Childhood immune thrombocytopenic purpura: diagnosis and management

IVIg treatment increases thrombin activation of platelets and thrombin generation in paediatric patients with immune thrombocytopenia

Clinical manifestations and laboratory parameters of haemostasis were investigated in 23 children with newly diagnosed immune thrombocytopenia (ITP) before and after intravenous immunoglobulin (IVIg) treatment. ITP patients with platelet counts of less than 20 × 109 /L and mild bleeding symptoms, graded by a standardized bleeding score (BS), were compared with healthy children with normal platelet counts and children with chemotherapy-related thrombocytopenia. Markers of platelet activation and platelet apoptosis in the absence and presence of platelet activators were analysed by flow cytometry; thrombin generation in plasma was determined. ITP patients at diagnosis presented with increased proportions of platelets expressing CD62P and CD63 and activated caspases, and with decreased thrombin generation. Thrombin-induced activation of platelets was reduced in ITP compared with controls, while increased proportions of platelets with activated caspases were observed. Children with a higher BS had lower proportions of CD62P-expressing platelets compared with those with a lower BS. IVIg treatment increased the number of reticulated platelets, the platelet count to more than 20 × 109 /L and improved bleeding in all patients. Decreased thrombin-induced platelet activation, as well as thrombin generation, were ameliorated. Our results indicate that IVIg treatment helps to counteract diminished platelet function and coagulation in children with newly diagnosed ITP.

Expression of B-cell activating factor in pediatric patients with immune thrombocytopenia: a single institutional series and review of literature

B-cell-activating factor (BAFF) is a crucial cytokine supporting survival and differentiation of B cells. Dysregulation of BAFF is involved in the pathogenesis of B-cell related autoimmune diseases including immune thrombocytopenia (ITP). The aim of this study was to evaluate the significance of BAFF expression in pediatric ITP patients. Eighty pediatric patients with ITP are subdivided in three groups. Group I included (32 patients) diagnosed with acute ITP less than 3 months, group II (48 patients) diagnosed with persistent ITP (from 3 to 12 months) and chronic ITP (more than 12 months) and group III 20 healthy controls. Complete blood picture, autoimmune profile, antiplatelet antibodies, coagulation profile, bone marrow examination, and RT-PCR were performed to detect the expression for BAF for all participants in this study. BAFF expression levels significantly increased in cases rather than in controls. BAFF Expression Value significantly increased in groups I & II (3.10 ± 1.99&3.29 ± 2.58) compared to controls (0.83 ± 0.45) as p < .001 for both. On the other hand, groups I & II were comparable in BAFF Expression Value (p = .470). BAFF expression increased in ITP patients, implying a function in the disease's pathogenesis.

Autoimmune- and complement-mediated hematologic condition recrudescence following SARS-CoV-2 vaccination

Severe exacerbation of underlying hematologic conditions can occur within 1 to 4 days after dose 2 of a 2-dose SARS-CoV-2 vaccine series.

A mild exacerbation after dose 1 and/or a history of vaccine-related adverse events may portend a more serious event after dose 2.

A variety of autoimmune disorders have been reported after viral illnesses and specific vaccinations. Cases of de novo immune thrombocytopenia (ITP) have been reported after SARS-CoV-2 vaccination, although its effect on preexisting ITP has not been well characterized. In addition, although COVID-19 has been associated with complement dysregulation, the effect of SARS-CoV-2 vaccination on preexisting complementopathies is poorly understood. We sought to better understand SARS-CoV-2 vaccine-induced recurrence of autoimmune- and complement-mediated hematologic conditions. Three illustrative cases were identified at the University of Washington Medical Center and the Seattle Cancer Care Alliance from January through March 2021. We describe the recrudescence of 2 autoimmune conditions (ITP and acquired von Willebrand Disease [AvWD]/acquired hemophilia A) and 1 complementopathy (paroxysmal nocturnal hemoglobinuria [PNH]). We report the first known case of AvWD/acquired hemophilia A, and describe the first PNH exacerbation in the absence of complement inhibition after SARS-CoV-2 vaccination. Although SARS-CoV-2 vaccine-induced ITP is a known concern, our case clearly depicts how thrombocytopenia in the setting of preexisting ITP can sequentially worsen with each vaccine dose. Based on our experiences and these examples, we provide considerations for how to monitor and assess risk in patients with underlying autoimmune- and complement-mediated hematologic conditions.

A Narrative Approach to Describe QoL in Children With Chronic ITP

Objective: Primary immune thrombocytopenia (ITP) is a hemorrhagic disorder. Spontaneous recovery within 12 months occurs in the majority of pediatric patients. Nevertheless, in 20-30% of children the disease is chronic. The impact extends to the patients' families, whose everyday life, in terms of interpersonal relationships and financial status, is adversely affected. This study investigated the ability of a narrative instrument to improve the quality of life of pediatric chronic ITP patients and their families and quantified the familial burden imposed by the illness. Method: A quantitative survey and a narrative plot delivered through an online platform were adopted for the analysis. Results: Pediatricians of ten Italian Hematologic Centers explained the projects to patients and their family in the outpatient clinic. 70 caregivers of children with ITP filled the ad-hoc questionnaire. Data from 53 caregivers revealed the emotional impact of pediatric chronic ITP. The narrative approach highlighted the specific resources used by patients and their families to cope with the disease and its chronicity. Discussion: Caregivers underlined the need for "humaneness" in their interactions with clinical personnel. The majority of respondents provided positive feedback regarding the narrative project, defining the experience as "liberating" and improving their quality of life.

Thrombopoietin and its receptor expression in pediatric patients with chronic immune thrombocytopenia

OBJECTIVES

Chronic immune thrombocytopenia (cITP) is common in children. However, the pathogenesis has not been fully elucidated. This study aimed to determine whether thrombopoietin (TPO) and its receptor c-mannosylation of the TPO receptor (c-Mpl) have an impact on childhood cITP.

METHODS

Sixty-four patients with newly diagnosed ITP (nITP), 64 patients with persistent ITP, 80 patients with cITP, and 64 healthy children (control) were enrolled in this study. Plasma TPO was measured with an ELISA, and c-Mpl was determined by flow cytometry.

RESULTS

Plasma TPO levels showed differences among the four groups (p = 0.001). TPO levels in the cITP group were significantly decreased compared to those in the nITP group (p < 0.05). The mean fluorescence intensity (MFI) of c-Mpl was significantly different among the four groups (p = 0.0275). c-Mpl MFI was lower in the cITP group than in the nITP group(p < 0.05). Quantitative real-time PCR analysis showed that TPO mRNA expression was higher in the control group than in the ITP groups (p < 0.0001). The c-Mpl mRNA levels also showed significant differences among the four groups (p = 0.023). The control group, compared with the other groups, had lower levels of c-Mpl mRNA.

CONCLUSIONS

The expression of TPO and c-Mpl was significantly decreased in the cITP group compared to the nITP group, suggesting that TPO and its receptor may play important roles in childhood cITP pathogenesis.

Health-related quality of life in children with chronic immune thrombocytopenia in China

Background

The concept of health-related quality of life (HRQoL) was brought up decades ago and has been well utilized in many different areas. Regarding immune thrombocytopenia (ITP) management, much work has been done to emphasize the necessity of taking HRQoL into consideration. However, data on HRQoL of children with chronic ITP remain rare.

Methods

This is a cross-sectional study. Children with chronic ITP aged from 2 to 18 and their parents were recruited. Participants completed the Pediatric Quality of Life Inventory™ (PedsQL™) and Kids’ ITP Tools (KIT) questionnaires at only one time. The Pearson’s correlation was examined between these measures for the pooled samples.

Results

A total of 42 families participated. Mean child self-report scores of KIT and PedsQL™ were 78.60 (SD = 12.40) and 85.13 (SD = 14.12), respectively, corresponding to parent proxy report scores, which were 73.40 (SD = 19.96) and 85.10 (SD = 13.56), respectively. Mean score of KIT parent impact report was only 40.39 (SD = 19.96). Significantly higher KIT scores (self-report and parent proxy) were observed in children with PLT more than 30 × 10*9/L compared to others, and this difference was even more noticeable in the PedsQL™ parent proxy report group (p < 0.001). As with intravenous immunoglobulin, the statistics difference appeared only in KIT child self-report group (p = 0.03), while for bone marrow examination, the difference appeared only in PedsQL™ parent proxy report group (p = 0.01). A negative relationship was apparent between duration of disease and scores. Gender and use of corticosteroids had no impact on the KIT and PedsQL™ scores here. Internal consistency reliability was demonstrated with Cronbach’s alpha for all scales above the acceptable level of 0.89 (range from 0.88 to 0.97). There was a substantial concordance (p < 0.001) between the child and parent proxy scores (ICC for KIT is 0.59, ICC for PedsQL™ is 0.85). Meanwhile, KIT scores are correlated with PedsQL™ (r = 0.75 for child self report, r = 0.61 for parent proxy report).

Conclusions

ITP affects HRQoL of children and parents. Parents are much more concerned with the disease than their children, which seriously influence their HRQoL as a result. The cross-culture translated KIT is reliable and valid with acceptable correlation to the PedsQL™. KIT provides valuable information of childhood ITP and will be a reliable outcome measure for further clinical research on HRQoL.

A Case of Immune Thrombocytopenic Purpura After Rabies Vaccination

We describe a case of immune thrombocytopenic purpura (ITP) occurring 15 days after the first dose of a 4-dose rabies vaccination series. ITP is thought to be an immune-mediated process triggered by an infection or toxin. There is little evidence in the literature beyond case reports of an association of ITP with vaccines other than with the measles, mumps, and rubella vaccine. This is the third reported case of ITP associated with rabies vaccination. Because of the rare occurrence of this adverse event relative to the severity of rabies infection, the benefits of rabies vaccination, when indicated, outweigh the low and possible risk of ITP.

Immune thrombocytopenic purpura in a liver transplant patient

Thrombocytopenia is common during the early posttransplant period. Most cases are mild and recover in 1 month. Occasionally, severe thrombocytopenia may occur in the late posttransplant period. We report a 10-year-old boy with severe thrombocytopenia 3.5 years after liver transplant. We exclude secondary causes of thrombocytopenia. Bone marrow aspiration findings and treatment response were suggestive for immune thrombocytopenic purpura. The patient was treated with intravenous immunoglobulin at thrombocytopenia periods successfully. We continued tacrolimus, but preferred a reduced dose. In conclusion, immune thrombocytopenic purpura should be borne in mind as a reason of late onset, severe thrombocytopenia after liver transplant.

Cerebral infarctions after intravenous immunoglobulin therapy for ITP in a child

BACKGROUND

Intravenous immunoglobulin is the favored therapy in childhood immune thrombocytopenic purpura. It is usually well tolerated with manageable side effects, but venous and arterial thrombosis following its administration have been described, mostly in adults.

METHODS

We describe a 3-year-old girl with immune thrombocytopenic purpura and intracranial hemorrhage who received intravenous immunoglobulin therapy and subsequently developed multifocal cerebral infarctions.

RESULTS

Product specific as well as other factors may play a role in the development of this complication of intravenous immunoglobulin therapy. This is the only reported case of intravenous immunoglobulin-related thrombosis in a child with immune thrombocytopenic purpura and intracranial hemorrhage.

CONCLUSIONS

Thrombotic complications are associated with intravenous immunoglobulin administration and this includes cerebral infarcts.

Hemorrhagic Stroke in an Adolescent Female with HIV-Associated Thrombotic Thrombocytopenic Purpura

HIV-1 infection can trigger acute episodes of Idiopathic Thrombocytoponic Purpura (ITP), and Thrombotic Thrombocytopenic Purpura (TTP), particularly in populations with advanced disease and poor adherence to antiretroviral therapy (ART). These diseases should be distinguished because they respond to different treatments. Previous studies done in adults with HIV-TTP have recommended the prompt initiation or re-initiation of ART in parallel with plasma exchange therapy to improve the clinical outcome of these patients. Here, we describe a case of HIV-TTP resulting in an acute hemorrhagic stroke in a 16 year old female with perinatally acquired HIV infection and non-adherence to ART, who presented with severe thrombocytopenia, microangiopathic hemolytic anemia, and a past medical history of HIV-ITP. Both differential diagnosis and treatments for HIV-ITP and HIV-TTP were considered simultaneously. A decrease in plasma ADAMTS13 activity (<5%) without detectable inhibitory antibodies confirmed the diagnosis of HIV-TTP. Re-initiation of ART and plasma exchange resulted in a marked decrease in the HIV-RNA viral load, recovery of the platelet count, and complete recovery was achieved with sustained virologic suppression.

Age and duration of bleeding symptoms at diagnosis best predict resolution of childhood immune thrombocytopenia at 3, 6, and 12 months

OBJECTIVE

To evaluate the predictive value of clinical features at diagnosis of immune thrombocytopenia (ITP) for resolution of disease.

STUDY DESIGN

Hospital records of 472 consecutive children (<18 years old) with ITP cared for at 2 participating centers were reviewed retrospectively and data related to the initial presentation were recorded. Logistic regression analysis was used for calculating prediction of resolution at 3, 6, and 12 months from diagnosis.

RESULTS

The most significant predictors for resolution of ITP at 3, 6, and 12 months were age at onset <10 years and abrupt onset (history of <2 weeks of bleeding). We designed a prediction rule for ITP chronicity based on these criteria. The rate of developing chronic ITP for low, intermediate, and high risk children at diagnosis of ITP was 11%, 39%, and 63%, respectively. Recovery rate at 3 months for low, intermediate, and high risk children was 72%, 43% and 30%, respectively.

CONCLUSIONS

We present a simple rule to predict recovery from ITP at 3, 6, and 12 months from diagnosis. For prediction of resolution at 3 months, our rule was in agreement with the more complex, previously described Nordic score. Prediction of resolution of ITP may enable practitioners to better inform children and parents at the time of diagnosis, resulting in reduced anxiety and improved quality of life.

ITP in children: pathophysiology and current treatment approaches

Primary immune thrombocytopenia (ITP) is one of the most common bleeding disorders of childhood. In most cases, it presents with sudden widespread bruising and petechiae in an otherwise well child. Thought to be mainly a disorder of antibody-mediated platelet destruction, ITP can be self-limited or develop into a chronic condition. In this review, we discuss current concepts of the pathophysiology and treatment approaches to pediatric ITP.

CD4+CD25+High Foxp3+ Regulatory T Cells, B Lymphocytes, and T Lymphocytes in Patients With Acute ITP in Assiut Children Hospital

We aimed to examine the levels of lymphocyte subsets and regulatory T cells in patients with newly diagnosed immune thrombocytopenia (ITP) and their correlation with the course of ITP. The study included 40 pediatric patients with acute ITP and 30 controls. Lymphocytes and regulatory T cells were analyzed by flow cytometry. The percentages of CD19+ and CD8+ cells were significantly increased while that of CD4+ cells and CD4+/CD8+ ratio were significantly decreased. The percentages of CD4+CD25+High and CD4+CD25+High forkhead box protein 3 (Foxp3+) cells and the expression of Foxp3+ in CD4+CD25+High cells were significantly decreased in patients. Age, platelet count, and mean platelet volume (MPV) in patients with brief duration of thrombocytopenia were significantly decreased than in those with prolonged duration. The percentages of CD8+, CD4+CD25+High, and CD4+CD25+High Foxp3+ were significantly increased in patients with brief duration. Age, platelet count and MPV, and CD8+ cells had prognostic significance. CD4+CD25+High Foxp+ T cells may be a helpful prognostic marker in children with acute ITP.

Management of children and adolescents with primary immune thrombocytopenia: controversies and solutions

The management including diagnostic procedures, prophylaxis, treatment and follow-up of patients with primary immune thrombocytopenia (ITP) in childhood is controversial due to limited clinical data, difficulties in the estimation of individual bleeding risk and heterogeneity of pathophysiology potentially causing various treatment responses. Advances in the management of children include increased international collaborations, improved quality of diagnosis and treatment, increased clinical data, refinement of consensus statements where clinical evidence is absent, new drugs and last but not least establishment of watch-and-wait strategies. The Intercontinental Cooperative ITP Study Group promotes international collaboration since more than 10 years based on a worldwide network and experience in registries. Future considerations include concentration of available resources, strengthening international collaboration, focusing on most important scientific and clinical questions, such as identification of the subgroup of patients that benefits most from prophylactic platelet-enhancing treatments and investigation of treatment endpoints other than concepts solely based on the platelet count, including bleeding symptoms, health-related quality of life and economical aspects of treatments.

Use of romiplostim for primary immune thrombocytopenia in children

Very little has been published on the use of romiplostim to treat primary immune thrombocytopenia (ITP), refractory to previous treatments, in children. The objective of this study was to determine its efficacy and safety in pediatric patients in a university general hospital. Retrospective, longitudinal observational study of pediatric patients on treatment with romiplostim. The principal efficacy variable was platelet count. Safety was evaluated by recording possible adverse reactions to the medication, monitoring the appearance of thrombosis, thrombocytopenia during dose reduction, hemorrhage, and myelodysplastic syndromes. Three patients in the authors' center have been treated with romiplostim (subcutaneous [SC], initial dose: 1 μg/kg/week) for ITP refractory to various treatments: 1 with newly diagnosed ITP and 2 with chronic ITP. Patients were followed up for 27 to 39 weeks after starting treatment. Responses were achieved in 7 to 28 days, and complete responses were maintained for 37% to 91% of the follow-up period, with median platelet counts between 40 × 10(3)/μL and 215 × 10(3)/μL. The adverse reactions observed during follow-up were headache and asthenia in one patient and mucocutaneous bleeding after dose suspension in another one. With regard to effectiveness, the response in the 3 patients was varied. The drug was considered to be safe, as there were only mild adverse reactions. Although further studies and long-term follow-up are required, these results show that romiplostim could be considered an alternative to immunosuppressive therapies, such as rituximab, or splenectomy in refractory chronic ITP.

The risk of immune thrombocytopenic purpura after vaccination in children and adolescents

BACKGROUND

The risk of immune thrombocytopenic purpura (ITP) after childhood vaccines other than measles-mumps-rubella vaccine (MMR) is unknown.

METHODS

Using data from 5 managed care organizations for 2000 to 2009, we identified a cohort of 1.8 million children ages 6 weeks to 17 years. Potential ITP cases were identified by using diagnostic codes and platelet counts. All cases were verified by chart review. Incidence rate ratios were calculated comparing the risk of ITP in risk (1 to 42 days after vaccination) and control periods.

RESULTS

There were 197 chart-confirmed ITP cases out of 1.8 million children in the cohort. There was no elevated risk of ITP after any vaccine in early childhood other than MMR in the 12- to 19-month age group. There was a significantly elevated risk of ITP after hepatitis A vaccine at 7 to 17 years of age, and for varicella vaccine and tetanus-diphtheria-acellular pertussis vaccine at 11 to 17 years of age. For hepatitis A, varicella, and tetanus-diphtheria-acellular pertussis vaccines, elevated risks were based on one to two vaccine-exposed cases. Most cases were acute and mild with no long-term sequelae.

CONCLUSIONS

ITP is unlikely after early childhood vaccines other than MMR. Because of the small number of exposed cases and potential confounding, the possible association of ITP with hepatitis A, varicella, and tetanus-diphtheria-acellular pertussis vaccines in older children requires further investigation.

Management of immune thrombocytopenic purpura in children: potential role of novel agents

The treatment of immune thrombocytopenic purpura (ITP) in children is controversial, requiring individualized assessment of the patient and consideration of treatment options. If the platelet count is >10 000/μL and the patient is asymptomatic, a 'watch and wait' strategy is appropriate since most children with ITP will recover completely without pharmacotherapy. If therapy is indicated because of bleeding or a platelet count <10 000/μL, then treatment with glucocorticoids, intravenous immunoglobulin (IVIg), or anti-D are possible initial choices. Glucocorticoid treatment is the least expensive and is our usual first choice of therapy. Its use assumes that the blood counts and blood film have been evaluated to ensure the absence of evidence of alternative diagnoses, such as thrombotic thrombocytopenic purpura or incipient acute leukemia. IVIg is expensive and often causes severe headache, nausea and vomiting, and requires hospitalization at our institution. Anti-D therapy is also expensive and can only be used in patients who are Rhesus D positive. These therapies, even if only transiently effective, can be repeated if necessary. Children usually recover from newly diagnosed ITP, with or without multiple courses of medical therapy. If the disease becomes 'persistent' with severe thrombocytopenia and/or bleeding, and is no longer responsive to the three first-line therapies, the next approach includes the use of thrombopoietin receptor agonists or rituximab. When the disease persists for more than 1 year, it is considered chronic, and, if symptomatic, it may become necessary to consider third-line therapies, including splenectomy, alternative immunosuppressive agents, or combination or investigative chemoimmunotherapy. This review considers the indications, mechanism of action, and effectiveness of the traditional and novel treatment options for patients with ITP.

[What is the prognosis of chronic immune thrombocytopenia?]

OBJECTIVES

To analyse the characteristics of children with chronic ITP (chronic immune thrombocytopenia) in the Hospital Infantil Universitario Niño Jesús (HIUNJ) between 2003 and 2008. To also evaluate whether clinical variables as age, gender, initial platelet count, and treatment have any prognostic significance on the outcome of ITP.

PATIENTS AND METHODS

Data were retrospectively collected from 288 patients diagnosed with "Purpura and other haemorrhagic illnesses". Forty-two out of these 288 satisfied the criteria for "chronic ITP".

RESULTS

Ten patients out of 42 (23.8%) achieved remission with splenectomy, and 25 (almost 60%) achieved it without splenectomy (14 were complete remissions and 11 were partial remissions). Eight patients (almost 20% of patients with chronic ITP) had spontaneous remissions between 6 and 12 months from initial diagnosis. None of the clinical variables analysed were related to the outcome of the disease and the prognosis of the disease.

CONCLUSIONS

Almost 60% of children with chronic ITP achieve remission without treatment regardless of age, gender, initial treatment or platelet count. Splenectomy is one of the treatments with best results; however the high spontaneous recovery rate in children with cITP, the low percentage of bleeding, and the generally benign outcome should encourage delaying this as long as possible. As it is possible to have a remission between 6 and 12 months from the initial diagnosis, the term "chronic" should be reserved for patients with ITP lasting more than 1 year.

Short-course high-dose dexamethasone therapy for chronic idiopathic thrombocytopenic purpura in children

First-line therapies of acute and chronic idiopathic thrombocytopenic purpura (ITP) include intravenous immunoglobulin, IV anti-D and corticosteroids. A short-course high-dose dexamethasone (HDD-SC) therapy has recently been reported to be efficacious in acute ITP. The present study was conducted to assess the efficacy of HDD-SC in children with chronic ITP. Over a period of 10 months, 13 patients with chronic ITP were given HDD-SC (20 mg m(-2) IV daily for 4 days, four cycles repeated every 15 days). Of the 12 patients who could be evaluated, complete response was observed in 8 (66.6%) and moderate response in 2 (17%) patients, whereas 2 (17%) patients had no response. HDD-SC appears to be a safe and effective therapy in childhood ITP.

Chronic immune thrombocytopenic purpura-who needs medication?

Chronic ITP (immune thrombocytopenic purpura; now defined as duration of more than 12 months) is not always associated with significant bleeding problems so that most children and adults can be managed expectantly with no medication unless surgery, accidents or other pathology mandate it. A cut-off platelet count of 30 x 10(9)/l divides a group with no increased mortality from those whose risk is greater and in whom medication is usually appropriate. There is increasing recognition of long-term morbidity and mortality associated with immune suppression induced by medication and more recently new concerns have arisen about the long-term vascular complications of splenectomy. A more conservative approach to medication is warranted in many patients with chronic ITP.

Association between drug and vaccine use and acute immune thrombocytopenia in childhood: a case-control study in Italy

Immune thrombocytopenic purpura (ITP) is an immunomediated disease characterized by a decrease in platelet count and, in its more severe forms, by bleeding symptoms. Many drugs have been implicated in the pathogenesis of drug-induced thrombocytopenia in adults; only limited data on drug-related ITP in children have been published. Our study was set up to evaluate the consistency of the association between drug and vaccine use and ITP in children. This study is part of an Italian multicentre study on adverse drug reactions in children, coordinated by the Italian National Institute of Health, which was started in November 1999 and is ongoing. The study was conducted by enrolling all children aged more than 1 month who were hospitalized through the paediatric emergency department for the following conditions: thrombocytopenia (platelet count <100 x 103/L); acute neurological disorders; non-infectious mucocutaneous diseases and vasculitis; and endoscopically confirmed gastroduodenal lesions and/or clinically defined haematemesis and melaena. Children with chronic pathologies or concomitant diagnoses of cancer or immunodeficiency were not included in our study. During hospital admission, a physician interviewed parents using a structured questionnaire. The main aim of the interview was to collect information on drug exposure in a time period of 3 weeks and vaccine exposure in a period of 6 weeks preceding hospitalization. Using a case-control study design, exposure of children with thrombocytopenia (cases) to drugs and vaccines was compared with similar exposure of children with gastroduodenal lesions and neurological disorders (controls); this allowed us to estimate the odds ratios (ORs) of the occurrence of thrombocytopenia associated with the use of drugs or vaccines. Up to December 2007, the study population included 387 cases of thrombocytopenia and 1924 controls. Despite the low platelet count, ITP was generally a mild disease, without serious bleeding in the majority of cases and associated with a short length of hospital stay. After adjusting for concurrent use of other drugs, use of the antibacterials was associated with a more than 2-fold increase in the risk of developing ITP (OR 2.4; 95% CI 1.8, 3.1). Mucolytics and NSAIDs were associated with an OR of 1.9; 95% CI 1.2, 2.9 and 1.5; 95% CI 1.0, 2.1 respectively, while paracetamol (acetaminophen) was associated with an OR of 1.5; 95% CI 1.2, 2.0. MMR vaccination was associated with an increased risk of developing ITP (OR 2.4; 95% CI 1.2, 4.7). The results of this study provide evidence for an association between ITP and exposure to selected antibacterials, NSAIDs, paracetamol, mucolytics and MMR vaccination.

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.

The geoepidemiology of immune thrombocytopenic purpura

First described in 1735 (Watson-Williams et al., 1958), immune-mediated platelet destruction is a phenomenon of protean associations that has historically varied in its definition. Recently, consensus guidelines were proposed for a standardized system of nomenclature that preserves the acronym "ITP" but encompasses a number of causes of immune-mediated thrombocytopenias, including both primary immune thrombocytopenia as well as such entities as thrombocytopenia associated with connective tissue diseases or cancer. In this paper, we will focus on current aspects of geoepidemiology, pathophysiology, diagnosis and management of adult and pediatric primary immune thrombocytopenia. It is clear that both genetic and extrinsic factors exist for ITP and are likely different between children and adults. Immune thrombocytopenia remains a challenging problem but our understanding of its pathophysiology has greatly improved.

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.

Treatment of immune thrombocytopenic purpura: focus on eltrombopag

Immune thrombocytopenic purpura (ITP) is a relatively common autoimmune disorder in which antibodies are produced to circulating platelets. Symptoms can be mild, but for most patients the risk of severe bleeding is unacceptable and treatment is required. Glucocorticoids followed by splenectomy had been the mainstays of therapy. High dose intravenous immunoglobulin and anti-RhD therapy are available for patients with severe illness, but produce only temporary benefit. Rituximab may provide more durable responses, danazol may be underutilized, and immunosuppressants and cytotoxic agents are less often required. Recently the pathophysiology of ITP has been more clearly elucidated, particularly the importance of decreased production of platelets in most patients and the very blunted rise that occurs in serum thrombopoietin (TPO). The isolation of TPO and better understanding of its role in thrombopoiesis has led to the development of new highly effective treatments. TPO analogs had some successes in treating highly refractory ITP patients but were taken out of development due to TPO-antibody induction. Two second-generation TPO-mimetics, romiplostim and the orally available eltrombopag, have recently been licensed in some territories for the treatment of ITP. Approval of eltrombopag was based on results from Phase II and III placebo-controlled clinical trials and a long-term extension study. About 80% of patients achieve significant increases in platelet count (11% of placebo patients), with reduced bleeding and reduced use of concomitant medications; responses are often durable with no tachyphylaxis. The side effects of eltrombopag are generally mild and not worse than placebo, although there are concerns about hepatic dysfunction, and the potentials for thromboses, marrow reticulin fibrosis, rebound thrombocytopenia and cataracts. This is an important new option for highly refractory patients, and its niche in earlier treatment (and for other thrombocytopenic disorders) is yet to be defined.

Absence of platelet recovery following Helicobacter pylori eradication in childhood chronic idiopathic thrombocytopenic purpura: a multi-center randomized controlled trial

OBJECTIVE

To investigate the effect of Helicobacter pylori eradication on platelet recovery in childhood chronic idiopathic thrombocytopenic purpura (ITP).

PATIENTS AND METHODS

A multi-center randomized controlled trial was conducted. Patients aged 4-18 years, diagnosed with chronic ITP, defined by platelet count below 100 x 10(9)/L lasting more than 6 months without identified causes, were enrolled and underwent (13)C-urea breath test for diagnosis of H. pylori infection. Patients who received prednisolone more than 0.5 mg/kg per day or received other platelet-enhancing therapy were excluded. Patients with H. pylori infection were randomized into two groups: treatment and control groups. Treatment group received a standard protocol for H. pylori eradication and repeated (13)C-UBT at 4-6 weeks to confirm successful therapy while the control group received no specific treatment. Monthly platelet count was monitored for 6 months in both groups. Primary outcome was platelet recovery, defined by platelet count over 100 x 10(9)/L for at least 3 months.

RESULTS

Of the 55 ITP children, 16 (29.1%) had H. pylori infection. There were no differences in age, sex, duration of disease, platelet count, and the dose of prednisolone between the treatment group (n = 7) and control group (n = 9). One patient in control group was withdrawn due to massive gastrointestinal bleeding requiring a high dose prednisolone. At 6 months, platelet recovery was demonstrated in one patient in the treatment group as well as one in the control group.

CONCLUSION

No beneficial effect of H. pylori eradication on platelet recovery in childhood chronic ITP was identified.

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.

One year follow-up of children and adolescents with chronic immune thrombocytopenic purpura (ITP) treated with rituximab

BACKGROUND

We previously showed in a prospective study that rituximab appears to be effective in some children and adolescents with severe chronic immune thrombocytopenia. Eleven of 36 patients achieved and maintained platelet counts over 50,000/mm(3) within the first 12 weeks. These patients were followed for the next year.

METHODS

Platelet counts were monitored monthly and all subsequent bleeding manifestations and need for further treatment was noted.

RESULTS

Eight of the 11 initial responders maintained a platelet count over 150,000/mm(3) without further treatment intervention. Three patients had a late relapse. One initial non-responder achieved a remission after 16 weeks, and two additional patients maintained platelet counts around 50,000/mm(3) without the need for further intervention.

CONCLUSIONS

Rituximab resulted in sustained efficacy with platelet counts of 50,000/mm(3) or higher in 11 of 36 patients (31%).