Current Options for the Treatment of Idiopathic Thrombocytopenic Purpura

The long-term efficacy of eltrombopag in children with immune thrombocytopenia

Immune thrombocytopenia (ITP) is the most common autoimmune disorder characterized by decreased platelet counts and impaired platelet production. Eltrombopag has been demonstrated to be safe and effective for children with ITP. It is reported eltrombopag can achieve a sustained response off treatment. However, data on its overall efficacy and safety profile are scarce in children. This study aimed to investigate the long-term efficacy of eltrombopag in children with ITP. Treatment overall response (OR), complete response (CR), response (R), durable response (DR), no response (NR), treatment free remission (TFR), and relapse rate, were assessed in 103 children with ITP during eltrombopag therapy. The OR rate, CR rate, R rate, DR rate, NR rate, TFR rate, and relapse rate were 67.0%, 55.3%, 11.7%, 56.3%, 33.0%, 60%, 36.2%, respectively. Importantly, we discovered that newly diagnosed ITP patients showed a higher DR rate, TFR rate and lower relapse rate compared to persistent and chronic ITP patients. Furthermore, the CR rate, DR rate, and TFR rate of 5 patients under six months were 100%. None of them suffered relapse. The most common adverse event (AEs) was hepatotoxicity (7.77%). Our study highlighted the critical role of eltrombopag as the second-line treatment in children with ITP who were intolerant to first-line therapy.

Alnustone promotes megakaryocyte differentiation and platelet production via the interleukin-17A/interleukin-17A receptor/Src/RAC1/MEK/ERK signaling pathway

OBJECTIVES

Thrombocytopenia is a disease in which the number of platelets in the peripheral blood decreases. It can be caused by multiple genetic factors, and numerous challenges are associated with its treatment. In this study, the effects of alnustone on megakaryocytes and platelets were investigated, with the aim of developing a new therapeutic approach for thrombocytopenia.

METHODS

Random forest algorithm was used to establish a drug screening model, and alnustone was identified as a natural active compound that could promote megakaryocyte differentiation. The effect of alnustone on megakaryocyte activity was determined using cell counting kit-8. The effect of alnustone on megakaryocyte differentiation was determined using flow cytometry, Giemsa staining, and phalloidin staining. A mouse model of thrombocytopenia was established by exposing mice to X-rays at 4 Gy and was used to test the bioactivity of alnustone in vivo. The effect of alnustone on platelet production was determined using zebrafish. Network pharmacology was used to predict targets and signaling pathways. Western blotting and immunofluorescence staining determined the expression levels of proteins.

RESULTS

Alnustone promoted the differentiation and maturation of megakaryocytes in vitro and restored platelet production in thrombocytopenic mice and zebrafish. Network pharmacology and western blotting showed that alnustone promoted the expression of interleukin-17A and enhanced its interaction with its receptor, and thereby regulated downstream MEK/ERK signaling and promoted megakaryocyte differentiation.

CONCLUSIONS

Alnustone can promote megakaryocyte differentiation and platelet production via the interleukin-17A/interleukin-17A receptor/Src/RAC1/MEK/ERK signaling pathway and thus provides a new therapeutic strategy for the treatment of thrombocytopenia.

Illustrated State-of-the-Art Capsules of the ISTH 2023 Congress

This year's Congress of the International Society of Thrombosis and Haemostasis (ISTH) took place in person in Montréal, Canada, from June 24-28, 2023. The conference, held annually, highlighted cutting-edge advances in basic, translational, population and clinical sciences relevant to the Society. As for all ISTH congresses, we offered a special, congress-specific scientific theme; this year, the special theme was immunothrombosis. Certainly, over the last few years, COVID-19 infection and its related thrombotic and other complications have renewed interest in the concepts of thromboinflammation and immunothrombosis; namely, the relationship between inflammation, infection and clotting. Other main scientific themes of the Congress included Arterial Thromboembolism, Coagulation and Natural Anticoagulants, Diagnostics and Omics, Fibrinolysis and Proteolysis, Hemophilia and Rare Bleeding Disorders, Hemostatic System in Cancer, Inflammation and Immunity, Pediatrics, Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies, Platelets and Megakaryocytes, Vascular Biology, Venous Thromboembolism and Women's Health. Among other sessions, the program included 28 State-of-the-Art (SOA) sessions with a total of 84 talks given by internationally recognized leaders in the field. SOA speakers were invited to prepare brief illustrated reviews of their talks that were peer reviewed and are included in this article. These illustrated capsules highlight the major scientific advances with potential to impact clinical practice. Readers are invited to take advantage of the excellent educational resource provided by these illustrated capsules. They are also encouraged to use the image in social media to draw attention to the high quality and impact of the science presented at the Congress.

First-in-patient study of hetrombopag in patients with chronic idiopathic thrombocytopenic purpura

BACKGROUND

Idiopathic thrombocytopenic purpura (ITP) especially refractory and (or) relapsed ITP, is a serious and global health burden and its clinical treatment is far from being satisfied. Hetrombopag is a novel, small-molecule thrombopoietin receptor agonist for the treatment of chronic idiopathic thrombocytopenic purpura (CITP).

OBJECTIVES

This first-in-patient study aimed to investigate the safety, pharmacokinetics, and anticipated therapeutic dose of hetrombopag in CITP patients.

METHODS

In this multicenter, first-in-patient study, CITP patients received hetrombopag in a dose escalation (2.5 mg/day, 5 mg/day, or 7.5 mg/day) cohort. All patients received hetrombopag in fasting condition once daily for 2 weeks.

RESULTS

Of 44 patients screened, 32 were enrolled and treated. Most adverse events were graded 1 to 2 (ie, mild to moderate), and the incidence and severity were similar for three study cohorts. The pharmacokinetics of hetrombopag were found to be nonlinear with greater than dose-proportional: 12.5% of patients (1/8) in the 2.5 mg/d cohort, 58.3% of patients (7/12) in the 5 mg/d cohort, 66.7% of patients (8/12) in the 7.5 mg/d cohort reached the primary study endpoint of a platelet count exceeding 50 × 109 /L on day 28.

CONCLUSION

Hetrombopag was well tolerated and preliminarily efficacious. Efficacy, safety, and pharmacokinetic data suggest that 7.5 mg hetrombopag once daily was the anticipated therapeutic dose of hetrombopag in CITP patients and has been recommended for investigation in a later confirmatory clinical study of hetrombopag.

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).

Efficacy and safety of thrombopoietin receptor agonists in children with chronic immune thrombocytopenia: a meta-analysis

Background and Aim

Thrombopoietin receptor agonists (TPO-RAs) have been shown to be safe and effective for adults with chronic immune thrombocytopenia (ITP). The aim of this meta-analysis is to assess the efficacy and safety of thrombopoietin receptor agonists for children with chronic ITP.

Materials and Methods

Clinical randomized controlled trials (RCTs) evaluating the efficacy and safety of TPO-RAs in pediatric ITP patients published up to June 2017 were retrieved from PubMed, Cochrane Library, and Embase databases. Relevant data were extracted, and the Physiotherapy Evidence Database scale was used to assess the methodological quality. Stata/SE 12.0 was used to perform a meta-analysis.

Results

Seven RCTs were included, with 238 patients and 107 patients in the TPO-RA group and the control group, respectively. Assessing efficacy, better results were found in the TPO-RA group for the rate of overall platelet response, durable response, and rescue medication needed. Furthermore, the TPO-RA group yielded superior results in the incidence of clinically significant bleeding events but had a comparable result in the incidence of any bleeding events and severe bleeding events. No significant difference was found between the two groups in health-related quality of life and parental burden. Assessing safety, no significant difference was found between the two groups in the incidence of any adverse events and severe adverse events.

Conclusions

TPO-RAs are effective and safe agents for the treatment of chronic ITP in pediatric patients. Eltrombopag appears to be better than romiplostim in terms of the rate of rescue medication needed and clinically significant bleeding events.

