Rebalanced hemostasis in patients with liver disease: evidence and clinical consequences. Blood. 2010;116:878-885. [PMID: 20400681 DOI: 10.1182/blood-2010-02-261891]

The effect of chronic liver disease on venous thromboembolism among medically managed patients in Singapore General Hospital

BACKGROUND

Chronic liver disease (CLD) has been suggested to be associated with venous thromboembolism (VTE) in western populations. However, little is known about the risk effects of CLD on VTE among Asians.

OBJECTIVE

To compute the prevalence of VTE among hospitalised Asian patients, and to evaluate the pattern and scale of risk effects of CLD on VTE occurrence.

METHOD

Retrospective study of hospital discharge database from 2004 to 2011 to identify patients with VTE and CLD using International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Australian Modification (ICD-9-AM) codes.

RESULTS

Of 199904 medically managed inpatients during the 8years, 1744 (0.9%) patients had VTE. Patients with CLD had significant higher prevalence of VTE (non-cirrhosis CLD 1.5%, cirrhosis 2.0%) than patients without CLD (0.8%, p<0.001). In the logistic regression analyses, non-cirrhosis CLD (odds ratio, OR 1.4, 95% CI 1.2-1.7, p<0.001) and cirrhosis (OR 1.5, 95% CI 1.2-2.0, p=0.002) were significant predictors of VTE after adjustment for age, gender, ethnicity, hospital long stayer, cancer, infectious disease, and other comorbid conditions such as diabetic mellitus, anaemia, and cardiovascular, cerebrovascular, renal and pulmonary diseases.

CONCLUSION

CLD, particular liver cirrhosis, increases the risks of VTE in hospitalised Asian patients. As CLD patients are perceived to be at risks of bleeding due to the prolonged clotting times and thrombocytopenia, the results of this study brings attention to opposite end of the haemostatic pendulum in patients with chronic liver disease.

Thromboelastographic Evaluation of Dogs with Acute Liver Disease

BACKGROUND

Given the liver's pivotal role in hemostasis and fibrinolysis, the coagulopathy accompanying hepatic disease is complex.

HYPOTHESIS/OBJECTIVES

To prospectively evaluate kaolin-activated thromboelastography (TEG) in dogs with acute liver disease (ALD) and compare with plasma-based coagulation tests.

ANIMALS

Twenty-one dogs with a diagnosis of ALD based on recent onset of clinical signs accompanied by increases in serum bilirubin concentration and alanine aminotransferase activity.

METHODS

Clinical presentation, CBC, serum biochemistry, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), and TEG analysis were evaluated in 21 dogs with a subset also having fibrinogen, antithrombin (AT) activity, protein C (PC) activity, d-dimers, and von Willebrand's factor (vWF) activity analyzed. A PT >1.5 times the upper limit of normal defined acute liver failure (ALF).

RESULTS

Dogs with ALD had mean increases in R, K, LY30, PT, aPTT, and vWF activity, and decreases in angle, maximal amplitude (MA), G, AT activity, and PC activity. The TEG results defined dogs as hypocoagulable (11/21), normocoagulable (8/21), or hypercoagulable (2/21). Increases in LY30 defined 8/21 dogs as hyperfibrinolytic. Hypocoagulable and hyperfibrinolytic dogs had lower fibrinogen and PC activity than dogs without these abnormalities. Overall, ALF dogs had greater increases in K and LY30, and decreases in MA, G, and PC activity than dogs with less severe hepatic impairment. Results for MA and LY30 were positively correlated with serum bilirubin concentration and white blood cell count, and negatively correlated with serum cholesterol concentration.

CONCLUSIONS AND CLINICAL IMPORTANCE

ALD dogs have a range of coagulation abnormalities that trend toward hypocoagulability and hyperfibrinolysis as functional impairment occurs.

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.

Safety and efficacy of pharmacological thromboprophylaxis for hospitalized patients with cirrhosis: a single-center retrospective cohort study

BACKGROUND

Hospitalized patients with cirrhosis are at increased risk for venous thromboembolism (VTE). The benefits and risks of pharmacological thromboprohylaxis in these patients have not been well studied.

OBJECTIVES

To examine the safety and efficacy of pharmacological VTE prophylaxis in hospitalized cirrhotic patients.

PATIENTS/METHODS

Retrospective cohort study of patients with cirrhosis hospitalized at an academic tertiary care referral center over a 5-year period.

RESULTS

Six hundred hospital admissions accounting for 402 patients were included. VTE prophylaxis was administered during 296 (49%) admissions. Patients receiving VTE prophylaxis were older (59 years vs. 55 years, P < 0.001), had longer lengths of stay (9.6 days vs. 6.8 days, P = 0.002), and lower Model for End-Stage Liver Disease scores (13.2 vs. 16.1, P < 0.001). In-hospital bleeding events (8.1% vs. 5.5%, P = 0.258), gastrointestinal bleeding events (3.0% vs. 3.2% P = 0.52), new VTE events (2.37% vs. 1.65%, P = 0.537), and mortality (8.4% vs. 7.3%, P = 0.599) were similar in the two groups. VTE prophylaxis did not reduce the risk of VTE (odds ratio 0.94, 95% confidence interval 0.23-3.71), and patients receiving unfractionated heparin, but not low molecular weight heparin, were at increased risk for in-hospital bleeding events (odds ratio 2.38, 95% confidence interval 1.15-4.94 vs. 0.87, 0.37-2.05, respectively).

CONCLUSION

The rate of VTE in this cohort of hospitalized cirrhotic patients was low and was unaffected by pharmacological thromboprophylaxis. Unfractionated heparin was associated with an increased risk for in-hospital bleeding, suggesting that if thromboprophylaxis is indicated, low molecular weight heparin may be favored.

Pediatric transplantation: managing bleeding

There has been extraordinary progress over the last half-century in the field of medical transplantation in which tissue, organs, or body parts from one human are placed into another. Solid organ transplants have allowed thousands of children with otherwise devastating inherited or acquired disorders to survive. Depending upon the clinical situation, there are many specific peri-transplant issues that must be carefully addressed to optimize outcomes. Although surgical, immunologic, and infectious concerns are usually in the forefront, important aspects regarding hemostasis frequently arise. The number of solid organs that can be successfully transplanted in children has expanded over the last decades and includes kidney, liver, heart, lung, intestine, pancreas, and thymus. Bleeding complications may occur in the setting of organ failure prior to transplantation, during the surgical procedure, or in the post-transplant setting, and can results in significant morbidity. This report will focus on preventing and managing non-surgical-related bleeding complications in children undergoing liver, heart, kidney transplantation, in whom there are often unique aspects of coagulation to be considered.

