Clinical and laboratory predictors of chronic immune thrombocytopenia in children: a systematic review and meta-analysis

Autoimmune cytopenia and Kabuki syndrome in paediatrics: Insights in 11 patients

Kabuki syndrome (KS) is now listed in the Human Inborn Errors of Immunity (IEI) Classification. It is a rare disease caused by KMT2D and KDM6A variants, dominated by intellectual disability and characteristic facial features. Recurrently, pathogenic variants are identified in those genes in patients examined for autoimmune cytopenia (AIC), but interpretation remains challenging. This study aims to describe the genetic diagnosis and the clinical management of patients with paediatric-onset AIC and KS. Among 11 patients with AIC and KS, all had chronic immune thrombocytopenic purpura, and seven had Evans syndrome. All had other associated immunopathological manifestations, mainly symptomatic hypogammaglobinaemia. They had a median of 8 (5-10) KS-associated manifestations. Pathogenic variants were detected in KMT2D gene without clustering, during the immunological work-up of AIC in three cases, and the clinical strategy to validate them is emphasized. Eight patients received second-line treatments, mainly rituximab and mycophenolate mofetil. With a median follow-up of 17 (2-31) years, 8/10 alive patients still needed treatment for AIC. First-line paediatricians should be able to recognize and confirm KS in children with ITP or multiple AIC, to provide early appropriate clinical management and specific long-term follow-up. The epigenetic immune dysregulation in KS opens exciting new perspectives.

HIF-1α induced by hypoxic condition regulates Treg/Th17 axis polarization in chronic immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired immune disorder characterized by increased platelet destruction and reduced platelet (Plt) production. Hypoxia-inducible factor-1α (HIF-1α) have regulatory effects on Treg/Th17 axis balance and may represent relevant factors in the pathogenesis of ITP. Treg/Th17 ratio, serum levels and gene expression were investigated in new diagnosed ITP (NITP) and chronic ITP (CITP). The Treg/Th17 ratio obviously decreased in CITP (P = 0.001). The ratio of Treg/Th17 was correlated with the level of HIF-1α level both in mRNA (r = 0.49, P < 0.0001) and serum level (r = 0.50, P < 0.0001). However, none statistical upregulation of HIF-1α was observed in CITP. In vitro, There was significant polarization difference of Treg/Th17 axis (P = 0.042) and Foxp3-MFI/IL17-MFI (P = 0.0003) in hypoxic condition between NITP and CITP. These findings suggest that HIF-1α induced by hypoxia plays a crucial role in the chronicity of ITP by mediating the imbalance of the Treg/Th17 axis.

Pathophysiology, Clinical Manifestations and Diagnosis of Immune Thrombocytopenia: Contextualization from a Historical Perspective

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by an isolated decrease in the platelet count and an increased risk of bleeding. The pathogenesis is complex, affecting multiple components of the immune system and causing both peripheral destruction of platelets and impaired central megakaryopoiesis and platelet production in the bone marrow. Here, we intend to contextualize the current knowledge on the pathophysiology, terminology, epidemiology, clinical manifestations, diagnosis, and prognosis of ITP from a historical perspective and the first references to the never-stopping garnering of knowledge about this entity. We highlight the necessity to better understand ITP in order to be able to provide ITP patients with personalized treatment options, improving disease prognosis and reducing the incidence or frequency of refractoriness.

Machine learning models developed and internally validated for predicting chronicity in pediatric immune thrombocytopenia

BACKGROUND

Primary immune thrombocytopenia (ITP) in children is typically self-limiting; however, 20% to 30% of patients may experience prolonged thrombocytopenia lasting over a year. The challenge is predicting chronicity to ensure personalized treatment approaches.

OBJECTIVES

To address this issue, we developed and internally validated 4 machine learning (ML) models using demographic and immunologic characteristics to predict the likelihood of chronicity.

METHODS

The present study was conducted at Beijing Children's Hospital from June 2018 to December 2021, aiming to develop predictive models for determining the chronicity of pediatric ITP. Four ML models, based on a logistic regression classifier, random forest classifier, eXtreme Gradient Boosting (XGBoost), and support vector machine, were employed. These models used a set of 16 variables, including 14 immunologic and 2 demographic predictors. The performance evaluation criteria included prediction accuracy, precision, recall, F1 score, and area under the receiver operating characteristic curve (AUROC).

RESULTS

Data were collected from 662 patients who were randomly assigned to either a training dataset or a testing dataset using a random number generator. Among them, 26.5% had chronic disease. All models performed well, with AUROC values ranging from 0.81 to 0.84, and XGBoost was selected for its highest AUROC score and interpretability in constructing the predictive model. Age, T helper 17, T helper 17-to-regulatory T cell ratio, T helper 1, and double-negative T cells were identified as significant predictors by the XGBoost algorithm.

CONCLUSION

We developed a precise predictive model for chronicity in pediatric ITP using ML during the initial phase. The XGBoost model achieved high predictive accuracy by using individual patient clinical parameters and demonstrated commendable interpretability.

Prediction of the Clinical Course of Immune Thrombocytopenia in Children by Platelet Kinetics

Childhood immune thrombocytopenia (ITP) is a rare autoimmune disorder characterized by isolated thrombocytopenia. Prolonged ITP (persistent and chronic) leads to a reduced quality of life for children in many domains. To provide optimal support for children, with ITP, it is important to be able to predict those who will develop prolonged ITP. This study aimed to develop a mathematical model based on platelet recovery that allows the early prediction of prolonged ITP. In this retrospective study, we used platelet counts from the 6 months following the diagnosis of ITP to model the kinetics of change in platelet count using a pharmacokinetic-pharmacodynamic model. In a learning set (n = 103), platelet counts were satisfactorily described by our kinetic model. The Kheal parameter, which describes spontaneous platelet recovery, allowed a distinction between acute and prolonged ITP with an area under the curve (AUC) of 0.74. In a validation set (n = 58), spontaneous platelet recovery was robustly predicted using platelet counts from 15 (AUC = 0.76) or 30 (AUC = 0.82) days after ITP diagnosis. In our model, platelet recovery quantified using the kheal parameter allowed prediction of the clinical course of ITP. Future prospective studies are needed to improve the predictivity of this model, in particular, by combining it with the predictive scores previously reported in the literature.

Idiopathic Thrombocytopenic Purpura: Current Limitations and Management

Idiopathic thrombocytopenic purpura (ITP), also known as immune thrombocytopenia, is a blood disorder characterized by a reduction in the number of platelets. A reduction in the number of platelets beyond the normal levels leads to several consequences. A severe reduction in blood platelet levels leads to a rash of purple spots on the skin, joints, etc. due to leakage in the small blood vessels, easy bruising, bleeding gums, intestinal bleeding, and hemorrhage. Suppose a case of ITP resolves in fewer than six months. In that case, it is an acute case of ITP. Still, if a case settles in more than six months, it is a case of ITP. The cause of a reduced platelet count can be increased peripheral destruction or impaired production; this is termed an autoimmune condition in which the body's immune system attacks platelets thinking it to be a foreign antigen. ITP in children occurs commonly following a previous viral attack. Even though evaluating patients' reports is useful for understanding and guiding the treatment, these estimates might not be regularly evaluated in clinical settings. First-line drugs in the treatment of ITP are corticosteroids, and long-term use of these drugs has several side effects, such as excessive increase in weight, mental health disturbances, and sleep disturbances; additional therapies to treat hemorrhage are usually momentary. As a result, it is essential to recognize the flaws in current procedures and adopt innovative measures for the management and minimization of difficulties.

Clinical significance of antinuclear antibodies in primary immune thrombocytopenia

There are discrepancies across guidelines about whether the dosage of antinuclear antibodies (ANAs) is of use at the diagnosis of primary immune thrombocytopenia (ITP). This review describes the current knowledge about ANA prevalence in patients with primary ITP, and their potential usefulness as biomarkers for ITP evolution, response to treatments and increased risk of subsequent development of systemic lupus and thrombosis.

Early immunomodulation in immune thrombocytopenia-A report of the ICIS meeting in Lenzerheide, Switzerland 2022

The only way to prevent immune thrombocytopenia (ITP) from becoming refractory would be to restore tolerance to platelets at an early phase of the disease. Numerous immune alterations probably accumulate in chronic ITP; thus, the chances of cure decrease significantly with time. Currently, sustained remission off treatment (SROT) is a clinical definition describing patients who can discontinue their ITP treatment without risk and maintain a state of remission. Different treatment strategies are presently being evaluated with the goal of attaining SROT, mostly combining drugs targeting the innate and/or the adaptive immune system, the inflammation state, so as increasing the platelet load. In this sense, thrombopoietin receptor agonists (TPO-RAs) have shown promising results if used as upfront treatment. TPO-RAs seem to exhibit immunomodulation and immune tolerance properties, increasing not only the platelet antigen mass but also increasing the transforming growth factor-β concentration, and stimulating regulatory T and B lymphocytes. However, more immunological studies are needed to establish accurate molecular alterations in ITP that are potentially reversed with treatments.

Adolescents and young adults with newly diagnosed primary immune thrombocytopenia

Current immune thrombocytopenia (ITP) guidelines target children and adults, leading to oversimplification. Adolescents and young adults (AYAS) comprise a separate group with distinct health and psychosocial issues. This study aimed to describe the clinical presentation and therapeutic strategies of ITP among AYAS. We analyzed data from two large ITP registries (PARC-ITP; CARMEN-France) and included newly diagnosed ITP patients (aged 12-25 years) with an initial platelet counts of <100×109/L. Patients with secondary ITP or non-immune thrombocytopenia (n=57) and pregnant women (n=10) were excluded. Of the 656 cases of AYAS with primary ITP registered from 2004 up to 2021, 12-month follow-up data were available for 72%. The initial median platelet count was 12×109/L. In 109 patients (17%), the diagnosis was incidental, without documented bleeding. Apart from gynecological bleeding, the clinical and therapeutical characteristics of females and males were similar. Platelet-enhancing drugs were reported in 66%, 45%, and 30% of patients at diagnosis, 1-6 months, and 6-12 months after diagnosis, respectively. Corticosteroids were the preferred treatment at all time points. At 12 months, 50% of all patients developed chronic ITP. In the subgroup of patients with initial severe thrombocytopenia (<20×109/L), those receiving frontline treatment had a higher remission rate at 1 year than those who followed an initial watch-and-wait strategy (53% and 32%; P<0.05). Our analysis indicates that the remission rate at 1 year may be associated with the initial treatment strategy. This hypothesis must be confirmed in prospective studies.

[Relationship between coronavirus disease 2019 vaccination and the risk of immune thrombocytopenia]

OBJECTIVES

To study the relationship between coronavirus disease 2019 (COVID-19) vaccination and the risk of immune thrombocytopenia (ITP).

METHODS

A retrospective analysis was conducted on children aged 3-17 years with newly diagnosed ITP who were hospitalized in Children's Hospital Affiliated to Zhengzhou University from November 2021 to December 2022. Clinical data and COVID-19 vaccination status were compared among three groups: ITP patients vaccinated within 12 weeks before onset, vaccinated more than 12 weeks before onset, and unvaccinated. Changes in serum immunoglobulin and complement levels were analyzed among five groups: ITP patients vaccinated <4 weeks before onset, 4-<8 weeks before onset, 8-<12 weeks before onset, ≥12 weeks before onset, and unvaccinated. A case-control design was used to estimate the risk of ITP: 387 children aged 3-17 years with fractures hospitalized during the same period in the emergency department of the hospital were selected as the control group, and the exposure to COVID-19 vaccination within 12, 8, and 4 weeks before onset in ITP children was compared to estimate the risk of ITP.

RESULTS

Among 129 ITP children, there were no statistically significant differences in age, gender, rate of preceding infections, absolute platelet count at initial diagnosis, absolute lymphocyte count at initial diagnosis, bleeding score, positive anti-nuclear antibody rate, absolute platelet count after 4 days of treatment, recurrence rate, and proportion of patients with disease duration ≥3 months among the three groups vaccinated within 12 weeks before onset, vaccinated more than 12 weeks before onset, and unvaccinated (P>0.05). There was a statistically significant difference in serum immunoglobulin G, immunoglobulin A, and complement component 3 levels among the groups vaccinated <4 weeks, 4-<8 weeks, 8-<12 weeks, and ≥12 weeks before onset, and unvaccinated (P<0.05). The risk estimation results showed that COVID-19 vaccination within 12 weeks, 8 weeks, and 4 weeks before onset did not increase the risk of ITP (P>0.05).

CONCLUSIONS

COVID-19 vaccination does not increase the risk of ITP.

Predictor Factors for Chronicity in Immune Thrombocytopenic Purpura in Children

(1) Background: Immune thrombocytopenia (ITP) is an acute autoimmune blood disorder that is the main cause of thrombocytopenia in children. It is characterized by a decrease in platelets below 100 × 10⁹/L, and limited evolution with severe complications such as intracranial hemorrhage. The chronic form is defined by the persistence of thrombocytopenia more than 12 months after diagnosis. (2) Methods: We performed a retrospective study over a period of 10 years (1 January 2011-31 December 2020) at the Emergency Clinical Hospital for Children "Sf. Maria", Iasi. The aim of the study was to describe the clinical characteristics and to determine the prognostic factors in immune thrombocytopenia in children. (3) Results: In this study we included 271 children with ITP, comprising 123 females (45.4%) and 148 males (54.6%). The remission rate was higher in males, being 68.9% compared to 56.1% in females. Children with ITP under 9 years of age had a higher remission rate. Children with a platelet count > 10 × 10⁹/L at diagnosis had a higher likelihood-of-remission rate compared to patients who presented initial platelet count below this value. (4) Conclusions: The risk factors highly suggestive for chronicity are: age at diagnosis, female sex, and the number of platelets at the onset of the disease.

The effect of antinuclear antibody titre and its variation on outcomes in children with primary immune thrombocytopenia

Antinuclear antibody (ANA) can be positive in children with primary immune thrombocytopenia (ITP), but the effect of ANA titre and its variation on outcomes of children with primary ITP remains unclear. Here, we conducted a single-centre retrospective cohort study of children with primary ITP at the Peking Union Medical College Hospital in China. A total of 324 children with primary ITP included in this study were followed for a median time of 25 months. In this cohort, 39.2% had an ANA titre of 1:160 or higher. Results from a generalized estimating equation model revealed that patients with higher ANA titres had lower platelet counts at onset but a higher recovery rate of subsequent platelet counts. Results from Cox regression models adjusted for potential confounders revealed that patients with ANA titres of 1:160 or more were more likely to develop to autoimmune disease (AID) than those without, and the risk of AID development increased with the rise of ANA titres (p value for trend less than 0.001). These data highlight the predictive value of ANA titre for platelet counts and the risk of AID development in children with primary ITP.

Impact of age at diagnosis, sex, and immunopathological manifestations in 886 patients with pediatric chronic immune thrombocytopenia

Pediatric chronic immune thrombocytopenia (cITP) is a heterogeneous condition in terms of bleeding severity, second-line treatment use, association with clinical and/or biological immunopathological manifestations (IMs), and progression to systemic lupus erythematosus (SLE). No risk factors for these outcomes are known. Specifically, whether age at ITP diagnosis, sex, or IMs impact cITP outcomes is unknown. We report the outcomes of patients with pediatric cITP from the French nationwide prospective cohort OBS'CEREVANCE. We used multivariate analyses to investigate the effect of age at ITP diagnosis, sex, and IMs on cITP outcomes. We included 886 patients with a median (min-max) follow-up duration of 5.3 (1.0-29.3) years. We identified an age cutoff that dichotomized the risk of the outcomes and defined two risk groups: patients with ITP diagnosed <10 years (children) and ≥ 10 years (adolescents). Adolescents had a two to four-fold higher risk of grade ≥3 bleeding, second-line treatment use, clinical and biological IMs, and SLE diagnosis. Moreover, female sex and biological IMs were independently associated with higher risks of biological IMs and SLE diagnosis, second-line treatment use, and SLE diagnosis, respectively. The combination of these three risk factors defined outcome-specific risk groups. Finally, we showed that patients clustered in mild and severe phenotypes, more frequent in children and adolescents, respectively. In conclusion, we identified that age at ITP diagnosis, sex, and biological IMs impacted the long-term outcomes of pediatric cITP. We defined risk groups for each outcome, which will help clinical management and further studies.

Novel Biomarkers for Diagnosis and Monitoring of Immune Thrombocytopenia

Lower-than-normal platelet counts are a hallmark of the acquired autoimmune illness known as immune thrombocytopenia, which can affect both adults and children. Immune thrombocytopenia patients' care has evolved significantly in recent years, but the disease's diagnosis has not, and it is still only clinically achievable with the elimination of other causes of thrombocytopenia. The lack of a valid biomarker or gold-standard diagnostic test, despite ongoing efforts to find one, adds to the high rate of disease misdiagnosis. However, in recent years, several studies have helped to elucidate a number of features of the disease's etiology, highlighting how the platelet loss is not only caused by an increase in peripheral platelet destruction but also involves a number of humoral and cellular immune system effectors. This made it possible to identify the role of immune-activating substances such cytokines and chemokines, complement, non-coding genetic material, the microbiome, and gene mutations. Furthermore, platelet and megakaryocyte immaturity indices have been emphasized as new disease markers, and prognostic signs and responses to particular types of therapy have been suggested. Our review's goal was to compile information from the literature on novel immune thrombocytopenia biomarkers, markers that will help us improve the management of these patients.

How we treat primary immune thrombocytopenia in adults

Primary immune thrombocytopenia (ITP) is an immune-mediated bleeding disorder characterized by decreased platelet counts and an increased risk of bleeding. Multiple humoral and cellular immune abnormalities result in accelerated platelet destruction and suppressed platelet production in ITP. The diagnosis remains a clinical exclusion of other causes of thrombocytopenia. Treatment is not required except for patients with active bleeding, severe thrombocytopenia, or cases in need of invasive procedures. Corticosteroids, intravenous immunoglobulin, and anti-RhD immunoglobulin are the classical initial treatments for newly diagnosed ITP in adults, but these agents generally cannot induce a long-term response in most patients. Subsequent treatments for patients who fail the initial therapy include thrombopoietic agents, rituximab, fostamatinib, splenectomy, and several older immunosuppressive agents. Other potential therapeutic agents, such as inhibitors of Bruton's tyrosine kinase and neonatal Fc receptor, are currently under clinical evaluation. An optimized treatment strategy should aim at elevating the platelet counts to a safety level with minimal toxicity and improving patient health-related quality of life, and always needs to be tailored to the patients and disease phases. In this review, we address the concepts of adult ITP diagnosis and management and provide a comprehensive overview of current therapeutic strategies under general and specific situations.

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.

Evaluation of paediatric immune thrombocytopenia patients with clinical and laboratory findings: emphasizing the role of monocytosis

We aimed to investigate the relationship between demographics, clinical features, laboratory findings including monocytosis and clinical course in children with immune thrombocytopenia (ITP). Data of 100 ITP patients were analysed. Complete blood count findings of the patients at certain time points were evaluated to classify the disease as acute, persistent and chronic. An effect of sex on chronicity was not observed ( P  = 0.166). Of the patients enrolled in the study, 38% ( n  = 38) had chronic course. The mean age of patients with the chronic course was 7 ± 4.1 years, which was significantly higher than the other groups ( P  = 0.007). Sixty-five percent ( n  = 13) of the patients presenting with mucosal bleeding and 27.4% ( n  = 20) of the patients presenting with skin bleeding became chronic ( P  = 0.008). MPV was found to be significantly high in chronic ITP patients ( P  = 0.049). Monocytosis was noted in 80% of the patients at diagnosis. Intravenous immunoglobulin was used in 84% of the patients with acute ITP; 33% of them developed chronic ITP. The age at diagnosis, presence of mucosal bleeding and increased MPV on admission were high-risk factors for the development of the chronic course. Monocytosis was detected in 80% of the patients on admission, and it may play a role in the pathogenesis of ITP.

Thrombopoietin receptor agonists and rituximab for treatment of pediatric immune thrombocytopenia: A systematic review and meta-analysis of prospective clinical trials

BACKGROUND

Children with immune thrombocytopenia (ITP) may require second-line ITP therapies. The high remission rate in pediatric patients, need for extended-duration use of thrombopoietin receptor agonists (TPO-RAs), drug adherence, potential side effects, monitoring, and cost effectiveness are factors that should be considered in decision-making about second-line therapies. Rituximab (RTX) has been used off-label for years to treat ITP but there are limited studies about its efficacy and safety in children. To date, no studies have directly compared TPO-RAs with RTX for the treatment of childhood ITP.

METHODS

This systematic review analyzed the overall platelet response, durability of treatment effect, and safety for RTX use in comparison to TPO-RAs in pediatric ITP. MEDLINE/PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched through December 2020 and meta-analysis was conducted using proportions of success/failure for each intervention in the selected studies.

RESULTS

The proportion of participants achieving the primary endpoint of a platelet response above 50,000 was similar for TPO-RAs (proportion = 0.71, 95% CI: 0.63-0.78) and RTX (proportion = 0.68, 95% CI: 0.53-0.82). However, considerable variation was found between the two groups with regards to the sustainability of the response and other secondary outcomes such as need for rescue and adverse events. RTX was associated with higher rates of rescue therapy.

CONCLUSIONS

In this analysis of prospective pediatric ITP studies, RTX and TPO-RAs had similar rates of overall platelet response but differed in other important measures. Prospective comparative studies are needed to better characterize second-line treatments for pediatric ITP.

The Use of Clinical Scores in the Management of Immune Thrombocytopenic Purpura in Children

While the majority of children with recently diagnosed ITP have a benign, self-limiting condition, most often with a spontaneously recovery, 40% of children with ITP progress toward persistent ITP and 10-20% goes toward chronicity. Several clinical scores have been developed with the aim to perform a better monitoring outcome or to differentiate transient vs. persistent ITP (e.g., Donato score). Our paper aims to describe and to compare the most important scores used in the management of ITP in children: bleeding severity scores and chronicity prediction scores. These scores include a combination of different already known risk factors: age, gender, presence of a previous infections or vaccination, bleeding grade, type of onset, platelet count at diagnosis. The real utility of these scores has been a matter of debate and no consensus has been reached so far as to their necessity to be implemented as compulsory tool in the care of children with ITP.

Increased proportion of Th17/Treg cells at the new diagnosed stage of chronic immune thrombocytopenia in pediatrics: the pilot study from a multi-center

Chronic immune thrombocytopenia (CITP) is an autoimmune disease with many immune dysfunctions, including T helper type 17 cell (Th17)/regulatory T cells (Tregs) imbalance. Low quality of life and side effects of drugs are severe, especially in pediatrics. This study aimed to determine Th17/Treg polarization in pediatric CITP when first diagnosing ITP and evaluate its use as a predictive marker for pediatric CITP. This was a pilot study from a multi-center. Setting the effective data size to 100 patients, data entry ended in the 142nd patient who had completed a 1-year follow-up. The percentages of Treg cells and Th17 cells were quantified by flow cytometry when new diagnosed ITP patients first arrived. The association between the Th17/Treg ratio and CITP was analyzed statistically. The percentages of Treg cells and Th17 cells were lower (P = 0.0008) and higher (P = 0.0001), respectively, in the CITP-outcome group compared with the remission group. The receiver operating characteristic analysis showed that the area under the curve (AUC) of Treg and Th17 cells was 0.811 and 0.834, respectively. The ratio of Th17/Treg exhibited the largest AUC of 0.897 (cutoff value 0.076).Conclusions: Thus, the percentage of Th17 /Treg ratio of pediatric CITP is elevated at new diagnosed ITP stage. It is a promising predictive marker for the development of CITP to some extent.Trial registration: ChiCTR1900022419 (10^th April 2019) What is Known: • The percentage of Th17 /Treg ratio of pediatric CITP is elevated. What is New: • This study shows that the percentage of Th17 /Treg ratio of pediatric CITP is elevated at new diagnosed ITP stage. This work may provide a new point for pediatric CITP's prediction. The imbalanced ratio of Th17/Treg was obvious when first diagnose ITP in pediatric CITP patients, rendering them as potential predictive tools for discriminating CITP to facilitate with the management of pediatric patient care. In addition, the combination of them may serve as a predictive marker in pediatric CITP.

A retrospective analysis of 122 immune thrombocytopenia patients treated with dapsone: Efficacy, safety and factors associated with treatment response

BACKGROUND

The optimum second-line treatment or best sequence of treatments for immune thrombocytopenia (ITP) are yet to be determined. Our institution has accumulated extensive experience regarding the use of dapsone as second-line therapy for ITP.

OBJECTIVES

We aimed to assess the efficacy rate and safety of dapsone treatment in ITP patients.

PATIENTS/METHODS

Here we report our experience in a retrospective study, including 122 patients, with a median treatment duration with dapsone of 6 months and a median follow-up period of 3.4 years.

RESULTS

The overall response rate in this cohort was 66%, including 24% of complete responses. Among responders, in 24% a relapse occurred while on treatment. Therefore, a sustained response was observed in 51% of patients. Interestingly, 81% of the responders maintained the response after the interruption of treatment, for a median time of 26 months. Side effects were reported in 16% of the patients in this cohort and treatment was interrupted due to side effects in 11% of patients. The main cause in these cases was hemolytic anemia and methemoglobinemia. Reductions in hemoglobin levels during the use of dapsone were seen in 94% of the patients. Responders presented significantly greater reductions in their hemoglobin levels than nonresponders did: median hemoglobin drop of 1.9 g/dl vs. 1.2 g/dl (p = .004).

CONCLUSIONS

Our findings suggest that dapsone has adequate efficacy and is well tolerated. Although the mechanism of action is still unclear, our observation that the degree in the drop of hemoglobin is greater in responders suggest a possible role of the blockage of the reticuloendothelial system in the therapeutic effect of the drug.

Pediatric immune thrombocytopenia: apoptotic markers may help in predicting the disease course

BACKGROUND

In all, 15-30% of pediatric immune thrombocytopenia (ITP) patients will remain chronically thrombocytopenic at 1 year post diagnosis. All attempts to classify patients at diagnosis have proven unsuccessful. We hypothesized that a different pathophysiology is responsible for non-chronic versus chronic pediatric ITP. We aimed to examine differences in the apoptotic markers' presentation at diagnosis between non-chronic and chronic patients.

METHODS

Blood samples were collected from 42 pediatric patients with newly diagnosed ITP prior to initiation of treatment. We incubated patients' sera with control platelets and compared the results among three research groups: healthy controls, chronic ITP, and non-chronic ITP patients. We measured apoptotic markers phosphatidylserine (PS) exposure and mitochondrial inner membrane potential (ΔΨm) by flow cytometry and the level of human apoptotic proteins by Human Apoptosis Array.

RESULTS

We found increased platelet PS exposure and decreased ΔΨm in response to all ITP patients' sera compared to control subjects. Human Apoptotic Array revealed an increased expression of five apoptotic proteins: BIM, CD40, IGFBP2, P21, and SMAC, following sera incubation of non-chronic pediatric ITP patients, compared to chronic patients' sera, at diagnosis.

CONCLUSIONS

Our data contribute to knowledge on apoptosis markers that may aid in predicting the prognosis of children with ITP.

IMPACT

The key message of our article is that children with chronic ITP have a different apoptotic profile compared to non-chronic ITP. Addition to existing literature: This is the first study comparing apoptotic markers between children with chronic ITP to non-chronic ITP.

IMPACT

Our findings indicate that, in the future, apoptotic markers may help to classify ITP patients into non-chronic versus chronic ones, at diagnosis.

Variables related to chronic immune thrombocytopenia: experience from a single center and comparison to a meta-analysis

Classically, several variables have been related to the disease course of chronic primary immune thrombocytopenia (cITP), though to date, there is no consensus on their clinical relevance. In a recent systematic review, a meta-analysis was made and confirmed the existence of certain cITP-related variables that may be related to prognosis in pediatric patients. We retrospectively analyzed a cohort of patients diagnosed with ITP, identified prognostic variables, and compared our results to the variables described by the authors. A multivariate study revealed that older age at diagnosis and higher platelet count were the only independent variables related to cITP. Children up to age 4 years and those with lower platelet counts (below 20 × 10⁹/L) were at lower risk for cITP.Conclusion: We therefore concluded that only age and platelet count at diagnosis are independent variables that should be considered when evaluating the risk of developing cITP. What is Known: • Around 20% of patients with immune thrombocytopenia progress to chronic disease as determined by a sustained platelet count below 100×10⁹/L for more than 12 months. • A number of variables potentially related to the development of cITP are being studied, such as age, sex, cell count, and previous treatment. What is New: • This is a new group of patients diagnosed with ITP in which the platelet count and age at diagnosis are the only independent variables closely related to cITP. • In this new series, we could not confirm other variables previously related to cITP such as total leukocyte count or the absence of treatment at diagnosis.

IVMP+IVIG raises platelet counts faster than IVIG alone: results of a randomized, blinded trial in childhood ITP

Children with immune thrombocytopenia (ITP) rarely suffer from life-threatening bleeds (eg, intracranial hemorrhage). In such settings, the combination of IV methylprednisolone (IVMP) with IV immune globulin (IVIG) is used to rapidly increase platelet counts (PCs). However, there are no controlled data to support using combination therapy over IVIG alone. We conducted a randomized, double-blind, placebo-controlled study to evaluate the rapidity of the PC increment and associated adverse events (AEs) between 2 regimens: A (IV placebo) and B (IVMP 30 mg/kg), both given over 1 hour, followed in both cases by IVIG (Gamunex 10%) 1 g/kg over 2-3 hours in children 1-17 years old with primary ITP and PCs <20 × 109/L in whom physicians had decided to treat with IVIG. Thirty-two children (ages: median, 8 years; range, 1.2-17.5 years) with a mean baseline PC of 9.2 × 109/L participated. Eighteen were randomized to regimen A and 14 to regimen B. By 8 hours after initiating therapy, 55% of all children had a PC ≥20 × 109/L (no group difference). By 24 hours, mean PCs were 76.9 × 109/L (B) vs 55 × 109/L (A) (P = .06; P = .035 when adjusted for intergroup differences in patient ages). No patient experienced severe bleeding/unexpected severe AEs. There were statistically fewer IVIG-related headaches in the group receiving combination therapy (P = .046). Our findings show a rapid response to IVIG with/without steroids and provide evidence to support the use of IVMP+IVIG in life-threatening situations. This trial was registered at www.clinicaltrials.gov as #NCT00376077.

Efficacy and safety of rituximab for minors with immune thrombocytopenia: a systematic review and meta-analysis

Objective

We reviewed relevant research on rituximab (RTX) treatment for pediatric immune thrombocytopenia (ITP) to elucidate the efficacy and safety of RTX.

Methods

Prospective clinical trials of RTX for the treatment of pediatric ITP were collected by searching the PubMed, Cochrane Library, Web of Science, and OVID: EMBASE databases and ClinicalTrials.gov. We examined rates of overall response (OR), complete response (CR), partial response (PR), sustained response (SR), relapse (R), and adverse drug reaction (ADR). The Methodological Index for Nonrandomized Studies scale was used, and sensitivity analyses were performed.

Results

For five studies, including 100 patients, the pooled OR, CR, PR, SR, R, and ADR rates were 52% (95% CI: 0.36–0.77, I² = 78%), 52% (95% CI: 0.41–0.67, I² = 45%), 18% (95% CI: 0.10–0.33, I² = 33%), 43% (95% CI: 0.29–0.63, I² = 0%), 25% (95% CI: 0.06–0.96, I² = 52%), and 30% (95% CI: 0.15–0.58, I² = 64%), respectively.

Conclusion

There is evidence, albeit low quality, that RTX may be a better second-line therapy than splenectomy for children with ITP; however, its efficacy and safety need to be validated by further high-quality clinical trials, such as randomized controlled trials.

Biological stratification of clinical disease courses in childhood immune thrombocytopenia

BACKGROUND

In childhood immune thrombocytopenia (ITP), an autoimmune bleeding disorder, there is a need for better prediction of individual disease courses and treatment outcomes.

OBJECTIVE

To predict the response to intravenous immunoglobulins (IVIg) and ITP disease course using genetic and immune markers.

METHODS

Children aged younger than 7 years with newly diagnosed ITP (N = 147) from the Treatment With or Without IVIG for Kids with ITP study were included, which randomized children to an IVIg or observation group. A total of 46 variables were available: clinical characteristics, targeted genotyping, lymphocyte immune phenotyping, and platelet autoantibodies.

RESULTS

In the treatment arm, 48/80 children (60%) showed a complete response (platelets ≥100 × 109 /L) that lasted for at least 1 month (complete sustained response [CSR]) and 32 exhibited no or a temporary response (absence of a sustained response [ASR]). For a biological risk score, five variables were selected by regularized logistic regression that predicted ASR vs CSR: (1) hemoglobin; (2) platelet count; (3) genetic polymorphisms of Fc-receptor (FcγR) IIc; (4) the presence of immunoglobulin G (IgG) anti-platelet antibodies; and (5) preceding vaccination. The ASR sensitivity was 0.91 (95% confidence interval, 0.80-1.00) and specificity was 0.67 (95% confidence interval, 0.53-0.80). In the 67 patients of the observation arm, this biological score was also associated with recovery during 1 year of follow-up. The addition of the biological score to a predefined clinical score further improved the discrimination of favorable ITP disease courses.

CONCLUSIONS

The prediction of disease courses and IVIg treatment responses in ITP is improved by using both clinical and biological stratification.

Diagnostic and Predictive Contribution of Autoantibodies Screening in a Large Series of Patients With Primary Immunodeficiencies

Objectives

To evaluate the diagnostic and predictive contribution of autoantibodies screening in patients with primary immunodeficiencies (PIDs).

Methods

In the present study, PID patients and healthy controls have been screened for 54 different autoantibodies. The results of autoantibodies screening in PID patients were correlated to the presence of autoimmune diseases.

Results

A total of 299 PID patients were included in this study with a predominance of antibody deficiencies (27.8%) followed by immunodeficiencies affecting cellular and humoral immunity (26.1%) and complement deficiencies (22.7%). Autoimmune manifestations were present in 82 (27.4%) patients. Autoimmune cytopenia (10.4%) was the most common autoimmune disease followed by gastrointestinal disorders (10.0%), rheumatologic diseases (3.7%), and endocrine disorders (3.3%). Autoantibodies were found in 32.4% of PID patients and 15.8% of healthy controls (P < 0.0005). Anti-nuclear antibodies (ANA) (10.0%), transglutaminase antibody (TGA) (8.4%), RBC antibodies (6.7%), anti-smooth muscle antibody (ASMA) (5.4%), and ASCA (5.0%) were the most common autoantibodies in our series. Sixty-seven out of the 82 patients with autoimmune manifestations (81.7%) were positive for one or more autoantibodies. Eleven out of the 14 patients (78.6%) with immune thrombocytopenia had positive platelet-bound IgM. The frequencies of ASCA and ANCA among patients with IBD were 47.4% and 21.0% respectively. All patients with celiac disease had TGA-IgA, while six out of the 11 patients with rheumatologic diseases had ANA (54.5%). Almost one third of patients (30/97) with positive autoantibodies had no autoimmune manifestations. ANA, rheumatoid factor, ASMA, anti-phospholipid antibodies and ANCA were often detected while specific AID was absent. Despite the low positive predictive value of TGA-IgA and ASCA for celiac disease and inflammatory bowel disease respectively, screening for these antibodies identified undiagnosed disease in four patients with positive TGA-IgA and two others with positive ASCA.

Conclusion

The present study provides valuable information about the frequency and the diagnostic/predictive value of a large panel of autoantibodies in PIDs. Given the frequent association of some AIDs with certain PIDs, screening for corresponding autoantibodies would be recommended. However, positivity for autoantibodies should be interpreted with caution in patients with PIDs due to their low positive predictive value.

Evidence-based clinical practice guideline for the management of primary immune thrombocytopenia (ITP) in pediatric population

Introduction: Primary immune thrombocytopenia (ITP) is the most common cause of thrombocytopenia in children, with a reported incidence of 1.1-12.5 cases per 100 000 children. However, currently, there are several definitions of ITP, as well as diagnostic and therapeutic approaches. Objective: To develop an evidence-based clinical practice guideline (CPG) to standardize the definition of ITP and, in this way, reduce the variability of its diagnosis, and to provide indications for the treatment of acute, persistent, and chronic ITP in patients under 18 years of age. Materials and methods: The CPG was prepared by a multidisciplinary group that followed the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) guidelines for developing CPGs, formulated PICO clinical questions, and conducted systematic reviews. GRADE evidence profiles were created and recommendations, with their corresponding level of evidence and strength, were made after a panel of experts assessed the benefit-risk balance, the quality of evidence, the patients’ values and preferences, and the context in which they should be implemented. Results: A total of 23 recommendations were made to pediatricians, hematologists, and health professionals working in emergency services for treating acute, persistent, and chronic ITP. Overall, the CPG has low quality of evidence, and the recommendations were made in order to improve the success rate of ITP treatment and the prognosis of children with this condition. Conclusions: Although ITP is the main cause of thrombocytopenia in pediatrics, to date there is not enough high-quality evidence that supports the recommendations presented here for its proper classification and treatment in children. Thus, further studies providing high-quality evidence on this issue are required.

Insights on chronic immune thrombocytopenia pathogenesis: A bench to bedside update

Immune thrombocytopenia (ITP) is a heterogeneous disease with an unpredictable course. Chronicity can develop in up to two-thirds of adults and 20-25% of children, representing a significant burden on patients' quality of life. Despite acceptable responses to treatment, precise etiology and pathophysiology phenomena driving evolution to chronicity remain undefined. We analyzed reported risk factors for chronic ITP and associated them with proposed underlying mechanisms in its pathogenesis, including bone marrow (BM) microenvironment disturbances, clinical features, and immunological markers. Their understanding has diagnostic implications, such as screening for the presence of specific antibodies or BM examination employing molecular tools, which could help predict prognosis and recognize main pathogenic pathways in each patient. Identifying these underlying mechanisms could guide the use of personalized therapies such as all-trans retinoic acid, mTor inhibitors, FcRn inhibitors, oseltamivir, and others. Further research should lead to tailored treatments and chronic course prevention, improving patients' quality of life.

Fatigue perception in a cohort of children with chronic immune thrombocytopenia and their caregivers using the PedsQL MFS: Real-life multicenter experience of the Italian Association of Pediatric Hematology and Oncology (AIEOP)

BACKGROUND

Fatigue is an important clinical and psychological aspect for a significant number of children affected by immune thrombocytopenia (ITP). To date, few studies have explored fatigue and its relationship with chronic ITP in pediatric age. The aim of the present multicentric pilot study is to determine fatigue perception in a large group of children with chronic ITP and their caregivers using the PedsQL Multidimensional Fatigue Scale (PedsQL MFS), and to compare the results with those of healthy control subjects.

PROCEDURE

Children with chronic ITP aged 5-18 years and/or caregivers of children aged 2-18 years were enrolled. Child/adolescent self-report was used for patients aged 5-18 years, and parent proxy-report for patients aged 2-18 years. The questionnaire was offered as online survey. PedsQL MFS is composed of 18 items covering three dimensions: General Fatigue Scale, Sleep/Rest Fatigue Scale, and Cognitive Fatigue Scale.

RESULTS

One hundred ninety-one patients affected by chronic ITP and 248 caregivers answered the PedsQL MFS. We have highlighted that lower values of PedsQL MFS scores are obtained in the 13-18 age group. Moreover, sleep/rest fatigue domain appears to be more compromised in all age groups. For all PedsQL MFS scores, pediatric patients with chronic ITP and their caregivers reported statistically significant worse fatigue than healthy children.

CONCLUSIONS

This study suggests that fatigue is relevant among children and adolescents affected by chronic ITP. The PedsQL MFS represents an adequate instrument for measuring fatigue in patients with chronic ITP. Therefore, symptoms of fatigue should be routinely assessed in clinical practice.

Primary immunodeficiencies, autoimmune hyperthyroidism, coeliac disease and systemic lupus erythematosus in childhood immune thrombocytopenia

AIM

To evaluate the cumulative prevalence of coeliac disease, systemic lupus erythematosus, autoimmune hyperthyroidism and primary immunodeficiencies in children with either newly diagnosed/persistent or chronic immune thrombocytopenia (ITP).

METHODS

Monocentric retrospective analysis of the clinical and biochemical features of 330 consecutive patients with ITP referred to our Pediatric Hematology Unit between January 2009 and December 2018.

RESULTS

The prevalence of systemic lupus erythematosus (0.3%), coeliac disease (0.3%) and autoimmune hyperthyroidism (0.6%) was not increased compared to general paediatric population. Of note, the prevalence of underlying primary immunodeficiencies was 2.4%, remarkably higher than the general paediatric population (P = .005). All the patients diagnosed with immunodeficiency developed either bi-/trilinear cytopenia or splenomegaly.

CONCLUSION

Whilst autoimmune and immunological screening is already recommended at the onset of immune thrombocytopenia, we recommend that primary immunodeficiencies be regularly screened during follow-up, especially in case of additional cytopenia or lymphoproliferation.

A clinical prediction score for transient versus persistent childhood immune thrombocytopenia

Essentials There is a need for improved tools to predict persistent and chronic immune thrombocytopenia (ITP). We developed and validated a clinical prediction model for recovery from newly diagnosed ITP. The Childhood ITP Recovery Score predicts transient vs. persistent ITP and response to intravenous immunoglobulins. The score may serve as a useful tool for clinicians to individualize patient care. ABSTRACT: Background Childhood immune thrombocytopenia (ITP) is an autoimmune bleeding disorder. The prognosis (transient, persistent, or chronic ITP) remains difficult to predict. The morbidity is most pronounced in children with persistent and chronic ITP. Clinical characteristics are associated with ITP outcomes, but there are no validated multivariate prediction models. Objective Development and external validatation of the Childhood ITP Recovery Score to predict transient versus persistent ITP in children with newly diagnosed ITP. Methods Patients with a diagnosis platelet count ≤ 20 × 109 /L and age below 16 years were included from two prospective multicenter studies (NOPHO ITP study, N = 377 [development cohort]; TIKI trial, N = 194 [external validation]). The primary outcome was transient ITP (complete recovery with platelets ≥100 × 109 /L 3 months after diagnosis) versus persistent ITP. Age, sex, mucosal bleeding, preceding infection/vaccination, insidious onset, and diagnosis platelet count were used as predictors. Results In external validation, the score predicted transient versus persistent ITP at 3 months follow-up with an area under the receiver operating characteristic curve of 0.71. In patients predicted to have a high chance of recovery, we observed 85%, 90%, and 95% recovered 3, 6, and 12 months after the diagnosis. For patients predicted to have a low chance of recovery, this was 32%, 46%, and 71%. The score also predicted cessation of bleeding symptoms and the response to intravenous immunoglobulins (IVIg). Conclusion The Childhood ITP Recovery Score predicts prognosis and may be useful to individualize clinical management. In future research, the additional predictive value of biomarkers can be compared to this score. A risk calculator is available (http://www.itprecoveryscore.org).

Chronic Refractory Immune Thrombocytopenia Is Associated With Variants in Immune Genes

The pathogenesis of chronic refractory immune thrombocytopenia (C/RITP) is mechanistically complex and considerably varies across patients. Few studies have focused on the genetic characteristics of C/RITP in children. The aim of this study was to analyze and summarize the clinical manifestations and genetic characteristics of C/RITP children with mutations in immune-related genes. In the study, 51 children with variants in immune-related genes (mutation group) and 103 children with no abnormal mutations (control group) were enrolled. Children in the mutation group showed severity of hemorrhage, a higher incidence of abnormal immunological indices, and an increased expression of SLE biomarkers. The number of peripheral T and B lymphocytes in the mutation group significantly increased. Nine patients (17.6%) had probable pathogenic variant genes associated with primary immunodeficiencies (TNFRSF13B, CARD11, CBL, and RAG2), and 42 patients (82.4%) had variants of uncertain significance in 23 genes. C/RITP patients with variants in immune-related genes had more severe bleeding, abnormal immunological indices, and an increased expression of SLE biomarker. Next-generation sequenciong (NGS) might be a useful way to differentiate those patients from C/RITP.

Immune Thrombocytopenia (ITP): Current Limitations in Patient Management

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by isolated thrombocytopenia caused by increased platelet destruction and impaired platelet production. First-line therapies include corticosteroids, intravenous immunoglobulin, and anti-D immunoglobulin. For patients who are refractory to these therapies, those who become corticosteroid dependent, or relapse following treatment with corticosteroid, options include splenectomy, rituximab, and thrombopoietin-receptor agonists, alongside a variety of additional immunosuppressive and experimental therapies. Despite recent advances in the management of ITP, many areas need further research. Although it is recognized that an assessment of patient-reported outcomes in ITP is valuable to understand and guide treatment, these measures are not routinely measured in the clinical setting. Consequently, although corticosteroids are first-line therapies for both children and adults, there are no data to suggest that corticosteroids improve health-related quality of life or other patient-related outcomes in either children or adults. In fact, long courses of corticosteroids, in either children or adults, may have a negative impact on a patient's health-related quality of life, secondary to the impact on sleep disturbance, weight gain, and mental health. In adults, additional therapies may be needed to treat overt hemorrhage, but unfortunately the results are transient for the majority of patients. Therefore, there is a need to recognize the limitations of current existing therapies and evaluate new approaches, such as individualized treatment based on the probability of response and the size of effect on the patient's most bothersome symptoms and risk of adverse effects or complications. Finally, a validated screening tool that identifies clinically significant patient-reported outcomes in routine clinical practice would help both patients and physicians to effectively follow a patient's health beyond simply treating the laboratory findings and physical symptoms of ITP. The goal of this narrative review is to discuss management of newly diagnosed and refractory patients with ITP, with a focus on the limitations of current therapies from the patient's perspective.

New insights into the epidemiology of immune thrombocytopenia in adult patients: Impact for clinical practice

New insights into immune thrombocytopenia (ITP) epidemiology in adult patients highlight three main outcomes of morbidity and mortality: bleeding, infection and thrombosis. This review depicts current evidence about incidence and risk factors of bleeding, infection and thrombosis as well as predictors of chronicity, and shows how this assessment impacts the choice of ITP second-line treatment at the individual-level basis.

Anti-platelet antibody immunoassays in childhood immune thrombocytopenia: a systematic review

BACKGROUND

In adult immune thrombocytopenia (ITP), an acquired autoimmune bleeding disorder, anti-platelet autoantibody testing may be useful as a rule-in test. Childhood ITP has different disease characteristics, and the diagnostic and prognostic value of anti-platelet antibody testing remains uncertain.

OBJECTIVE

To systematically review the diagnostic accuracy of anti-platelet autoantibody testing in childhood ITP.

METHODS

PubMed and EMBASE were searched for studies evaluating immunoassays in childhood ITP. