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

Pediatric Immune Thrombocytopenia

Pediatric immune thrombocytopenia (ITP) is a fairly common bleeding disorder PRESENTING with a decreased number of platelets. The typical clinical presentation involves mild bleeding symptoms with bruising and petechiae and occasional mucosal bleeding. ITP is thought to be an autoimmune disorder and more recently other mechanisms have been described. Most cases resolve spontaneously and can undergo watchful waiting as the platelet count improves. Initially, steroids or intravenous immunoglobulin G (IVIg) can be used to increase platelets. For those cases that do not resolve and become persistent or chronic, there are multiple treatment options, with new agents being studied in adults that will hopefully make it to clinical trials in pediatrics in the future.

Predictors of Remission in Severe Childhood Immune Thrombocytopenia

Childhood immune thrombocytopenia (ITP; platelet count < 100 × 10⁹/L) is the most common bleeding disorder in children. A total of 3-5% of children with ITP face a greater risk of bleeding, resulting in significant morbidity and mortality. Childhood ITP is often benign and self-limited; however, children with severe ITP (platelet count < 30 × 10⁹/L) require investigation and monitoring. In addition, 20% of ITP patients may not go into remission (platelet counts < 100 × 10⁹/L by 12 months after diagnosis) and may develop chronic ITP. The early identifying predictors associated with the resolution of severe ITP at the time of diagnosis may be helpful for family guidance. However, there is still controversy about the associations between the clinical factors at the time of initial diagnosis and the definitions of disease remission assessed at different timepoints after diagnosis. This retrospective study aimed to analyze the shared clinical factors among the disease remission definitions at three arbitrarily set timepoints-3, 6, and 12 months after diagnosis. This study retrieved records for hospitalized children aged under 18 years and diagnosed with ITP from the hospital registry in a tertiary university hospital. Clinical variables were recorded by reviewing the medical records with structured data entry for ITP admission. The serial follow-up platelet counts within 12 months after diagnosis were recorded. The times of ITP remission were identified by experienced pediatric hematologists. Patients with mild-form ITP (platelet counts ≥ 30 × 10⁹/L) at diagnosis or who were lost to follow-up within 3 months were excluded. From 1988 to 2019, 546 children were enrolled, and a total of 497 children with severe ITP were included in the further analysis. In total, one (0.2%) died of an intracranial hemorrhage, 363 (73.2%) children went into remission at 3 months, 40 (8.1%) went into remission between 6 and 12 months, and 104 (20.9%) developed chronic ITP. The shared significant predictors for remission by the third, sixth, and twelfth months included pre-adolescent age (<10 years) at diagnosis, abrupt onset (duration of symptoms prior to admission ≤ 2 weeks), and speedy recovery (platelet count > 100 × 10⁹/L at 1 month post diagnosis). ITP patients with positive viral serology tests or vaccination within 4 weeks had trends of delayed remission. In conclusion, diagnosis before preadolescent age, abrupt onset, and speedy recovery may share favorable factors for the remission of childhood ITP assessed at different timepoints.

IL-23/Th17 pathway and IL-17A gene polymorphism in Egyptian children with immune thrombocbytopenic purpura

Background

Immune thrombocytopenic purpura (ITP) is an acquired complex autoimmune thrombocytopenia. Uncontrolled cellular immune response is one of the key triggers for the loss of immune tolerance in ITP patients. The purpose of this study was to investigate the association of IL-23/Th17, IL-17A and IL-17A rs2275913 gene polymorphism with ITP in Egyptian children.

Methods

60 patients with ITP and 50 healthy control children from Minia city- Egypt were involved. Serum levels of IL-23 and IL-17A were determined by enzyme-linked immunosorbent assay. The frequency of Th17 cells was measured using flow cytometer. Genotyping for IL-17A was performed via polymerase chain reaction-restriction fragment length polymorphism.

