Hepatitis C virus-related adult chronic idiopathic thrombocytopenic purpura: experience from a single Chinese center

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.

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.

Tazobactam and piperacillin-induced thrombocytopenia: A case report

The present study reports a case of tazobactam and piperacillin (TZP)-induced thrombocytopenia in an elderly patient, from which complete clinical data and peripheral blood samples were collected. Platelet numbers were decreased 1 day following TZP treatment initiation; however, they were revealed to have increased 1–2 days following withdrawal of TZP, and had reached normal levels 3–5 days later. There was no evidence of bone marrow suppression, antibodies against peripheral plasma platelets were absent and levels of complement C3 were decreased. These results suggested that TZP was able to cause rapid and reversible thrombocytopenia, which was not associated with bone marrow suppression but may have involved activation of complement C3. The results of the present study therefore suggest that doctors should be aware of the risk of thrombocytopenia in patients treated with TZP.

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.

Elevated NKT cell levels in adults with severe chronic immune thrombocytopenia

The aim of this study was to investigate the frequency of circulating natural killer T (NKT) cells and regulatory T cells (Tregs), as well as serum cytokine profiles, in adult chronic primary immune thrombocytopenia (ITP). The frequency of circulating T cell receptor (TCR) Vα24⁺Vβ11⁺CD3⁺ NKT cells and CD4⁺CD25⁺CD127^−/low Tregs was measured using multi-color flow cytometry. The serum concentrations of 11 cytokines were determined with a cytometric bead assay. The frequency of circulating NKT cells in patients with ITP was 0.13±0.03%, whereas the frequency in healthy controls was 0.07±0.01% of CD3⁺ (P>0.05). However, the frequency of NKT cells in patients with ITP with platelet counts ≤20×10⁹/l (0.22±0.05%) was significantly higher than that in patients with platelet counts >20×10⁹/l (0.05±0.01%; P<0.05) and that in healthy controls (0.07±0.01%; P<0.05). The frequency of peripheral Tregs was comparable between patients with ITP (3.97±0.44% of CD4⁺) and healthy controls (3.69±0.31%; P>0.05). No significant differences were observed in the serum concentrations of 11 cytokines between patients with ITP and healthy controls, despite the fact that the serum levels of interleukin (IL)-12p70, IL-8, IL-4, interferon (IFN)-γ and tumor necrosis factor (TNF)-α in patients with ITP were higher than those in the healthy controls. The platelet count was negatively correlated with the frequency of circulating NKT cells in chronic ITP. These results indicate that NKT cells may be involved in ITP with severe thrombocytopenia, and NKT and Tregs may be important in cytokine deregulation in chronic 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.

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.

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.

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.

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.

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.

Profile of Th17 cytokines (IL-17, TGF-beta, IL-6) and Th1 cytokine (IFN-gamma) in patients with immune thrombocytopenic purpura

The data on polarization of the immune system towards T helper 1 (Th1) or T helper 2 (Th2) cells in immune thrombocytopenic purpura (ITP) are limited and contradictory. Th17 characterized by the production of Interleukin 17 (IL-17) has been shown to play a crucial part in the induction of autoimmune diseases. To further investigate the role of Th cytokines in the pathogenesis of ITP, we measured the plasma concentration of three Th17-associated cytokines [IL-17, transforming growth factor-ss (TGF-ss), IL-6] and Th1 cytokine interferon-gamma (IFN-gamma) in ITP patients, and evaluated their clinical relevance. The concentration of IL-17, TGF-ss, IL-6, and IFN-gamma in plasma specimens from 29 adults with chronic ITP and 38 controls was analyzed by enzyme-linked immunosorbent assay method. No significant differences of Th17 cytokines (IL-17, TGF-ss, and IL-6) and Th1 cytokine (IFN-gamma) concentration were observed between patients with active ITP and the control group. And the IFN-gamma/IL-17 ratio representing Th1/Th17 cytokine profile was not significantly different between ITP patients and control, either. However, significantly positive correlation between IL-6 and IFN-gamma in ITP patients was observed (r = 0.48, P = 0.01). Among the ITP patients, Plasma IL-17 levels in male were marginally higher than those in female, while similar for TGF-ss, IL-6 or IFN-gamma. There was a significantly positive correlation between age and IL-6 concentration in ITP patients (r = 0.56, P = 0.0002), while no statistical significance between age and the other three cytokines. No significant correlation between cytokine concentrations and platelets or megakaryocytes number was found in ITP patients. In summary, ITP may not be associated with changes of plasma Th17 and Th1 cytokine concentrations relative to control population.

