HCV-associated thrombocytopenia: clinical characteristics and platelet response after recombinant alpha2b-interferon therapy

Different impacts of common risk factors associated with thrombocytopenia in patients with hepatitis B virus and hepatitis C virus infection

BACKGROUND

Thrombocytopenia is a common extrahepatic manifestation in chronic liver disease. However, there have been rare studies of impacts of risk for hepatitis C virus-associated thrombocytopenia (HCV-TP) and hepatitis B virus-associated thrombocytopenia (HBV-TP). The aim of this study is to evaluate different impacts of risk factors for HCV-TP and HBV-TP.

MATERIAL AND METHODS

We retrospectively collected 1803 HCV patients and 1652 HBV patients to examine the risk factors for time to moderate and severe thrombocytopenia (platelet counts <100 × 10⁹/L and <50 × 10⁹/L, respectively) by Cox proportional hazards models. Moreover, we prospectively enrolled 63 HCV-TP patients, 11 HBV-TP patients, and 27 HCV controls to detect specific antiplatelet antibodies by enzyme-linked immunosorbent assay and analyze their effects.

RESULTS

Prevalence of platelet <100 × 10⁹/L was 11.86% and 6.35% in HCV and HBV patients without cancer history, respectively. HCV-to-HBV incidence rate ratio for thrombocytopenia was 6.95. Initial thrombocytopenia was the most significant risk factor for HCV-TP and HBV-TP regardless of thrombocytopenia severity. Splenomegaly and cirrhosis were significant risk factors for moderate, but not severe HCV-TP. Hyperbilirubinemia was an important moderate and severe HBV-TP risk factor. Antiplatelet antibodies were correlated with HCV-TP severity, of which anti-glycoprotein IIb/IIIa antibody being associated with smaller spleen size. This antiplatelet autoantibody might contribute thrombocytopenia either independently or with splenomegaly as the important risk in HCV-TP patients without advanced cirrhosis.

CONCLUSION

HCV was associated with higher thrombocytopenia incidence than HBV. Thrombocytopenia risk factors varied with virus type and severity. Different management for HCV-TP and HBV-TP was suggested.

Hepatitis C Virus Infection as a Predictor of Complications and Increased Costs Following Primary Lumbar Fusion Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to identify whether hepatitis C virus (HCV) diagnosis influences in-hospital lengths of stay (LOS), postoperative complications, readmission rates, or costs following primary posterior lumbar fusions in an elective setting.

SUMMARY OF BACKGROUND DATA

Although joint arthroplasty literature has shown increased complication rates and costs for patients seropositive with HCV without liver disease compared to those without HCV, this comorbidity has not been explored in the spine literature. To our knowledge, this is the first publication in the lumbar spine literature to solely focus on HCV as the disease burden.

METHODS

A national database was queried for patients who underwent primary lumbar spine fusion for degenerative lumbar pathology with Medicare insurance from 2005 to 2014. The 90-day postoperative complication rates, readmission rates, and treatment costs were queried. To limit confounding, HCV patients were matched with a control cohort of non-HCV patients using patient demographics, treatment modality, and comorbid conditions, and then analyzed by multivariate logistic regression. Patients with active liver disease were excluded to better isolate HCV as the comorbidity.

RESULTS

A cohort of 28,841 patients were included in the final analysis. Postoperatively, compared to those without HCV infection, those with HCV had significantly higher odds of blood transfusions (odds ratio [OR]: 3.06), pneumonia (OR: 2.49), respiratory failure (OR: 2.49), urinary tract infections (OR: 1.89), wound-/implant-related infections (OR: 1.74), cerebrovascular events (OR: 1.70), or any postoperative complication within 90 days (OR: 2.93; all P < 0.0001). Furthermore, HCV positive patients had higher day of surgery costs ($28,713.26 vs. $25,448.26, P < 0.0001) and 90-day costs ($33,447.39 vs. $29,016.77, P < 0.0001). There was not a significant difference for patients with HCV infection compared to those without in regard to hospital LOS (10 days vs. 8 days, P = 0.332) and rates of a 90-day readmission (0.37% vs. 0.22%; OR: 1.70, 95% confidence interval: 1.00-2.90, P: 0.050).

CONCLUSION

In patients undergoing primary lumbar fusion, a seropositivity for HCV without liver disease is associated with higher costs and complication rates, including higher rates of blood transfusion requirements and pneumonia-related complications. This data shed new light on elective spine surgery in HCV patients and may influence the risks and benefits considerations for surgeons considering lumbar fusion in this population.

LEVEL OF EVIDENCE

3.

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

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

Rapid increase of platelet counts during antiviral therapy in patients with hepatitis C virus infection

AIM

The cause of thrombocytopenia in patients with chronic hepatitis C virus (HCV) infection is multifactorial: hypersplenism, decreased thrombopoietin levels, and myelosuppression induced by HCV. Platelet counts increase after eradication of HCV; however, this mechanism is not fully understood. Therefore, the aim of this study was to determine the influence of these three factors on platelet counts.

METHODS

We retrospectively analyzed data from 109 HCV-infected patients with platelet counts ≤150 × 10³ /μL who achieved viral eradication using interferon-free anti-HCV therapy. Changes in hematological parameters, thrombopoietin levels, HCV titers, and spleen volumes, and the correlations among them were evaluated.

RESULTS

HCV RNA levels significantly decreased at 4 weeks after initiating antiviral therapy. Platelet counts rapidly increased at 4 weeks from baseline (120 ± 35 vs. 106 ± 28 × 10³ /μL, P < 0.001), and remained at a plateau until 48 weeks after initiating antiviral therapy. Neutrophil counts showed the same pattern. Spleen volume was evaluated in 32 patients and, among them, it decreased in 21 patients, but remained unchanged in seven and increased in four. In addition to patients with decreased spleen volume, patients with unchanged spleen volume showed marginally increased platelet counts. Thrombopoietin levels did not correlate with platelet counts.

CONCLUSIONS

Platelet counts increased at 4 weeks after starting anti-HCV treatment. Our results suggest that this rapid change was possibly caused by improvement of hypersplenism and HCV-induced myelosuppression resulting from anti-HCV therapy.

Thioacetamide-induced liver damage and thrombocytopenia is associated with induction of antiplatelet autoantibody in mice

Thrombocytopenia is usually associated with liver injury, elevated plasma aspartate aminotransferase and alanine aminotransferase levels, and high antiplatelet immunoglobulin (Ig) titers, although the mechanism behind these effects remains elusive. Deciphering the mechanism behind acute liver disease–associated thrombocytopenia may help solve difficulties in routine patient care, such as liver biopsy, antiviral therapy, and surgery. To determine whether liver damage is sufficient per se to elicit thrombocytopenia, thioacetamide (TAA)-induced hepatitis rodent models were employed. The analysis results indicated that TAA treatment transiently induced an elevation of antiplatelet antibody titer in both rats and mice. B-cell-deficient (BCD) mice, which have loss of antibody expression, exhibited markedly less thrombocytopenia and liver damage than wild-type controls. Because TAA still induces liver damage in BCD mice, this suggests that antiplatelet Ig is one of the pathogenic factors, which play exacerbating role in the acute phase of TAA-induced hepatitis. TNF-α was differentially regulated in wild-type versus BCD mice during TAA treatment, and anti-TNF treatment drastically ameliorated antiplatelet Ig induction, thrombocytopenia, and liver injury, suggesting that the TNF pathway plays a critical role in the disease progression.

