Preoperative use of romiplostim in thrombocytopenic patients with chronic hepatitis C and liver cirrhosis

Hematological Abnormalities in Cirrhosis: A Narrative Review

Liver cirrhosis remains a major public health issue. Liver fibrosis leading to cirrhosis is the terminal stage of various chronic liver diseases. Inflammatory cytokines are involved in the pathogenesis. Patients with cirrhosis often have hematological abnormalities, such as anemia and thrombocytopenia, which have multifactorial etiologies. Anemia in cirrhosis could be related to bleeding leading to iron deficiency anemia or other nutritional anemia such as vitamin B12 and folate deficiency. The pathophysiology of thrombocytopenia in liver cirrhosis has been postulated to range from splenic sequestration to bone marrow suppression from toxic agents, such as alcohol. It often complicates management due to the risk of bleeding with severely low platelets. This review aimed to highlight pathogenesis of liver cirrhosis, hematological abnormalities in liver cirrhosis, and their clinical significance.

Thrombocytopenia in chronic liver disease: Physiopathology and new therapeutic strategies before invasive procedures

Chronic liver disease is characterized by several hematological derangements resulting in a complex and barely rebalanced haemostatic environment. Thrombocytopenia is the most common abnormality observed in these patients and recent advances have led to researchers focus the attention on the multifactorial origin of thrombocytopenia and on the key role of thrombopoietin (TPO) in its physiopathology. Severe thrombocytopenia (platelet count < 50000/μL) complicates the management of patients with chronic liver disease by increasing the potential risk of bleeding for invasive procedures, which may be therefore delayed or canceled even if lifesaving. In the very last years, the development of new drugs which exceed the limits of the current standard of care (platelet transfusions, either immediately before or during the procedure) paves the way to a new scenario in the management of this population of patients. Novel agents, such as the TPO-receptor agonists avatrombopag and lusutrombopag, have been developed in order to increase platelet production as an alternative to platelet transfusions. These agents have demonstrated a good profile in terms of efficacy and safety and will hopefully allow reducing limitations and risks associated with platelet transfusion, without any delay in scheduled interventions. Altogether, it is expected that patients with chronic liver disease will be able to face invasive procedures with one more string in their bow.

Sequential Use of Romiplostim after Eltrombopag for Refractory Thrombocytopenia in Hydrocarbon-Induced Myelodysplasia

We describe the clinical course of a 65-year-old male patient who suffered from hydrocarbon-induced myelodysplasia and was successfully treated with the thrombopoietin receptor agonist (TPO-RA), romiplostim. Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis, cytopenias, and increased risk of leukemic transformation. Here, we present a clinical vignette of MDS-associated thrombocytopenia refractory to first-line drugs as well as the TPO-RA, eltrombopag. To date, romiplostim is an U.S. Food and Drug Administration (FDA)-approved drug for idiopathic thrombocytopenic purpura and thrombocytopenia secondary to liver disease. Of note, currently the FDA advises against its use in MDS based on previous long-term safety concerns. Since the therapeutic options for thrombocytopenia in MDS patients are sparse, repurposing and reassessing romiplostim in this setting have been the focus of recent studies. At the time of writing, no published double-blind randomized clinical trials have conducted a head-to-head comparison between romiplostim and eltrombopag in thrombocytopenic MDS patients. To the best of our knowledge, for a thrombocytopenic patient in the setting of MDS, this is the first documented report of refractory clinical response after a 2-year use of eltrombopag in which replacement of treatment with romiplostim resulted in sustained physiological counts of thrombocytes within four weeks.

Treatment of Severe Acute on Chronic Liver Failure: Management of Organ Failures, Investigational Therapeutics, and the Role of Liver Transplantation

Acute on chronic liver failure (ACLF) is a unique syndrome that afflicts patients with chronic liver disease and results in high short-term mortality, in the setting of organ system failures. Given this prognosis, there is an urgent need to understand risk factors for this condition, for appropriate medical management of organ failures, and for selection criteria for patients who may benefit from liver transplantation (LT). Although several definitions exist to identify ACLF, all of them are designed to identify patients with uniquely high mortality. Currently, management of severe ACLF relies on best supportive care for specific organ failures. Thromboelastography should guide the evaluation of coagulation pathways and hyperfibrinolysis in ACLF; prophylactic blood product transfusions and thrombopoetin agonists are not recommended. Combination therapy with terlipressin and albumin has been shown to be efficacious in the management of the hepatorenal syndrome but should be administered with caution in patients with ACLF-3. Recent data have characterized the role of beta-blockers and transjugular intrahepatic portosystemic shunt placement in the management of ACLF. Investigational therapies such as extracorporeal liver support and hepatocyte stem cell therapies have shown promise; larger scale studies may better define the subpopulations of patients with ACLF mostly likely to benefit from these evolving therapeutics. Regarding LT in ACLF, data suggest that even patients with 3 or more organ system failures may have a 1-year survival >80%. However, further efforts are needed to understand the predictors of post-LT survival to facilitate LT criteria for this condition.

