic hepatitis, liver cirrhosis, or chemotherapy-associated steatohepatitis before surgery. Therefore, complications due to poor liver function are inevitable after liver resection. Although the mortality rate of liver resection has been reduced to a few percent in recent case series, its overall morbidity rate is reported to range from 4.1% to 47.7%. The large degree of variation in the post-liver resection morbidity rates reported in previous studies might be due to the lack of consensus regarding the definitions and classification of post-liver resection complications. The Clavien-Dindo (CD) classification of post-operative complications is widely accepted internationally. However, it is hard to apply to some major post-liver resection complications because the consensus definitions and grading systems for post-hepatectomy liver failure and bile leakage established by the International Study Group of Liver Surgery are incompatible with the CD classification. Therefore, a unified classification of post-liver resection complications has to be established to allow comparisons between academic reports.

Does decreased fibrinolysis have a role to play in the development of non-neoplastic portal vein thrombosis in patients with hepatic cirrhosis?

Hepatic cirrhosis is characterized by complex abnormalities of the fibrinolytic system. Little is known about the possible association between these alterations and thrombosis. The aim of this study was to evaluate the fibrinolytic profile in cirrhotic individuals with and without portal vein thrombosis (PVT). We measured thrombin activatable fibrinolysis inhibitor (TAFI), total amount of activated TAFI (TAFIa/ai), plasminogen activator inhibitor (PAI-1), plasminogen and fibrinogen plasma levels in 66 cirrhotic patients (33 with and 33 without PVT) and in 66 healthy volunteers. TAFI plasma levels (median [range]) were significantly lower in cirrhotic individuals (5.6 μg/ml [1.7-11.7]) than in controls (10.1 μg/ml [6.6-14.2], p < 0.0001), while TAFIa/ai levels were significantly higher in cases (18.3 ng/ml [0.3-35.4]) than in controls (15.9 ng/ml [7.4-41], p = 0.02). Cirrhotic patients with PVT had higher TAFI (6.6 μg/ml [2.9-10.1]), TAFIa/ai (19.2 ng/ml [11.6-35.4]) and PAI-1 (33.1 ng/ml [27.6-56.3]) plasma levels than those without PVT (3.9 μg/ml [1.7-11.7], p = 0.001; 15.6 ng/ml [10.3-33.9], p = 0.037; 15.9 ng/ml [2.5-29.1], p = 0.004. The fibrinolytic profile in cirrhotic individuals with PVT is characterized by higher levels of TAFI, TAFIa/ai and PAI-1 than in those without PVT. These alterations identify a hypofibrinolytic condition that may increase the risk of developing a thrombotic event.

Hemostasis in liver disease: implications of new concepts for perioperative management

The hemostatic profile of patients with liver diseases is frequently profoundly different from that of healthy individuals. These complex alterations lead to abnormal results from routine laboratory tests, but because of the nature of these assays, they fail to accurately represent the patient's hemostatic state. Nevertheless, based on abnormal laboratory coagulation values, it has long been assumed that patients with liver disease have a natural bleeding tendency and are protected from thrombosis. This assumption is false; the average patient with liver disease is actually in a state of "rebalanced hemostasis" that can relatively easily be tipped toward both bleeding and thrombosis. The new paradigm of rebalanced hemostasis has strong implications for the clinic, which are presented in this review. There is no evidence that prophylactic transfusion of plasma helps to prevent procedure-related bleeding. In addition, the presence of independent risk factors such as poor kidney status or infections should be carefully assessed before invasive procedures. Furthermore, central venous pressure plays an important role in the risk of bleeding in patients with liver diseases, so during procedures, a restrictive infusion policy should be applied. Finally, thrombosis prophylaxis should not be withheld from patients with cirrhosis or acute liver failure, and clinicians should be alert to the possibility of thrombosis occurring in these patients.

Therapeutic rather than prophylactic platelet transfusion policy for severe thrombocytopenia during liver transplantation