Bleeding complications in immune thrombocytopenia

Bleeding manifestations in patients with immune thrombocytopenia (ITP) range from mild skin bruises to life-threatening intracranial hemorrhage (ICH). Severe bleeding is distinctly uncommon when the platelet count is >30 × 109/L and usually only occurs when the platelet count falls <10 × 109/L. Based on estimates from clinical studies, ITP registries and administrative databases, the frequency of ICH in patients with ITP is ∼0.5% in children and 1.5% in adults. Estimates of severe (non-ICH) bleeding are difficult to obtain because of the lack of standardized case definitions; the lack of a universally accepted, ITP-specific bleeding assessment tool; and the omission of reporting bleeding outcomes in many clinical studies. In practice, the presence of bleeding should dictate whether or not treatment is needed because many patients, especially children, can be safely managed with observation alone. Guiding principles for the management of ITP, based on the bleeding risk are: (1) Decide when treatment is needed and when it can safely be withheld; (2) for patients with chronic ITP, use the least toxic treatment at the lowest dose; (3) emergency treatment of severe thrombocytopenia-associated bleeding requires combination therapy; and (4) early aggressive therapy may result in durable platelet count responses.

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.

Sustained remission of chronic immune thrombocytopenia after discontinuation of treatment with thrombopoietin-receptor agonists in adults

Thrombopoietin-receptor agonists (TPO-RAs) are highly effective in immune thrombocytopenia (ITP). Recently, reports of sustained remission after TPO-RA discontinuation in adult ITP have been reported. We aimed to describe the subset of patients in whom TPO-RA therapy may induce a durable response. We retrospectively analyzed all of our adult ITP patients treated with TPO-RAs, and focused on patients with discontinued TPO-RA therapy due to treatment response. Forty-six relapsed or refractory ITP patients were treated with TPO-RAs. In 11 of these cases, TPO-RA therapy (seven romiplostim; four eltrombopag) was stopped after achieving treatment response. No side effects of TPO-RAs were observed. These patients were pretreated with 1-3 therapy lines plus splenectomy in six patients prior to TPO-RA administration. None of these patients experienced disease relapse after therapy discontinuation over a median follow-up of 33 months (16-54). Substantial proportion of ITP patients receiving TPO-RAs can maintain a durable response after treatment discontinuation. Sustained ITP remission probably does not depend on previous treatment, splenectomy, or disease duration.

Intravenous Immunoglobulin (IVIg) Utilization in Immune Thrombocytopenia (ITP): A Multi-Center, Retrospective Review

Introduction

Intravenous immunoglobulin (IVIg) is an immune thrombocytopenia (ITP) therapy, which is associated with toxicities, limited availability, increasing utilization, and high cost. This study aimed to assess short- and long-term IVIg utilization in patients with ITP at two tertiary care centers in Ontario, Canada, to determine the proportion of IVIg used in ITP compared with all usage, and to forecast IVIg demand in ITP.

Methods

Records from all adult ITP patients who received IVIg between January 1, 2003, and September 30, 2012, at Hamilton Health Sciences and London Health Sciences Centre were reviewed retrospectively.

Results

During the study period, 383 adult ITP patients (mean age 51.3 years) received a total of 2,098 IVIg infusions (London 547 infusions in 150 patients; Hamilton 1,551 infusions in 233 patients). ITP accounted for 5.6 and 9.1 % of all IVIg usage in London and Hamilton, respectively. The treatments included 264 (53.7 %) acute, 172 (35.0 %) short-term, and 56 (11.4 %) long-term treatments. The amounts of IVIg used for short- and long-term treatment of ITP are forecasted to be approximately 5,000 and 11,000 g per year, respectively, up to 2018. Together, these two centers represent 19.9 % of the provincial IVIg utilization. Assuming similar patient populations and practice patterns in Ontario, the overall provincial cost of IVIg use in ITP may be as high as $5 million annually.

Conclusion

Short- and long-term IVIg utilization for ITP will remain an expensive resource within the Ontario provincial health care system. Physicians and policy makers should reflect on the impact of treating ITP with IVIg and should consider alternatives, where appropriate, to improve patient quality of life and decrease economic costs.

Electronic supplementary material

The online version of this article (doi:10.1007/s40801-015-0009-6) contains supplementary material, which is available to authorized users.

Reduced corticosteroid use in adult patients with primary immune thrombocytopenia receiving romiplostim

Adult patients with primary immune thrombocytopenia requiring first-line treatment typically receive corticosteroids, which are associated with low response rates and many potential side effects. In a retrospective analysis of two 6-month, placebo-controlled, phase III trials, corticosteroid use decreased from 30 to 26% among patients treated with the novel thrombopoietin-mimetic romiplostim (n = 83) and remained above 30% for placebo-treated patients (n = 42). Moreover, compared to placebo, patients were spared 7 weeks of corticosteroid treatment for every 100 weeks of romiplostim treatment. Thereafter, corticosteroid use continued to decrease significantly, from 35 to 20%, in patients treated with romiplostim for up to 3 years in an open-label extension study (n = 101), and patients were spared a further 8 weeks of corticosteroid treatment for each additional 100 weeks of romiplostim treatment. Such reductions in corticosteroids may improve health-related quality of life in patients with primary immune thrombocytopenia.

The isotype of autoantibodies influences the phagocytosis of antibody-coated platelets in autoimmune thrombocytopenic purpura

Autoimmune thrombocytopenic purpura (AITP) is an acquired autoimmune bleeding disorder, characterized by isolated thrombocytopenia because of destruction of auto-antibody-coated platelets by Fc-receptor-mediated phagocytosis. The destruction of autoantibody-sensitized platelets by FcγR-bearing phagocytic cells and the following antigen presentation are considered to play a key role for the pathophysiology of AITP. Although different isotypes of AITP-mediating autoantibodies, e.g. IgG, IgM and IgA, are frequently found in AITP patients, their role in the pathophysiology of AITP remains unclear. Using a flow cytometric monocyte-based phagocytosis assay, we investigated the impact of disease-associated autoantibody isotype in antibody-mediated phagocytosis of platelets. Platelets, labelled with 5-chloromethyl fluorescein diacetate (CMFDA), were incubated with AITP patients' serum characterized by pure IgG or IgM antiplatelet autoantibodies. Labelled platelets were incubated with monocytes. Phagocytosis was defined as the product of percentage of CMFDA-positive monocytes and mean fluorescence intensity of CMFDA. Adherence of platelets to monocytes was quantified by anti-CD61-PerCp in a CMFDA(+) CD14(+) gate. IgG-coated platelets showed a significantly higher phagocytic index than IgM-coated platelets (mean 796 ± 157 versus 539 ± 78, P < 0.01). There were no significant differences regarding platelet adherence to monocytes. The isotype of autoantibodies influences the quantity of in vitro phagocytosis of autologous platelets by monocytes. Therefore, the AITP-mediating autoantibody isotype should be considered more carefully in pathophysiologic models and furthermore in diagnostic, therapeutic and prognostic approaches in AITP.

Eltrombopag for management of chronic immune thrombocytopenia (RAISE): a 6-month, randomised, phase 3 study

BACKGROUND

Eltrombopag is an oral thrombopoietin receptor agonist for the treatment of thrombocytopenia. We aimed to compare the response to once daily eltrombopag versus placebo in patients with chronic immune thrombocytopenia during a 6-month period.

METHODS

We undertook a phase 3, double-blind, placebo-controlled study in adults with previously treated immune thrombocytopenia of more than 6 months' duration who had baseline platelet counts lower than 30,000 per μL. Patients were randomly allocated (in a 2:1 ratio) treatment with local standard of care plus 50 mg eltrombopag or matching placebo once daily for 6 months. Randomisation was done centrally with a computer-generated randomisation schedule and was stratified by baseline platelet count (≤ 15,000 per μL), use of treatment for immune thrombocytopenia, and splenectomy status. Patients, investigators, and those assessing data were masked to allocation. Dose modifications were made on the basis of platelet response. Patients were assessed for response to treatment (defined as a platelet count of 50,000-400,000 per μL) weekly during the first 6 weeks and at least once every 4 weeks thereafter; the primary endpoint was the odds of response to eltrombopag versus placebo. Analysis was by intention to treat. This study is registered at ClinicalTrials.gov, number NCT00370331.