A Review of Romiplostim Mechanism of Action and Clinical Applicability

Thrombocytopenia results from a variety of conditions, including radiation, chemotherapy, autoimmune disease, bone marrow disorders, pathologic conditions associated with surgical procedures, hematopoietic stem cell transplant (HSCT), and hematologic disorders associated with severe aplastic anemia. Immune thrombocytopenia (ITP) is caused by immune reactions that accelerate destruction and reduce production of platelets. Thrombopoietin (TPO) is a critical component of platelet production pathways, and TPO receptor agonists (TPO-RAs) are important for the management of ITP by increasing platelet production and reducing the need for other treatments. Romiplostim is a TPO-RA approved for use in patients with ITP in the United States, European Union, Australia, and several countries in Africa and Asia, as well as for use in patients with refractory aplastic anemia in Japan and Korea. Romiplostim binds to and activates the TPO receptor on megakaryocyte precursors, thus promoting cell proliferation and viability, resulting in increased platelet production. Through this mechanism, romiplostim reduces the need for other treatments and decreases bleeding events in patients with thrombocytopenia. In addition to its efficacy in ITP, studies have shown that romiplostim is effective in improving platelet counts in various settings, thereby highlighting the versatility of romiplostim. The efficacy of romiplostim in such disorders is currently under investigation. Here, we review the structure, mechanism, pharmacokinetics, and pharmacodynamics of romiplostim. We also summarize the clinical evidence supporting its use in ITP and other disorders that involve thrombocytopenia, including chemotherapy-induced thrombocytopenia, aplastic anemia, acute radiation syndrome, perisurgical thrombocytopenia, post-HSCT thrombocytopenia, and liver disease.

Thrombopoietin Receptor Agonists in Patients with Chronic Liver Disease

Thrombocytopenia is one of the most common hematologic complications in cirrhosis. Despite limited data linking platelet count and bleeding risk in patients with cirrhosis, the use of platelets transfusions for invasive procedures has been a common practice. Recently, thrombopoietin (TPO) receptor agonists have been approved for use in patients with chronic liver disease (CLD) undergoing invasive procedures. The aim of this study was to review current literature on bleeding risk in patients with cirrhosis and the use of platelet transfusions and TPO receptor agonists in the context of invasive procedures. PubMed search was conducted to find articles relating to cirrhosis, thrombocytopenia, and new novel treatments for this condition. Search terms included CLD, cirrhosis, thrombocytopenia, bleeding, thrombosis, coagulopathy, hemostasis, and TPO receptor agonists. Romiplostim, eltrombopag, avatrombopag, and lusutrombopag are approved TPO receptor agonists, with avatrombopag and lusutrombopag specifically approved for use in patients with CLD undergoing invasive procedures. In patients with platelet counts < 50,000/mm³, avatrombopag and lusutrombopag increased the platelet counts above this threshold in the majority of treated patients and reduced the frequency of platelet transfusions. At the approved doses, incidence of thrombosis was not increased and therapies were well tolerated. Studies were not powered to assess whether risk of bleeding complications was reduced and the fundamental question of whether correction of thrombocytopenia is warranted in patients undergoing invasive procedures remains unanswered. The use of TPO receptor agonists has resulted in less requirement for platelet transfusions. In patients with cirrhosis undergoing invasive procedures for whom platelet transfusion is planned, TPO receptor agonists are an alternative and avoid the risks associated with transfusions. However, there is need for a thoughtful approach to manage bleeding risk in patients with cirrhosis undergoing procedures, with the consideration of a comprehensive hemostatic profile, the severity of portal hypertension, and the complexity of the invasive procedure to guide decisions regarding transfusions or use of TPO receptor agonists.

Thrombocytopenia in Chronic Liver Disease: New Management Strategies

Thrombocytopenia is common in advanced liver disease, and such patients frequently need invasive procedures. Numerous mechanisms for thrombocytopenia exist, including splenic sequestration and reduction of levels of the platelet growth factor thrombopoietin. Traditionally, platelet transfusions have been used to increase platelet counts before elective procedures, usually to a threshold of greater than or equal to 50,000/μL, but levels vary by provider, procedure, and specific patient. Recently, the thrombopoietin receptor agonists avatrombopag and lusutrombopag were studied and found efficacious for increasing platelet count in the outpatient setting for select patients with advanced liver disease who need a procedure.

Thalidomide for the Treatment of Thrombocytopenia and Hypersplenism in Patients With Cirrhosis or Thalassemia

Hypersplenism and thrombocytopenia are common complications of liver cirrhosis or thalassemia, but current treatment strategies are limited. This study aimed to evaluate the efficacy and safety of thalidomide in the treatment of hypersplenism and thrombocytopenia in patients with liver cirrhosis or thalassemia. A total of 31 patients with hepatic cirrhosis (n=19) or thalassemia (n=12) diagnosed with hypersplenism and thrombocytopenia (platelet count [PLT] <100×10⁹/L) were included in this prospective cohort study between January 2015 and May 2017. Patients were treated with thalidomide (150-200 mg/d) plus conventional therapy. Spleen length, PLT, leukocyte count (WBC), absolute neutrophil count (ANC), and hemoglobin level (Hb) were measured at baseline, 3, 6, and 12 months. Any adverse events were noted. All of the 31 patients were showed a progressive increase PLT during the 12-month follow-up, and similar results were obtained when subgroup analyses were performed based on the primary disease (cirrhosis or thalassemia). WBC, ANC, and Hb also increased progressively during the 12-month follow-up. Spleen length decreased progressively during the follow-up. No serious adverse events occurred. Thalidomide is a potential treatment for thrombocytopenia caused by hypersplenism in patients with cirrhosis or thalassemia.

Treatment Options for Thrombocytopenia in Patients With Chronic Liver Disease Undergoing a Scheduled Procedure

Thrombocytopenia is a consequence of portal hypertension and is the most common hematological manifestation of chronic liver disease (CLD) (ie, cirrhosis). Data indicates the rates of CLD are increasing and, as a result, so will the incidence of this complication. Although bleeding risks are only relevant when elective procedures are performed, this is a frequent concern as these procedures are commonly part of the spectrum of care for patients with cirrhosis. As such, thrombocytopenia remains a pertinent issue. Fortunately, we now have effective and accurate treatment modalities to raise platelet counts before scheduled procedures, known as thrombopoietin receptor agonists. Two drugs in this therapeutic class (avatrombopag and lusutrombopag) are now approved for the treatment of thrombocytopenia in adults with CLD undergoing a procedure and have revolutionized how this is managed. Although there is progress in the field, peer-reviewed literature and expert guidance are lacking. Recognizing these unmet needs, a group of expert hepatologists comprised this review, which summarizes the most current and relevant peer-reviewed literature on thrombocytopenia in CLD and provides clinical expertise on this timely topic.