Platelet transfusion (PTx) has been identified as an important risk factor for morbidity and mortality after liver transplantation (LTx). Our aim was to evaluate the safety of therapeutic rather than prophylactic PTx policy in severe thrombocytopenic patients undergoing LTx. Recipients of LTx were divided into two groups: group I (GI) (n = 76) platelet count (PC) ≥ 50 × 10(9)/l and group II (GII) PC < 50 × 109/l (n = 76). Platelets were transfused following a thromboelastometry protocol and clinical signs of diffuse bleeding. Both groups were compared regarding hemoglobin (Hb), international normalized ratio (INR), fibrinogen level, blood loss (BL), blood products required, percentage of bloodless surgery, duration of mechanical ventilation, ICU stay, and vascular complications. Each group was further subdivided according to PTx into (GI NPTx and GII NPTx) with no platelet transfusion (NPTx) and (GI PTx and GII PTx) received PTx. These subgroups were further compared for some variables. Base line Hb was significantly higher while INR was significantly lower in GI.75% avoided PTx in GII. Comparisons of BL, packed red blood cells (PRBCs), and cryoprecipitate transfusion were insignificant. Fresh frozen plasma (FFP) transfusion was higher and the percentage of bloodless surgery was lower in GII. In GII, PC increased after start of surgery. Two cases of hepatic artery thrombosis in GI and one in GII were recorded. Recovery of platelets was quicker, and duration of mechanical ventilation and ICU stay was shorter in NPTx patients regardless the base line PC. Cut-off values of PC 30 × 10(9)/l (with sensitivity 73.7% and specificity 78.8%, p < 0.01), BL of 3750 ml in GI (sensitivity of 75% and specificity of 69%, p < 0.01) and of 3250 ml in GII (sensitivity of 84.2% and specificity of 87.7% (p < 0.01)) could indicate the need of PTx. With therapeutic approach, 75% of patients in GII could avoid unnecessary PTx with its hazards without excessive bleeding. PC in GII increased intraoperatively, PTx may lead to delayed recovery of platelets, increased duration of mechanical ventilation and ICU stay. The given cut-off values may help to guide PTx.

Evaluation of hemostatic and fibrinolytic markers in dogs with ascites attributable to right-sided congestive heart failure

OBJECTIVE

To determine whether dogs with ascites secondary to right-sided congestive heart failure (CHF) have bleeding disorders associated with hypofibrinogenemia and discordant plasma fibrin-fibrinogen degradation products (FDPs) and D-dimer assay results (ie, a circulating concentration of FDPs higher than the reference range and a circulating concentration of D-dimer within the reference range).

DESIGN

Retrospective case-control study.

ANIMALS

80 client-owned dogs.

PROCEDURES

Dogs with ascites secondary to right-sided CHF (group 1; n = 20), unhealthy dogs without cardiac disease (group 2; 40), and dogs with left-sided CHF (group 3; 20) were included in the study. Urine bile acids-to-creatinine concentration ratios were calculated as a marker of liver function. Differences among groups regarding coagulation profile analysis results and prevalence of discordant FDPs and D-dimer assay results were determined.

RESULTS

No significant differences were detected among the 3 groups regarding urine bile acids-to-creatinine concentration ratios. Plasma fibrinogen concentration was significantly lower for group 1 versus groups 2 or 3. Prevalence of discordant FDPs and D-dimer assay results was significantly higher for group 1 versus groups 2 or 3. Eighteen group 1 dogs had discordant FDPs and D-dimer assay results. Ten of these dogs had concurrent hypofibrinogenemia, 2 of which had clinical signs of bleeding. Only 10 dogs in groups 2 or 3 had discordant FDPs and D-dimer assay results; none of these dogs had hypofibrinogenemia or clinical signs of bleeding.

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs with right-sided CHF and ascites may be at increased risk for primary hyperfibrinogenolysis (ie, hypofibrinogenemia and discordant FDPs and D-dimer assay results).

Novel biomarker candidates to predict hepatic fibrosis in hepatitis C identified by serum proteomics

BACKGROUND

Liver biopsy remains the gold standard to assess hepatic fibrosis. It is desirable to predict hepatic fibrosis without the need for invasive liver biopsy. Proteomic techniques allow unbiased assessment of proteins and might be useful to identify proteins related to hepatic fibrosis.

AIMS

We utilized two different proteomic methods to identify serum proteins as candidate biomarkers to predict hepatic fibrosis stage in patients with chronic hepatitis C virus (HCV) infection.

METHODS

Serum was obtained from 24 people with chronic HCV at time of liver biopsy and from 6 normals. Liver biopsy fibrosis was staged 1-4 (Batts-Ludwig). Pooled serum samples (six in each of four fibrosis groups and controls) were analyzed with 4- and 8-plex isobaric tags for relative and absolute quantitation (iTRAQ), determining protein identification (ID) and ratios of relative protein abundance. Nonpooled samples were analyzed with two-dimensional (2-D) gels and difference in gel electrophoresis (DIGE) comparing different samples on the same gel and across gels. Spots varying among groups were measured with densitometry, excised, digested, and submitted for tandem mass spectrometry (MS/MS) protein ID.

RESULTS

iTRAQ identified 305 proteins (minimum 99% ID confidence); 66 were increased or decreased compared with controls. Some proteins were increased or decreased for specific fibrosis scores. From 704 DIGE protein spots, 66 were chosen, 41 excised, and 135 proteins identified, since one gel spot often identified more than one protein.

CONCLUSIONS

Both proteomic methods identified two proteins as biomarker candidates for predicting hepatic fibrosis: complement C4-A and inter-alpha-trypsin inhibitor heavy chain H4.

Coagulopathy in liver diseases

Liver cirrhosis is associated with number of hematological complications and coagulation disturbances. In view of various haemostatic abnormalities it is surprising that many patients do not bleed spontaneously. Severe coagulopathy of liver disease is more frequently seen in acute liver failure, but still remains important complication of liver cirrhosis and chronic liver failure. Decreased production of blood coagulation factors by the liver plays a key role in altered haemostasis in liver diseases. Altered fragile balance of blood coagulation proteins and infection are associated with both worsening coagulopathy and bleeding risk. Additional haemostatic abnormalities in patients with severe liver diseases are thrombocytopenia, chronic disseminated intravascular coagulation, accelerated fibrinolysis, hypofibrinogenemia and dysfibrinogenemia. In this review we discuss a complicated issue of multiple coagulopathies in patients with advanced liver dysfunction.

Systematic review: portal vein thrombosis in cirrhosis

BACKGROUND

As current imaging techniques in cirrhosis allow detection of asymptomatic portal vein thrombosis during routine ultrasonography, more patients with cirrhosis are diagnosed with portal vein thrombosis. Although a consensus on noncirrhotic extra-hepatic portal vein thrombosis has been published, no such consensus exists for portal vein thrombosis with cirrhosis.

AIM

To perform a systematic review of nonmalignant portal vein thrombosis in cirrhosis in terms of prevalence, pathogenesis, diagnosis, clinical course and management.

METHODS

Studies were identified by a search strategy using MEDLINE and EMBASE.

RESULTS

Portal vein thrombosis is encountered in 10-25% of cirrhotics. In terms of pathophysiology, cirrhosis is no longer considered a hypocoagulable state; rather than a bleeding risk in cirrhosis, various clinical studies support a thrombotic potential. Clinical findings of portal vein thrombosis in cirrhosis vary from asymptomatic disease to a life-threatening condition at first presentation. Optimal management of portal vein thrombosis in cirrhosis is currently not addressed in any consensus publication. Treatment strategies most often include the use of anticoagulation, while thrombectomy and transjugular intrahepatic portosystemic shunts are considered second-line options.

CONCLUSIONS

Portal vein thrombosis in cirrhosis has many unresolved issues, which are often the critical problems clinicians encounter in their everyday practice. We propose a possible research agenda to address these unresolved issues.

The effect of hepatectomy on coagulation: an evaluation by thromboelastography

OBJECTIVES

Liver has a major role in coagulation. The hemostatic derangements measured by the mostly used coagulation parameters as prothrombin time, activated partial thromboplastin time, and thrombocyte count do not always correlate with the bleeding associated with liver diseases and these factors do not measure the thrombotic risks. So, thromboelastography is used in new clinical and laboratory research. The aim of this study is to study the effect of different levels of hepatectomy on coagulation.

METHODS

Laparatomy, 40% hepatectomy, and 70% hepatectomy was performed in three different groups of rats. Prothrombin time, international normalized ratio, activated partial thromboplastin time, thrombocyte count, fibrinogen levels, and thromboelastography parameters were obtained at the 0, 6, and 24th hour of the study.

RESULTS

Fibrinogen level at the 24th hour was greater than the early hours in both of the hepatectomy groups. Prothrombin time and international normalized ratio values were significantly higher in hepatectomy groups than in the sham group. There were no statistically significant difference in the clotting time, clot formation time, alpha-angle, and maximum clot firmness values in any of the thromboelastography channels, in any of the study times, in between the sham, 40% hepatectomy, and 70% hepatectomy groups.

CONCLUSION

There is no difference between 40 and 70% hepatectomy when the coagulopathy is evaluated. The coagulation derangements as reflected by the increase in fibrinogen and prolongation of prothrombin time and activated partial thromboplastin time after hepatectomy were not supported by thromboelastography parameters in this study.

Viral cirrhosis: an overview of haemostatic alterations and clinical consequences

Viral hepatitis is a major health problem worldwide, the principal cause of cirrhosis and hepatocarcinoma. Once cirrhosis occurs, the consequences of liver dysfunction and portal hypertension become evident and, sometimes, life threatening for patients. Among the various complications of liver cirrhosis, the alteration of haemostatic balance is often a hard challenge for the clinician, since it is capable to predispose both to bleeding or thrombosis. In this review, we analyze the principal aspects of procoagulant, anticoagulant and fibrinolytic capacity of cirrhotic patients, which appears to be variably altered in all these aspects, not only in the direction of a tendency to bleeding. Laboratory investigations, at present, may provide only a partial representation of this condition, because of the impossibility to obtain a test capable to furnish a global overview of the haemostatic system and to reproduce in vivo conditions. Furthermore, we describe the pathophysiological mechanisms underlying bleeding manifestations and thrombosis development in cirrhotic patients, which should be considered not only as obvious consequences of the advanced liver disease but, rather, as the result of a complex interaction between inherited and acquired factors.