Fresh frozen plasma transfusion fails to influence the hemostatic balance in critically ill patients with a coagulopathy

BACKGROUND

Coagulopathy has a high prevalence in critically ill patients. An increased International Normalized Ratio (INR) is a common trigger to transfuse fresh frozen plasma (FFP), even in the absence of bleeding. Therefore, FFP is frequently administered to these patients. However, the efficacy of FFP in correcting hemostatic disorders in non-bleeding recipients has been questioned.

OBJECTIVES

To assess whether INR prolongation parallels changes in the results of other tests investigating hemostasis, and to evaluate the coagulant effects of a fixed dose of FFP in non-bleeding critically ill patients with a coagulopathy.

METHODS

Markers of coagulation, individual factor levels and levels of natural anticoagulants were measured. Also, thrombin generation and thromboelastometry (ROTEM) assays were performed before and after FFP transfusion (12 mL kg(-1) ) to 38 non-bleeding critically ill patients with an increased INR (1.5-3.0).

RESULTS

At baseline, levels of factor II, FV, FVII, protein C, protein S and antithrombin were reduced, and thrombin generation was impaired. ROTEM variables were within reference ranges, except for a prolonged INTEM clot formation time. FFP transfusion increased the levels of coagulation factors (FII, 34% [interquartile range (IQR) 26-46] before vs. 44% [IQR 38-52] after; FV, 48% [IQR 28-76] before vs. 58% [IQR 44-90] after; and FVII, 25% [IQR 16-38] before vs. 37% [IQR 28-55] after), and the levels of anticoagulant proteins. Thrombin generation was unaffected by FFP transfusion (endogenous thrombin potential, 72% [IQR 51-88] before vs. 71% [IQR 42-89] after), whereas ROTEM EXTEM clotting time and maximum clot firmness slightly improved in response to FFP.

CONCLUSION

In non-bleeding critically ill patients with a coagulopathy, FFP transfusion failed to induce a more procoagulant state.

Viral hepatitis and anti-phospholipid antibodies positivity: A systematic review and meta-analysis

BACKGROUND

Anti-phospholipid antibodies positivity is associated with several clinical conditions, including infectious diseases.

AIMS

We performed a meta-analysis evaluating the association of hepatitis B and C with anti-phospholipid antibody positivity and with anti-phospholipid antibody-related thrombotic complications.

METHODS

Studies evaluating the association of viral hepatitis with anti-cardiolipin, anti-β2 glycoprotein-I and lupus anticoagulant antibodies and anti-phospholipid antibody-related thrombotic events were systematically searched.

RESULTS

20 studies (2319 cases, 1901 controls) were included. The analyses showed that viral hepatitis is associated with the presence of anti-cardiolipin and anti-β2 glycoprotein-I antibodies. The association with anticardiolipin antibodies was confirmed in both hepatitis B (OR 11.22, 95% CI: 6.68-18.84) and hepatitis C (OR 11.26, 95% CI: 6.82-18.59). Similarly, compared to controls, anti-β2 glycoprotein-I antibodies were found more frequently in hepatitis B (OR 14.07, 95% CI: 3.06-64.66) and hepatitis C (OR 5.64, 95% CI: 1.69-18.77). Moreover, 11 studies (257 cases, 1079 controls) showed a higher prevalence of venous and/or arterial thrombosis in patients with hepatitis and anti-cardiolipin antibody positivity compared hepatitis alone (OR 3.29, 95% CI: 1.79-6.07). This result was consistently confirmed in hepatitis C (OR 3.64, 95% CI: 1.78-7.46) but not in hepatitis B.

CONCLUSIONS

Viral hepatitis is significantly associated with anti-phospholipid antibody positivity and with anti-phospholipid antibody-related thrombotic complications.

[Coagulation management in patients with liver disease]

BACKGROUND

End-stage liver disease is associated with complex alterations in hemostasis. Whereas prognosis is essentially affected by life-threatening bleeding complications in some patients, others, especially those with cholestatic liver diseases, suffer from thromboembolic complications. Standard laboratory values (SLVS; prothrombin time, activated partial thrombin time, platelet count) cannot sufficiently reflect the altered balance of pro- and anticoagulatory factors. Moreover, a couple of studies indicated that SLVS are not able to predict bleeding complications in patients with acute liver failure or decompensated liver cirrhosis.

DIAGNOSIS AND THERAPY

Use of bed-side coagulation diagnostics such as thrombelastometry/-graphy, detection of thrombocyte function by multiple electrode aggregometry and selective measurement of single factors allows a targeted and causal therapy of hepatic coagulopathies especially in the context of bleeding complications or surgical interventions. In recent years, coagulation management guided by these new devices has contributed to a reduction in transfusion of allogenic blood products, which may be associated with undesirable side effects.

DISCUSSION

The current review summarizes the complex pathophysiological alterations of hemostasis associated with advanced liver insufficiency and discusses recent upcoming diagnostics and coagulation management in this patient cohort.

Acute liver failure in dogs and cats

OBJECTIVE

To define acute liver failure (ALF), review the human and veterinary literature, and discuss the etiologies and current concepts in diagnostic and treatment options for ALF in veterinary and human medicine.

ETIOLOGY

In veterinary medicine ALF is most commonly caused by hepatotoxin exposure, infectious agents, inflammatory diseases, trauma, and hypoxic injury.

DIAGNOSIS

A patient may be deemed to be in ALF when there is a progression of acute liver injury with no known previous hepatic disease, the development of hepatic encephalopathy of any grade that occurs within 8 weeks after the onset of hyperbilirubinemia (defined as plasma bilirubin >50 μM/L [>2.9 mg/dL]), and the presence of a coagulopathy. Diagnostic testing to more specifically characterize liver dysfunction or pathology is usually required.

THERAPY

Supportive care to aid the failing liver and compensate for the lost functions of the liver remains the cornerstone of care of patients with ALF. Advanced therapeutic options such as extracorporeal liver assist devices and transplantation are currently available in human medicine.

PROGNOSIS

The prognosis for ALF depends upon the etiology, the degree of liver damage, and the response to therapy. In veterinary medicine, the prognosis is generally poor.

The safety of ultrasound guided central venous cannulation in patients with liver disease

BACKGROUND

Central venous cannulation (CVC) is frequently required during the management of patients with liver disease with deranged conventional coagulation parameters (CCP). Since CVC is known to be associated with vascular complications, it is standard practice to transfuse Fresh-Frozen Plasma or platelets to correct CCP. These CCP may not reflect true coagulopathy in liver disease. Additionally CVC when performed under ultrasound guidance (USG-CVC) in itself reduces the incidence of complications.

AIM

To assess the safety of USG-CVC and to evaluate the incidence of complications among liver disease patients with coagulopathy.

SETTING AND DESIGN

An audit of all USG-CVCs was performed among adult patients with liver disease in a tertiary care center.

MATERIALS AND METHODS

Data was collected for all the adult patients (18-60 years) of either gender suffering from liver disease who had required USG-CVC. Univariate and multivariate regression analysis was done to identify possible risk factors for complications.

RESULTS

The mean age of the patients was 42.1 ± 11.6 years. Mean international normalized ratio was 2.17 ± 1.16 whereas median platelet count was 149.5 (range, 12-683) × 10(9)/L. No major vascular or non-vascular complications were recorded in our patients. Overall incidence of minor vascular complications was 18.6%, of which 13% had significant ooze, 10.3% had hematoma formation and 4.7% had both hematoma and ooze. Arterial puncture and multiple attempts were independent risk factors for superficial hematoma formation whereas low platelet count and presence of ascites were independent risk factors for significant oozing.

CONCLUSION

Ultrasound guidance -CVC in liver disease patients with deranged coagulation is a safe and highly successful modality.

The balance of pro- and anticoagulant processes underlying thrombin generation

BACKGROUND

The generation of thrombin in time is the combined effect of the processes of prothrombin conversion and thrombin inactivation. Measurement of prothrombin consumption used to provide valuable information on hemostatic disorders, but is no longer used, due to its elaborate nature.

OBJECTIVES

Because thrombin generation (TG) curves are easily obtained with modern techniques, we developed a method to extract the prothrombin conversion curve from the TG curve, using a computational model for thrombin inactivation.

METHODS

Thrombin inactivation was modelled computationally by a reaction scheme with antithrombin, α(2) Macroglobulin and fibrinogen, taking into account the presence of the thrombin substrate ZGGR-AMC used to obtain the experimental data. The model was validated by comparison with data obtained from plasma as well as from a reaction mixture containing the same reactants as plasma.

RESULTS

The computational model fitted experimental data within the limits of experimental error. Thrombin inactivation curves were predicted within 2 SD in 96% of healthy subjects. Prothrombin conversion was calculated in 24 healthy subjects and validated by comparison with the experimental consumption of prothrombin during TG. The endogenous thrombin potential (ETP) mainly depends on the total amount of prothrombin converted and the thrombin decay capacity, and the peak height is determined by the maximum prothrombin conversion rate and the thrombin decay capacity.

CONCLUSIONS

Thrombin inactivation can be accurately predicted by the proposed computational model and prothrombin conversion can be extracted from a TG curve using this computational prediction. This additional computational analysis of TG facilitates the analysis of the process of disturbed TG.

Hemostatic status in liver transplantation: association between preoperative procoagulants/anticoagulants and postoperative hemorrhaging/thrombosis

The delicate rebalanced hemostatic status of liver transplant recipients may lead to both hemorrhagic and thrombotic tendencies in this population. The aim of this study was to investigate the association between pretransplant procoagulants/anticoagulants and posttransplant bleeding and thrombosis among living donor liver transplant recipients. The study subjects were 403 consecutive recipients with chronic liver disease. Perioperative variables, including preoperative values for procoagulants and anticoagulants, were assessed to determine their association with posttransplant hemorrhaging and thrombosis. There were 35 hemorrhagic complications (9%) and 21 thrombotic complications (5%). In logistic regression analyses, a higher Model for End-Stage Liver Disease score (P = 0.01) and a lower fibrinogen value (P < 0.001) were independently associated with hemorrhaging, whereas only a lower protein C value (P < 0.001) was independently associated with thrombosis. In a receiver operating characteristic analysis, a low preoperative protein C value (with the most accurate cutoff value being 25%) was a reliable predictor of thrombotic complications after liver transplantation (area under the curve = 0.921, P < 0.001, sensitivity = 0.9, specificity = 0.8). In conclusion, the decreases in both procoagulants and anticoagulants in liver transplant recipients may additively result in a delicate hemostatic balance and predispose patients to both hemorrhagic and thrombotic complications. A lower preoperative protein C value (<25%) was demonstrated to be a significant and reliable predictor of postoperative thrombotic complications in liver transplant recipients.

Management of coagulation abnormalities in liver disease

Liver disease is characterized by changes in all phases of hemostasis. These hemostatic alterations were long considered to predispose patients with liver disease towards a bleeding tendency, as they are associated with prolonged conventional coagulation tests. However, these patients may also suffer from thrombotic complications, and we now know that the hemostatic system in patient with liver disease is, in fact, in a rebalanced state. In this review we discuss the concept of rebalanced hemostasis and its implications for clinical management of patients with liver disease. For instance, there is no evidence that the use of prophylactic blood product transfusion prior to invasive procedures reduces bleeding risk. Clinicians should also be aware of the possibility of thrombosis occurring in patients with a liver disease, and regular thrombosis prophylaxis should not be withheld in these patients.

Thrombosis and hemorrhage in the critically ill cirrhotic patients: five years retrospective prevalence study

BACKGROUND

Cirrhotic patients present a complex interaction between deficient synthetic liver function, hemodynamic abnormalities and superimposed conditions that alter coagulation system. This alters both coagulation and fibrinolytic processes,increasing bleeding and thrombosis risks. Particularly, critically ill cirrhotic patients represent a diagnostic challenge since they have multiple comorbidities making the thrombotic and bleeding risks unpredictable. The prevalence of bleeding and thrombosis in this subset of patients remains poorly described. The main aim of this article is to describe the prevalence of thrombotic and hemorrhagic complications in cirrhotic patients admitted between 2007 and 2012 at Médica Sur Clinic and Foundation ICU.