Association between Aspartate Aminotransferase-to-Platelet Ratio Index and Hepatocellular Carcinoma Risk in Patients with Chronic Hepatitis: A Meta-Analysis of Cohort Study

Background and Aim

Aspartate aminotransferase-to-platelet ratio index (APRI) is widely used in the assessment of fibrosis and cirrhosis, especially in patients with chronic hepatitis. However, the prognostic value of APRI in patients with chronic hepatitis with regard to the prediction of hepatocellular carcinoma (HCC) occurrence remains controversial. The objective of this meta-analysis is to investigate the association between APRI and HCC risk on the basis of cohort studies.

Methods

We systematically reviewed PubMed, EMBASE, Web of Science, and Chinese National Knowledge Infrastructure databases for relevant cohort studies up to May 1, 2019. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for total and subgroup analyses were calculated with Stata 12.0 software for the assessment of the relationship between APRI and HCC risk.

Results

A total of 13 studies, involving 8897 patients, were included in the meta-analysis, of which 11 explored the association between pretreatment APRI and HCC risk and four reported the relationship between posttreatment APRI and HCC risk. Pooled results showed that an elevated level of pretreatment APRI was associated with increased HCC risk (HR = 2.56, 95% CI: 1.78–3.68). When stratified by hepatitis type, high pretreatment APRI predicted HCC development in patients with chronic hepatitis B (CHB) and C (CHC) but not in alcoholic liver cirrhosis (ALC). In the subgroup analyses of study region, cut-off value, sample size, and analysis method, the relationship between high pretreatment APRI and increased HCC risk was significant. Meanwhile, patients with a high level of posttreatment APRI suffered from high HCC risk (HR = 3.69, 95% CI: 2.52–5.42). Conclusion: Results revealed a significant association between elevated APRI and HCC development in patients with chronic hepatitis, suggesting that APRI might serve as a valuable predictor for HCC risk in patients with chronic hepatitis.

Platelets as Modulators of Liver Diseases

Platelets are key players in thrombosis and hemostasis. Alterations in platelet count and function are common in liver disease, and may contribute to bleeding or thrombotic complications in liver diseases and during liver surgery. In addition to their hemostatic function, platelets may modulate liver diseases by mechanisms that are incompletely understood. Here, we present clinical evidence for a role of platelets in the progression of chronic and acute liver diseases, including cirrhosis, acute liver failure, and hepatocellular carcinoma. We also present clinical evidence that platelets promote liver regeneration following partial liver resection. Subsequently, we summarize studies in experimental animal models that support these clinical observations, and also highlight studies that are in contrast with clinical observations. The combined results of clinical and experimental studies suggest that platelets may be a therapeutic target in the treatment of liver injury and repair, but the gaps in our understanding of mechanisms involved in platelet-mediated modulation of liver diseases call for caution in clinical application of these findings.

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.

Metabolic Dysregulation in Hepacivirus Infection of Common Marmosets (Callithrix jacchus)

Chronic hepatitis C has been associated with metabolic syndrome that includes insulin resistance, hepatic steatosis and obesity. These metabolic aberrations are risk factors for disease severity and treatment outcome in infected patients. Experimental infection of marmosets with GBV-B serves as a tangible, small animal model for human HCV infection, and while virology and pathology are well described, a full investigation of clinical disease and the metabolic milieu is lacking. In this study six marmosets were infected intravenously with GBV-B and changes in hematologic, serum biochemical and plasma metabolic measures were investigated over the duration of infection. Infected animals exhibited signs of lymphocytopenia, but platelet and RBC counts were generally stable or even increased. Although most animals showed a transient decline in blood glucose, infection resulted in several fold increases in plasma insulin, glucagon and glucagon-like peptide 1 (GLP-1). All infected animals experienced transient weight loss within the first 28 days of infection, but also became hypertriglyceridemic and had up to 10-fold increases in adipocytokines such as resistin and plasminogen activator inhibitor 1 (PAI-1). In liver, moderate to severe cytoplasmic changes associated with steatotic changes was observed microscopically at 168 days post infection. Collectively, these results suggest that GBV-B infection is accompanied by hematologic, biochemical and metabolic abnormalities that could lead to obesity, diabetes, thrombosis and atherosclerosis^, even after virus has been cleared. Our findings mirror those found in HCV patients, suggesting that metabolic syndrome could be conserved among hepaciviruses, and both mechanistic and interventional studies for treating HCV-induced metabolic complications could be evaluated in this animal model.

Dynamic α-fetoprotein, platelets and AST-to-platelet ratio index predict hepatocellular carcinoma in chronic hepatitis C patients with sustained virological response after antiviral therapy

BACKGROUND

Hepatitis C virus (HCV)-infected patients who achieve viral eradication may still develop hepatocellular carcinoma (HCC). Little is known about the impact of dynamic change of serum markers on HCC development.

METHODS

We enrolled 1351 HCV-infected patients who achieved sustained virological response (SVR). Laboratory data were collected at least 1 year after IFN-based therapy and to the latest follow-up. Data on α-fetoprotein (AFP) were obtained >6 months prior to HCC development to exclude HCC-related AFP elevation.

RESULTS

HCC developed in 49 patients. Risk factors for HCC in SVR patients were old age, liver cirrhosis, higher pre- and post-treatment AFP and high post-treatment AST-to-platelet ratio index (APRI). Patients with pre-AFP ≥15 ng/mL → post-AFP ≥15 ng/mL (at 1 year, 23.1%; 5 years, 42.3%) and pre-AFP <15 ng/mL → post-AFP ≥15 ng/mL (at 1 year, 25%; 5 years, 50%) had the highest risk of HCC development, followed by pre-AFP ≥15 ng/mL → post-AFP <15 ng/mL (at 1 year, 5.2%; 5 years, 7.6%) and pre-AFP <15 ng/mL → post-AFP ng/mL <15 ng/mL (at 1 year, 0.5%; 5 years, 0.9%) (P < 0.001). The pattern was similar for platelets and APRI (P < 0.001). SVR patients with pre-APRI ≥0.7 → post-APRI ≥0.7 had the highest risk of HCC development, followed by comparable risks among the other three groups.

CONCLUSIONS

SVR patients with a persistently high AFP level (≥15 ng/mL) and a high APRI (≥0.7) before and after treatment had the highest incidence of HCC development. Patients with a reduction of AFP and APRI to the normal range after treatment had a markedly decreased risk of HCC. The risk was lowest for patients who kept persistently normal AFP and APRI before and after treatment.