Management of portal vein thrombosis in cirrhotic patients

Portal vein thrombosis (PVT) not associated with hepatocellular carcinoma is considered a frequent complication of liver cirrhosis but, unlike PVT occurring in non-cirrhotic patients, very few data are available on its natural history and management. The reduced portal blood flow velocity is the main determinant of PVT but, as in other venous thromboses, multiple factors local and systemic, inherited or acquired often can concur with. PVT has a variety of clinical presentations ranging from asymptomatic to life-threatening diseases like gastroesophageal bleeding or acute intestinal ischemia. It is usually diagnosed by Doppler ultrasound but computed tomography and magnetic resonance imaging are useful to study the extent of thrombosis and the involvement of the abdominal organs. The risk of bleeding mainly determined by the presence of gastroesophageal varices and clotting alterations causes concern for the treatment of PVT in cirrhotic patients. To date, anticoagulant therapy seems to be indicated only in patients awaiting liver transplantation. This review focuses on the definition of the subgroups of patients with cirrhosis that might benefit from treatment of PVT and examines the pros and cons of the available treatments in terms of efficacy, monitoring and safety, providing also perspectives for future studies.

Coagulation disorders in dogs with hepatic disease

Liver disease has been associated with abnormalities in haemostasis. In this study, coagulation times, platelet counts, platelet activity parameters, activities of individual coagulation factors, D-dimers, antithrombin (AT) and protein C activity were measured in 42 dogs with histologically confirmed liver disease. Outcome was correlated with histological diagnosis. One or more coagulation abnormalities were present in 57% of dogs with hepatic disease. Activated partial thromboplastin time was significantly prolonged in dogs with chronic hepatitis (CH), with or without cirrhosis. Mean platelet numbers, AT and factor IX activity were significantly lower in dogs with CH plus cirrhosis, compared to dogs with other hepatopathies. D-dimers were not significantly increased in any group. Only three dogs, all with different histological diagnoses, satisfied the criteria for disseminated intravascular coagulation (DIC). Haemostatic abnormalities were primarily seen in dogs with cirrhosis and this may be due to reduced synthesis rather than increased consumption of coagulation factors.

Coagulopathy of acute liver failure

Coagulopathy is an essential component of the acute liver failure (ALF) syndrome and reflects the central role of liver function in hemostasis. ALF is a syndrome characterized by the development of hepatic encephalopathy and coagulopathy within 24 weeks of the onset of acute liver disease. Coagulopathy in this setting is a useful prognostic tool in ALF and a dynamic indicator of the hepatic function. If severe, it can be associated with bleeding and is commonly a major obstacle to the performance of invasive procedures in patients with ALF. This review focuses on the epidemiology, pathophysiology, presentation, evaluation, and management of coagulopathy in ALF.

Hyperfibrinolysis in liver disease

The incidence of hyperfibrinolysis in patients with cirrhosis is still debated. The reasons for this uncertainty probably lie in the lack of appropriate laboratory tests for its evaluation. There is a relative consensus, however, that hyperfibrinolysis can complicate the clinical course of liver cirrhosis, especially in cases of moderate to severe liver failure. Hyperfibrinolysis correlates positively with the severity of underlying liver disease, and low-grade systemic fibrinolysis is found in 30% to 46% of patients who have end-stage liver disease. Accelerated intravascular coagulation with secondary hyperfibrinolysis has been reported in patients who have liver failure. Hyperfibrinolysis may delay primary hemostasis, thereby aggravating variceal bleeding and facilitating recurrence.

The coagulation cascade in cirrhosis

The coagulation "cascade" model accurately represents the mechanisms of the prothrombin time and activated partial thromboplastin time tests. However, these tests and the "cascade" model do not accurately reflect the risk of hemorrhage or thrombosis in vivo. In hepatic insufficiency, a balanced reduction in the levels of most of pro- and anticoagulant proteins produced in the liver does not impair thrombin generation until levels are quite low. However, the ability of the coagulation system to tolerate or recover from an insult is markedly impaired in liver disease. This allows the coagulation system to be more easily tipped into a state favoring either hemorrhage or thrombosis.

The platelet and platelet function testing in liver disease

Patients who have liver disease commonly present with alterations in platelet number and function. Recent data have questioned the contribution of these changes to bleeding complications in these patients. Modern tests of platelet function revealed compensatory mechanisms for the decreased platelet number and function, the most prominent compensatory mechanism being substantially elevated levels of the adhesive protein von Willebrand's factor. Consequently, standard diagnostic tests of platelet functions seem to be of little use to predict bleeding complication in patients who have liver disease. This article outlines the role of platelet abnormalities and possibilities for platelet function testing in patients who have liver disease.

Platelets in liver transplantation: friend or foe?

Apart from the well-known role of blood platelets in hemostasis, there is emerging evidence that platelets have various nonhemostatic properties that play a critical role in inflammation, angiogenesis, tissue repair and regeneration, and ischemia/reperfusion (I/R) injury. All these processes may be involved in the (patho)physiological alterations occurring in patients undergoing liver transplantation. Experimental and clinical research points toward a dualistic role of platelets in patients undergoing liver transplantation, resulting in both beneficial and detrimental effects. Although a low platelet count is generally considered a risk factor for perioperative bleeding, recent studies have indicated that platelet function in patients with cirrhosis may not be as abnormal as previously assumed. Platelet transfusions are frequently considered in liver transplant recipients to correct low platelet counts and to prevent bleeding; however, evidence-based transfusion thresholds are lacking, and the other detrimental and nonhemostatic properties of platelets are generally not weighed in this respect. First, platelets have been shown to contribute to I/R injury of the liver graft via induction of sinusoidal endothelial cell apoptosis. Second, platelet transfusion has been identified as an independent risk factor for reduced survival via mechanisms that are not completely understood yet. On the other hand, recent studies indicate that platelets are critically involved in restoration after liver injury and in liver regeneration via serotonin-mediated mechanisms. These findings make platelets both friend and foe in liver transplantation. The scientific challenge will be to further dissect the mechanisms and clinical relevance of these contrasting roles of platelets in liver transplantation.

Hemostasis and global fibrinolytic capacity in chronic liver disease

Accelerated fibrinolysis associated with liver disease can be demonstrated by various tests that are either nonspecific in liver disease or that demonstrate only an extrinsic pathway. In the present study we used a new method to assess the global fibrinolytic capacity (GFC) of both the intrinsic and extrinsic pathways in patients with chronic liver disease. Forty patients with the diagnosis of chronic liver disease were included in the study. Seventeen age-matched and gender-matched healthy control individuals were enrolled as a control group. The GFC was studied with semiquantitative macrolatex agglutination. The study population consisted of 40 patients with chronic liver disease (group 1, patients with chronic hepatitis; group 2, patients with cirrhosis; group 3, patients with hepatocellular carcinoma), mean age 53.3 +/- 13 years, and a control group (group 4) consisting of 17 healthy individuals (mean age 55 +/- 12.2 years). The GFC was significantly higher in patients than in control individuals (13.8 +/- 9 microg/ml, 13.6 +/- 11 microg/ml, 14.1 +/- 14 microg/ml, 1.9 +/- 2.2 microg/ml, respectively; P < 0.05). There was no difference between the patient groups (P > 0.05). There was a significant positive relationship between the GFC and the prothrombin time and activated partial thromboplastin time values (P < 0.05). A negative correlation was also observed between the GFC and thrombocyte counts (P < 0.05). In conclusion, our results suggest that patients with chronic liver disease have hyperfibrinolysis, as reflected by the increased GFC. Elucidation of the GFC in chronic liver disease can reflect the net fibrinolytic capacity of those patients who are prone to hyperfibrinolysis resulting in bleeding tendencies and hemorrhages.

Review article: coagulation disorders in chronic liver disease

BACKGROUND

The liver is the site for synthesis of the vast majority of proteins that play a central role in maintaining hemostasis, by participating in the regulation of coagulation and fibrinolysis.

AIM

To summarize the available data on the impact of coagulation disorders in patients with chronic liver disease.

RESULTS

Hepatocellular damage in patients with severe liver disease can lead to abnormalities in the production and function of coagulation and fibrinolytic factors, disrupting the balance between coagulation and anticoagulation systems.

CONCLUSIONS

Hemostatic abnormalities (eg. impaired synthesis of clotting factors, heightened fibrinolysis, disseminated intravascular coagulation, thrombocytopenia, and platelet dysfunction) can increase the risk of bleeding in cirrhotic patients.

New insights into the coagulopathy of liver disease and liver transplantation

The liver is an essential player in the pathway of coagulation in both primary and secondary haemostasis. Only von Willebrand factor is not synthetised by the liver, thus liver failure is associated with impairment of coagulation. However, recently it has been shown that the delicate balance between pro and antithrombotic factors synthetised by the liver might be reset to a lower level in patients with chronic liver disease. Therefore, these patients might not be really anticoagulated in stable condition and bleeding may be caused only when additional factors, such as infections, supervene. Portal hypertension plays an important role in coagulopathy in liver disease, reducing the number of circulating platelets, but platelet function and secretion of thrombopoietin have been also shown to be impaired in patients with liver disease. Vitamin K deficiency may coexist, so that abnormal clotting factors are produced due to lack of gamma carboxylation. Moreover during liver failure, there is a reduced capacity to clear activated haemostatic proteins and protein inhibitor complexes from the circulation. Usually therapy for coagulation disorders in liver disease is needed only during bleeding or before invasive procedures. When end stage liver disease occurs, liver transplantation is the only treatment available, which can restore normal haemostasis, and correct genetic clotting defects, such as haemophilia or factor V Leiden mutation. During liver transplantation haemorrage may occur due to the pre-existing hypocoagulable state, the collateral circulation caused by portal hypertension and increased fibrinolysis which occurs during this surgery.

Molecular adsorbent recirculating system and hemostasis in patients at high risk of bleeding: an observational study

Introduction

Liver failure is associated with reduced synthesis of clotting factors, consumptive coagulopathy, and platelet dysfunction. The aim of the study was to evaluate the effects of liver support using a molecular adsorbent recirculating system (MARS) on the coagulation system in patients at high risk of bleeding.

Methods

We studied 61 MARS treatments in 33 patients with acute liver failure (n = 15), acute-on-chronic liver failure (n = 8), sepsis (n = 5), liver graft dysfunction (n = 3), and cholestasis (n = 2). Standard coagulation tests, standard thromboelastography (TEG), and heparinase-modified and abciximab-fab-modified TEG were performed immediately before and 30 minutes after commencement of MARS, and after the end of MARS treatment. Prostaglandin I₂ was administered extracorporeally to all patients; 17 patients additionally received unfractioned heparin.

Results

Three moderate bleeding complications in three patients, requiring three to four units of packed red blood cells, were observed. All were sufficiently managed without interrupting MARS treatment. Although there was a significant decrease in platelet counts (median, 9 G/l; range, -40 to 145 G/l) and fibrinogen concentration (median, 15 mg/dl; range, -119 to 185 mg/dl) with a consecutive increase in thrombin time, the platelet function, as assessed by abciximab-fab-modified TEG, remained stable. MARS did not enhance fibrinolysis.

Conclusion

MARS treatment appears to be well tolerated during marked coagulopathy due to liver failure. Although MARS leads to a further decrease in platelet count and fibrinogen concentration, platelet function, measured as the contribution of the platelets to the clot firmness in TEG, remains stable. According to TEG-based results, MARS does not enhance fibrinolysis.

Coagulation disorders and hemostasis in liver disease: pathophysiology and critical assessment of current management

Normal coagulation has classically been conceptualized as a Y-shaped pathway, with distinct "intrinsic" and "extrinsic" components initiated by factor XII or factor VIIa/tissue factor, respectively, and converging in a "common" pathway at the level of the FXa/FVa (prothrombinase) complex. Until recently, the lack of an established alternative concept of hemostasis has meant that most physicians view the "cascade" as a model of physiology. This view has been reinforced by the fact that screening coagulation tests (APTT, prothrombin time--INR) are often used as though they are generally predictive of clinical bleeding. The shortcomings of this older model of normal coagulation are nowhere more apparent than in its clinical application to the complex coagulation disorders of acute and chronic liver disease. In this condition, the clotting cascade is heavily influenced by numerous currents and counter-currents resulting in a mixture of pro- and anticoagulant forces that are themselves further subject to change with altered physiological stress such as super-imposed infection or renal failure. This report represents a summary of a recent multidisciplinary symposium held in Charlottesville, VA. We present an overview of the coagulation system in liver disease with emphasis on the limitations of the current clinical paradigm and the need for a critical re-evaluation of the current tenets governing clinical practice. With the realization that there is often limited or conflicting data, we have attempted to represent diverse opinion and experience from the perspectives of both hepatology and hematology beginning with a brief update on the physiology of normal coagulation.

Coagulation abnormalities in patients who have liver disease

The liver plays a central role in the maintenance of normal hemostatic function. Because liver disease alters pathways of coagulation and anticoagulation, patients who have advanced disease can experience severe bleeding or thrombotic complications. Complications of advanced liver disease may also contribute to bleeding or thrombosis. This article reviews and discusses the management of the most common coagulation problems encountered in patients who have end-stage liver disease, which are thrombocytopenia and impaired humoral coagulation as measured by prolongation of the prothrombin time and international normalized ratio.

Elevated levels of von Willebrand Factor in cirrhosis support platelet adhesion despite reduced functional capacity

Cirrhosis of the liver is frequently accompanied by complex alterations in the hemostatic system, resulting in a bleeding tendency. Although many hemostatic changes in liver disease promote bleeding, compensatory mechanisms also are found, including high levels of the platelet adhesive protein von Willebrand Factor (VWF). However, conflicting reports on the functional properties of VWF in cirrhosis have appeared in literature. We have measured a panel of VWF parameters in plasma from patients with cirrhosis of varying severity and causes. Furthermore, we assessed the contribution of VWF to platelet adhesion, by measuring the ability of plasma from patients with cirrhosis to support adhesion of normal or patient platelets under flow conditions. VWF antigen levels were strongly increased in patients with cirrhosis. In contrast, the relative collagen binding activity, as well as the relative ristocetin cofactor activity, was significantly lower in patients as compared with controls, indicating loss of function. Accordingly, patients had a reduced fraction of high-molecular-weight VWF multimers. Both strongly elevated and reduced activity and antigen levels of the VWF cleaving protease ADAMTS13 were found in individual patients. Adhesion of either normal or patient platelets to a collagen surface was substantially increased when these platelets were resuspended in plasma of patients with cirrhosis, as compared with control plasma. In conclusion, highly elevated levels of VWF in patients with cirrhosis contribute to the induction of primary hemostasis despite reduced functional properties of the molecule. This phenomenon might compensate for defects in platelet number and function in patients with cirrhosis.

