Hepatitis C virus-related thrombocytopenia: clinical and laboratory characteristics compared with chronic immune thrombocytopenic purpura

Immune thrombocytopenia (ITP) - could it be part of autoimmune/inflammatory syndrome induced by adjuvants (ASIA)?

Immune thrombocytopenia (ITP) is a complex autoimmune disorder characterized by thrombocytopenia and an increased bleeding risk, arising from autoantibody-mediated platelet destruction and impaired megakaryocyte function. The pathogenesis of ITP involves a multifaceted interplay of genetic predispositions, immune dysregulation, and environmental triggers, though the precise mechanisms remain uncertain. Several infectious agents, mostly viruses, have been implicated in both acute and chronic ITP through mechanisms such as molecular mimicry, direct bone marrow suppression, and immune dysregulation. Vaccinations, particularly those containing adjuvants like aluminum and those capable of inducing molecular mimicry, have also been associated with ITP, either as a new onset or as a relapse in preexisting cases. The role of drugs, particularly quinine, quinidine and certain antibiotics, in inducing ITP through various immunological pathways further illustrates the diverse etiologies of this condition. The multiple triggers of the disease raise the question of whether ITP may be classified as an autoimmune/inflammatory syndrome induced by adjuvants (ASIA). This condition encompasses a range of autoimmune and inflammatory symptoms triggered by adjuvants, such as silicones, polypropylene meshes, metal implants, and mineral oils present in various medical materials and medications. Similar to that observed in some cases of ITP, adjuvants can trigger autoimmune or autoinflammatory responses via molecular mimicry, epitope spreading, and polyclonal activation. This narrative review explores the underlying environmental factors related to ITP and examines ITP triggers that could potentially support an association between ITP and ASIA syndrome.

Treatment outcomes and adherence to treatment in patients with immune thrombocytopenia in two Ethiopian teaching hospitals: a retrospective cohort study

The treatment of immune thrombocytopenia (ITP) is challenging and treatment outcomes depend on numerous unknown and patient-specific factors. Corticosteroids are the cornerstone of ITP treatment, but they are associated with many side effects. In this retrospective cohort study, treatment outcomes and treatment adherence in patients with ITP were investigated in 214 ITP patients from November 15, 2022 to March 15, 2023. Multinomial regression analysis models were used to identify predictive factors for treatment outcomes. A p value of less than 0.05 was considered statistically significant. Most study participants were female 161 (75.5%), and the majority 172 (80.4%) of them were taking prednisolone only. In terms of treatment adherence, 178 (83.2%) of the study participants adhered well to their ITP medications. The complete response rate at 3 months was 139 (65.0%). Predictive factors for partial response were increased negative impact of ITP on health-related quality of life (AOR = 1.221, 95% CI 1.096-1.360), being treated at Tikur Abessa Sepcialazed Hospital (AOR = 0.431, 95% CI 0.197-0.941) and the presence of heavy menstrual bleeding (AOR = 2.255, 95% CI 0.925-5.497) compared to patients with complete response. Hepatitis B virus-infected ITP patients (AOR = 0.052, 95% CI 0.004-0.621) were also a predictive factor for no response compared to complete response.

Recent advances in the management of immune thrombocytopenic purpura (ITP): A comprehensive review

Autoimmune disorders place a substantial burden on the healthcare system all over the world affecting almost 3% to 8% of the population. Immune thrombocytopenic purpura (ITP), also known as idiopathic thrombocytopenic purpura, is a blood disorder in which the body immune system destroys platelets, leading to low platelet counts in the blood (peripheral blood platelet count < 150 × 109/L). Although the pathophysiology of ITP is not fully understood, it is believed to result from a complex interplay between hereditary and environmental variables. Certain factors, such as a low platelet count, history of bleeding, and certain comorbidities can increase the risk of severe bleeding in patients with ITP. Corticosteroids, intravenous immunoglobulin (IVIG), immunosuppressants, rituximab, and thrombopoietin receptor agonists (TPO-RAs) are some of the advanced treatments for ITP. Although these therapies may be successful, they also carry the risk of negative effects. Recently, significant advancements have been made in the understanding and treatment of ITP. There is still much to learn about the disease, and new, more effective treatments are needed. This comprehensive review offers a comprehensive assessment of recent advancements in ITP management, with a focus on active research projects, novel therapeutic targets, new treatment modalities, and areas of uncertainty and unmet needs. According to research, it is crucial to develop individualized treatment plans for ITP patients based on their age, platelet count, risk of bleeding, and comorbidities. The article also looks at how future developments in gene editing, bispecific antibody therapies, and cellular therapy may completely change the treatment of ITP.

The many facets of immune-mediated thrombocytopenia: Principles of immunobiology and immunotherapy

Immune thrombocytopenia (ITP) is a rare autoimmune condition, due to peripheral platelet destruction through antibody-dependent cellular phagocytosis, complement-dependent cytotoxicity, cytotoxic T lymphocyte-mediated cytotoxicity, and megakaryopoiesis alteration. This condition may be idiopathic or triggered by drugs, vaccines, infections, cancers, autoimmune disorders and systemic diseases. Recent advances in our understanding of ITP immunobiology support the idea that other forms of thrombocytopenia, for instance, occurring after immunotherapy or cellular therapies, may share a common pathophysiology with possible therapeutic implications. If a decent pipeline of old and new agents is currently deployed for classical ITP, in other more complex immune-mediated thrombocytopenic disorders, clinical management is less harmonized and would deserve further prospective investigations. Here, we seek to provide a fresh overview of pathophysiology and current therapeutical algorithms for adult patients affected by this disorder with specific insights into poorly codified scenarios, including refractory ITP and post-immunotherapy/cellular therapy immune-mediated thrombocytopenia.

Review: Advances in the Pathogenesis and Treatment of Immune Thrombocytopenia Associated with Viral Hepatitis

Hepatitis B virus and hepatitis C virus are the hepatitis subtypes that most commonly induce immune thrombocytopenia (ITP). Although the pathogenesis of viral hepatitis-associated ITP remains unclear, it may involve antibody cross-reactivity due to molecular mimicry, the formation of virus-platelet immune complexes, and T cell-mediated suppression of bone marrow hematopoiesis. Moreover, there is significant correlation between platelet count and the severity of viral hepatitis, the risk of progression to liver cirrhosis, and clinical prognosis. However, treatment of viral hepatitis-associated ITP is hindered by some antiviral drugs. In this review, we summarize research progress to date on the pathogenesis and treatment of viral hepatitis-related ITP, hoping to provide a reference for clinical diagnosis and treatment.

The Impact of Human Platelet Antigen Allele on Antiplatelet Antibodies and Cryoglobulins in Patients with Primary Immune Thrombocytopenia and Hepatitis C Virus-Associated Immune Thrombocytopenia

Background And Objectives

Human platelet antigens (HPAs) are alloantigens associated with antiplatelet alloantibodies and the risk of immune thrombocytopenia (ITP). However, few studies have investigated associations among HPAs, antiplatelet autoantibodies, and cryoglobulins.

Methods

We enrolled 43 patients with primary ITP, 47 with hepatitis C virus-associated ITP (HCV-ITP), 21 with hepatitis B virus-associated ITP (HBV-ITP), 25 controls with HCV, and 1013 normal controls. We analyzed HPA allele frequencies, including HPA1-6 and 15, antiplatelet antibodies binding to platelet glycoprotein (GP) IIb/IIIa, Ia/IIa, Ib/IX, IV, human leukocyte antigen class I, cryoglobulin IgG/A/M, and their associations with thrombocytopenia.

Results

In the ITP cohort, HPA2ab, rather than HPA2aa, predicted a low platelet count. HPA2b was associated with the risk of developing ITP. HPA15b was correlated with multiple antiplatelet antibodies. In HCV-ITP patients, HPA3b was correlated with anti-GPIIb/IIIa antibodies. HCV-ITP patients with anti-GPIIb/IIIa antibodies had a higher positive rate of cryoglobulin IgG and IgA compared with those without anti-GPIIb/IIIa antibodies. Overlapping detection was also found among other antiplatelet antibodies and cryoglobulins. Like the antiplatelet antibodies, cryoglobulins were associated with clinical thrombocytopenia, implying their close relationship. Finally, we extracted cryoglobulins to confirm the exhibition of cryoglobulin-like antiplatelet antibodies. In contrast, in primary ITP patients, HPA3b was correlated with cryoglobulin IgG/A/M rather than anti-GPIIb/IIIa antibodies.

Conclusion

HPA alleles were associated with antiplatelet autoantibodies and had different impacts in primary ITP and HCV-ITP patients. HCV-ITP was considered to be a symptom of mixed cryoglobulinemia in HCV patients. The pathophysiology may differ between these two groups.

Platelets accumulate in lung lesions of tuberculosis patients and inhibit T-cell responses and Mycobacterium tuberculosis replication in macrophages

Platelets regulate human inflammatory responses that lead to disease. However, the role of platelets in tuberculosis (TB) pathogenesis is still unclear. Here, we show that patients with active TB have a high number of platelets in peripheral blood and a low number of lymphocytes leading to a high platelets to lymphocytes ratio (PL ratio). Moreover, the serum concentration of different mediators promoting platelet differentiation or associated with platelet activation is increased in active TB.

Immunohistochemistry analysis shows that platelets localise around the lung granuloma lesions in close contact with T lymphocytes and macrophages. Transcriptomic analysis of caseous tissue of human pulmonary TB granulomas, followed by Gene Ontology analysis, shows that 53 platelet activation‐associated genes are highly expressed compared to the normal lung tissue.

In vitro activated platelets (or their supernatants) inhibit BCG‐induced T‐ lymphocyte proliferation and IFN‐γ production. Likewise, platelets inhibit the growth of intracellular macrophages of Mycobacterium (M.) tuberculosis. Soluble factors released by activated platelets mediate both immunological and M. tuberculosis replication activities. Furthermore, proteomic and neutralisation studies (by mAbs) identify TGF‐β and PF4 as the factors responsible for inhibiting T‐cell response and enhancing the mycobactericidal activity of macrophages, respectively. Altogether these results highlight the importance of platelets in TB pathogenesis.