MATERIAL AND METHODS

We performed a five years retrospective study including every cirrhotic patient admitted to ICU between January 2007 and December 2012.

RESULTS

The incidence of hemorrhage was 48.5%, the overall incidence of thrombotic complications was 13.66%. Variceal bleeding was the most prevalent hemorrhagic event and portal vein thrombosis the most common thrombotic event. Factors associated with presenting a bleeding episode included kidney injury, infection an thrombosis. Factors associated with increased thrombotic risk included ascitis,infection and bleeding.

CONCLUSION

Critically ill cirrhotic patients have an high risk for both thrombotic and bleeding episodes. The association between the presence of bleeding and thrombotic events was statistically significant.

Hypercoagulability following major partial liver resection - detected by thrombomodulin-modified thrombin generation testing

BACKGROUND

Conventional coagulation tests are frequently prolonged after liver surgery, suggesting a post-operative hypocoagulability. However, these tests are unreliable for assessment of the haemostatic status in these patients. In contrast, thrombin generation testing measures the true balance between pro- and anti-coagulant factors.

AIM

To study the perioperative coagulation status in patients undergoing hemi-hepatectomy using thrombin generation assays.

METHODS

We examined thrombin generation profiles in serial plasma samples taken from seventeen patients undergoing right hemi-hepatectomy. Results were compared to ten patients undergoing pancreatic resection and twenty-four healthy volunteers. In addition, we measured conventional coagulation tests and plasma levels of several haemostatic proteins.

RESULTS

Following liver resection, the endogenous thrombin potential (ETP) slightly decreased until post-operative day 7. However, in the presence of thrombomodulin, the ETP increased [from 542 nM*min (417-694) at baseline to 845 nM*min (789-1050) on post-operative day 3] to values higher than that in healthy subjects (558 nM*min (390-680); P < 0.001), which contrasts with substantially prolonged PT levels. Normal to decreased thrombin generation was observed following pancreatic resection. Thrombin generation was only slightly affected by thrombomodulin after hemi-hepatectomy, while thrombin generation in healthy subjects decreased profoundly upon addition of thrombomodulin. This hypercoagulability following liver resection may be explained by decreased levels of protein C, S, and antithrombin and by elevated levels of factor VIII.

CONCLUSIONS

Thrombin generation in the presence of thrombomodulin revealed hypercoagulability in patients following liver resection. These results support the recently advocated restrictive use of plasma during liver resection and the exploration of more extensive use of post-operative thrombosis prophylaxis.

Thrombin generation test in children and adolescents with chronic liver disease

INTRODUCTION

The aim of this study was to evaluate if real-time thrombin generation assay provides additional information to assess the hemostatic balance in children with liver disease as compared to routine coagulation tests.

PATIENTS AND METHODS

Sixty-three children with chronic liver disease were enrolled at our tertiary referral center for pediatric hepatology, eight whose routine coagulation tests gave abnormal results (Group A) and 55 whose test results were normal (Group B). Abnormal routine coagulation test was defined as at least one of the following: international normalized ratio≥1.4, activated partial thromboplastin time>44 sec., fibrinogen<1.5 g/L. Platelet-poor plasma was analyzed with the fluorogenic Calibrated Automated Thrombogram to test for thrombin generation, including endogenous thrombin potential. Further, routine coagulation tests and plasma levels of pro- and anticoagulant factors were measured. Twenty age-matched children without liver disease served as controls.

RESULTS

The endogenous thrombin potential in the 55 patients with normal routine coagulation tests was not significantly different from that in controls. Group A had significantly lower levels not only of procoagulant factors (II, V, VII, X) but simultaneously also of the anticoagulant factors antithrombin, protein S free, and protein C. These patients had a reduced endogenous thrombin potential compared to Group B, in agreement with their routine coagulation test results.

CONCLUSION

Thrombin generation analysis seems to give information on the hemostatic balance consistent with routine coagulation test results in children with liver disease. Further development and clinical evaluation of the method are warranted.

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

ADAMTS13 Levels in Young Patients With β-Thalassemia Major: Relation to Hepatitis C Virus Infection, Liver Cirrhosis, and Iron Overload

We measured levels of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) in 50 children and adolescents with β-thalassemia major (25 without hepatitis C virus [HCV] infection and 25 with HCV infection) compared to 25 healthy controls and assessed their relation to iron overload, HCV infection, and liver cirrhosis. Hematological and coagulation profiles, serum ferritin, and von Willebrand factor antigen were assessed. Levels of ADAMTS13 were significantly lower in β-thalassemia major with and without HCV infection compared to healthy controls, with a more significant reduction in levels among patients with HCV (P < .001). HCV-positive patients with thalassemia having liver cirrhosis had the lowest ADAMTS13 levels than those without cirrhosis (P = .012) or HCV-negative patients with thalassemia (P < .001). Levels of ADAMTS13 were positively correlated with platelet count while inversely correlated with partial thromboplastin time, serum ferritin, and VWF: Ag (P < .05).

CONCLUSION

Patients with β-thalassemia major infected with HCV have low ADAMTS13 levels, and a marked reduction was observed among patients with liver cirrhosis and, therefore, may be liable to thromboembolic manifestations.

Four factor prothrombin complex concentrate (human): review of the pharmacology and clinical application for vitamin K antagonist reversal

Vitamin K antagonists (VKAs) have been used for decades for the treatment and prophylaxis of thromboembolic events. Due to their wide range of therapeutic indications, they are the most prescribed oral anticoagulant worldwide. However, they are associated with bleeding complications due to their narrow therapeutic range, variability in individual dose responses and laboratory monitoring, and overdoses. Despite off-label use of 3-factor prothrombin complex concentrates and recombinant activated factor VII, until recently, vitamin K and plasma were the only recommended therapeutic options for reversing VKAs in the USA. In 2013, a 4-factor prothrombin complex concentrate (4F-PCC) was approved in the USA for VKA reversal in patients with bleeding or requiring emergency surgery and invasive procedure. Recent randomized controlled clinical trials have shown that 4F-PCC (Kcentra™) is non-inferior for hemostatic efficacy and superior for international normalized ratio correction as compared to plasma and has a similar safety profile.