Results

Comparing children with ITP to controls, serum levels of IL-23 and IL-17A as well as Th17 cells percentage were significantly increased (p <  0.001). Also, higher levels of these ILs and Th17 cells percentage were associated with decreased platelet count within ITP patients (p <  0.001). Analysis of genotype frequencies for IL-17A rs2275913 polymorphism and its alleles (A, G) showed no significant difference between cases and controls. Likewise, no significant differences were demonstrated between acute and chronic ITP regarding both IL-17A rs2275913 polymorphism prevalence and levels of IL-23, IL-17A plus Th17 cells percentage. The frequency of A alleles was 85 and 86% within patients and controls, respectively.

Conclusions

Elevated levels of IL-23, IL-17A and Th17 cells may be involved in ITP pathogenesis while IL-17A polymorphism rs2275913 is not prevalent in Egyptian children with ITP.

Hematopoietic stem cell response to acute thrombocytopenia requires signaling through distinct receptor tyrosine kinases

Although bone marrow niche cells are essential for hematopoietic stem cell (HSC) maintenance, their interaction in response to stress is not well defined. Here, we used a mouse model of acute thrombocytopenia to investigate the cross talk between HSCs and niche cells during restoration of the thrombocyte pool. This process required membrane-localized stem cell factor (m-SCF) in megakaryocytes, which was regulated, in turn, by vascular endothelial growth factor A (VEGF-A) and platelet-derived growth factor-BB (PDGF-BB). HSCs and multipotent progenitors type 2 (MPP2), but not MPP3/4, were subsequently activated by a dual-receptor tyrosine kinase (RTK)-dependent signaling event, m-SCF/c-Kit and VEGF-A/vascular endothelial growth factor receptor 2 (VEGFR-2), contributing to their selective and early proliferation. Our findings describe a dynamic network of signals in response to the acute loss of a single blood cell type and reveal the important role of 3 RTKs and their ligands in orchestrating the selective activation of hematopoietic stem and progenitor cells (HSPCs) in thrombocytopenia.

Retrospective evaluation of children with immune thrombocytopenic purpura and factors contributing to chronicity

OBJECTIVE

Immune thrombocytopenic purpura (ITP) is the most common cause of acquired thrombocytopenia children. The aim of this retrospective study is to describe presenting features and clinical characteristics of ITP and evaluate clinical course, treatment modalities, and complications and determine the effects of preceding infection history, age, gender, treatment modality, and admission platelet count on chronicity.

METHOD

Two hundred and eleven patients who were diagnosed ITP and followed-up in Department of Pediatric Hematology, Ankara Children Hematology Oncology Education and Research Hospital between January 2008 and September 2012 were included. Age of the patients, gender, date of admission, date of diagnosis, complaint in the application, previous infection and laboratory tests were recorded.

RESULTS

Mean age of the patients on diagnosis was 5.4 ± 4.1 years. The female/male ratio was 1.03. The clinical courses were determined as acute or chronic in 72% and 28% of patients respectively. Mean age at diagnosis was significantly higher in chronic ITP (p < 0.01). Chronic course was significantly higher in female patients (p < 0.05). The most frequent complaint was bruises on the skin (68%). The most common physical examination findings were petechiae, purpura and ecchymosis (89%). Patients with a history of past infection (53.6%) and who had serologically positive infection (15.6%) frequently had acute course (p < 0.01). The most common serologically positive infection was Rubella. The mean platelet count was significantly higher in chronic ITP (p < 0.01). In the initial treatment of patients admitted in the acute phase, megadose methylprednisolone (MDMP) was used in 31% of patients, intravenous immune globulin (IVIG) in 55% of patients and anti-D in 2% of patients while 12% did not receive any treatment. There were no significant differences between the recurrence rate and treatment modality (p > 0.05).

CONCLUSION

In our study, in females and in patients without any history of past infection, platelet count >20 × 10⁹/L and initial diagnosis age > 10 years were found to increase the probability of chronic disease, which is compatible with the literature.

Severe Hemorrhage in Chinese Children With Immune Thrombocytopenia

To better understand the clinical features, therapy, and clinical outcome of Chinese patients with immune thrombocytopenia (ITP) who suffered severe hemorrhage, we retrospectively analyzed 663 children with ITP diagnosed in our hospital during the last 10 years. Of the total 663 patients enrolled in our study, 520 were eligible for bleeding severity assessment, of which 20 children (3.8%) had severe bleeding, including intracranial hemorrhage (ICH) (n = 9), gastrointestinal hemorrhage (n = 6), massive epistaxis (n = 3), urinary tract hemorrhage (n = 1), and pulmonary hemorrhage (n = 1). The age at diagnosis of severe hemorrhage ranged from 47 days to 14 years. Thirteen patients were newly diagnosed with ITP, 3 had persistent ITP, and 4 had chronic ITP. The latency between the onset of ITP and severe bleeding ranged from 6 hours to 10 years. The median platelet count at the time of severe hemorrhage was 6.5 × 10/L (range, 0 to 32 × 10/L). Most patients with severe hemorrhage were treated with intravenous immunoglobulin (90%), corticosteroids (65%), or both (60%). Two patients (10%) died because of ICH and pulmonary hemorrhage, respectively. Four patients (20%) recovered from thrombocytopenia. Our observation showed that severe hemorrhage is rare but can occur anywhere and at any time during the course of ITP. The majority of children with ITP in China should be observed rather than treated.

Childhood Immune Thrombocytopenia: Long-term Follow-up Data Evaluated by the Criteria of the International Working Group on Immune Thrombocytopenic Purpura

Objective: Immune thrombocytopenia (ITP) is a common bleeding disorder in childhood, characterized by isolated thrombocytopenia. The International Working Group (IWG) on ITP recently published a consensus report about the standardization of terminology, definitions, and outcome criteria in ITP to overcome the difficulties in these areas.

Materials and Methods: The records of patients were retrospectively collected from January 2000 to December 2009 to evaluate the data of children with ITP by using the new definitions of the IWG.

Results: The data of 201 children were included in the study. The median follow-up period was 22 months (range: 12-131 months). The median age and platelet count at presentation were 69 months (range: 7-208 months) and 19x10⁹/L (range: 1x10⁹/L to 93x10⁹/L), respectively. We found 2 risk factors for chronic course of ITP: female sex (OR=2.55, CI=1.31-4.95) and age being more than 10 years (OR=3.0, CI=1.5-5.98). Life-threatening bleeding occurred in 5% (n=9) of the patients. Splenectomy was required in 7 (3%) cases. When we excluded 2 splenectomized cases, complete remission at 1 year was achieved in 70% (n=139/199). The disease was resolved in 9 more children between 12 and 90 months.

Conclusion: Female sex and age above 10 years old significantly influenced chronicity. Therefore, long-term follow-up is necessary in these children.

Rare bleeding disorders in children: identification and primary care management

Bleeding symptoms are common in healthy children but occasionally may indicate an underlying congenital or acquired bleeding diathesis. The rare bleeding disorders (RBDs) comprise inherited deficiencies of coagulation factors I (congenital fibrinogen deficiencies), II, V, VII, X, XI, and XIII and combined factor deficiencies, most notably of factors V and VIII and of vitamin K-dependent factors. These disorders often manifest during childhood and may present with recurrent or even serious or life-threatening bleeding episodes, particularly during the neonatal period. Accordingly, primary care and other nonhematologist pediatric providers should be familiar with the clinical presentation and initial evaluation of these rare disorders. Bleeding manifestations generally vary within the same RBD and may be indistinguishable from 1 RBD to another or from other more common bleeding disorders. Serious bleeding events such as intracranial hemorrhage may be heralded by less serious bleeding symptoms. The results of initial coagulation studies, especially prothrombin time and activated partial thromboplastin time, are often helpful in narrowing down the potential factor deficiency, with factor XIII deficiency being an exception. Consultation with a hematologist is advised to facilitate accurate diagnosis and to ensure proper management and follow-up. The approach to bleeding episodes and invasive procedures is individualized and depends on the severity, frequency, and, in the case of procedures, likelihood of bleeding. Prophylaxis may be appropriate in children with recurrent serious bleeding and specifically after life-threatening bleeding episodes. When available, specific purified plasma-derived or recombinant factor concentrates, rather than fresh frozen plasma or cryoprecipitate, are the treatment of choice.