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.

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.

Abnormality of CD4(+)CD25(+) regulatory T cells in idiopathic thrombocytopenic purpura

OBJECTIVES

The aim of this study was to explore the profile and function of CD4(+)CD25(+) regulatory T cells (Treg cells) in idiopathic thrombocytopenic purpura (ITP) patients.

METHODS

Treg cell numbers were analyzed by flow cytometric analysis in peripheral blood mononuclear cells collected from healthy donors or patients with ITP. Quantification of cell proliferation was assayed by an enzyme-linked immunosorbent assay kit, based on the measurement of BrdU incorporation during DNA synthesis.

RESULTS

The percentage of Treg cells was significantly decreased in ITP patients in active and non-remission state(5.79 +/- 1.22%) when compared with the patients in remission(11.63 +/- 4.56%) and to healthy subjects(12.68 +/- 3.59%). The suppressive activity of Treg cells in ITP patients was also found to be impaired.

CONCLUSION

These results suggest that decreased number and function of Treg cells might be one of mechanisms that cause immune regulation dysfunction in ITP.

Unappreciated HLA Antibodies in Adult Immune Thrombocytopenic Purpura

BACKGROUND/PURPOSE

Immune thrombocytopenic purpura (ITP) is an autoimmune disease. Platelet refractoriness is frequently seen in patients with ITP. Platelets express platelet-specific antigens and human leukocyte antigens (HLA). Platelet antibodies to platelet-specific antigens and HLA may be present, but HLA antibodies in patients with ITP have rarely been reported.

METHODS

Sera from 44 adult patients with ITP were screened for platelet antibodies by two flow cytometric assays. In method I, platelets from normal donor platelets were used as target cells to screen both platelet-specific antibodies and HLA class I antibodies. In method II, the FlowPRA Class I Screening Test kit was used to screen HLA class I antibodies. Fluorescein isothiocyanate (FITC)-conjugated sheep anti-human IgG Fc was used as the staining reagent in both methods. The negative serum control was from one of the normal males with AB blood group who had never received a transfusion. Sera from a pool of five highly sensitized patients were used as the positive control.

RESULTS

Of the 44 sera from patients with ITP, 31 (70.5%) were method I positive, and 28 (63.6%) were method II positive. There was no significant difference between the results of method I and method II (p = 0.439). The distribution of the results of these two tests was: both tests positive in 22 sera, method I positive and method II negative in nine sera, method I negative and method II positive in six sera, and both tests negative in seven sera. The mean platelet counts of patients with positive (41.0 +/- 40.0 x 10(9)/L) and negative (40.4 +/- 26.8 x 10(9)/L) tests by method I did not differ significantly (p = 0.643). The mean platelet counts of patients with (36.7 +/- 31.5 x 10(9)/L) and without (48.1 +/- 43.6 x 10(9)/L) HLA class I antibodies did not differ significantly (p = 0.59).

CONCLUSION

HLA class I antibodies are frequently found in ITP. The screening of platelet antibodies including platelet-specific antibodies and unappreciated HLA class I antibodies is warranted in patients with ITP.