Impact of antithrombin III on hepatic and intestinal microcirculation in experimental liver cirrhosis and bowel inflammation: An in vivo analysis

AIM: To analyze the hepatic and intestinal microcirculation in an animal model of liver cirrhosis and inflammatory bowel disease (IBD) and to characterize the anti-inflammatory action of antithrombin III (ATIII) on leukocyte kinetics and liver damage.

METHODS: Hepatic and intestinal microcirculation was investigated by intravital videomicroscopy. Standardized models of experimental chronic liver cirrhosis and bowel inflammation were employed. Animals were divided into four groups (n = 6/group): controls, animals with cirrhosis, animals with cirrhosis and IBD, animals with cirrhosis and IBD treated with ATIII.

RESULTS: Cirrhosis facilitated leukocyte rolling and sticking in hepatic sinusoids (1.91±0.28 sticker/µm vs 0.5±0.5 sticker/µm in controls, P<0.05). The effect enhanced in animals with cirrhosis and IBD (5.4±1.65 sticker/µm), but reversed after ATIII application (3.97±1.04 sticker/µm, P<0.05). Mucosal blood flow showed no differences in cirrhotic animals and controls (5.3±0.31 nL/min vs 5.4±0.25 nL/min) and was attenuated in animals with cirrhosis and IBD significantly (3.49±0.6 nL/min). This effect was normalized in the treatment group (5.13±0.4 nL/min, P<0.05). Enzyme values rose during development of cirrhosis and bowel inflammation, and reduced after ATIII application (P<0.05).

CONCLUSION: Liver cirrhosis in the presence of IBD leads to a significant reduction in mucosal blood flow and an increase in hepatic leukocyte adherence with consecutive liver injury, which can be prevented by administration of ATIII.

Hemostatic defects in end stage liver disease

End stage liver disease results in a complex and variably severe failure of hemostasis that predisposes to abnormal bleeding. The diverse spectrum of hemostatic defects includes impaired synthesis of clotting factors, excessive fibrinolysis, disseminated intravascular coagulation, thrombocytopenia, and platelet dysfunction. Hemostasis screening tests are used to assess disease severity and monitor the response to therapy. Correction of hemostatic defects is required in patients who are actively bleeding or require invasive procedures. Fresh frozen plasma, cryoprecipitate, and platelet transfusion remain the mainstays of therapy until larger trials confirm the safety and efficacy of recombinant factor VIIa in this population.

Haemostatic abnormalities in liver disease: could some haemostatic tests be useful as liver function tests?

The liver plays a central role in haemostasis, being the site of synthesis of most of the clotting factors, coagulation inhibitors and fibrinolytic parameters, in addition to its clearance of activated clotting and fibrinolytic factors. Nonetheless, no haemostatic test(s) is included among the routine liver function tests and this study aims to probe this possibility. The liver disease group (n=258) included acute hepatitis (n=25), chronic viral hepatitis (n=128), hepatitis B (HB) carriers (n=25), liver cirrhosis (n=67), and hepatocellular carcinoma (HCC) (n=13). The prothrombin time was significantly prolonged in acute hepatitis, liver cirrhosis and HCC. However, the reptilase time was prolonged in all the groups except in HB carriers, while the thrombin time was prolonged only in the HCC group. Antithrombin III and protein C levels exhibited significant reduction in acute hepatitis, liver cirrhosis and HCC. On the other hand, protein S levels (total and free) were reduced significantly in all the patients groups, including HB carriers when compared with healthy controls. Derangement of haemostatic tests is a common feature in liver disease, being most significant in acute hepatitis, liver cirrhosis and hepatocellular carcinoma. The most sensitive markers of hepatocyte malfunction are protein S (total and free) and the reptilase time as they were abnormal, in the mildest liver affections, when other biochemical tests as well as other haemostatic tests were normal. Further studies are needed to see whether these two tests qualify for inclusion among the routine liver function tests.