The pathophysiology of thrombocytopenia in chronic liver disease

Thrombocytopenia is the most common hematological abnormality encountered in patients with chronic liver disease (CLD). In addition to being an indicator of advanced disease and poor prognosis, it frequently prevents crucial interventions. Historically, thrombocytopenia has been attributed to hypersplenism, which is the increased pooling of platelets in a spleen enlarged by congestive splenomegaly secondary to portal hypertension. Over the past decade, however, there have been significant advances in the understanding of thrombopoiesis, which, in turn, has led to an improved understanding of thrombocytopenia in cirrhosis. Multiple factors contribute to the development of thrombocytopenia and these can broadly be divided into those that cause decreased production, splenic sequestration, and increased destruction. Depressed thrombopoietin levels in CLD, together with direct bone marrow suppression, result in a reduced rate of platelet production. Thrombopoietin regulates both platelet production and maturation and is impaired in CLD. Bone marrow suppression can be caused by viruses, alcohol, iron overload, and medications. Splenic sequestration results from hypersplenism. The increased rate of platelet destruction in cirrhosis also occurs through a number of pathways: increased shear stress, increased fibrinolysis, bacterial translocation, and infection result in an increased rate of platelet aggregation, while autoimmune disease and raised titers of antiplatelet immunoglobulin result in the immunologic destruction of platelets. An in-depth understanding of the complex pathophysiology of the thrombocytopenia of CLD is crucial when considering treatment strategies. This review outlines the recent advances in our understanding of thrombocytopenia in cirrhosis and CLD.

Helicobacter pylori infection influences the severity of thrombocytopenia and its treatment response in chronic hepatitis B patients with compensatory cirrhosis: A multicenter, observational study

The role of Helicobacter pylori (H. pylori) infection on thrombocytopenia in chronic hepatitis B (CHB) related compensatory cirrhotic patients is unknown. We conducted an observational study to determine whether H. pylori plays a role in these patients. A total of 255 patients from three centers in China were enrolled in the study. All patients received nucleoside analogs (NA) therapy and were screened for H. pylori infection. Patients were divided into three groups based on their H. pylori infection status and the therapy administered: patients without H. pylori infection who received NA therapy alone (N = 146); patients with H. pylori infection who received NA therapy alone (n = 48); and patients with H. pylori infection who received H. pylori eradication combined with NA therapy (N = 61). We observed that in CHB compensatory cirrhotic patients with H. pylori infection, the platelets count was significantly lower relative to uninfected patients (31 versus 60 × 10(9)/L, p < 0.01). During a 2-year follow-up, the elevation in platelet count was significantly higher in HBV/H. pylori co-infected patients who received the NA and H. pylori eradication treatment compared to the other two groups (p < 0.01). It suggested that H. pylori infection and eradication treatment combined with NA were independent risk factors associated with platelets response during treatment of thrombocytopenia in CHB compensatory cirrhosis (p < 0.01). In conclusion, H. pylori infection may associate with thrombocytopenia in CHB compensatory cirrhosis. H. pylori eradication combined with NA treatment may prove to be beneficial to CHB compensatory cirrhotic patients with thrombocytopenia who are infected with H. pylori.

Non-cirrhotic thrombocytopenic patients with hepatitis C virus: Characteristics and outcome of antiviral therapy

BACKGROUND AND AIM

Thrombocytopenia is frequently observed in patients with chronic hepatitis C virus (HCV) infection and cirrhosis, although it can also be observed in patients without cirrhosis by a virus-mediated phenomenon. This study assessed the prevalence, characteristics, and outcomes of antiviral therapy in patients with chronic HCV infection and thrombocytopenia not associated with cirrhosis.

METHODS

The study included 1268 patients with HCV infection and thrombocytopenia enrolled in the phase 3 ENABLE studies that assessed the impact of eltrombopag on achieving a sustained virologic response to pegylated interferon and ribavirin. The study population was subdivided according to baseline FibroSURE test results into patients with non-cirrhosis (FibroSURE < 0.4) and cirrhosis-related (FibroSURE ≥ 0.75) thrombocytopenia.

RESULTS

Compared with patients with cirrhosis-related thrombocytopenia (n = 995; 78.5%), non-cirrhotic patients with thrombocytopenia (n = 59; 4.6%) were younger (mean age [95% confidence interval (CI)]: 43.9 [40.7-47.2] vs 52.7 [52.2-53.3] years; P < 0.0001), predominantly female (64% [51-76] vs 30% [27-33]; P < 0.0001), and less frequently had a Model for End-Stage Liver Disease score ≥ 10 (24% [14-37] vs 45% [42-49]; P = 0.0012), low albumin levels (≤ 35 g/L; 2% [0-9] vs 32% [29-35]; P < 0.0001), and prevalence of diabetes mellitus (3% [0-12] vs 21% [19-24]; P = 0.0005). The sustained virologic response rate was higher in non-cirrhotic patients with thrombocytopenia (46% [95% CI, 33-59] vs 16% [14-18]; P < 0.0001).

CONCLUSIONS

Patients with thrombocytopenia associated with HCV who have lower FibroSURE test results may have better preserved liver function and higher sustained virologic response rates than patients with cirrhosis.

The effect of antiviral therapy on hepatitis C virus-related thrombocytopenia: a case report

Background

Autoimmune thrombocytopenic purpura is an immunological disorder characterized by increased platelet destruction due to presence of anti-platelet autoantibodies. Hepatitis C virus infection, which is one of the most common chronic viral infections worldwide, may cause secondary chronic immune thrombocytopenic purpura.

Case presentation

We report a case of a 51-year-old Caucasian female with hepatitis C virus infection who developed a severe, reversible, immune thrombocytopenia. Platelet count was as low as 56.000/mm³, hepatitis C virus serology was positive, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and gamma-glutamyltransferase serum levels were elevated. Disorders potentially associated with autoimmune thrombocytopenic purpura were ruled out. A corticosteroid treatment was started and led to an increase in platelet count. The patient was then treated with pegylated-interferon alpha 2a and ribavirin. After four weeks of treatment hepatitis C virus - ribonucleic acid became undetectable and steroid treatment was discontinued. Six months of antiviral therapy achieved a sustained biochemical and virological response together with persistence of normal platelet count.

Conclusion

In our case report hepatitis C virus seemed to play a pathogenic role in autoimmune thrombocytopenic purpura. Moreover, the successful response (negative hepatitis C virus - ribonucleic acid) to tapered steroids and antiviral therapy was useful to revert thrombocytopenia.

Immunological alterations in hepatitis C virus infection

A higher prevalence of immunological processes has recently been reported in patients with hepatitis C virus (HCV) infection, focusing the attention of physicians and researchers on the close association between HCV and immune disorders. HCV lymphotropism represents the most important step in the pathogenesis of virus-related immunological diseases and experimental, virologic, and clinical evidence has demonstrated a trigger role for HCV both in systemic autoimmune diseases, such as rheumatoid arthritis, Sjögren syndrome, hemolytic anemia and severe thrombocytopenia, and in organ-specific autoimmune diseases, such as autoimmune hepatitis, thyroid disorders and diabetes. This review will outline the principal aspects of such HCV-induced immunological alterations, focusing on the prevalence of these less characterized HCV extrahepatic manifestations.