The pathogenesis of immune thrombocytopaenic purpura

Immune thrombocytopaenic purpura (ITP) is an autoimmune bleeding disease that is rarely fatal. However, in many adults treatment is unsatisfactory, with as much morbidity from the immunosuppressive effects of treatment as from bleeding. Identifying the underlying disease process should help us to identify more targeted therapies and improve not only the treatment but also the quality of life of patients with this disorder.

Splenectomy for chronic idiopathic thrombocytopenic purpura in children: a single center study in China

The management of chronic and refractory idiopathic thrombocytopenic purpura (ITP) in children is controversial. We conducted a retrospective review of our single center experience in China between 1990 and 2003 with splenectomy for chronic ITP in children in order to determine the initial and long-term hematological response, morbidity, mortality, predictors of response to splenectomy and the therapy in children who failed splenectomy. Of 65 children analyzed, the overall immediate clinical response to splenectomy was 89.2%. The median postsplenectomy follow-up time was 52 months (8-124). During follow-up, 9 children (13.8%) relapsed within a median time of 6 months (2-58). The overall morbidity was 1.5% and perioperative mortality was zero. During follow-up, 1 child died of intracranial hemorrhage (ICH) and 1 died of overwhelming postsplenectomy infection (OPSI). The platelet count at day 7 after splenectomy was a predictor of a sustained response to splenectomy but no preoperative parameters were predictors of the response to splenectomy. Of the 15 children who failed splenectomy, excluding the one who died of ICH, only 2 children intermittently required corticosteroids and IVIG. Splenectomy is a potential therapy to provide long-term control of disease in children with chronic ITP and is associated with low morbidity and mortality. The risk of fulminant sepsis remains an omnipresent concern. Antipneumococcal vaccination and antibiotic prophylaxis should be recommended and children should receive timely and adequate antibiotics for bacteria infection to lessen the problem of OPSI.

Splenectomy for adult chronic idiopathic thrombocytopenic purpura: experience from a single center in China

OBJECTIVES

The aim of this study was to explore the results of Chinese chronic idiopathic thrombocytopenic purpura (ITP) patients who underwent splenectomy (SE).

SUBJECTS AND METHODS

Data of 149 chronic ITP patients were retrospectively analyzed. Relapse-free survival was estimated by Kaplan-Meier analysis. Differences between responders and non-responders were evaluated using the chi-square.

RESULTS

The immediate response rate was 82.6% and the sustained response rate was 63.1%. Twenty-nine patients (19.5%) relapsed during follow-up. The 5-year actuarial relapse-free survival was about 75%. The overall morbidity was 26.1% and mortality was 2.7%. Patients with higher postsplenectomy peak platelet count, shorter time from diagnosis to SE and previous response to IVIG therapy were more likely to have sustained response to SE.

CONCLUSION

SE is potentially a useful therapy to provide long-term control of disease in adults with chronic ITP and is associated with low morbidity and mortality. Postsplenectomy peak platelet count, time from diagnosis to SE and previous response to intravenous immune globulin therapy appear predictive for response to SE.

Improvement of thrombocytopenia with disappearance of HCV RNA in patients treated by interferon-alpha therapy: possible etiology of HCV-associated immune thrombocytopenia

We evaluated the relationship between the severity of thrombocytopenia and the serum hepatitis C virus (HCV) RNA level to investigate the mechanism of thrombocytopenia in patients with HCV infection. Patients who had chronic hepatitis without splenomegaly were divided into two groups according to the platelet count, which were 18 patients with a platelet count < or =150 x 10(9)/L and 22 patients with a platelet count >150 x 10(9)/L. HCV RNA, platelet-associated immunoglobulin G (PAIgG), rheumatoid factor (RF), and other immunological parameters were measured and correlations were investigated. Patients in the low platelet group had higher levels of PAIgG, Th1 cells, thrombopoietin (TPO), and RF than those in the normal platelet group (textitP < 0.05). Twenty-two patients completed 6 months of IFN therapy and were followed for more than 1 yr afterwards. Twelve patients who responded to IFN therapy with clearance of HCV showed an increase of the platelet count, whereas the 10 patients who did not respond to IFN showed a decrease of the platelet count. The improvement of thrombocytopenia after interferon therapy suggests a contribution of HCV infection to this condition.