FINDINGS

Between Nov 22, 2006, and July 31, 2007, 197 patients were randomly allocated to treatment groups and were included in the intention-to-treat analysis (135 eltrombopag, 62 placebo). 106 (79%) patients in the eltrombopag group responded to treatment at least once during the study, compared with 17 (28%) patients in the placebo group. The odds of responding were greater in patients in the eltrombopag group compared with those in the placebo group throughout the 6-month treatment period (odds ratio 8·2, 99% CI 3·59-18·73; p<0·0001). 37 (59%) patients receiving eltrombopag reduced concomitant treatment versus ten (32%) patients receiving placebo (p=0·016). 24 (18%) patients receiving eltrombopag needed rescue treatment compared with 25 (40%) patients receiving placebo (p=0·001). Three (2%) patients receiving eltrombopag had thromboembolic events compared with none in patients on placebo. Nine (7%) eltrombopag-treated patients and two (3%) in the placebo group had mild increases in alanine aminotransferase concentration, and five (4%) eltrombopag-treated patients (vs none allocated to placebo) had increases in total bilirubin. Four (7%) patients taking placebo had serious bleeding events, compared with one (<1%) patient treated with eltrombopag.

INTERPRETATION

Eltrombopag is effective for management of chronic immune thrombocytopenia, and could be particularly beneficial for patients who have not responded to splenectomy or previous treatment. These benefits should be balanced with the potential risks associated with eltrombopag treatment.

FUNDING

GlaxoSmithKline.

Efficacy and safety of anti-D for immune thrombocytopenic purpura in children

This study was conducted in 20 children (16 males) (mean age 9.2 +/- 4.34y) with immune thrombocytopenic purpura (ITP) to assess the response to anti-D immunoglobulin. Six patients had newly diagnosed ITP, 6 had persistent ITP and 8 had chronic ITP. The overall response rate was 70% (14/20). The median time to response was 3 days (1-13 days). Response to anti-D was not related to age, sex, severity of bleeding, platelet counts at presentation, ABO blood group, or prior steroid or IVIG response.

High dose dexamethasone therapy shows better responses in acute immune thrombocytopenia than in chronic immune thrombocytopenia

Oral high dose dexamethasone (HDD) was given as a single daily dose for four consecutive days, every 14 days for four courses. Twenty-nine patients were enrolled. Overall 20 patients (69%) responded: complete response (CR) was achieved in 16 (55%) patients, partial response (PR) in three (10%) patients and MR in one (3%) patient. In acute immune thrombocytopenic purpura (ITP) response rates after the first, second, third and fourth cycles were as follows: 64% (9/14), 64% (9/14), 79% (11/14), and 85.7% (12/14), respectively. In chronic ITP, overall response rates after the first, second, third and fourth cycles were as follows: 33% (5/15), 40% (6/15), 53% (8/15) and 53% (8/15) respectively. The median time to response was 14 days (4-42 days). Twelve out of 20 patients (5/12 acute ITP and 7/8 chronic ITP) relapsed; median relapse free survival till last follow-up in the remaining eight patients was 130 days (65-365 days).

Efficacy and safety of anti-D for treatment of adults with immune thrombocytopenia

This study was planned to assess the response of anti-D in patients with immune thrombocytopenia (ITP). Twenty adults (8 males: 12 females) with a median age 33.5 years (19-59 years) were included. Nine patients had newly-diagnosed ITP, 6 had persistent ITP and 5 had chronic ITP. The overall response rate was 65%. Patients with newly diagnosed ITP showed response rates of 77% (7/9), persistent ITP had response rates 50% (3/6) and patients with chronic ITP had response rates of 60% (3/5). The median time to response was 3 days (1-11 days). There was no correlation of response with age, sex, severity of bleeding, presenting platelet counts, ABO blood group or prior steroid or IVIG response.