Effects of increased von Willebrand factor levels on primary hemostasis in thrombocytopenic patients with liver cirrhosis

In patients with liver cirrhosis procoagulant and anticoagulant changes occur simultaneously. During primary hemostasis, platelets adhere to subendothelial structures, via von Willebrand factor (vWF). We aimed to investigate the influence of vWF on primary hemostasis in patients with liver cirrhosis. Therefore we assessed in-vitro bleeding time as marker of primary hemostasis in cirrhotic patients, measuring the Platelet Function Analyzer (PFA-100) closure times with collagen and epinephrine (Col-Epi, upper limit of normal ≤ 165 s) or collagen and ADP (Col-ADP, upper limit of normal ≤ 118 s). If Col-Epi and Col-ADP were prolonged, the PFA-100 was considered to be pathological. Effects of vWF on primary hemostasis in thrombocytopenic patients were analyzed and plasma vWF levels were modified by adding recombinant vWF or anti-vWF antibody. Of the 72 included cirrhotic patients, 32 (44.4%) showed a pathological result for the PFA-100. They had mean closure times (± SD) of 180 ± 62 s with Col-Epi and 160 ± 70 s with Col-ADP. Multivariate analysis revealed that hematocrit (P = 0.027) and vWF-antigen levels (P = 0.010) are the predictors of a pathological PFA-100 test in cirrhotic patients. In 21.4% of cirrhotic patients with platelet count ≥ 150/nL and hematocrit ≥ 27.0%, pathological PFA-100 results were found. In thrombocytopenic (< 150/nL) patients with cirrhosis, normal PFA-100 results were associated with higher vWF-antigen levels (462.3 ± 235.9% vs. 338.7 ± 151.6%, P = 0.021). These results were confirmed by multivariate analysis in these patients as well as by adding recombinant vWF or polyclonal anti-vWF antibody that significantly shortened or prolonged closure times, respectively. In conclusion, primary hemostasis is impaired in cirrhotic patients. The effect of reduced platelet count in cirrhotic patients can at least be partly compensated by increased vWF levels. Recombinant vWF could be an alternative to platelet transfusions in the future.

Is there a rationale for treatment of chronic liver disease with antithrombotic therapy?

Recent advances in the understanding of the coagulopathy in chronic liver disease have provided a strong support for anticoagulation as a new therapeutic paradigm for patients with cirrhosis. Laboratory studies indicate that the net effect of changes in hemostasis in many patients with chronic liver disease is a hypercoagulable status. In turn, clinical thrombosis is increasingly recognized as a complication of liver disease. When occurring within the liver, thrombosis may even progress the disease course. Exciting preliminary data regarding the potential of low-molecular-weight heparin to slow down the progression of liver disease indicate that this class of drugs may improve outcome without a major increase in bleeding risk. However, this new era for antithrombotic therapy in chronic liver disease is still hindered by a persistent false notion that patients with cirrhosis are "auto-anticoagulated" by their underlying liver disease. In addition, there is insufficient clinical evidence on safety and efficacy of anticoagulant therapy in cirrhosis and the studies conducted so far are limited by small sample sizes, uncontrolled treatment arms, or by their retrospective nature. Finally, a lack of knowledge on how or when to monitor antithrombotic treatment to optimize the risk-benefit ratio has restricted a widespread application of anticoagulant treatment in clinical management algorithms. Nonetheless, by systematically covering possibilities and pitfalls, this review highlights the potential of antithrombotic therapy to improve the quality of life and the clinical outcome of patients with chronic liver disease.

Procoagulant therapeutics in liver disease: a critique and clinical rationale

The complex nature of haemostasis in patients with liver disease can result in bleeding and/or thrombosis. These opposing outcomes, which have multiple contributing factors, can pose diagnostic and therapeutic dilemmas for physicians. With the high rate of haemorrhagic complications in patients with cirrhosis, we examine the various procoagulants available for use in this population. In this Review, we describe the clinical and current rationale for using each of the currently available procoagulants-vitamin K, fresh frozen plasma (FFP), cryoprecipitate, platelets, recombinant factor VIIa (rFVIIa), antifibrinolytics, prothrombin concentrate complexes (PCC), desmopressin and red blood cells. By examining the evidence and use of these agents in liver disease, we provide a framework for targeted, goal-directed therapy with procoagulants.

Abnormal hemostatic function one year after orthotopic liver transplantation can be fully attributed to endothelial cell activation

Background: The long-term risk of thrombotic and vascular complications is elevated in liver transplant recipients compared to the general population. Patients with cirrhosis are in a hypercoagulable status during and directly after orthotopic liver transplantation, but it is unclear whether this hypercoagulability persists over time.

Aim: We aimed to investigate the hemostatic status of liver transplant recipients one year after transplantation.

Methods: We prospectively collected blood samples of 15 patients with a functioning graft one year after orthotopic liver transplantation and compared the hemostatic status of these patients with that of 30 healthy individuals.

Results: Patients one year after liver transplantation had significantly elevated plasma levels of von Willebrand factor (VWF). Thrombin generation, as assessed by the endogenous thrombin potential, was decreased in patients, which was associated with increased plasma levels of the natural anticoagulants antithrombin and tissue factor pathway inhibitor.  Plasma fibrinolytic potential was significantly decreased in patients and correlated inversely with levels of plasminogen activator inhibitor-1.

Conclusion: One year after liver transplantation, liver graft recipients have a dysregulated hemostatic system characterised by elevation of plasma levels of endothelial-derived proteins. Increased levels of von Willebrand factor and decreased fibrinolytic potential may (in part) be responsible for the increased risk for vascular disease seen in liver transplant recipients.

Venous thromboembolic prophylaxis after a hepatic resection: patterns of care among liver surgeons

INTRODUCTION

No consensus exists for post-hepatectomy venous thromboembolic (VTE) prophylaxis. Factors impacting VTE prophylaxis patterns among hepato-pancreato-biliary (HPB) surgeons were defined.

METHOD

Surgeons were invited to complete a web-based survey on VTE prophylaxis. The impact of physician and clinical factors was analysed.