Idiopathic thrombocytopenic purpura in childhood: twenty years of experience in a single center

BACKGROUND

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder with a variable clinical course.

METHODS

A retrospective analysis was carried out of ITP patients presenting to a pediatric hematology-oncology department during a period of 20 years, with a focus on treatment and outcome.

RESULTS

One hundred and twenty-four cases were recorded (mean patient age, 8.4 years). Forty-nine children (39.5%) had platelet counts <10,000/µL at diagnosis. No episode of severe bleeding was observed. Peak incidence was observed during spring and summer. Respiratory infections proceeded in 58% of cases. Treatment consisted of i.v. immunoglobulin (IVIG) in 93 children at four dosing schedules. Sixteen children received corticosteroids, 10 children received anti-D immunoglobulin and 14 received no treatment. Recovery was observed in 67% of children on IVIG and in 50% on anti-D globulin. Eight patients did not respond initially and received corticosteroids. Three children with refractory thrombocytopenia received anti-CD20 (rituximab). Fourteen children (11%) had persistent/chronic disease. In 10 of them recovery was observed in 13 months-8 years. Splenectomy was performed in six children with resistant/chronic disease.

CONCLUSION

ITP has a benign course in the majority of cases. Anti-D globulin can effectively be used as an alternative first-line treatment. Rituximab can successfully be used in refractory cases, while splenectomy has currently limited indications.

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.

Clinical features, prognostic factors, and their relationship with antiplatelet antibodies in children with immune thrombocytopenia

We investigated and evaluated the demographics, clinical and laboratory features, treatment responses, and disease duration of 25 children with immune thrombocytopenia (ITP) eligible for detection of antiplatelet antibodies. We found that patients without antecedent of preceding infection (API) were more likely to have anti-GPIa/IIa than those with API (42.9% vs. 5.5%, P=0.048). Age groups of <2 years and 2 to 10 years were more likely to show response (R) or complete response (CR) to given treatments, whereas none of the patients whose onset age >10 years showed R or CR to given treatments (88.9% and 100% vs 0%, P=0.001). The percentage of newly diagnosed ITP was higher in age groups of <2 years (100%) and in 2 to 10 years (90%) than the age group of >10 years (16.7%, P=0.001). Patients without API (71.4%) were more likely to develop chronic ITP than those with API (5.6%, P=0.002). In conclusion, younger age was a favorable prognostic factor, especially in patients <2 years of age with respect to treatment responses and disease duration. In addition, API was associated with a short disease course as well as absence of anti-GPIa/IIa.

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.

Thrombocytopenic syndromes masquerading as childhood immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is the most common cause of thrombocytopenia in children and adolescents. However, there are a number of other diagnoses that are often mistaken for ITP. A 10-year retrospective chart review was performed at the Children's Hospital of Alabama to characterize ITP. Initially, 492 patients who had the coded diagnosis of ITP (ICD 287.3) were identified. However, 83 (17%) of patients were found to have alternative diagnoses on chart review. Of the 83 patients, 13 patients (3%) represented coding errors or study classification errors. The 70 remaining patients (14%) had an alternative explanation for their thrombocytopenia, consisting of 31 different diagnoses. The most common diagnoses were familial thrombocytopenia (10%), systemic lupus erythematosus (9%), hypersplenism (9%), neonatal alloimmune thrombocytopenia (7%), Wiskott-Aldrich syndrome (7%), or systemic infection (6%). In total, 16 of the patients (23%) were ultimately diagnosed with one of a number of congenital syndromes with concurrent thrombocytopenia. Although this review confirms that most children with thrombocytopenia are diagnosed with ITP, 14% of the study population manifested other diagnoses. The clinician evaluating a child with thrombocytopenia must keep an open mind about the possible diagnosis and perform a comprehensive and thoughtful evaluation based on the clinical picture. ITP must be a diagnosis of exclusion as misdiagnosis in a child with thrombocytopenia may have a significant impact on morbidity and mortality.

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.