Thrombopoietin-receptor agonists in perioperative treatment of patients with chronic liver disease

Thrombocytopenia is a multifactorial disorder that is common in patients with chronic liver disease (CLD), leading to challenging perioperative planning. As thrombocytopenia in CLD is associated with thrombopoietin (TPO) deficiency, the use of TPO-receptor agonists (TPO-RAs) to increase platelet counts is a promising approach. This has led to the development of various TPO-RAs, including romiplostim, eltrombopag, avatrombopag, and lusutrombopag. Of these, only avatrombopag and lusutrombopag are approved by the United States Food and Drug Administration for the perioperative treatment of thrombocytopenia in patients with CLD. Platelet transfusion is commonly used for the clinical management of thrombocytopenia in patients with CLD undergoing invasive procedures. However, the limitations and possible risks of transfusion, including short duration of efficacy, development of antiplatelet antibodies, risk of infections and such complications as transfusion-related acute lung injury or circulatory overload, and possibility of refractoriness, limit its use. Moreover, there is no consensus among guidelines as to the platelet count at which transfusions are indicated. Results from studies using TPO-RAs perioperatively in patients with thrombocytopenia and CLD are promising and provide an alternative to platelet transfusions in the pre- and post-operative setting. These TPO-RAs are the subject of this review, with focus on their use in the perioperative setting in patients with thrombocytopenia, associated supporting clinical trials, efficacy and safety data, and their use with respect to platelet transfusions.

Pathogenesis of Thrombocytopenia in Chronic HCV Infection: A Review

A large proportion of patients with chronic hepatitis C have associated thrombocytopenia (TCP). Due to bleeding risks, TCP, when severe, can limit diagnostic and therapeutic procedures, treatments, and increases risk of complications, especially excessive bleeding. It is important to understand the mechanisms that cause TCP in order to manage it. In general, TCP can be due to increased destruction or decreased production. Proposed mechanisms of increased destruction include autoantibodies to platelets and hypersplenism with sequestration. Proposed mechanisms of decreased production include virus-induced bone marrow suppression and decreased TPO production. Autoantibodies directed against platelet surface antigens have demonstrated an inverse correlation with platelet counts. Hypersplenism with sequestration involves the interaction of portal hypertension, splenomegaly, and platelet destruction. Decreased production mechanisms involve appropriate and inappropriate levels of TPO secretion. There is limited evidence to support viral-induced bone marrow suppression. In contrast, there is strong evidence to support low levels of TPO in liver failure as a major cause of TCP. TPO-agonists, specifically eltrombopag, have been shown in hepatitis C patients to increase platelet counts without reducing portal hypertension or splenomegaly. We conclude that TCP in hepatitis C virus-induced liver disease is often multifactorial, but an understanding of the mechanisms can lead to judicious use of new drugs for treatment.

Management of Hepatic Coagulopathy in Bleeding and Nonbleeding Patients: An Evidence-Based Review

Patients with varying degrees of hepatic dysfunction often present with presumed bleeding diathesis based on interpretation of routine measures of coagulation (prothrombin time [PT], international normalized ratio [INR], and activated partial thromboplastin time). However, standard markers of coagulation do not reflect the actual bleeding risk in this population and may lead to inappropriate administration of hemostatic agents and blood products. The concept of "rebalanced hemostasis" explains both the risk of bleeding and clotting seen in patients with liver dysfunction. The role of pharmacologic agents and blood products for prevention of bleeding during high-risk procedures and treatment of clinically significant bleeding remains unclear. Viscoelastic measurements of the clotting cascade provide information about platelets, fibrinogen/fibrin polymerization, coagulation factors, and fibrinolysis that might better represent hemostasis in vivo and may better inform management strategies. Due to the paucity of available data, firm recommendations for the use of blood products and pharmacologic agents in patients with hepatic coagulopathies are lacking, and thus, these products should not be routinely administered. Traditional laboratory tests such as PT/INR should not be the sole determinant of potential interventions. Rather, clinicians should assess factors such as the severity of bleed or bleeding risk of the procedure, the patient's risk of thromboembolism, and the strength of available evidence for specific agents and blood products to guide decision-making.

Current Advance in Thrombopoietin Receptor Agonists in the Management of Thrombocytopenia Associated With Chronic Liver Disease: Focus on Avatrombopag

Chronic liver disease (CLD) is a condition that progresses over time toward advanced disease state which is known as liver cirrhosis. Liver cirrhosis leads to dangerous health problems among people living across the world. One such problem that observed in about 75% of cirrhotic patients is thrombocytopenia; which in turn associated with poor prognosis and recovery from CLD. Beyond these, thrombocytopenia in cirrhotic patients led to impairment of coagulation cascade and significantly influenced the utilization of effective mechanism in the management of CLD. By nature, treatment of CLD involves invasive diagnostic and treatment procedures; therefore, in the presence of thrombocytopenia implementing these methods put the lives of patients in a critical health problem due to increased risk of bleeding and mortality. Because of these reasons, prophylactic transfusion of platelets is considered to be one of the most effective options that reduce the risk of bleeding in patients with CLD that required to undergo an invasive procedure. Although platelet transfusion presented with significant advantages in facilitating the invasive procedure in patients with CLD, refractoriness with repeated use and various problems associated with its transfusion limit the continuous utilization of this important option. With these challenges and current advance in the knowledge of thrombopoiesis, the development of relatively safe and alternative drugs that enhance the production of platelets by interacting with thrombopoietin receptor agonists provides a promising option to platelet transfusion. The discovery and approval of romiplostim and eltrombopag in August 2008 and November 2008, respectively, for the treatment of chronic immune thrombocytopenia paved a way and followed by the Food and Drug Administration (FDA) approval of 2 potentially advantageous drugs, lusutrombopag, and avatrombopag, in 2018 for the treatment of thrombocytopenia in patients with CLD that required to undergo elective surgery. Therefore, this review aims to assess pathogenesis of thrombocytopenia and its challenges in the management of liver-related issues and, more importantly, gives emphasis to address the potential use of avatrombopag in the treatment of thrombocytopenia underlying CLD, its pharmacokinetics and pharmacodynamics, as well as its toxicological profiles by presenting the most commonly reported adverse events in various trials.

Management of Thrombocytopenia in Patients with Chronic Liver Disease

BACKGROUND

Thrombocytopenia is the most common hematologic complication associated with chronic liver disease (CLD) with important clinical implications. While the mechanisms for thrombocytopenia are multifactorial, platelet sequestration in the spleen and decreased thrombopoietin (TPO) production are the main mechanisms in patients with CLD.

AIM

This review outlines the current treatment options for thrombocytopenia in patients with CLD, explores their limitations, and proposes a revised treatment algorithm for the management of thrombocytopenia in this patient group.

METHODS

A PubMed search of the literature was undertaken with search terms focused on CLD and thrombocytopenia.

RESULTS

Until now, the standard-of-care treatment in these patients has been the use of platelet transfusions either prophylactically or periprocedurally to control bleeding. Treatment options, such as splenic artery embolization and splenectomy, are invasive, and their utility is limited by significant complications. The US Food and Drug Administration recently approved 2 s-generation TPO-receptor agonists, avatrombopag and lusutrombopag, as safe and effective therapies for the treatment of thrombocytopenia in patients with CLD scheduled to undergo a procedure.

CONCLUSIONS

The addition of avatrombopag and lusutrombopag offers physicians an alternative to platelet transfusions in patients with CLD who have to undergo medical/dental procedures that could potentially put them at an increased risk of bleeding. There are several other drugs in the research pipeline at various stages of development, including a new class of monoclonal antibodies that can bind to and activate TPO-receptor agonists. The outlook for treatment choices for thrombocytopenia in patients with liver disease is promising.

Thrombocytopenia and Procedural Prophylaxis in the Era of Thrombopoietin Receptor Agonists

Thrombocytopenia is common in patients with advanced liver disease. These patients frequently require invasive diagnostic or therapeutic procedures in the setting of thrombocytopenia. A common platelet goal before such procedures is ≥50,000/μL, but target levels vary by provider and the procedure. Platelet transfusion has disadvantages, including safety and cost. No other short‐term options for ameliorating thrombocytopenia before procedures were available until the thrombopoietin receptor agonists were recently approved. Avatrombopag and lusutrombopag can be used in certain patients with thrombocytopenia due to advanced liver disease undergoing elective invasive procedures; these new agents are highly effective in carefully selected patients, and real world data of safety and efficacy are awaited.

TPO receptor agonists are an exciting new development that can raise platelet counts in liver patients with thrombocytopenia before elective procedures. We review the strategies to address peri‐procedure thrombocytopenia including data on the most recent trials involving TPO receptor agonists.

Romiplostim as a transfusion saving strategy in 20 patients after heart or lung transplantation: a single centre before-after pilot study

BACKGROUND

Thrombocytopenia is a common disorder after heart or lung transplantation. Platelet transfusion is often required to maintain haemostasis but represents a specific cause of morbidity and mortality in this setting including alloimmunisation and graft rejection.

STUDY DESIGN AND METHODS

As part of a health-care quality improvement project, in a single-centre before-after pilot study, the relevance of a platelet transfusion saving strategy based on romiplostim administration after transplantation was assessed in patients with platelet count <100 × 10⁹/L. Transfusions on days 28 and 90 were compared using propensity matched score for adjustment of demographic characteristics at baseline. The primary outcome was platelet transfusion until day 28 after transplantation.

RESULTS

Ninety-three patients were analysed (73 before vs. 20 after). The median [interquartile range] number of platelet concentrate was 1 [0;4.0] before versus 0.5 [0;2.0] in the after period, mean difference 0.5 confidence interval 95% [-0.7 to 1.7], p = 0.39. On day 28, median [interquartile range] red blood cell transfusion was significantly higher in the before versus the after period, 7 [2.0;13.5] versus 6 [1.5;8.5], mean difference 3.2 CI 95% [0.4-6.0], p = 0.02. At 6 months, the rate of patients with de novo anti-human leukocyte antigen alloimmunisation was 45% before versus 53% in the after period (p = 0.56). Deep venous thrombosis was detected in nine patients (12%) before versus seven patients (35%) in the after period (p = 0.04).

CONCLUSION

Romiplostim did not significantly reduce platelet transfusion after heart or lung transplantation. Its relevance and safety in a global transfusion strategy remains to be studied in this setting in a large randomised study.

Bleeding Risk with Invasive Procedures in Patients with Cirrhosis and Coagulopathy

PURPOSE OF REVIEW

Previous perceptions of cirrhosis as a hypocoagulable state have resulted in empirical blood product transfusions prior to invasive procedures. We evaluate procedure-related bleeding risks in patients with cirrhosis, assess the utility of conventional and newer global coagulation tests, and explore evidence surrounding prophylactic transfusion strategies.