RESULTS

Two hundred responses were received. Most respondents were male (91%) and practiced at academic centres (88%) in the United States (80%). Surgical training varied: HPB (24%), transplantation (24%), surgical oncology (34%), HPB/transplantation (13%), or no specialty (5%). Respondents estimated VTE risk was higher after major (6%) versus minor (3%) resections. Although 98% use VTE prophylaxis, there was considerable variability: sequential compression devices (SCD) (91%), unfractionated heparin Q12h (31%) and Q8h (32%), and low-molecular weight heparin (39%). While 88% noted VTE prophylaxis was not impacted by operative indication, 16% stated major resections reduced their VTE prophylaxis. Factors associated with the decreased use of pharmacologic prophylaxis included: elevated international normalized ratio (INR) (74%), thrombocytopaenia (63%), liver insufficiency (58%), large EBL (46%) and complications (8%). Forty-seven per cent of respondents wait until ≥post-operative day 1 (POD1) and 35% hold pharmacologic VTE prophylaxis until no signs of coagulopathy. A minority (14%) discharge patients on pharmacologic prophylaxis. While 81% have institutional VTE guidelines, 79% believe hepatectomy-specific guidelines would be helpful.

CONCLUSION

There is considerable variation regarding VTE prophylaxis among liver surgeons. While most HPB surgeons employ VTE prophylaxis, the methods, timing and purported contraindications differ significantly.

Cirrhosis patients have a coagulopathy that is associated with decreased clot formation capacity

BACKGROUND

The coagulopathy in cirrhosis is associated with thrombosis and bleeding.

OBJECTIVES

To gain better insights into the coagulopathy in patients with cirrhosis, we evaluated plasma thrombin generation and whole blood clot formation in a cross-sectional study.

METHODS

Blood was collected from 73 patients with all-cause cirrhosis (Child-Pugh-A n = 52, B n = 15, C n = 6) and 20 healthy controls. Activity of the coagulation pathways was measured with assays for factor (F) VIIa and FIXa-antithrombin and FXa-antithrombin complexes, respectively. Thrombin generation by calibrated automated thrombography was determined in platelet-poor plasma using a 1 or 5 pm tissue factor trigger with/without thrombomodulin. ROTEM measurements were performed in whole blood triggered with 35 pm tissue factor without/with 175 ng mL(-1) tissue plasminogen activator (the latter refered to as 'tPA-ROTEM').

RESULTS

We observed an increased generation of FVIIa and a moderately elevated amount of FIXa (in complex with antithrombin) without apparent increase in FX activation in patients with cirrhosis. In accordance with this prothrombotic state, markers of thrombin generation potential were also increased upon increasing severity of cirrhosis. In the whole blood clotting assay we observed delayed clot formation and decreased clot strength associated with increased severity of cirrhosis. No significant differences were found for tPA-ROTEM parameters of clot degradation.

CONCLUSION

These results indicate that cirrhosis patients have an overall procoagulant plasma milieu but a decreased whole blood clot formation capacity with an apparently unaltered resistance to clot lysis.

Natural course of nonmalignant partial portal vein thrombosis in cirrhotic patients

BACKGROUND/AIM

Portal vein thrombosis (PVT) has a high incidence in patients with liver cirrhosis and determines a poor prognosis of hepatic disease. The aim of our study was to define the natural course of partial PVT in cirrhotic patients, including survival and decompensation rates.

PATIENTS AND METHODS

We performed a prospective, cohort study, in a tertiary referral center. There were 22 cirrhotic patients with partial nonmalignant PVT, without anticoagulant treatment, who were followed-up between January 2011 and October 2013. All patients were evaluated by Doppler abdominal ultrasound and computed tomography. Kaplan-Meier method was used to determine the difference in clinical events between the study subgroups.

RESULTS

After a mean follow-up period of 20.22 months, partial PVT improved in 5 (22.73%), was stable in 11 (50%), and worsened in 6 (27.27%) patients. Hepatic decompensation rate at 6 and 18 months was higher in patients with worsened PVT than in those with stable/improved PVT (50% vs. 25%, P < 0.0001 and 100% vs. 56.25%, P < 0.0001, respectively). The survival rate at 6 months was 66.66% in worsened PVT group vs. 81.25% (P = 0.005) in stable/improved group, and 16.66% vs. 81.25% (P < 0.0001) at 18 months, respectively. Multivariate analysis showed that Model of End-Life Disease was the independent predictor of hepatic decompensation [hazard ratio (HR) 1.42; 95% confidence interval (CI): 1.08-1.87, P = 0.012] and survival (HR 1.76; 95% CI: 1.06-2.92, P = 0.028).

CONCLUSIONS

Nonmalignant partial PVT remained stable/improved in over half of cirrhotic patients and aggravated in more than one fourth in whom it negatively influenced the survival and decompensation rates.

Delicate balance of bleeding and thrombosis in end-stage liver disease and liver transplantation

Liver transplantation in cirrhotic patients is accompanied by severe bleeding. Indeed, the first 100 recipients of liver allografts transplanted by Thomas E. Starzl died mainly by uncontrolled bleeding. Since then, much progress has been made as to the understanding of the pathophysiology and the treatment of hemostatic disorders in cirrhotic patients. The aim of this review is to provide a state-of-the-art overview on recent developments and treatment options for hemostatic disorder in cirrhotic patients. Patients with end-stage-liver disease (ESLD) do not suffer only from procoagulant deficiency; there is also a lack of natural anticoagulants (i.e. proteins C and S) and profibrinolytics. Conventional laboratory methods such as the determination of the international normalized ratio or the activated partial thromboplastin time cannot predict bleeding complications in these patients. Progressive diagnostic techniques reveal that cirrhotic patients have the same capacity to produce thrombin like healthy volunteers. Moreover, cirrhotic patients--and particularly those with primary biliary cirrhosis or primary sclerosing cholangitis-- are at a higher risk for developing thrombosis as compared with healthy controls. Hemostatic alterations are common in cirrhotic patients; they involve both the pro- and the anticoagulant pathways. However, this is a very delicate balance, which may be shifted to either of these pathways by different treatments thereby causing bleeding or thrombosis, respectively.

Dispelling myths about coagulation abnormalities in internal medicine

The clotting screen is an 'integral' part of the routine blood tests in most medical wards. It is likely that only with the increasing requests for prothrombin time and activated partial thromboplastin time are abnormal results noted. Interpretation of these results requires good understanding of the coagulation system and problems with the laboratory analysis. Due to variable understanding of this complex system, many misconceptions have arisen in relation to the clinical effects expected from abnormal clotting screens. Some of these are discussed with considerations of appropriate management in those situations.