Immune Thrombocytopenic Purpura as a Hemorrhagic Versus Thrombotic Disease: An Updated Insight into Pathophysiological Mechanisms

Immune thrombocytopenic purpura (ITP) is a blood disorder characterized by a low platelet count of (less than 100 × 109/L). ITP is an organ-specific autoimmune disease in which the platelets and their precursors become targets of a dysfunctional immune system. This interaction leads to a decrease in platelet number and, subsequently, to a bleeding disorder that can become clinically significant with hemorrhages in skin, on the mucous membrane, or even intracranial hemorrhagic events. If ITP was initially considered a hemorrhagic disease, more recent studies suggest that ITP has an increased risk of thrombosis. In this review, we provide current insights into the primary ITP physiopathology and their consequences, with special consideration on hemorrhagic and thrombotic events. The autoimmune response in ITP involves both the innate and adaptive immune systems, comprising both humoral and cell-mediated immune responses. Thrombosis in ITP is related to the pathophysiology of the disease (young hyperactive platelets, platelets microparticles, rebalanced hemostasis, complement activation, endothelial activation, antiphospholipid antibodies, and inhibition of natural anticoagulants), ITP treatment, and other comorbidities that altogether contribute to the occurrence of thrombosis. Physicians need to be vigilant in the early diagnosis of thrombotic events and then institute proper treatment (antiaggregant, anticoagulant) along with ITP-targeted therapy. In this review, we provide current insights into the primary ITP physiopathology and their consequences, with special consideration on hemorrhagic and thrombotic events. The accumulated evidence has identified multiple pathophysiological mechanisms with specific genetic predispositions, particularly associated with environmental conditions.

A Review on Secondary Immune Thrombocytopenia in Malaysia

Immune thrombocytopenia (ITP) is an acquired autoimmune disease that occurs in adults and children. In Malaysia, the clinical practice guideline (CPG) for the management of ITP was issued in 2006, which focused almost exclusively on primary ITP (pITP), and only a few secondary ITP (sITP) forms were addressed. All published (twenty-three) sITP articles among children and adults in Malaysia, identified on the academic databases were retrieved. The articles were published between 1981 and 2019, at a rate of 0.62 publications per year. The publications were considered low and mainly focused on rare presentation and followed-up of secondary diseases. This review revealed that sITP in Malaysia is commonly associated with autoimmune diseases (Evan’s syndrome, SLE and WAS), malignancy (Kaposi’s sarcoma and breast cancer) and infection (dengue haemorrhagic fever, Helicobacter pylori and hepatitis C virus). The relationship between ITP and autoimmune diseases, malignancy and infections raise the question concerning the mechanism involved in these associations. Further studies should be conducted to bridge the current knowledge gap, and the further information is required to update the existing CPG of management of ITP in Malaysia.

Eltrombopag treatment of patients with secondary immune thrombocytopenia: retrospective EHR analysis

Immune thrombocytopenia (ITP) may occur in isolation (primary) or in association with a predisposing condition (secondary ITP [sITP]). Eltrombopag is a well-studied treatment for primary ITP, but evidence is scarce for sITP. We evaluated real-world use of eltrombopag for sITP using electronic health records. Eligible patients had diagnoses of ITP and a qualifying predisposing condition, and eltrombopag treatment. We described patient characteristics, treatment patterns, platelet counts, and thrombotic and bleeding events. We identified 242 eligible patients; the most common predisposing conditions were hepatitis C and systemic lupus erythematosus. Average duration of eltrombopag treatment was 6.1 months. Most (81.4%) patients achieved a platelet count ≥ 30,000/µL at a mean of 0.70 months, 70.2% reached ≥ 50,000/µL at a mean of 0.95 months, and 47.1% achieved a complete response of > 100,000/µL at a mean of 1.43 months after eltrombopag initiation. At eltrombopag discontinuation, 105 patients (43%) experienced a treatment-free period for a mean 3.3 months. Bleeding events occurred with similar frequency before and during eltrombopag treatment whereas thrombotic events were less frequent during eltrombopag treatment. Our results suggest similar rates of platelet response with eltrombopag in patients with sITP as compared with primary ITP. In addition, a treatment-free period is possible for a substantial minority of patients.

Idiopathic thrombocytopenic purpura (ITP) - new era for an old disease

Immune thrombocytopenia is an autoimmune hematological disorder characterized by severely decreased platelet count of peripheral cause: platelet destruction via antiplatelet antibodies which may also affect marrow megakaryocytes. Patients may present in critical situations, with cutaneous and/or mucous bleeding and possibly life-threatening organ hemorrhages (cerebral, digestive, etc.) Therefore, rapid diagnosis and therapeutic intervention are mandatory. Corticotherapy represents the first treatment option, but as in any autoimmune disorder, there is a high risk of relapse. Second line therapy options include: intravenous immunoglobulins, thrombopoietin receptor agonists, rituximab or immunosuppression, but their benefit is usually temporary. Moreover, the disease generally affects young people who need repeated and prolonged treatment and hospitalization and therefore, it is preferred to choose a long term effect therapy. Splenectomy - removal of the site of platelet destruction - represents an effective and stable treatment, with 70-80% response rate and low complications incidence. A challenging situation is the association of ITP with pregnancy, which further increases the risk due to the immunodeficiency of pregnancy, major dangers of bleeding, vital risks for mother and fetus, potential risks of medication, necessity of prompt intervention in the setting of specific obstetrical situations - delivery, pregnancy loss, obstetrical complications, etc. We present an updated review of the current clinical and laboratory data, as well as a detailed analysis of the available therapeutic options with their benefits and risks, and also particular associations (pregnancy, relapsed and refractory disease, emergency treatment).