The role of eltrombopag in the management of hepatitis C virus-related thrombocytopenia

Eltrombopag is a 2nd generation thrombopoietin-receptor agonist. It binds with the thrombopoietin-receptors found on the surfaces of the megakaryocytes & increases platelet production. Many recent studies have suggested a potential role for this novel agent in the treatment of thrombocytopenia associated with hepatitis-C infection. Studies have shown that adjunct treatment with Eltrombopag can help avoid dose reductions/withdrawals of pegylated interferon secondary to thrombocytopenia. It may also have a role in priming up platelet levels to help initiate antiviral therapy. Similarly, chronic liver disease patients with thrombocytopenia who need to undergo an invasive procedure may be potential candidates for short two-week courses of eltrombopag in the periprocedural period to help reduce the risk of bleeding. Besides the price (deemed very expensive and probably not cost-effective), there are some legitimate concerns about the safety profile of this novel agent (most importantly, portal vein thrombosis, bone marrow fibrosis and hepatotoxicity). In this article, the potential role of eltrombopag in the context of hepatitis C virus (HCV)-related thrombocytopenia is reviewed. To write this article, a MEDLINE search was conducted (1990 to November 2012) using the search terms “eltrombopag,” “HCV,” and “thrombocytopenia.”

Immunological HCV-associated thrombocytopenia: short review

Infection with Hepatitis C virus (HCV) is affecting about 3% of the world's population, leading to liver damage, end-stage liver disease, and development of hepatocellular carcinoma, being thus the first indication for liver transplantation in the USA. Apart from the cirrhotic-liver-derived clinical signs and symptoms several conditions with immunological origin can also arise, such as, glomerulonephritis, pulmonary fibrosis, and thrombocytopenia. HCV-related autoimmune thrombocytopenia shows specific pathogenetic characteristics as well as symptoms and signs that differ in severity and frequency from symptoms in patients that are not HCV infected. Aim of this short paper is to estimate the epidemiological characteristics of the disease, to investigate the pathogenesis and clinical manifestation, and to propose treatment strategies according to the pertinent literature.

Factors linked to severe thrombocytopenia during antiviral therapy in patients with chronic hepatitis c and pretreatment low platelet counts

BACKGROUND

Baseline low platelet count (< 150,000/μL) increases the risk of on-treatment severe thrombocytopenia (platelet count < 50,000/μL) in patients with chronic hepatitis C (CHC) undergoing antiviral therapy, which may interrupt treatment. The purpose of this study was to identify risk factors for severe thrombocytopenia during treatment for CHC in patients with baseline thrombocytopenia.

METHODS

Medical records were reviewed for 125 patients with CHC treated with antiviral therapy according to the standard of care, with regular follow-up examinations. Early platelet decline was defined as platelet decrease during the first 2 weeks of therapy.

RESULTS

Severe thrombocytopenia developed in 12.8% of patients with baseline thrombocytopenia, and predicted a higher therapeutic dropout rate. Multivariate analysis revealed baseline platelet count < 100,000/μL and rapid early platelet decline (> 30% decline in the first 2 weeks) were significantly associated with severe thrombocytopenia (P < 0.001 and 0.003, odds ratios, 179.22 and 45.74, respectively). In these patients, baseline PLT ≥ 100,000/μL and lack of rapid early platelet decline predicted absence of severe thrombocytopenia (negative predictive values were 95.1% and 96.6%, respectively). In contrast, baseline platelet count < 100,000/μL combined with rapid early platelet decline predicted severe thrombocytopenia (positive predictive value was 100%).

CONCLUSIONS

For patients with CHC on antiviral therapy, baseline platelet counts < 100,000/μL and rapid early platelet decline can identify patients at high risk of developing on-treatment severe thrombocytopenia.

Patients with liver cirrhosis suffer from primary haemostatic defects? Fact or fiction?

Patients with cirrhosis can have abnormalities in laboratory tests reflecting changes in primary haemostasis, including bleeding time, platelet function tests, markers of platelet activation, and platelet count. Such changes have been considered particularly relevant in the bleeding complications that occur in cirrhosis. However, several studies have shown that routine diagnostic tests, such as platelet count, bleeding time, PFA-100, thromboelastography are not clinically useful to stratify bleeding risk in patients with cirrhosis. Moreover, treatments used to increase platelet count or to modulate platelet function could potentially do harm. Consequently the optimal management of bleeding complications is still a matter of discussion. Moreover, in the last two decades there has been an increased recognition that not only bleeding but also thrombosis complicates the clinical course of cirrhosis. Thus, we performed a literature search looking at publications studying both qualitative and quantitative aspects of platelet function to verify which primary haemostasis defects occur in cirrhosis. In addition, we evaluated the contribution of qualitative and quantitative aspects of platelet function to the clinical outcome in cirrhosis and their therapeutic management according to the data available in the literature. From the detailed analysis of the literature, it appears clear that primary haemostasis may not be defective in cirrhosis, and a low platelet count should not necessarily be considered as an automatic index of an increased risk of bleeding. Conversely, caution should be observed in patients with severe thrombocytopenia where its correction is advised if bleeding occurs and before invasive diagnostic and therapeutic procedures.

Immune thrombocytopenia: no longer 'idiopathic'

Immune thrombocytopenia (ITP) is a common hematologic disorder. Its pathogenesis involves both accelerated platelet destruction and impaired platelet production. First-line agents are usually effective initially but do not provide long-term responses. Splenectomy remains an effective long-term therapy, as does rituximab (Rituxan) in a subset of patients. Thrombopoietic agents offer a new alternative, although their place in the overall management of ITP remains uncertain.

Hepatitis C virus infection among patients with chronic immune thrombocytopenic purpura in northern India

BACKGROUND

Hepatitis C virus (HCV) has been reported to be associated with the occurrence of autoimmune disorders, including immune thrombocytopenic purpura (ITP). This has suggested that HCV could be responsible for thrombocytopenia in these patients. This study was performed to estimate the frequency of HCV infection in patients of chronic ITP (cITP), and to find the frequency of thrombocytopenia in chronic HCV infection.

MATERIALS

A total of 150 subjects were included in the study. Fifty consecutive adult patients with cITP (< 6 months' duration) and 50 age-matched patients with chronic HCV were included for comparison of platelet counts in two groups. Fifty age-matched healthy subjects were also included in the control group. All patients' sera were tested for the presence or absence of HCV-RNA. Anti-HCV antibodies were tested in patients as well as in controls. Complete blood count and examination of peripheral blood smear were done followed by bone-marrow aspiration to confirm the diagnosis of ITP.

RESULTS

Three patients (6%) were tested positive for anti-HCV antibodies while no subject was positive in control group (P=0.24). The prevalence of severe thrombocytopenia (platelet counts <50,000/mL) was significantly higher in ITP patients compared with that in chronic HCV patients (P=0.0001). Thrombocytopenia occurred more frequently in patient with moderate to severe than mild stage of fibrosis (P=0.001).

CONCLUSION

In conclusion, thrombocytopenia in ITP patients was not associated with HCV infection. The prevalence of thrombocytopenia was more common and more severe in ITP patients when compared with that in patients with chronic HCV. Thrombocytopenia in chronic HCV patients was related to the stage of fibrosis and to the duration of HCV infection.