RECENT FINDINGS

Recent literature supports the concept of a rebalanced, albeit fragile, haemostasis equilibrium in cirrhosis, with a potential hypercoagulable tendency in stable patients. Standard coagulation tests provide a poor reflection of bleeding risks and yet are relied upon for transfusion thresholds. Consequently, a sizeable proportion of patients receive unnecessary blood products. The role of viscoelastic tests to guide transfusions requires further evaluation. In stable cirrhotic patients, procedure-related bleeding rates appear low. Prophylactic transfusion strategies based on arbitrary thresholds lack evidence of clinical benefit. There is a pressing need for point-of-care coagulation tests that represent the complex coagulopathy of cirrhosis and well-powered randomised controlled trials to develop evidence-based pre-procedure transfusion guidelines.

A novel recombinant human thrombopoietin therapy for the management of immune thrombocytopenia in pregnancy

The aim of this study was to determine the safety and efficacy of recombinant human thrombopoietin (rhTPO) for the management of immune thrombocytopenia (ITP) during pregnancy. Pregnant patients with ITP were enrolled in the study if they had a platelet count less than 30 × 10⁹/L, were experiencing bleeding manifestations, had failed to respond to corticosteroids and/or intravenous immunoglobulin (IVIG), and had developed refractoriness to platelet transfusion. Thirty-one patients received rhTPO at an initial dose of 300 U/kg once daily for 14 days. Twenty-three patients responded (74.2%), including 10 complete responders (>100 × 10⁹/L) and 13 responders (30-100 × 10⁹/L). It appears that rhTPO ameliorated the bleeding symptoms remarkably, even in the nonresponders. rhTPO was well tolerated. Dizziness, fatigue, and pain at an injection site were reported in 1 patient each. No congenital disease or developmental delays were observed in the infants in a median follow-up of 53 (range, 39-68) weeks. In conclusion, rhTPO is a potentially safe and effective treatment choice for patients with ITP during pregnancy. Our work has paved the way for further study on the clinical application of rhTPO and other thrombopoietic agents for the management of ITP during pregnancy. This study is registered at www.clinicaltrials.gov as NCT02391272.

Thrombocytopenia in chronic liver disease

Thrombocytopenia is a common haematological disorder in patients with chronic liver disease. It is multifactorial and severity of liver disease is the most influential factor. As a result of the increased risk of bleeding, thrombocytopenia may impact upon medical procedures, such as surgery or liver biopsy. The pathophysiology of thrombocytopenia in chronic liver disease has long been associated with the hypothesis of hypersplenism, where portal hypertension causes pooling and sequestration of all corpuscular elements of the blood, predominantly thrombocytes, in the enlarged and congested spleen. Other mechanisms of importance include bone marrow suppression by toxic substances, such as alcohol or viral infection, and immunological removal of platelets from the circulation. However, insufficient platelet recovery after relief of portal hypertension by shunt procedures or minor and transient recovery after splenic artery embolization have caused many to question the importance and relative contribution of this mechanism to thrombocytopenia. The discovery of the cytokine thrombopoietin has led to the elucidation of a central mechanism. Thrombopoietin is predominantly produced by the liver and is reduced when liver cell mass is severely damaged. This leads to reduced thrombopoiesis in the bone marrow and consequently to thrombocytopenia in the peripheral blood of patients with advanced-stage liver disease. Restoration of adequate thrombopoietin production post-liver transplantation leads to prompt restoration of platelet production. A number of new treatments that substitute thrombopoietin activity are available or in development.

Thrombocytopenia in Patients with Chronic Hepatitis C Virus Infection

Thrombocytopenia in patients with chronic hepatitis C virus (HCV) infection is a major problem. The pathophysiology is multifactorial, with auto-immunogenicity, direct bone marrow suppression, hypersplenism, decreased production of thrombopoietin and therapeutic adverse effect all contributing to thrombocytopenia in different measures. The greatest challenge in the care of chronic HCV patients with thrombocytopenia is the difficulty in initiating or maintaining IFN containing anti-viral therapy. Although at present, it is possible to avoid this challenge with the use of the sole Direct Antiviral Agents (DAAs) as the primary treatment modality, thrombocytopenia remains of particular interest, especially in cases of advanced liver disease. The increased risk of bleeding with thrombocytopenia may also impede the initiation and maintenance of different invasive diagnostic and therapeutic procedures. While eradication of HCV infection itself is the most practical strategy for the remission of thrombocytopenia, various pharmacological and non-pharmacological therapeutic options, which vary in their effectiveness and adverse effect profiles, are available. Sustained increase in platelet count is seen with splenectomy and splenic artery embolization, in contrast to only transient rise with platelet transfusion. However, their routine use is limited by complications. Different thrombopoietin analogues have been tried. The use of synthetic thrombopoietins, such as recombinant human TPO and pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMDGF), has been hampered by the development of neutralizing antibodies. Thrombopoietin-mimetic agents, in particular, eltrombopag and romiplostim, have been shown to be safe and effective for HCV-related thrombocytopenia in various studies, and they increase platelet count without eliciting any immunogenicity Other treatment modalities including newer TPO analogues-AMG-51, PEG-TPOmp and AKR-501, recombinant human IL-11 (rhIL-11, Oprelvekin), recombinant human erythropoietin (rhEPO), danazol and L-carnitine have shown promising early result with improving thrombocytopenia. Thrombocytopenia in chronic HCV infection remain a major problem, however the recent change in DAAs without IFN, as the frontline therapy for HCV, permit to avoid the dilemmas associated with initiating or maintaining IFN based anti-viral therapy.

Romiplostim therapy as a second-line treatment before splenectomy for refractory immune thrombocytopenia in a cirrhotic patient with iatrogenic Cushing syndrome secondary to corticosteroids

Our case report discusses the usefulness of administering romiplostim as a second‐line treatment before splenectomy in a cirrhotic patient with immune thrombocytopenia who developed corticosteroid‐induced Cushing's syndrome. Corticosteroids were tapered and consequently withdrawn. The patient made a full recovery postsplenectomy.