Coagulation management with factor concentrates in liver transplantation: a single-center experience

BACKGROUND

Allogeneic blood products transfusion during liver transplantation (LT) can be associated with increased morbidity and mortality. Data on thromboelastometry (ROTEM)-guided coagulation management with coagulation factor concentrates (CFCs)-fibrinogen concentrate and/or prothrombin complex concentrate (PCC)-are sparse. We aimed to retrospectively evaluate the safety events observed with this approach in our clinic.

STUDY DESIGN AND METHODS

LT patients from January 2009 to December 2010 (n = 266) were identified by chart review. A ROTEM-based algorithm with CFC guided the hemostatic therapy. Doppler ultrasound was used to evaluate thrombosis in the hepatic artery, portal vein, and hepatic veins. Stroke, myocardial ischemia, pulmonary embolism, and transfusion variables were recorded. Patients receiving CFC were included in the CFC group (n = 156); those not receiving CFC were included in the non-CFC group (n = 110). Safety events were compared between these two groups.

RESULTS

Allogeneic transfusion(s) in the 266 patients was low, with medians of 2 (interquartile range [IQR], 0-5), 0 (IQR 0-0), and 0 (IQR 0-1) units for red blood cells (RBCs), fresh-frozen plasma (FFP), and platelets (PLTs), respectively. Ninety-seven of 266 LTs (36.5%) were performed without RBCs transfusion, 227 (85.3%) without FFP, and 190 (71.4%) without PLTs. There were no significant differences in thrombotic, thromboembolic, and ischemic adverse events occurrence between the CFC group and the non-CFC group (11/156 patients vs. 5/110; p = 0.31).

CONCLUSION

In LT, ROTEM-guided treatment with fibrinogen concentrate and/or PCC did not appear to increase the occurrence of thrombosis and ischemic events compared to patients who did not receive these concentrates.

Abnormal hemostatic function one year after orthotopic liver transplantation can be fully attributed to endothelial cell activation

BACKGROUND

The long-term risk of thrombotic and vascular complications is elevated in liver transplant recipients compared to the general population. Patients with cirrhosis are in a hypercoagulable status during and directly after orthotopic liver transplantation, but it is unclear whether this hypercoagulability persists over time.

AIM

We aimed to investigate the hemostatic status of liver transplant recipients one year after transplantation.

METHODS

We prospectively collected blood samples of 15 patients with a functioning graft one year after orthotopic liver transplantation and compared the hemostatic status of these patients with that of 30 healthy individuals.

RESULTS

Patients one year after liver transplantation had significantly elevated plasma levels of von Willebrand factor (VWF). Thrombin generation, as assessed by the endogenous thrombin potential, was decreased in patients, which was associated with increased plasma levels of the natural anticoagulants antithrombin and tissue factor pathway inhibitor.  Plasma fibrinolytic potential was significantly decreased in patients and correlated inversely with levels of plasminogen activator inhibitor-1.

CONCLUSION

One year after liver transplantation, liver graft recipients have a dysregulated hemostatic system characterised by elevation of plasma levels of endothelial-derived proteins. Increased levels of von Willebrand factor and decreased fibrinolytic potential may (in part) be responsible for the increased risk for vascular disease seen in liver transplant recipients.

Importance of Kupffer cells in the development of acute liver injuries in mice

Kupffer cells reside within the liver sinusoid and serve as gatekeepers. They produce pro- and anti-inflammatory cytokines and other biologically important molecules upon the engagement of pattern recognition receptors such as Toll-like receptors. Kupffer cell-ablated mice established by in vivo treatment with clodronate liposomes have revealed many important features of Kupffer cells. In this paper, we review the importance of Kupffer cells in murine acute liver injuries and focus on the following two models: lipopolysaccharide (LPS)-induced liver injury, which is induced by priming with Propionibacterium acnes and subsequent challenge with LPS, and hypercoagulability-mediated acute liver failure such as that in concanavalin A (Con A)-induced hepatitis. Kupffer cells are required for LPS sensitization induced by P. acnes and are a major cellular source of interleukin-18, which induces acute liver injury following LPS challenge. Kupffer cells contribute to Con A-induced acute liver failure by initiating pathogenic, intrasinusoidal thrombosis in collaboration with sinusoidal endothelial cells. The mechanisms underlying these models may shed light on human liver injuries induced by various etiologies such as viral infection and/or abnormal metabolism.

Evidence of rebalanced coagulation in acute liver injury and acute liver failure as measured by thrombin generation

BACKGROUND & AIMS

Patients with liver disease often show profound abnormalities in their haemostatic system. Studies using thrombin generation demonstrate rebalanced coagulation in patients with chronic liver disease. Our aim was to evaluate the haemostatic profile in patients with acute liver injury/failure (ALI/ALF) compared with healthy controls.

METHODS

Thrombin generation was measured in the presence and absence of thrombomodulin (TM) to activate protein C (PC) with endogenous thrombin potential (ETP; the area under the thrombin generation curve) a key parameter. Routine coagulation assays were also performed.

RESULTS

Thirty two patients with ALI/ALF and 40 controls were recruited. Patients had grossly abnormal coagulation profiles with decreased pro- and anticoagulant factors compared with controls (P < 0.001 for all comparisons), except for median Factor VIII which was increased 247 U/dl [interquartile range: 214-347] in patients compared with 120 U/dl [97-139; P < 0.001] in controls. Mean ETP was significantly lower in patients 886 nM.min (± 436) compared with controls 1596 nM.min (± 259; P < 0.001). However, when the assay was repeated with TM to activate PC, there was no significant difference in mean ETP + TM between patients and controls (632 ± 418 vs 709 ± 301 nM.min respectively; P = 0.666). Furthermore, the ETP ratio (ETP + TM/ETP) was significantly higher in patients 0.89 (0.60-0.97) compared with controls 0.48 (0.3-0.6; P = 0.002) and negatively correlated with PC (R = -0.487, P = 0.003) and Factor V (R = -0.431, P = 0.01).

CONCLUSION

ALI/ALF patients have normal ETP in the presence of TM. This supports rebalanced coagulation mediated by acquired PC resistance because of the reduction in PC, Factor V and concomitant increase in Factor VIII.