Evidence of normal thrombin generation in cirrhosis despite abnormal conventional coagulation tests

The role played by coagulation defects in the occurrence of bleeding in cirrhosis is still unclear. This is partly due to the lack of tests that truly reflect the balance of procoagulant and anticoagulant factors in vivo. Conventional coagulation tests such as prothrombin time and activated partial thromboplastin time are inadequate to explore the physiological mechanism regulating thrombin, because they do not allow full activation of the main anticoagulant factor, protein C, whose levels are considerably reduced in cirrhosis. We used a thrombin generation test to investigate the coagulation function in patients with cirrhosis. Thrombin generation measured without thrombomodulin was impaired, which is consistent with the reduced levels of procoagulant factors typically found in cirrhosis. However, when the test was modified by adding thrombomodulin (i.e., the protein C activator operating in vivo), patients generated as much thrombin as controls. Hence, the reduction of procoagulant factors in patients with cirrhosis is compensated by the reduction of anticoagulant factors, thus leaving the coagulation balance unaltered. These findings help clarify the pathophysiology of hemostasis in cirrhosis, suggesting that bleeding is mainly due to the presence of hemodynamic alterations and that conventional coagulation tests are unlikely to reflect the coagulation status of these patients. In conclusion, generation of thrombin is normal in cirrhosis. For a clinical validation of these findings, a prospective clinical trial is warranted where the results of thrombin generation in the presence of thrombomodulin are related to the occurrence of bleeding.

Disturbance of hepatic and intestinal microcirculation in experimental liver cirrhosis

AIM: To analyze hepatic, mesenteric and mucosal microcirculation and leukocyte-endothelium interaction (LEI) in a rat model with liver cirrhosis.

METHODS: Hepatic cirrhosis was induced in Wistar rats by gavage with carbon tetrachloride, and intravital videomicroscopy was performed in liver, mesentery and small intestine mucosa. Special emphasis is given on microcirculatory and morphometric changes during cirrhotic portal hypertension.

RESULTS: LEI was influenced significantly in the cirrhotic liver but not in the gut. Blood flow measurement showed significant differences among liver, main mesenteric vessels and the mucosa. The results of our study indicate that liver cirrhosis leads to alterations in hepatic and mesenteric blood flow but not in mucosal blood flow.

CONCLUSION: The enhanced inflammatory response in hepatic microvessels may be caused by a decrease of antithrombin III levels and could be responsible for disturbances of organ pathology.

Splenomegaly, hypersplenism and coagulation abnormalities in liver disease

Splenomegaly is a frequent finding in patients with liver disease. It is usually asymptomatic but may cause hypersplenism. Thrombocytopenia is the most frequent manifestation of hypersplenism and may contribute to portal hypertension related bleeding. A number of therapies are available for treating thrombocytopenia due to hypersplenism including splenectomy, partial splenectomy, partial splenic embolization, TIPS etc. None is entirely satisfactory. Hypersplenism usually improves following liver transplantation. Therapy with cytokines such as thrombopoietin may offer hope for the future. Patients with liver disease also have abnormalities in coagulation. This is not surprising as all coagulation proteins (except for von willebrand factor vWF) and most inhibitors of coagulation are synthesized in the liver. Genetic or acquired abnormalities of coagulation may predispose to thrombosis of the hepatic or portal veins with significant clinical sequelae. An understanding of the mechanisms involved in coagulation and thrombosis is valuable in choosing from the increasing treatment options available. These include clotting factors, haemeostatic drugs and newer therapies such as recombinant factor VIIa. Splenic artery aneurysms are the most common visceral artery aneurysms in man. Rupture is frequently catastrophic. These aneurysms are being increasingly recognized in liver transplant patients and require treatment before or during transplant surgery.

Biocompatibility of a cuprophane charcoal-based detoxification device in cirrhotic patients with hepatic encephalopathy

Extracorporeal detoxification has been proposed to treat patients with hepatic encephalopathy (HE) not responding to standard therapy. To investigate the biocompatibility of a cuprophane charcoal-based detoxification device, a prospective, randomized, controlled study was performed. Of 41 consecutive patients with cirrhosis and HE grade II or III who did not improve with conventional treatment, 20 patients (median age, 56 years; range, 33 to 71 years; 13 men) were randomly assigned to either ongoing conventional treatment or one additional 6-hour treatment with a sorbent suspension dialysis system. Main outcome parameters were physiological function and blood parameters of biocompatibility. In the 10 patients undergoing combined conventional and sorbent suspension dialysis treatment, blood pressure remained unchanged and body temperature and heart rate increased (P: < 0.01). Platelet count decreased (medians, from 75 to 26 g/L; P: < 0.001) and international normalized ratio increased after combined treatment (2.0 to 2.2; P: < 0.001). Three patients developed bleeding complications during treatment or shortly after. Treated patients showed increases in levels of plasma elastase (104 to 586 microg/L; P: = 0.001), tumor necrosis factor-alpha (5.4 to 7.5 pg/mL; P: = 0.04), and interleukin-6 (118 to 139 pg/mL; P: = 0.04), but not interferon-gamma and E-selectin. No changes were observed in the 10 patients treated conventionally. In conclusion, despite technical refinements compared with charcoal hemoperfusion, biocompatibility of sorbent suspension dialysis is still very limited. Clinical complications were apparently caused by blood-membrane interactions and disseminated intravascular coagulation. We suggest further developments in design and appropriate strategies of anticoagulation to improve the biocompatibility of artificial liver support.