Platelets in liver and renal disease

This review will discuss how 2 common and morbid conditions, renal disease and liver disease, alter platelet number and function. It will review the impact of thrombocytopenia on bleeding complications in patients with these disorders and whether the low platelet count actually correlates with bleeding risk. Emerging data also suggest that platelets are much more than bystanders in both renal and liver disease, but instead play an active role in the pathobiology of these disorders. This review will briefly cover the emerging information on novel roles of platelets in the biology of renal and liver disease.

Management of Thrombocytopenia in Chronic Liver Disease: Focus on Pharmacotherapeutic Strategies

Thrombocytopenia (platelet count <150 × 10⁹/L) often complicates chronic liver disease, impeding optimal management of these patients. The prevalence of this manifestation ranges from 6 % among non-cirrhotic patients with chronic liver disease to 70 % among patients with liver cirrhosis. It has also been shown that the severity of liver disease is associated with both prevalence and level of thrombocytopenia. Its development is often multifactorial, although thrombopoietin is thought to be a major factor. The discovery of and ability to clone thrombopoietin led to new treatment opportunities for this clinical manifestation. This review discusses data on the three most important thrombopoietin receptor agonists: eltrombopag, avatrombopag, and romiplostim. Currently, only eltrombopag is approved for usage among patients with thrombocytopenia and chronic hepatitis C virus infection in order to initiate and maintain interferon-based antiviral treatment. Nevertheless, the optimal management of hematologic abnormalities among patients with chronic liver disease, and its risk for bleeding complications, is still a matter of discussion. Thrombocytopenia definitely contributes to hemostatic defects but is often counterbalanced by the enhanced presence of procoagulant factors. Therefore, a thorough assessment of the patient’s risk for thrombotic events is essential when the use of thrombopoietin receptor agonists is considered among patients with chronic liver disease and thrombocytopenia.

AISF position paper on liver transplantation and pregnancy: Women in Hepatology Group, Italian Association for the Study of the Liver (AISF)

After the first successful pregnancy in a liver transplant recipient in 1978, much evidence has accumulated on the course, outcomes and management strategies of pregnancy following liver transplantation. Generally, liver transplantation restores sexual function and fertility as early as a few months after transplant. Considering that one third of all liver transplant recipients are women, that approximately one-third of them are of reproductive age (18-49 years), and that 15% of female liver transplant recipients are paediatric patients who have a >70% probability of reaching reproductive age, the issue of pregnancy after liver transplantation is rather relevant, and obstetricians, paediatricians, and transplant hepatologists ever more frequently encounter such patients. Pregnancy outcomes for both the mother and infant in liver transplant recipients are generally good, but there is an increased incidence of preterm delivery, hypertension/preeclampsia, foetal growth restriction, and gestational diabetes, which, by definition, render pregnancy in liver transplant recipients a high-risk one. In contrast, the risk of congenital anomalies and the live birth rate are comparable to those of the general population. Currently there are still no robust guidelines on the management of pregnancies after liver transplantation. The aim of this position paper is to review the available evidence on pregnancy in liver transplant recipients and to provide national Italian recommendations for clinicians caring for these patients.

Thrombopoietin receptor agonists for preparing adult patients with immune thrombocytopenia to splenectomy: results of a retrospective, observational GIMEMA study

In patients with immune thrombocytopenia (ITP) refractory to corticosteroids and intravenous immunoglobulins (IVIG), splenectomy may result at higher risk of peri-operative complications and, for this reason, potentially contraindicated. The thrombopoietin receptor agonists (TPO-RAs) romiplostim and eltrombopag have shown high therapeutic activity in primary ITP, but data of efficacy and safety regarding their use in preparation for splenectomy are missing. Thirty-one adult patients, median age 50 years, with corticosteroids and/or IVIG refractory persistent and chronic ITP who were treated with TPO-RAs (romiplostim= 24; eltrombopag= 7) with the aim to increase platelet count and allow a safer execution of splenectomy were retrospectively evaluated. Twenty-four patients (77%) responded to the use of TPO-RAs with a median platelet count that increased from 11 × 10(9) /L before starting TPO-RAs to 114 × 10(9) /L pre-splenectomy, but a concomitant treatment with corticosteroids and/or IVIG was required in 19 patients. Twenty-nine patients underwent splenectomy while two patients who responded to TPO-RAs subsequently refused surgery. Post-splenectomy complications were characterized by two Grade 3 thrombotic events (1 portal vein thrombosis in the patient with previous history of HCV hepatitis and 1 pulmonary embolism), with a platelet count at the time of thrombosis of 260 and 167 × 10(9) /L, respectively and one Grade 3 infectious event. TPO-RAs may represent a therapeutic option to improve platelet count and reduce the risk of peri-operative complications in ITP candidates to splenectomy. An increased risk of post-splenectomy thromboembolic events cannot be ruled out and thromboprophylaxis with low-molecular weight heparin is generally recommended.

The Use of Thrombopoietin Receptor Agonists for Correction of Thrombocytopenia prior to Elective Procedures in Chronic Liver Diseases: Review of Current Evidence

Patients with chronic liver diseases (CLD) undergo a range of invasive procedures during their clinical lifetime. Various hemostatic abnormalities are frequently identified during the periprocedural work-up; including thrombocytopenia. Thrombocytopenia of cirrhosis is multifactorial in origin, and decreased activity of thrombopoietin has been identified to be a major cause. Liver is an important site of thrombopoietin production and its levels are decreased in patients with cirrhosis. Severe thrombocytopenia (platelet counts < 60-75,000/µL) is associated with increased risk of bleeding with invasive procedures. In recent years, compounds with thrombopoietin receptor agonist activity have been studied as therapeutic options to raise platelet counts in CLD. We reviewed the use of Eltrombopag, Romiplostim, and Avatrombopag prior to various invasive procedures in patients with CLD. These agents seem promising in raising platelet counts before elective procedures resulting in reduction in platelet transfusions, and they also enabled more patients to undergo the procedures. However, these studies were not primarily aimed at comparing bleeding episodes among groups. Use of these agents had some adverse consequences, importantly being the occurrence of portal vein thrombosis. This review highlights the need of further studies to identify reliable methods of safely reducing the provoked bleeding risk linked to thrombocytopenia in CLD.