The American Society of Hematology 2011 evidence-based practice guideline for immune thrombocytopenia

Immune thrombocytopenia (ITP) is commonly encountered in clinical practice. In 1996 the American Society of Hematology published a landmark guidance paper designed to assist clinicians in the management of this disorder. Since 1996 there have been numerous advances in the management of both adult and pediatric ITP. These changes mandated an update in the guidelines. This guideline uses a rigorous, evidence-based approach to the location, interpretation, and presentation of the available evidence. We have endeavored to identify, abstract, and present all available methodologically rigorous data informing the treatment of ITP. We provide evidence-based treatment recommendations using the GRADE system in those areas in which such evidence exists. We do not provide evidence in those areas in which evidence is lacking, or is of lower quality--interested readers are referred to a number of recent, consensus-based recommendations for expert opinion in these clinical areas. Our review identified the need for additional studies in many key areas of the therapy of ITP such as comparative studies of "front-line" therapy for ITP, the management of serious bleeding in patients with ITP, and studies that will provide guidance about which therapy should be used as salvage therapy for patients after failure of a first-line intervention.

Use of thrombopoietic agents for the thrombocytopenia of liver disease

Thrombocytopenia can be a sign of advanced liver disease. This complicates the management of these patients, as patients with advanced liver disease frequently need therapeutic interventions, which are associated with an increased risk of bleeding. Thrombocytopenia may even be more pronounced in patients with hepatitis C virus (HCV) infection. This can limit current and future treatments for HCV, which remains based on interferon therapy, and this therapy can worsen thrombocytopenia. Thus, the ability to increase platelets to higher and safer levels would be desirable, but no treatment has yet been proven effective and safe in this setting. The small molecule thrombopoietin mimetic, eltrombopag, has demonstrated a dose-response increase in platelet counts in a phase II study in HCV patients without significant side effects, allowing initiation and completion of a 12-week course of pegylated interferon plus ribavirin in 36%, 53%, and 65% of patients receiving 30 mg, 50 mg, or 75 mg eltrombopag daily, respectively, compared to only 6% in the placebo arm. A current phase III study is currently evaluating whether this treatment allows successful outcomes and sustained viral eradication.

Determination of ADAMTS13 and Its Clinical Significance for ADAMTS13 Supplementation Therapy to Improve the Survival of Patients with Decompensated Liver Cirrhosis

The liver plays a central role in hemostasis by synthesizing clotting factors, coagulation inhibitors, and fibrinolytic proteins. Liver cirrhosis (LC), therefore, impacts on both primary and secondary hemostatic mechanisms. ADAMTS13 is a metalloproteinase, produced exclusively in hepatic stellate cells, and specifically cleaves unusually large von Willebrand factor multimers (UL-VWFM). Deficiency of ADAMTS13 results in accumulation of UL-VWFM, which induces platelet clumping or thrombi under high shear stress, followed by sinusoidal microcirculatory disturbances and subsequent progression of liver injuries, eventually leading to multiorgan failure. The marked imbalance between decreased ADAMTS13 activity (ADAMTS13 : AC) and increased production of UL-VWFM indicating a high-risk state of platelet microthrombi formation was closely related to functional liver capacity, hepatic encephalopathy, hepatorenal syndrome, and intractable ascites in advanced LC. Some end-stage LC patients with extremely low ADAMTS13 : AC and its IgG inhibitor may reflect conditions similar to thrombotic thrombocytopenic purpura (TTP) or may reflect "subclinical TTP." Hence, cirrhotic patients with severe to moderate deficiency of ADAMTS13 : AC may be candidates for FFP infusion as a source of ADAMTS13 or for recombinant ADAMTS13 supplementation. Such treatments may improve the survival of patients with decompensated LC.

Synthesis and biological evaluation of oxoindolin-3-ylidene ethyl benzothiohydrazides as non-peptide TPO mimics

A novel series of oxoindolin-3-ylidene ethyl benzohydrazides were designed, synthesized, and identified as small molecule agonists of thrombopoietin (TPO) receptor c-mpl. Sulfur-oxygen exchange in oxoindolin-3-ylidene ethyl benzohydrazides was found to improve their agonistic activities. Several oxoindolin-3-ylidene ethyl benzothiohydrazides have been identified as full agonists of c-mpl.

Hepatitis C virus and autoimmunity

Hepatitis C virus infection is associated with several extrahepatic manifestations. About 60% of patients infected with HCV develop at least one extrahepatic manifestation. The majority of these diseases seem to be triggered through autoimmune mechanisms, such as autoantibody production, autoreactive T cells and complex autoimmune mechanisms leading to systemic autoimmune disorders. In this review we categorize these diseases into three groups according to the main pathogenetic process involved, in particular B-cell-mediated, T-cell-mediated and complex autoimmune systemic diseases.

Infectious causes of chronic immune thrombocytopenia

Persistent thrombocytopenia may be the consequence of chronic infections with hepatitis C virus (HCV), human immunodeficiency virus (HIV), and Helicobacter pylori, and should be considered in the differential diagnosis of primary immune thrombocytopenia (ITP). Studies have shown that on diagnosis of infections, treatment of the primary disease often results in substantial improvement or complete recovery of the thrombocytopenia. In patients with thrombocytopenia due to HCV-related chronic liver disease, the use of eltrombopag, a thrombopoietin receptor agonist, normalizes platelet levels, thereby permitting the initiation of antiviral therapy. Antiviral therapy with highly active antiretroviral therapy for HIV has aided in platelet recovery, with a corresponding decrease in circulating viral load. Thrombocytopenia in the absence of other disease symptoms requires screening for H. pylori, especially in countries such as Japan, where there is a high prevalence of the disease and the chances of a platelet response to eradication therapy are high.

Bone marrow biopsy in patients with hepatitis C virus infection: spectrum of findings and diagnostic utility

Patients with hepatitis C virus (HCV) infection develop a number of hematologic disorders, with benign and malignant B-cell proliferations being the most common. HCV-infected patients are also prone to developing peripheral cytopenias, the etiologies of which are multifactorial and include hypersplenism and/or antiviral medications. Some of these patients may undergo bone marrow biopsy but no study has systematically recorded the bone marrow findings in this patient group. Here, we report on the range of bone marrow findings in 47 adult HCV-infected patients. These patients, who lacked concurrent human immunodefiency virus (HIV) infection, most commonly presented for a bone marrow biopsy due to abnormal peripheral cell counts. The bone marrow biopsies displayed a range of findings. Dyserythropoiesis, present in 19% of the cases, was the most common finding. Patients with pancytopenia(n = 6), as defined by current World Health Organization standards, were the most likely to have bone marrow abnormalities; two pancytopenic patients had acute myeloid leukemia, and one patient had a primary myelodysplastic syndrome. There was no correlation in bone marrow findings and antiviral medications, MELD score, cirrhosis or splenomegaly, suggesting that the degree of bone marrow dysfunction is independent of stage of HCV. The results of this study suggest that bone marrow biopsy in HCV-infected patients, even those with features of hypersplenism and/or documented antiviral therapy, can be a valid test for hematologic evaluation, especially for patients with severe pancytopenia and/or sudden alterations in peripheral cell counts.