Neutropénie et thrombopénie auto-immunes sévères associées à une hépatite chronique C : effet du traitement antiviral

We report the case of a 45-year-old man admitted for severe autoimmune thrombopenia and neutropenia associated with chronic viral C hepatitis. After failed, intravenous gammaglobulin and corticosteroid therapy antiviral treatment with interferon and ribavirin was given for one year. Thrombopenia improved progressively during antiviral therapy and worsened after the end of treatment. Neutropenia improved during antiviral therapy. Two years after the end of treatment, serum RNA-HCV was positive, white cell count was normal and platelet count was 77 G/L. In conclusion, these results suggest that antiviral therapy may be useful in patients with auto-immune cytopenia associated with viral hepatitis C infection.

Helicobacter pylori eradication: novel therapy for immune thrombocytopenic purpura? A review of the literature

Eradication of Helicobacter pylori (H. pylori ) from the gastric mucosa has been associated with improvement of several systemic diseases, including immune thrombocytopenic purpura (ITP). Over the last 5 years, several studies have reported improved platelet counts in H. pylori-positive ITP patients following standard triple H. pylori eradication therapy. Review of published studies in which eradication of H. pylori has been performed in the ITP population indicates an overall response rate of 52% in 193 subjects in whom H. pylori was eradicated. Cohorts from Japan and Italy report higher response rates. There is no established mechanism to explain how this organism, which does not invade the gastric mucosa, could be implicated in the pathogenesis of this immune-based platelet disorder. Several theories including molecular mimicry, platelet aggregation, and immunomodulatory effects of macrolides have been proposed to explain the platelet response to anti-H. pylori therapy. Large randomized-controlled studies enrolling patients from various ethnic backgrounds will be necessary to determine the response rate and mechanism of response and to gain a better understanding of the pathogenesis of ITP.

Management of Adult Idiopathic Thrombocytopenic Purpura

Idiopathic thrombocytopenic purpura (ITP) is a common hematologic disorder manifested by immune-mediated thrombocytopenia. The diagnosis remains one of exclusion, after other thrombocytopenic disorders are ruled out based on history, physical examination, and laboratory evaluation. The goal of treatment is to raise the platelet count into a hemostatically safe range. The disorder is usually chronic, although there is considerable variation in the clinical course and most patients eventually attain safe platelet counts off treatment. However, a subset of patients has severe disease refractory to all treatment modalities, which is associated with considerable morbidity and mortality. This article focuses on the management of primary ITP in adults. We discuss criteria for treatment, the roles of splenectomy and other treatment options along with their side effects, and the management of ITP during pregnancy.

Serum leptin levels in patients with idiopathic thrombocytopenic purpura

OBJECTIVES

The purpose of this study was to evaluate serum leptin levels in idiopathic thrombocytopenic purpura (ITP), in order to determine the influence of leptin on the pathogenesis of ITP.

SUBJECTS AND METHODS

Forty-six untreated patients with chronic ITP were compared with 40 healthy people of similar age, sex and body mass index (BMI). Serum leptin levels (ng/mL) were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that the mean serum leptin levels in patients with ITP (22.11 +/- 15.84 ng/mL) were significantly (P < 0.001) higher than that in healthy control volunteers (5.44 +/- 4.84 ng/mL). Furthermore, serum leptin levels in patients with ITP were inversely related (r = -0.86, P < 0.001) to the platelet counts and positively related to the platelet-associated IgG (PAIgG) levels (r = 0.7, P < 0.001). The levels of PAIgG and platelet counts were significantly different between leptin-positive (level greater than mean +/- 2 SD control value) and leptin-negative patients.

CONCLUSION

These findings suggest that leptin might play an important role in the pathogenesis of ITP.