Eltrombopag Use in Thrombocytopenia for Endoscopic Submucosal Dissection of a Gastric Carcinoid

Severe thrombocytopenia is a contraindication for therapeutic endoscopy due to the risk of bleeding. Platelet transfusions can temporarily increase platelet count, but are difficult to administer in the 2 weeks following endoscopic resection, during which the patient is at high risk for delayed bleeding. We present the use of a novel thrombopoietin receptor agonist, eltrombopag, to sustain platelet levels for the safe and complete endoscopic submucosal dissection of a gastric carcinoid in a patient with severe thrombocytopenia due to cirrhosis and idiopathic thrombocytopenic purpura. We performed complete and safe endoscopic removal of a gastric carcinoid after correcting the thrombocytopenia.

Romiplostim in the management of the thrombocytopenic surgical patient

BACKGROUND

Thrombopoietin receptor agonists increase platelet (PLT) counts and are approved for the treatment of chronic immune thrombocytopenia (ITP). These agents may also be useful for the management of thrombocytopenia in patients requiring surgical procedures.

STUDY DESIGN AND METHODS

We conducted a retrospective review of patients with thrombocytopenia (baseline PLT count, <150 × 10(9) /L) who received romiplostim before planned operative procedures. We characterized patient demographics, dosing and duration of romiplostim use, success in achieving PLT counts high enough for surgery, and clinical outcomes.

RESULTS

Eighteen patients underwent a total of 22 operative procedures, including three Jehovah's Witnesses who underwent five procedures. Etiologies of thrombocytopenia included mild ITP (not on romiplostim at baseline), liver disease, hematologic malignancy, and drug-related thrombocytopenia. Median PLT count at romiplostim initiation was 47 × 10(9) /L (range, 11 × 10(9) -120 × 10(9) /L). All patients experienced a PLT count increase over a median of 4 weeks; median PLT count at surgery was 144 × 10(9) /L (range, 28 × 10(9) -370 × 10(9) /L). PLT counts increase to more than 150 × 10(9) /L in four of five Jehovah's Witness patients by the time of surgery. There were no surgical delays or cancellations due to thrombocytopenia. Four bleeding events occurred; none were fatal and none occurred at a PLT count of fewer than 80 × 10(9) /L. No definitive thromboembolic events occurred.

CONCLUSION

Romiplostim successfully increased preoperative PLT counts allowing operative interventions, was well tolerated, did not lead to any significant thromboembolic events, and avoided the need for transfusion. Romiplostim may be of clinical utility in the preoperative management of thrombocytopenic patients, especially those unable to receive or unresponsive to PLT transfusion.

Big spleens and hypersplenism: fix it or forget it?

Hypersplenism is a common manifestation of portal hypertension in the cirrhotic. More than half of cirrhotics will have low platelet counts, but neutropenia is much less common. Despite being common in the cirrhotic population, the presence of hypersplenism is of little clinical consequence. The presence of hypersplenism suggests more advanced liver disease and an increase in risk of complications, but there is no data showing that correcting the hypersplenism improves patient survival. In most series, the most common indications for treating the hypersplenism is to increase platelet and white blood cell counts to allow for use of drugs that suppress the bone marrow such as interferon alpha and chemotherapeutic agents. There are several approaches used to treat hypersplenism. Portosystemic shunts are of questionable benefit. Splenectomy, either open or laparoscopically, is the most effective but is associated with a significant risk of portal vein thrombosis. Partial splenic artery embolization and radiofrequency ablation are effective methods for treating hypersplenism, but counts tend to fall back to baseline long-term. Pharmacological agents are also effective in increasing platelet counts. Development of direct acting antivirals against hepatitis C will eliminate the most common indication for treatment. We lack controlled trials designed to determine if treating the hypersplenism has benefits other than raising the platelet and white blood cell counts. In the absence of such studies, hypersplenism in most patients should be considered a laboratory abnormality and not treated, in other words forget it.

Coagulopathy in liver disease: a balancing act

Liver disease results in complex alterations of all 3 phases of hemostasis. It is now recognized that hemostasis is rebalanced in chronic liver disease. The fall in clotting factor levels is accompanied by a parallel fall in anticoagulant proteins. High von Willebrand factor levels counteract defects in primary hemostasis. Conventional coagulation tests do not fully reflect the derangement in hemostasis and do not accurately predict the risk of bleeding. Global coagulation assays (thrombin generation, thromboelastography) reflect the interaction between procoagulant factors, anticoagulant factors, platelets, and the fibrinolytic system and show promise for assessing bleeding risk and guiding therapy. These assays are not yet commercially approved or validated. Prevention of bleeding should not be aimed at correcting conventional coagulation tests. Thrombopoietin receptor agonists were shown to increase the platelet count in cirrhotic patients undergoing invasive procedures but may increase the risk of thrombosis. Rebalanced hemostasis in liver disease is precarious and may be tipped toward hemorrhage or thrombosis depending on coexisting circumstantial risk factors. Bacterial infection may impair hemostasis in cirrhosis by triggering the release of endogenous heparinoids. There are no evidence-based guidelines for hemostatic therapy of acute hemorrhage in liver disease. There is currently inadequate evidence to support the use of recombinant FVIIa, prothrombin complex concentrates, or tranexamic acid in acute variceal or other hemorrhage.