Thrombocytopenia and its Related Factors: A Hospital-based, Cross-sectional Study

Introduction: The objective of this study was to explore the association between thrombocytopenia and its related factors. Materials and Methods: This was a hospital-based, cross-sectional study. We retrospectively analysed the medical records of all patients who received periodic health examinations at a medical centre located at Taichung in Taiwan between 2000 and 2004. In all, 5585 subjects were included for further analysis. A complete physical examination, laboratory survey and abdominal ultrasonography were performed on each subject. The t-test, chi-square test and multivariate logistic regression analysis were used. Results: The subjects consisted of 3123 men (55.9%) and 2462 women (44.1%). The mean age was 49.4 ± 12.3 years (range, 20 to 87). The overall prevalence of thrombocytopenia was found to be 0.5%, higher in men than in women (0.6% vs 0.4%, P = 0.504). After controlling for the other covariates, multivariate logistic regression analysis exhibited that the factors significantly related to thrombocytopenia were increasing age (OR, 1.04; 95% CI, 1.004-1.08), anti-HCV positive (OR, 5.24; 95% CI, 2.08-13.20), liver cirrhosis (OR, 7.93; 95% CI, 2.28-27.62), and splenomegaly (OR, 18.86; 95% CI, 6.86-51.87). Conclusion: It is advisable to further check the hepatic status, if thrombocytopenia is noted. Key words: Hepatitis C, Liver cirrhosis, Splenomegaly, Thrombocytopenia

Considerations in the management of hepatitis C virus-related thrombocytopenia with eltrombopag

Thrombocytopenia is a common clinical problem in HCV-infected cases. Multiple studies have consistently shown a rise in platelet count following a successful HCV treatment thus proving a cause-effect relationship between the two. Although, many therapeutic strategies have been tried in the past to treat HCV-related thrombocytopenia (e.g. interferon dose reductions, oral steroids, intravenous immunoglobulins, splenectomy etc), the success rates have been variable and not always reproducible. After the cessation of clinical trials of PEG-rHuMGDF due to immunogenecity issues, the introduction of non-immunogenic second-generation thrombopoietin-mimetics (eltrombopag and Romiplostim) has opened up a novel way to treat HCV-related thrombocytopenia. Although the data is still sparse, eltrombopag therapy has shown to successfully achieve the primary endpoint platelet counts of >/=50,000/muL in phase II& III, randomized, double-blind, placebo-controlled trials. Likewise, though it is premature to claim safety of this drug especially in high-risk patient groups, reported side effects in the published literature were of insufficient severity to require discontinuation of the drug. Based on the current and emerging evidence, a review of the pharmacologic basis, pharmacokinetics, therapeutic efficacy, safety profile and future considerations of eltrombopag in the context of HCV-related thrombocytopenia is given in this article. A MEDLINE search was conducted (1990 to August 2009) using the search terms eltrombopag, HCV, thrombocytopenia.

Pathobiology and treatment of hepatitis virus-related thrombocytopenia

Thrombocytopenia is a well recognized complication of infections, including those from hepatotropic viruses. Thrombocytopenia may actually be the only manifestation of vital hepatitis, which should therefore be considered in the differential diagnosis of primary immune thrombocytopenia (ITP). The mechanisms of thrombocytopenia associated with viral hepatitis vary widely depending on the specific infectious agent and the severity of liver disease. Most of the studies have described thrombocytopenia in association with chronic hepatitis C virus (HCV) infection, the most common cause of chronic infection worldwide. Studies have shown that treatment of HCV infection often results in substantial improvement or complete recovery of the thrombocytopenia. In patients with thrombocytopenia associated with HCV-related chronic liver disease, the use of eltrombopag, a thrombopoietin receptor agonist, normalizes platelet levels thereby permitting the initiation of antiviral therapy.

Thrombocytopenia in Patients With Chronic Hepatitis C: A Possible Role of HCV on Platelet Progenitor Cell Maturation

A total of 30 patients with chronic hepatitis C (HCV) thrombocytopenia (TP) and 20 healthy controls were studied. Both groups were subjected to complete medical history, clinical examination in addition to assessment of hepatitis markers: level of thrombopoietin (Tpo), Geimsa-stained bone marrow smears, and in vitro short-term megakaryocytic progenitors culture (CFU-MK). Serum Tpo level was significantly elevated in patients with TP HCV. Short-term CFU-MK showed an evident depression in the colony-forming unit—megakaryocyte (CFU-meg). There is a positive correlation between the number of CFU-meg and the platelet count and between serum Tpo level and prothrombin time, transaminase, albumin, and the Child Pugh score of liver disease; a negative correlation between serum Tpo level and the number of CFU-meg and between serum Tpo level and the platelet count. Thus, the level of Tpo could be an indicator of intact functional response of the hepatocytes.

Therapeutic strategies for hepatitis- and other infection-related immune thrombocytopenias

Secondary thrombocytopenia may result from autoimmune diseases, lymphoproliferative disorders, infections, myelodysplastic syndromes, common variable immunodeficiency, agammaglobulinemia, hypogammaglobulinemia, immunoglobulin A deficiency, and drugs. The presence of thrombocytopenia may result from chronic infections with hepatitis C virus (HCV), human immunodeficiency virus (HIV), and Helicobacter pylori and should be considered in the differential diagnosis of immune thrombocytopenic purpura (ITP). Studies have shown that upon diagnosis of infections, treatment of the primary disease allows for stabilization of platelet counts. Antiviral therapy with highly active antiretroviral therapy (HAART) for HIV has aided in platelet recovery with a corresponding decrease in circulating viral load. In some cases, the use of a thrombopoietin (TPO) agonist, eltrombopag, normalizes platelet levels in patients with these infections. Thrombocytopenia in the absence of other disease symptoms requires screening for H pylori, especially in regions where there is a high prevalence of the disease, such as in Japan, and in cases where platelets have normalized following eradication therapy. In other regions where these infections are not prevalent, such testing is controversial.

Role of growth factors and thrombopoietic agents in the treatment of chronic hepatitis C

Advanced liver disease and interferon-based treatment are both associated with varying degrees of cytopenia in patients with chronic hepatitis C. Growth factors to increase hemoglobin and neutrophils are commonly used in clinical practice, despite the absence of data to indicate benefits in terms of sustained viral response. Thrombocytopenia is observed frequently, is multi-factorial in etiology, and may result in significant limitations on interventional and therapeutic options. A small-molecule thrombopoietin mimetic, eltrombo-pag, has demonstrated a dose-response associated increase in platelet count in a phase 2 study, allowing initiation and completion of a 12-week course of peginterferon plus ribavirin in 36%, 53%, and 65% of patients receiving 30 mg, 50 mg, or 75 mg of eltrombopag daily, respectively, compared with 6% in the placebo arm. Phase 3 studies are currently evaluating whether initiating and maintaining antiviral therapy with eltrombopag will lead to an increase in sustained virologic response in chronic hepatitis C infection.

Cytomegalovirus can make immune thrombocytopenic purpura refractory

Immune thrombocytopenic purpura (ITP) is characterized by decreased platelet numbers secondary to platelet destruction and reduced platelet production. Even if the ITP persists, it typically responds to 'ITP-specific' therapies, such as intravenous immunoglobulin, steroids, intravenous anti-D, and splenectomy. Several reports, including our previous study, have implicated cytomegalovirus (CMV) in the pathogenesis of infrequent cases of ITP that were not severe in nature. A recent study from China suggested that CMV is the aetiology of some cases of acute ITP of childhood and may require different treatment. We report two adult and two paediatric patients with refractory, severe, symptomatic thrombocytopenia, who were diagnosed with ITP and found to have active CMV infection. Their presentations included fever, transaminitis, neutropenia, and atypical lymphocytosis, but in particular, treatment-refractory, severe ITP. Treatment with steroids appeared to worsen the CMV-ITP. All four cases showed improvement in platelet counts within two weeks of starting ganciclovir and cytogam and tapering steroids. Based on the four patients described here, we believe that, in certain cases, CMV infection will result in symptomatic, severe, refractory ITP, which may be indistinguishable from typical ITP. Eradication of CMV with antiviral therapy improved the ITP in these cases.

Autoimmune thrombocytopenia related to chronic hepatitis C virus infection

Since the identification of hepatitis C virus (HCV) in 1989 as a causative agent for a number of the extrahepatic alterations related to HCV infection an underlying immune mediated pathogenetic mechanism has been postulated. HCV-associated thrombocytopenia may be considered complex and multifactorial in origin, since different mechanisms have been implicated in its pathophysiology. With respect to autoimmune thrombocytopenia in chronic HCV infection, the detection of specific antibodies against platelet glycoproteins have been reported only in a few studies, but no systematic study has been carried out. We examined the clinical, laboratory, and virological characteristics of a case series of 10 patients with autoimmune thrombocytopenia (platelet count <150.0 x 10(9)/L) related to chronic HCV infection. Cases, six males and four females, aged 57.1 +/- 12.6 years, presented high titers of antibodies against platelet glycoprotein (GP) IIb/IIIa, GP Ia/IIa, and/or GP Ib/IX, and no other mechanism involved in the pathogenesis of HCV-associated thrombocytopenia was identified. Furthermore, cases were not associated with particular HCV genotype. Complete platelet response was observed in two patients treated with pegylated interferon plus ribavirin, and partial platelet response was seen in two patients treated with anti-D Ig and one patient treated with corticosteroids. These findings indicate that an autoimmune mechanism may play a role in the pathogenesis of HCV-associated thrombocytopenia in a proportion of these patients.

Risk of immune thrombocytopenic purpura and autoimmune hemolytic anemia among 120 908 US veterans with hepatitis C virus infection

BACKGROUND

There is emerging evidence that hepatitis C virus (HCV) infection play a role in the etiology of immune thrombocytopenia purpura (ITP) and autoimmune hemolytic anemia (AIHA), both of which are severe autoimmune cytopenias.

METHODS

To determine if HCV infection increases the risk for ITP and AIHA, we calculated the incidence rates of ITP and AIHA among 120 691 HCV-infected and 454 905 matched HCV-uninfected US veterans who received diagnoses during the period 1997 to 2004. After excluding individuals with a prior diagnosis of a lymphoproliferative disease, human immunodeficiency virus, or cirrhosis, we fitted Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) as measures of risks.

RESULTS

We found 296 ITP and 90 AIHA cases. Among HCV-infected vs HCV-uninfected persons, the overall incidence rates of ITP were 30.2 and 18.5 per 100 000 person-years, and for AIHA they were 11.4 and 5.0 per 100 000 person-years, respectively. Hepatitis C virus was associated with elevated risks for ITP (HR, 1.8; 95% CI, 1.4-2.3) and AIHA (HR, 2.8; 95% CI, 1.8-4.2). The ITP incidence was increased among both untreated and treated HCV-infected persons (HR, 1.7; 95%, CI, 1.3-2.2 and HR, 2.4; 95% CI, 1.5-3.7, respectively), whereas AIHA incidence was elevated only among treated HCV-infected persons (HR, 11.6; 95% CI, 7.0-19.3).

CONCLUSIONS

Individuals infected with HCV are at an increased risk for ITP, whereas the development of AIHA seems to be associated with HCV treatment. It may be beneficial to test individuals newly diagnosed as having ITP for HCV infection.

Severe autoimmune cytopenias in treatment-naive hepatitis C virus infection: clinical description of 16 cases

OBJECTIVE

To describe the prevalence, main characteristics, and treatment of severe autoimmune cytopenias [autoimmune hemolytic anemia (AIHA), autoimmune thrombocytopenic purpura (AITP)] in patients with chronic hepatitis C virus (HCV) infection.

METHODS

Retrospective chart review of patients with chronic HCV infection seen at our institution. Two additional departments contributed eight more patients to assess therapy of HCV-related autoimmune cytopenias.

RESULTS

Eight patients (seven AITP, one AIHA) fulfilled the inclusion criteria in our population of 4345 HCV-infected patients. The number of patients with AITP was much greater than would be expected by chance (P<0.0001). Patients with HCV-related AITP were older and demonstrated more immunological markers than a group of 40 controls. Eight additional patients (six AITP, two Evans syndrome) were included. We only assessed the response for AITP patients because of the single case of AIHA. Patients with AITP had a poor response to initial corticosteroids [one complete response (CR), three partial response (PR), and four failures]. Intravenous immunoglobulins led to transient efficacy in three of four patients. In second-line therapy, five of seven patients responded to splenectomy. Rituximab proved effective in increasing platelets in two patients. Of eight patients treated with antiviral therapy (IFN-alpha+/-ribavirin), five responded (three CR, two PR).

CONCLUSION

AITP occurs more commonly in patients with chronic HCV infection than would be expected by chance. HCV-positive AITP requires a treatment strategy different from that used in HCV-negative AITP. On the basis of the results from our study and a literature analysis, we propose an algorithm for treatment of severe HCV-related autoimmune cytopenias.

Thrombocytopenia associated with chronic liver disease

Thrombocytopenia (platelet count <150,000/microL) is a common complication in patients with chronic liver disease (CLD) that has been observed in up to 76% of patients. Moderate thrombocytopenia (platelet count, 50,000/microL-75,000/microL) occurs in approximately 13% of patients with cirrhosis. Multiple factors can contribute to the development of thrombocytopenia, including splenic platelet sequestration, bone marrow suppression by chronic hepatitis C infection, and antiviral treatment with interferon-based therapy. Reductions in the level or activity of the hematopoietic growth factor thrombopoietin (TPO) may also play a role. Thrombocytopenia can impact routine care of patients with CLD, potentially postponing or interfering with diagnostic and therapeutic procedures including liver biopsy, antiviral therapy, and medically indicated or elective surgery. Therapeutic options to safely and effectively raise platelet levels could have a significant effect on care of these patients. Several promising novel agents that stimulate TPO and increase platelet levels, such as the oral platelet growth factor eltrombopag, are currently in development for the prevention and/or treatment of thrombocytopenia. The ability to increase platelet levels could significantly reduce the need for platelet transfusions and facilitate the use of interferon-based antiviral therapy and other medically indicated treatments in patients with liver disease.

Other immune thrombocytopenias

Immune thrombocytopenic purpura (ITP) can be classified as primary (known also as idiopathic thrombocytopenic purpura) or as secondary to an underlying condition such as a malignant or nonmalignant disorder. Commonly occurring conditions associated with secondary ITP include lymphoproliferative disorders (chronic lymphocytic leukemia [CLL], Hodgkin's disease and non-Hodgkin's lymphomas), autoimmune collagen vascular diseases (systemic lupus erythematosus [SLE], thyroid disease, antiphospholipid syndrome [APS]), and chronic infections (human immunodeficiency virus [HIV], Helicobacter pylori, hepatitis C virus [HCV]). The mechanism of platelet destruction in thrombocytopenias associated with lymphoproliferative disorders and collagen vascular diseases is identical to the autoimmune mechanism seen in primary ITP. Drug-induced thrombocytopenias are uncommon and generally resolve quickly upon drug discontinuation, but are often attributed to other causes. Platelet destruction in infection-associated ITP occurs via various mechanisms including accelerated platelet clearance due to immune complex disease as seen in HIV infection or cross-reactivity of anti-platelet glycoprotein antibodies and viral antigens in HIV, HCV, and H pylori infections (antigenic mimicry). In patients with HCV-related cirrhotic liver disease, splenic sequestration secondary to portal hypertension and decreased production of thrombopoietin may further contribute to development of thrombocytopenia. The current treatment paradigm for secondary ITP varies according to the underlying condition. Standard treatments for primary ITP (corticosteroids, IVIG, anti-D, splenectomy) are often successful in secondary ITP. In cases of ITP with H pylori and HCV infection, treatment should focus on the underlying disorder.

Overwhelming postsplenectomy infection syndrome in adults - A clinically preventable disease

Overwhelming postsplenectomy infection (OPSI) syndrome is a rare condition, but is associated with high mortality. However, recognition and clinical management of OPSI is not well established. The prevalence of splenectomy increased recently because it was a clinically effective treatment for hepatitis C virus-associated thrombocytopenia before the introduction of the interferon/ribavirin combination therapy. We reviewed the literature characterizing the clinicopathological features of OPSI and assessed the most effective and feasible administration of the condition. A Medline search was performed using the keywords 'overwhelming', 'postsplenectomy infection', 'postsplenectomy sepsis', 'chronic liver disease', and/or 'splenectomy'. Additional articles were obtained from references within the papers identified by the Medline search. Durations between splenectomy and onset of OPSI ranged from less than 1 wk to more than 20 years. Autopsy showed that many patients with OPSI also had Waterhouse-Friderichsen syndrome. Although the mortality rate from OPSI has been reduced by appropriate vaccination and education, the precise pathogenesis and a suitable therapeutic strategy remain to be elucidated. Protein energy malnutrition (PEM) is commonly observed in cirrhotic patients. Since the immune response in patients with PEM is compromised, a more careful management for OPSI should therefore be applied for cirrhotic patients after splenectomy. In addition, strict long-term follow up of OPSI patients including informed consent will lead to a better prognosis.

Viral-Associated Immune Thrombocytopenic Purpura

Chronic immune thrombocytopenic purpura (CITP) is a diagnosis of exclusion that occurs either de novo or secondary to other underlying disorders. Chronic infection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are now well-characterized causes of CITP. Between 6% and 15% of patients infected with HIV may develop thrombocytopenia. Patients with CITP with risk factors for HIV infection should be screened for the virus. Treatment of HIV-related CITP should be directed toward antiviral therapy with highly active antiretroviral therapy (HAART) regimens. Hepatitis C viral infection can also be associated with chronic thrombocytopenia, even in the absence of overt liver disease. While HCV-related thrombocytopenia is typically less severe than primary CITP, affected patients are at greater risk of major bleeding. Sustained suppression of HCV virus with interferon-ribavirin therapy can improve platelet counts. Screening for HCV infection should be considered in patients with ITP with risk factors for infection, from regions with high rates of infection or in patients with unexplained mild elevations of liver enzymes.

Review article: the pathophysiology of thrombocytopenia in hepatitis C virus infection and chronic liver disease

BACKGROUND

The pathophystology of thrombocytopenia in patients with chronic liver disease resulting from hepatitis C virus (HCV) infection is complex and involves several complementary mechanisms that likely act in concert.

AIM

To summarize the available data on the etiology of thrombocytopenia in patients with chronic liver disease.

RESULTS

In patients with untreated hepatitis C, both prevalence and severity of thrombocytopenia increase in parallel with the extent of disease, usually becoming clinically relevant when patients develop extensive fibrosis and/or cirrhosis. Pathogenetic mechanisms include hypersptenism secondary to portal hypertension, bone marrow suppression resulting from either HCV itself or interferon treatment, aberrations of the immune system resulting in the formation of anti-platelet antibodies and/or immune-complexes that bind to platelets and facilitate their premature clearance, development of immunologically-mediated extrahepatic manifestations including mixed cryoglobulinemia with or without associated joint, renal, or cutaneous involvement, and thrombopoietin (TPO) deficiency secondary to liver dysfunction. In chronic liver disease, the natural inverse relationship between TPO and platelet levels is not maintained; therefore, blood TPO levels fail to have clinical relevance or predictive value in assessing the thrombocytopenic status of a given patient.

CONCLUSIONS

The development of thrombocytopenisa in patients with chronic liver disease is complex and multifactorial.

Novel Thrombopoietic Agents

Thrombocytopenia is a primary manifestation of immune thrombocytopenic purpura (ITP) and may occur as a result of hepatitis C, malignancy, and treatment with chemotherapy. There is a need for additional means to treat thrombocytopenia in these settings. Recombinant thrombopoietin-like agents became available after the cloning of thrombopoietin in 1994. In clinical trials, these agents showed some efficacy in chemotherapy-induced thrombocytopenia, but their use was ultimately discontinued due to the development of neutralizing antibodies that cross-reacted with endogenous thrombopoietin and caused thrombocytopenia in healthy blood donors and other recipients. Subsequently, “second-generation” thrombopoietic agents without homology to thrombopoietin were developed. In the past 5 years, these second-generation thrombopoeitic growth factors have undergone substantial clinical development and have demonstrated safety, tolerability and efficacy in subjects with ITP and hepatitis C–related thrombocytopenia. These completed studies, many of which are available only in abstract form, and other ongoing studies suggest that thrombopoietic agents will enhance the hematologist’s ability to manage these and other causes of thrombocytopenia.

Autoimmune thrombocytopenia induced by PEG-IFN-alpha plus ribavirin in hepatitis C

Mild thrombocytopenia is a common adverse effect of interferon-alpha and pegylated interferon-alpha, largely ascribed to bone marrow suppression. Nevertheless, rare cases of autoimmune thrombocytopenia following standard or pegylated interferon treatment have been reported in the literature. In this report, we have presented a patient who developed an immune-mediated thrombocytopenia during the course of therapy with pegylated interferon/ribavirin for hepatitis C virus infection. After cessation of pegylated interferon/ribavirin treatment, thrombocytopenia was treated successfully with danazol and intravenous gamma-globulin.