Treatment practices in adults with chronic immune thrombocytopenia - a European perspective

Immune thrombocytopenia (ITP) is characterised by platelet destruction and impaired production leading to isolated thrombocytopenia. The aim of this study, comprising a retrospective longitudinal cohort study complemented by a Delphi panel of 35 physicians, was to describe standard treatment practices and treating physician's perception and preferences for available treatment options in chronic ITP. The medical records of 610 patients were reviewed over 12 months. Mean age at the start of the observational period was 54.6 yr, median platelet count 77 x 10(9)/L with 41% of patients having symptoms of ITP. Treated patients (61%) received an average of 2.7 medications either for ITP or ITP treatment-related side effects. An array of products was used, but the most frequent were corticosteroids. Delphi panel physicians (45%) indicated the main goals for treatment were to increase platelet levels to at least 30 x 10(9)/L to prevent bleeding or haemorrhage. The majority (89%) indicated that personal experience influenced treatment choice. Most (>80%) rated splenectomy and high-dose corticosteroids as the most effective but were concerned about side effects, and many (75%) would like access to interventions with improved efficacy and safety. The study highlights the need for updated evidence-based treatment guidelines to assist physicians in patient treatment decisions and to realise improvements in patient outcomes. It also identified perceived shortcomings of existing therapies and the need to establish an evidence base for newer interventions that could potentially make lasting response to treatment with fewer adverse effects an achievable goal.

New treatments for idiopathic thrombocytopenic purpura: rethinking old hypotheses

BACKGROUND

The efficacy of thrombopoietin (TPO) mimetics in patients with idiopathic thrombocytopenic purpura (ITP) reaffirms that impaired platelet production is an important mechanism. New strategies to reduce platelet destruction, like rituximab, are also effective.

OBJECTIVES

To describe the efficacy and safety of rituximab and the TPO mimetics, romiplostim and eltrombopag, and how they relate to ITP pathogenesis.

METHODS

Narrative review summarizing full publications and meeting abstracts.

RESULTS/CONCLUSIONS

A 4-week course of rituximab is associated with a platelet count response in 60% of patients with ITP, and durable responses have been observed. Subtle increases in infection have been reported. Romiplostim and eltrombopag are each associated with a 60 - 85% response while on treatment. Transient bone marrow reticulin with romiplostim and elevated liver enzymes with eltrombopag are rare side effects. The application of these agents in non-splenectomized patients requires further study.

Controversies in the diagnosis and management of childhood acute immune thrombocytopenic purpura

Acute immune thrombocytopenic purpura (ITP) occurs most commonly in young children who present with severe isolated thrombocytopenia and purpura. A marrow examination is not required unless glucocorticoids are used, lest treatment mask incipient acute lymphoblastic leukemia, but controversy exists here. The recommendations for evaluation and management remain controversial, since prospective controlled trials have not been done. There is some consensus based on experience and empiric data. Almost all children with acute ITP will recover completely without therapy. Although the various treatments may increase the platelet count, they do not influence the outcome of the illness, may increase cost, and cause significant side effects. Therefore, careful observation may be the best management option for the patient with ITP, in the absence of severe bleeding. The data available relevant to these issues are discussed.

Thrombopoietin agonists for the treatment of thrombocytopenia in liver disease and hepatitis C

Thrombocytopenia is a condition of unusually low level of platelets in blood, resulting from an imbalance between the production and destruction of platelets, and is associated with aplastic anemia, myelodysplasia, and idiopathic thrombocytopenic purpura (ITP). Thrombocytopenia can also be associated with severe chronic liver disease as a result of several factors that may act in concert, including reduced production of the endogenous thrombopoietic growth factor, thrombopoietin (TPO). This article examines the nature of thrombocytopenia, ITP, and TPO.

[Autoimmune thrombocytopenia, neutropenia and hemolysis]

Autoantibodies reduce the life span of platelets, granulocytes, and red blood cells. This may result in thrombocytopenia with bleeding, in neutropenia with infection, and in anemia, respectively. Immune-hemocytopenias can manifest as primary disease without another cause, or they are associated with other underlying morbidities such as autoimmune diseases, lymphoproliferative diseases, immune defects, or viral infections. Diagnosis is confirmed by laboratory tests showing autoantibodies against the respective blood cells. Indication for treatment is the clinical manifestation of symptoms: bleeding in autoimmune thrombocytopenia, infections in neutropenia, and symptomatic anemia, respectively. Especially in case of thrombocytopenia patients should not be treated because of abnormal laboratory values, only. To date steroids are the basic treatment in autoimmune thrombocytopenia and hemolytic anemia, while prophylactic antibiotics are the main treatment in autoimmune neutropenia. Growth factors like the new thrombopoietin receptor agnonists in autoimmune thrombocytopenia or G-CSF in autoimmune neutropenia, and anti-CD20 antibodies are new options for treatment.

Rituximab-associated changes in platelet count in patients with non-Hodgkin lymphoma

Rituximab is a monoclonal antibody specific for the CD20 antigen. Clinical factors associated with thrombocytopenia after administration of rituximab have only been reported as case reports. We have analysed retrospectively the change of platelet counts following the administration of rituximab in 253 patients with non-Hodgkin lymphoma (NHL). Correlations with clinical and laboratory parameters were assessed. A mean overall decrease in platelets was observed after rituximab infusion. A downward trend in platelet count of more than 30% was observed in 7.2% of the patients. The decline was observed when rituximab was given as a single agent or in combination with chemotherapy. The risk factors to develop a decline in platelets after infusion of rituximab were pre-existent thrombocytopenia, advanced lymphoma stage, bone marrow infiltration, splenomegaly, leukemic presentation, and Burkitt lymphoma histology. In conclusion, a decline in platelet count after administration of rituximab was observed in patients with NHL, mainly those with pre-existing thrombocytopenia.

Refractory immune thrombocytopenic purpura: current strategies for investigation and management

There is currently no consensus on how best to manage refractory immune thrombocytopenic purpura (ITP). In part, this reflects the need for individualized treatment due to the wide spectrum of patients' requirements and responsiveness to therapies. The objective of this review is to provide a clinically useful guide to current management strategies. This article suggests investigations to identify factors that may exacerbate thrombocytopenia and underlie poor therapeutic responses, and highlights emerging therapies, including the thrombopoietic agents, which are anticipated to dramatically alter the natural history of "refractory" ITP. Morbidity, mortality and heath-related quality of life are also discussed.

Standardization of terminology, definitions and outcome criteria in immune thrombocytopenic purpura of adults and children: report from an international working group

Diagnosis and management of immune thrombocytopenic purpura (ITP) remain largely dependent on clinical expertise and observations more than on evidence derived from clinical trials of high scientific quality. One major obstacle to the implementation of such studies and in producing reliable meta-analyses of existing data is a lack of consensus on standardized critical definitions, outcome criteria, and terminology. Moreover, the demand for comparative clinical trials has dramatically increased since the introduction of new classes of therapeutic agents, such as thrombopoietin receptor agonists, and innovative treatment modalities, such as anti-CD 20 antibodies. To overcome the present heterogeneity, an International Working Group of recognized expert clinicians convened a 2-day structured meeting (the Vicenza Consensus Conference) to define standard terminology and definitions for primary ITP and its different phases and criteria for the grading of severity, and clinically meaningful outcomes and response. These consensus criteria and definitions could be used by investigational clinical trials or cohort studies. Adoption of these recommendations would serve to improve communication among investigators, to enhance comparability among clinical trials, to facilitate meta-analyses and development of therapeutic guidelines, and to provide a standardized framework for regulatory agencies.