Use of eltrombopag in thrombocytopenia of liver disease

Second generation thrombopoietin agonists including eltrombopag and romiplostim act on the thrombopoietin receptor to increase the megakaryocyte production. These agents were needed as use of first generation recombinant products was associated with formation of autoantibodies. Eltrombopag is an oral thrombopoietin agonist found effective in raising platelet counts in patients with immune thrombocytopenia. The drug has now been found to be useful in raising platelet counts in thrombocytopenia related to liver disease including cirrhosis and chronic viral hepatitis. Although the drug may help enable adequate interferon therapy in patients with HCV infection and help carry out invasive procedures in patients with cirrhosis, concerns have been raised of possible thrombotic complications including portal vein thrombosis. Randomized trials have shown that use of eltrombopag concomitant with pegylated interferon and ribavirin increased the chances of sustained virologic response while decreasing the dose reductions of interferon. The data on use of romiplostim in these clinical indications is also emerging. However, in the future, availability of interferon free regimens is likely to decrease the use of eltrombopag for enabling antiviral therapy. The review discusses the role of eltrombopag in management of liver disease related thrombocytopenia in wake of recent data as also the dosage, precautions and adverse effects associated with its use.

Romiplostim treatment allows for platelet transfusion-free liver transplantation in pediatric thrombocytopenic patient with primary sclerosing cholangitis

Thrombocytopenia is a major risk factor for cirrhotic liver disease. Patients with thrombocytopenia may have esophageal or gastric varices secondary to portal hypertension, leading to variceal bleeding which exposes the liver to further damage. Here, we present a female pediatric patient with PSC and CD, whose progressive thrombocytopenia was successfully controlled by romiplostim, a TPO receptor agonist. The patient developed bloody diarrhea at four yr of age, and was subsequently diagnosed with PSC and CD when seven yr old. While CD was well-controlled by immunomodulators, the patient's thrombocytopenia gradually progressed resulting in petechiae (platelet count of 11 × 10(9) /L) when she was 10 yr and four months old. She responded poorly to immunoglobulin and corticosteroids. Weekly subcutaneous injection of romiplostim was therefore initiated, and platelet counts were maintained over at 50 × 10(9) /L. She was able to undergo successful LDLT without platelet transfusion seven months after the initiation of romiplostim. Romiplostim was not required after LDLT with improved platelet counts. This case report suggests that romiplostim may be effective in the treatment of thrombocytopenic children with liver cirrhosis and portal hypertension, and in eliminating the need for platelet transfusion during the peri-transplant period.

Management of thrombocytopenia due to liver cirrhosis: A review

Thrombocytopenia is a common complication in liver disease and can adversely affect the treatment of liver cirrhosis, limiting the ability to administer therapy and delaying planned surgical/diagnostic procedures because of an increased risk of bleeding. Multiple factors, including splenic sequestration, reduced activity of the hematopoietic growth factor thrombopoietin, bone marrow suppression by chronic hepatitis C virus infection and anti-cancer agents, and antiviral treatment with interferon-based therapy, can contribute to the development of thrombocytopenia in cirrhotic patients. Of these factors, the major mechanisms for thrombocytopenia in liver cirrhosis are (1) platelet sequestration in the spleen; and (2) decreased production of thrombopoietin in the liver. Several treatment options, including platelet transfusion, interventional partial splenic embolization, and surgical splenectomy, are now available for severe thrombocytopenia in cirrhotic patients. Although thrombopoietin agonists and targeted agents are alternative tools for noninvasively treating thrombocytopenia due to liver cirrhosis, their ability to improve thrombocytopenia in cirrhotic patients is under investigation in clinical trials. In this review, we propose a treatment approach to thrombocytopenia according to our novel concept of splenic volume, and we describe the current management of thrombocytopenia due to liver cirrhosis.

Contemporary treatment of immune thrombocytopenia

Immune thrombocytopenia is an autoimmune-mediated disorder and the treatment strategies were directed mainly to suppression of the immune system or to removal of the spleen as a place of thrombocyte destruction. In last years, it was shown that other mechanisms are responsible for development of immune thrombocytopenia: reduced thrombocyte lifespan and ineffective marrow platelet production. New treatment strategies, such as thrombopoietin receptor agonists, were developed to overcome this mechanism. Still there are a difficult minority of patients unresponsive to multiple treatments, whose have severe bleeding and another group of patients with extensive morbidity from therapy, not restricted to steroids. In this review, focused on adult patients, we discuss newer results of therapies and consider newer treatment strategies.

Advances in megakaryocytopoiesis and thrombopoiesis: from bench to bedside

Megakaryocytopoiesis involves the commitment of haematopoietic stem cells, proliferation and terminal differentiation of megakaryocytic progenitors (MK-p) and maturation of megakaryocytes (MKs) to produce functional platelets. This complex process occurs in specialized niches in the bone marrow where MKs align adjacent to vascular endothelial cells, form proplatelet projections and release platelets into the circulation. Thrombopoietin (THPO, TPO) is the primary growth factor for the MK lineage and necessary at all stages of development. THPO is constitutively produced in the liver, and binds to MPL (c-Mpl) receptor on platelets and MKs. This activates a cascade of signalling molecules, which induce transcription factors to drive MK development and thrombopoiesis. Decreased turnover rate and platelet number result in increased levels of free THPO, which induces a concentration-dependent compensatory response of marrow-MKs to enhance platelet production. Newly developed thrombopoietic agents operating via MPL receptor facilitate platelet production in thrombocytopenic states, primarily immune thrombocytopenia. Other drugs are available for attenuating malignant thrombocytosis. Herein, we review the regulation of megakaryocytopoiesis and platelet production in normal and disease states, and the innovative drugs and therapeutic modalities to stimulate or decrease thrombopoiesis.