Point of care perioperative coagulation management in liver transplantation and complete portal vein thrombosis

Liver transplantation (LT) is a serious hemostatic challenge in patients with portal vein thrombosis (PVT). Advances in monitoring systems have improved surgery in this setting. We report the successful application of a point-of-care (POC) rotational viscoelastic thromboelastometry-guided (TEM) testing system (ROTEM) which allowed management of coagulation during LT in a 64-year-old cirrhotic patient with a model for end-stage liver disease (MELD) score of 16. Perioperatively, the patient showed complete PVT, hepatomegaly, splenomegaly, recanalization of the umbilical vein, and portosystemic shunt. Macroscopic liver and spleen adherences with collateral circulation were evident. Coagulation factors and fibrinolysis were assessed preoperatively and at graft reperfusion to evaluate the need of hemostatic therapy. Based on ROTEM findings, the patient received 16 g of human fibrinogen concentrate, half preoperatively (with prothrombin complex concentrate 2000 IU, tranexamic acid 1 g, and platelets 2 IU), and two doses of 4 g before and after graft reperfusion; we achieved normalization of all monitored parameters. No ischemia-reperfusion syndrome was present. Postoperatively portal vein flux at Color-Doppler ultrasonography was normal. After a 3-day ICU stay, the patient was moved to the Department of Surgery and discharged on day 14. The postoperative course was uneventful and did not require any further haemostatic therapy.

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.

Differential in vitro inhibition of thrombin generation by anticoagulant drugs in plasma from patients with cirrhosis

Background

Treatment and prevention of thrombotic complications is frequently required in patients with cirrhosis. However anticoagulant therapy is often withheld from these patients, because of the perceived bleeding diathesis. As a result of the limited clinical experience, the anticoagulant of choice for the various indications is still not known.

Objectives

We evaluated the in vitro effect of clinically approved anticoagulant drugs in plasma from patients with cirrhosis.

Patients/Methods

Thirty patients with cirrhosis and thirty healthy controls were studied. Thrombin generation assays were performed before and after addition of unfractionated heparin, low molecular weight heparin, fondaparinux, dabigatran, and rivaroxaban, to estimate anticoagulant potencies of these drugs.

Results

Addition of dabigatran led to a much more pronounced reduction in endogenous thrombin potential in patients compared to controls (72.6% reduction in patients vs. 12.8% reduction in controls, P<0.0001). The enhanced effect of dabigatran was proportional to the severity of disease. In contrast, only a slightly increased anticoagulant response to heparin and low molecular weight heparin and even a reduced response to fondaparinux and rivaroxaban was observed in plasma from cirrhotic patients as compared to control plasma.

Conclusions

The anticoagulant potency of clinically approved drugs differs substantially between patients with cirrhosis and healthy individuals. Whereas dabigatran and, to a lesser extent, heparin and low molecular weight heparin are more potent in plasma from patients with cirrhosis, fondaparinux and rivaroxaban showed a decreased anticoagulant effect. These results may imply that in addition to dose adjustments based on altered pharmacokinetics, drug-specific dose adjustments based on altered anticoagulant potency may be required in patients with cirrhosis.

Eltrombopag in patients with chronic hepatitis C and thrombocytopenia

ABSTRACT: 

Eltrombopag is a thrombopoietic drug that acts by interacting with the TPO receptor and stimulates megakaryocytopoiesis and platelet production. Thrombocytopenia is a fairly frequent hematological abnormality in patients with chronic liver disease, and may represent an obstacle to interferon-based antiviral therapy in patients with chronic HCV infection who are otherwise good candidates for treatment. In large, multicenter, randomized, placebo-controlled studies, eltrombopag consistently enabled thrombocytopenic chronic hepatitis C patients to be treated with interferon-based therapy and, as an adjunct to antiviral therapy, has shown to be able to increase the sustained virologic response rate to treatment. The safety profile of the drug, with particular attention to the risk of thromboembolic events and the potential for hepatic decompensation, should be taken into account when planning treatment. The aim of this article is to review the information currently available regarding the pharmacokinetics, clinical efficacy and side-effect profile of eltrombopag, and to assess the role of this drug into the current and future hepatitis C treatment paradigm.

Management of Bleeding in Post-liver Disease, Surgery and Biopsy in Patients With High Uncorrected International Normalized Ratio With Prothrombin Complex Concentrate: An Iranian Experience

BACKGROUND

To evaluate the efficacy of prothrombin complex concentrate (PCC) in the management of bleeding in patients with liver disease and patients undergoing surgery or biopsy who had a high uncorrected international normalized ratio (INR).

OBJECTIVES

In this study, we examined an Iranian sample and investigated the efficacy of PCC to manage bleeding in patients with liver disease and also patients with high uncorrected INR who were scheduled for surgery or biopsy.

MATERIALS AND METHODS

A total of 25 patients including 16 patients with post-liver disease bleeding (group 1) and 9 patients with high uncorrected INR who were scheduled for surgery or biopsy (group 2) were enrolled. All patients were treated with 25 IU/kg PCC, and efficacy was defined as any reduction in or cessation of bleeding episodes and correction of INR before surgery or biopsy. The patients were also evaluated for any adverse effects.

RESULTS

INR decreased significantly in both groups of patients, with no bleeding episodes during or after the study in group 1 and during or after surgery/biopsy in group 2. All patients tolerated the therapy well without any significant adverse effects.

CONCLUSIONS

The efficacy of PCC therapy was satisfactory in this study. PCC therapy in patients with liver disease and patients undergoing surgery or biopsy seems to be effective and safe, and may be a good treatment strategy for these patients, if fresh frozen plasma or vitamin K are not effective.

Hemostasis, coagulation abnormalities, and liver disease

Coagulopathy-related bleeding events are a major concern in the management of acute and chronic liver disease. The liver attempts to maintain a balance between procoagulant and anticoagulant factors, and providers struggle with poor prognostic indicators to manage bleeding and critical complications. Subtle changes in patient presentation that may require extensive provider-directed interventions, such as blood transfusions, intravenous fluid management, mitigating possible sepsis, and evaluating appropriate pharmacologic treatment, are discussed.

Fresh frozen plasma: the most commonly prescribed hemostatic agent

Although fresh frozen plasma (FFP) is one of the most commonly prescribed therapies in clinical practice throughout the world today, there is little medical evidence available supporting its use. Recent guidelines have called for limiting FFP transfusions. Despite this, FFP use does not seem to be decreasing. The reasons for this are likely to be multifactorial, and may be based on ideas regarding medical practices dating back to Galen and Hippocrates. A review of the history of the development of FFP may shed some light on current clinical practice and guide the direction of future investigations and therapies.