Identifying and treating refractory ITP: difficulty in diagnosis and role of combination treatment

Immune thrombocytopenia (ITP) is the most common acquired thrombocytopenia after chemotherapy-induced thrombocytopenia. Existing guidelines describe the management and treatment of most patients who, overall, do well, even if they present with chronic disease, and they are usually not at a high risk for bleeding; however, a small percentage of patients is refractory and difficult to manage. Patients classified as refractory have a diagnosis that is not really ITP or have disease that is difficult to manage. ITP is a diagnosis of exclusion; no specific tests exist to confirm the diagnosis. Response to treatment is the only affirmative confirmation of diagnosis. However, refractory patients do not respond to front-line or other treatments; thus, no confirmation of diagnosis exists. The first section of this review carefully evaluates the diagnostic considerations in patients with refractory ITP. The second section describes combination treatment for refractory cases of ITP. The reported combinations are divided into the era before thrombopoietin (TPO) and rituximab and the current era. Current therapy appears to have increased effectiveness. However, the definition of refractory, if it includes insufficient response to TPO agents, describes a group with more severe and difficult-to-treat disease. The biology of refractory ITP is largely unexplored and includes oligoclonality, lymphocyte pumps, and other possibilities. Newer treatments, especially rapamycin, fostamatinib, FcRn, and BTK inhibitors, may be useful components of future therapy given their mechanisms of action; however, TPO agents, notwithstanding failure as monotherapy, appear to be critical components. In summary, refractory ITP is a complicated entity in which a precise specific diagnosis is as important as the development of effective combination treatments.

A case of immune thrombocytopenia due to miliary tuberculosis effectively treated with eltrombopag

An 80-year-old woman was diagnosed with miliary tuberculosis. Laboratory findings showed marked thrombocytopenia (3000/μl). Immune thrombocytopenia (ITP) was diagnosed because platelet transfusion was ineffective, and bone marrow puncture demonstrated a normal number of megakaryocytes. Anti-tuberculosis treatment was started promptly, followed by prednisolone 20 mg. However, the platelet count did not increase. The effect of high-dose intravenous immunoglobulin was temporary. She was not responded to prednisolone, and eltrombopag 12.5 mg was added. The eltrombopag dose was increased by 12.5 mg every two weeks. When the eltrombopag dose reached 50 mg, the thrombocytopenia improved sufficiently (44,000/μl). She didn't have any severe bleeding and thrombotic complications. The treatment of tuberculosis went well and there was no side effect of anti-tuberculosis treatment. Eltrombopag can be a useful treatment for ITP due to tuberculosis.

How do we diagnose immune thrombocytopenia in 2018?

In this report, we will review the various clinical and laboratory approaches to diagnosing immune thrombocytopenia (ITP), with a focus on its laboratory diagnosis. We will also summarize the results from a number of laboratories that have applied techniques to detect anti-platelet autoantibodies as diagnostic tests for ITP. Although there is considerable variability in methods among laboratories, there is general agreement that platelet autoantibody testing has a high specificity but low sensitivity. This suggests several possibilities: (1) the ideal test for ITP has yet to be developed, (2) current test methods need to be improved, or (3) ITP is the clinical expression of a variety of thrombocytopenic disorders with different underlying mechanisms. Even the clinical diagnosis of ITP is complex, and experienced clinicians do not always agree on whether a particular patient has ITP. Improvements in the diagnostic approach to ITP are necessary to improve the management of this disorder.

Emerging Concepts in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune disease defined by low platelet counts which presents with an increased bleeding risk. Several genetic risk factors (e.g., polymorphisms in immunity-related genes) predispose to ITP. Autoantibodies and cytotoxic CD8⁺ T cells (Tc) mediate the anti-platelet response leading to thrombocytopenia. Both effector arms enhance platelet clearance through phagocytosis by splenic macrophages or dendritic cells and by induction of apoptosis. Meanwhile, platelet production is inhibited by CD8⁺ Tc targeting megakaryocytes in the bone marrow. CD4⁺ T helper cells are important for B cell differentiation into autoantibody secreting plasma cells. Regulatory Tc are essential to secure immune tolerance, and reduced levels have been implicated in the development of ITP. Both Fcγ-receptor-dependent and -independent pathways are involved in the etiology of ITP. In this review, we present a simplified model for the pathogenesis of ITP, in which exposure of platelet surface antigens and a loss of tolerance are required for development of chronic anti-platelet responses. We also suggest that infections may comprise an important trigger for the development of auto-immunity against platelets in ITP. Post-translational modification of autoantigens has been firmly implicated in the development of autoimmune disorders like rheumatoid arthritis and type 1 diabetes. Based on these findings, we propose that post-translational modifications of platelet antigens may also contribute to the pathogenesis of ITP.

Other Extrahepatic Manifestations of Hepatitis C Virus Infection (Pulmonary, Idiopathic Thrombocytopenic Purpura, Nondiabetes Endocrine Disorders)

Extrahepatic manifestations of hepatitis C virus (HCV) infection are a rare but serious condition. This article summarizes the current literature on the association between HCV and endocrine and pulmonary manifestations, as well as idiopathic thrombocytopenic purpura (ITP). HCV may directly infect extrahepatic tissues and interact with the immune system predisposing for obstructive and interstitial lung disease, ITP, autoimmune thyroiditis, infertility, growth hormone and adrenal deficiencies, osteoporosis, and potentially lung and thyroid cancers. However, in many cases, the current evidence is divergent and cannot sufficiently confirm a true association, which emphasizes the need for future targeted projects in this field.

Thrombotic thrombocytopenic purpura related to ADAMTS13 deficiency, and successful treatment in a chimpanzee (Pan troglodytes verus)

A 27-year-old male chimpanzee (Pan troglodytes verus) developed signs of thrombotic thrombocytopenic purpura (TTP). ADAMTS13 deficiency appeared to be the cause of disease. After treatment with high-dose prednisone, haematological values and clinical signs recovered. This is the first description of spontaneous TTP associated with ADAMTS13 deficiency in a non-human primate.

Virus–Platelet Associations

Virus–platelet interplay is complex. Diverse virus types have been shown to associate with numerous distinct platelet receptors. This association can benefit the virus or the host, and thus the platelet is somewhat of a renegade. Evidence is accumulating to suggest that viruses are capable of entering platelets. For at least one type of RNA virus (dengue virus), the platelet has the necessary post-translational and packaging machinery required for production of replicative viral progeny. As a facilitator of immunity, the platelet also participates in eradicating the virus by direct and indirect mechanisms involving presentation of the pathogen to the innate and adaptive immune systems, thus enhancing inflammation by release of cytokines and other agonists. Virus-induced thrombocytopenia is caused by tangential imbalance of thrombopoeisis, autoimmunity, and loss of platelet function and integrity.

Thrombocytopenia and infections

INTRODUCTION

Acquired thrombocytopenia recognizes a myriad of causes. Among these, infectious diseases play a relevant role since a low platelet count is commonplace along with other abnormal laboratory data. Areas covered: This narrative review, after a brief presentation of the possible pathogenic mechanisms, is focused on the most prevalent infections associated with thrombocytopenia, namely those attributable to hepatitis C virus (HCV), human immunodeficiency virus (HIV) and Helicobacter pylori. Expert commentary: An underlying HCV or HIV infection should always be suspected in patients at risk who present with isolated thrombocytopenia. The eradication of Helicobacter pylori is advisable in infected patients with secondary immune thrombocytopenia, because this will increase the platelet count in a substantial number of cases, thus avoiding more aggressive and prolonged treatments.

Thrombopoietic cytokines in patients with hepatitis C virus-associated immune thrombocytopenia

OBJECTIVES

Complex and multiple mechanisms are involved in the etiology of Hepatitis C virus-associated immune thrombocytopenia (HCV-ITP). Many hematopoietic growth factors affect the thrombopoiesis. The aim of this study was to clarify the interaction of the thrombopoietic factors in patients with HCV-ITP.

METHODS

We selected 33 patients with HCV-ITP and 17 normal individuals. We compare serum interleukin (IL)-3, IL-6, IL-11, thrombopoietin (Tpo), stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor-α (TNFα), and spleen size between these two groups.

RESULTS

Our study shows that Tpo, IL-6, and TNFα significantly increased in patients with HCV-ITP compared to the normal population (Tpo:122.577 vs. 40.602; IL-6: 2.175 vs. 0.943; TNFα: 2.460 vs. 1.322). IL-11 was significantly lower in the HCV-ITP group (10.829 vs. 15.042). HCV-ITP patients had a higher spleen index (21.121 vs 13.498, P = 0.003). According to regression analysis and multiple linear regression analysis, only IL-11 had a significantly positive correlation with platelet count, while TNFα showed a negative correlation.

DISCUSSIONS

Tpo and IL-6 increased in patients with HCV-ITP, suggesting a positive feedback of low platelet count. TNFα-associated immune response is suspected to have an impact on low platelet count. IL-11 is assumed to directly affect thrombopoiesis.

CONCLUSIONS

This study is the most comprehensive study to evaluate the interaction between platelet count and the important thrombopoetic factors in patients with HCV-ITP. The thrombopoietic factors clearly play an important role in HCV-ITP.

Impact of Helicobacter pylori eradication on refractory thrombocytopenia in patients with chronic HCV awaiting antiviral therapy

The possibility of delaying treatment of HCV due to severe thrombocytopenia is challenging. This study aimed to detect the prevalence of active helicobacter infection as a claimed cause of thrombocytopenia in a cohort of Egyptian patients with chronic active HCV awaiting combined anti-viral therapy. The study included 400 chronic HCV patients with thrombocytopenia. Laboratory investigations included liver function tests, real time quantitative PCR, reticulocytic count, ESR, ANA, bone marrow aspiration, measurement of anti-helicobacter antibodies, and helicobacter stool antigen. Positive cases for active H. pylori were given the standard triple therapy for 2 weeks. Helicobacter stool antigen was detected 4 weeks after termination of therapy and the change in platelet count was detected 1 month after eradication. A total of 248 out of 281 seropositive patients for H. pylori (88.3 %) showed positive stool antigen (p = 0.01). Eradication was achieved in 169 (68.1 %) patients with platelet mean count 114.9 ± 18.8 × 10(3)/μl with highly significant statistical difference from pretreatment value (49.7 ± 9.2 × 10(3)/μl, p = 0.000). Seventy-nine patients were resistant to conventional triple therapy and given a 7-day course of moxifloxacin-based therapy; 61 patients responded (77.1 %) with mean platelet improvement from 76.4 ± 17.4 × 10(3)/μl to 104.2 ± 15.2 × 10(3)/μl (p = 0.000). The non-responders showed no improvement in their platelet count (74.6 ± 20.5 vs. 73.6 ± 15.3 × 10(3)/ul, P = 0.5). Eradication of active H. pylori in HCV augments platelet count and enhances the early start of antiviral therapy.

Prevalence of thrombocytopenia among Chinese adult antiretroviral-naïve HIV-positive patients

BACKGROUND

The prevalence of thrombocytopenia among Chinese antiretroviral therapy (ART)-naïve HIV-infected adults has not been well-described. The aim of this study was to investigate the prevalence and associated risk factors of thrombocytopenia among Chinese ART-naïve HIV-infected adults.

METHODS

We performed a cross-sectional study of Chinese adult ART-naïve HIV-infected patients from September 2005 through August 2014. Socio-demographic variables and laboratory results including platelets, CD4+ cell count, and viral load were obtained from medical records. Factors and outcomes associated with thrombocytopenia were assessed using logistic regression.

RESULTS

A total of 1730 adult ART-naïve HIV-infected patients was included. The mean age was 38 years. The prevalence of thrombocytopenia was 4.5%. There were significant differences in the prevalence of thrombocytopenia between patients <30 years of age (2.8%) and 30-39 years (4.0%) compared with patients greater than 50 years (7.0%) (P = 0.006 and P = 0.044, respectively). The prevalence of thrombocytopenia was also significantly different between patients with CD4+ counts of 200-349 cells/mm 3 (3.3%) and >350 cells/mm 3 (2.8%) compared with patients with CD4+ counts of 50-199 cells/mm 3 (7.1%) (P = 0.002 and P = 0.005, respectively). The prevalence of thrombocytopenia was significantly different by hepatitis C virus antibody (HCV-Ab) seropositivity (10.2% for HCV-Ab positive vs. 3.9% for HCV-Ab negative, P = 0.001). We observed differences in prevalence of thrombocytopenia by mode of transmission of HIV infection: Blood transmission (10.7%) versus men who have sex with men (3.9%) (P = 0.002) and versus heterosexual transmission (3.9%) (P = 0.001). In binary logistic regression analyses, age ≥ 50 years, HCV-Ab positivity and having a CD4+ cell count of 50-199 cells/mm 3 were significantly associated with thrombocytopenia with adjusted odds ratio of 2.482 (95% confidence interval [CI]: 1.167, 5.281, P = 0.018), 2.091 (95% CI: 1.078, 4.055, P = 0.029) and 2.259 (95% CI: 1.028, 4.962, P = 0.042), respectively.

CONCLUSIONS

Thrombocytopenia is not common among adult ART-naïve HIV-infected patients in China. Older age (age over 50 years), HCV-Ab positivity and lower CD4+ cell count are associated with an increased risk of thrombocytopenia. Therefore, early diagnosis and treatment of thrombocytopenia in these patients are necessary.

Inflammation-Induced Emergency Megakaryopoiesis Driven by Hematopoietic Stem Cell-like Megakaryocyte Progenitors

Infections are associated with extensive platelet consumption, representing a high risk for health. However, the mechanism coordinating the rapid regeneration of the platelet pool during such stress conditions remains unclear. Here, we report that the phenotypic hematopoietic stem cell (HSC) compartment contains stem-like megakaryocyte-committed progenitors (SL-MkPs), a cell population that shares many features with multipotent HSCs and serves as a lineage-restricted emergency pool for inflammatory insults. During homeostasis, SL-MkPs are maintained in a primed but quiescent state, thus contributing little to steady-state megakaryopoiesis. Even though lineage-specific megakaryocyte transcripts are expressed, protein synthesis is suppressed. In response to acute inflammation, SL-MkPs become activated, resulting in megakaryocyte protein production from pre-existing transcripts and a maturation of SL-MkPs and other megakaryocyte progenitors. This results in an efficient replenishment of platelets that are lost during inflammatory insult. Thus, our study reveals an emergency machinery that counteracts life-threatening platelet depletions during acute inflammation.

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.

Platelet destruction in immune thrombocytopenia. Understanding the mechanisms

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia. A dysfunctional proliferation of autoreactive T cells is suggested to be responsible for the loss of tolerance to self-platelet antigens in ITP patients. Autoreactive T cells induce uncontrolled proliferation of autoantibody producing B cells leading to persistent anti-platelet autoimmunity in some ITP patients. The autoimmune response causes an increased destruction of platelets by antibody-mediated phagocytosis, complement activation but also by T cell mediated cytotoxicity. In addition, abnormalities in thrombopoiesis and insufficient platelet production due to antibody or T cell mediated megakaryocyte inhibition and destruction contribute to the pathophysiology of ITP. These various effector cell responses may account for the heterogeneity in the clinical manifestation of ITP and also, to success or failure of different treatment strategies. A better understanding of the mechanisms behind ITP will hopefully allow for better diagnostic and, particularly, therapeutic strategies in the future.

Human platelets and their capacity of binding viruses: meaning and challenges?

Blood platelets are first aimed at ensuring primary hemostasis. Beyond this role, they have been acknowledged as having functions in the maintenance of the vascular arborescence and, more recently, as being also innate immune cells, devoted notably to the detection of danger signals, of which infectious ones. Platelets express pathogen recognition receptors that can sense bacterial and viral moieties. Besides, several molecules that bind epithelial or sub-endothelial molecules and, so forth, are involved in hemostasis, happen to be able to ligate viral determinants, making platelets capable of either binding viruses or even to be infected by some of them. Further, as platelets express both Fc-receptors for Ig and complement receptors, they also bind occasionally virus-Ig or virus-Ig-complement immune complexes. Interplays of viruses with platelets are very complex and viral infections often interfere with platelet number and functions. Through a few instances of viral infections, the present review aims at presenting some of the most important interactions from pathophysiological and clinical points of view, which are observed between human viruses and platelets.

Immune thrombocytopaenic purpura: an autoimmune cross-link between infections and vaccines

Immune thrombocytopaenic purpura (ITP) is an autoimmune systemic disease detectable by the presence of low blood platelets count (<10(5)/µl) and the production of autoantibodies against glycoproteins expressed on the platelet surface. The clinical course is often acute, and life-threatening events may occur especially in children, with 52% of paediatric patients recovering either spontaneously or after treatment. A chronic ITP evolution is observed in 64% of adults, of whom 12% will develop an overlapping autoimmune disease. Several microbial agents such as CagA-positive Helicobacter pylori or Candida albicans and a number of viruses including CMV, EBV or HIV can potentially trigger ITP through molecular mimicry. Moreover, ITP improves after treatment of the underlying infection. Similarly, vaccines such as MMR may prompt ITP (IRR 5.48, 1.61-18.64, p < 0.006). Early recognition of the underlying microbial trigger and the removal of modifiable aetiopathogenetic factors should be integrated as a complementary treatment strategy in all patients who do not readily improve with standard ITP care.

Extrahepatic immune related manifestations in chronic hepatitis C virus infection

The association of chronic hepatitis C with immune related syndromes has been frequently reported. There is a great range of clinical manifestations affecting various systems and organs such as the skin, the kidneys, the central and peripheral nervous system, the musculoskeletal system and the endocrine glands. Despite the high prevalence of immune related syndromes in patients with chronic hepatitis C, the exact pathogenesis is not always clear. They have been often associated with mixed cryoglobulinemia, a common finding in chronic hepatitis C, cross reaction with viral antigens, or the direct effect of virus on the affected tissues. The aim of this review is to analyze the reported hepatitis C virus immune mediated syndromes, their prevalence and clinical manifestations and to discuss the most supported theories regarding their pathogenesis.

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.

Immune thrombocytopenia

Immune thrombocytopenia (ITP) is a common hematologic disorder characterized by isolated thrombocytopenia. ITP presents as a primary or a secondary form. ITP may affect individuals of all ages, with peaks during childhood and in the elderly, in whom the age-specific incidence of ITP is greatest. Bleeding is the most common clinical manifestation of ITP. The pathogenesis of ITP is complex, involving alterations in humoral and cellular immunity. Corticosteroids remain the most common first line therapy for ITP. This article summarizes the classification and diagnosis of primary and secondary ITP, as well as the pathogenesis and options for treatment.

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 Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in immune thrombocytopenia

BACKGROUND

Although Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are known to trigger immune thrombocytopenia (ITP), the manifestations of EBV and CMV in ITP spleen tissues continue to be poorly understood.

METHODS

Our research retrospectively reviewed a total of 42 ITP patients and 20 healthy control cases from the West China Hospital of Sichuan University from 2008 to 2012. Patients' characteristics, preoperative platelet counts, and the expression of EBV and CMV in spleen tissue were analyzed.

RESULTS

No statistically significant differences were identified for age and gender between the ITP group and the healthy control group. The comparison of these two categories (the ITP group and the control group) showed substantial variations in the expression of EBV and CMV: nine (21.4%) and eight (19%) ITP patients had a positive expression of EBV and CMV, compared with none and one patient in the control group, respectively. In the EBV-ITP group, patients with a positive EBV expression revealed appreciably decreased preoperative platelet count compared with patients with a negative EBV expression. No other statistically significant difference was found in the CMV group.

CONCLUSION

We have demonstrated the presence of both EBV and CMV infections in the spleen tissue of ITP patients. EBV infections were implicated in the reduced platelet counts in ITP.

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.

How I treat immune thrombocytopenia: the choice between splenectomy or a medical therapy as a second-line treatment

The paradigm for managing primary immune thrombocytopenia (ITP) in adults has changed with the advent of rituximab and thrombopoietin receptor agonists (TPO-RAs) as options for second-line therapy. Splenectomy continues to provide the highest cure rate (60%-70% at 5+ years). Nonetheless, splenectomy is invasive, irreversible, associated with postoperative complications, and its outcome is currently unpredictable, leading some physicians and patients toward postponement and use of alternative approaches. An important predicament is the lack of studies comparing second-line options to splenectomy and to each other. Furthermore, some adults will improve spontaneously within 1-2 years. Rituximab has been given to more than 1 million patients worldwide, is generally well tolerated, and its short-term toxicity is acceptable. In adults with ITP, 40% of patients are complete responders at one year and 20% remain responders at 3-5 years. Newer approaches to using rituximab are under study. TPO-RAs induce platelet counts > 50 000/μL in 60%-90% of adults with ITP, are well-tolerated, and show relatively little short-term toxicity. The fraction of TPO-RA-treated patients who will be treatment-free after 12-24 months of therapy is unknown but likely to be low. As each approach has advantages and disadvantages, treatment needs to be individualized, and patient participation in decision-making is paramount.

Mechanism of thrombocytopenia in chronic hepatitis C as evaluated by the immature platelet fraction

INTRODUCTION

Thrombocytopenia occurs frequently in chronic hepatitis C. The mechanism of this association was investigated utilizing the immature platelet fraction (IPF%) as an index of platelet production together with assay of thrombopoietin (TPO).

METHODS

In a cross-sectional study, 47 patients with chronic hepatitis C were studied, 29 with thrombocytopenia and 18 without thrombocytopenia (six patients in each group were on interferon therapy).

RESULTS

IPF% was elevated in the thrombocytopenic compared with the nonthrombocytopenic group (9.0 ± 4.8% vs. 4.7 ± 2.4%, P < 0.001), and an increase in IPF% was significantly associated with thrombocytopenia on multivariable analysis (P < 0.05). Splenomegaly was more common in thrombocytopenic than in nonthrombocytopenic subjects (66% vs. 6%, P < 0.001), and on multivariable analysis, splenomegaly was the factor associated with the highest relative risk of thrombocytopenia (RR = 1.9, P < 0.05). IPF% values were elevated in a similar proportion of thrombocytopenic patients with and without splenomegaly (58% and 60%, respectively). There was no difference in TPO levels between thrombocytopenic and nonthrombocytopenic patients, and TPO levels were not related to the risk of thrombocytopenia on multivariable analysis. Significantly more thrombocytopenic than nonthrombocytopenic subjects had abnormal liver function tests, cirrhosis, and portal hypertension, and a decrease in serum albumin was significantly associated with thrombocytopenia (P < 0.005) on multivariable analysis.

CONCLUSIONS

Factors associated with liver disease in general are associated with thrombocytopenia in chronic hepatitis C. Peripheral platelet destruction or sequestration is the major mechanism for thrombocytopenia, with hypersplenism being an important cause. Low TPO levels were not related to the occurrence of thrombocytopenia in this study.

Diagnosis and Management of Immune Thrombocytopenia in the Era of Thrombopoietin Mimetics

The recognition of that patients with Immune Thrombocytopenia (ITP) have functional thrombopoietin deficiency and decreased platelet production due to immune-mediated megakaryocytic injury has challenged the traditional view of this disease as predominantly a disorder of antibody-mediated platelet destruction. The therapy of chronic refractory ITP has been transformed by the approval of the thrombopoietin minetics, romiplostim and eltrombopag, which have shown remarkable efficacy in randomized trials. The use of these agents earlier in the disease course after failure of corticosteroid therapy remains controversial. In this article, we review the current data on the efficacy and safety of thrombopoietin receptor agonists and discuss other therapies as well as diagnostic work up of ITP.

Autoantibodies in patients with chronic hepatitis C virus infection: pitfalls for the diagnosis of rheumatic diseases

Hepatitis C virus infection (HCV) is one of the best mimes in medicine. About 40-70% of patients suffering from this disorder develop at least one extra-hepatic disorder that can have a rheumatic nature (arthralgias, arthritis, vasculitis and sicca syndrome) and must be differentiated from the primitive rheumatic diseases. In addition, HCV infection can also alter the laboratory tests. Several alterations of first line laboratory tests can be usually found in both chronic HCV infection and chronic inflammatory rheumatic disorders. In the present review we analyze the interference of HCV in tests more specifically used in rheumatology: rheumatoid factor and other autoantibodies (ANA, anti-ENA, ANCA, anti-DNA, antiphospholipid, anti-CCP). In patients suffering from HCV infection, the diagnosis of connective tissue diseases (CTD) or rheumatoid arthritis (RA) should be made only when the detected symptoms or laboratory data are not inducible by HCV, otherwise only a diagnosis of "possible CTD" or "possible RA" should be considered.

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.

Romiplostim

Thrombocytopenia is a common clinical problem associated with a wide range of medical conditions including immune thrombocytopenia (ITP), chemotherapy-induced thrombocytopenia (CIT), hepatitis C-related thrombocytopenia, and myelodysplastic syndromes (MDS). Until recently, the only treatments for thrombocytopenia were to alleviate the underlying cause or to provide platelet transfusions. With the discovery and recent clinical availability of thrombopoietin (TPO) mimetics, a new treatment option has emerged. Two TPO mimetics are currently clinically available for treating ITP: romiplostim (an injectable peptide TPO mimetic) and eltrombopag (a non-peptide, orally available TPO mimetic). This chapter reviews the development, biology, and clinical trials with romiplostim. With few adverse effects, romiplostim is effective in raising the platelet count in over 80% of ITP patients, allowing them to discontinue other therapies, reduce the need for splenectomy, and improve their quality of life. Long-term theoretical side effects of romiplostim treatment include reticulin formation, thromboembolism, and antibody formation to romiplostim. A practical way of using romiplostim is provided: a higher starting dose of 3 mg/kg is recommended along with efforts to avoid withholding the dose. Future studies will assess the utility of romiplostim in CIT, hepatitis-C related thrombocytopenia, and MDS.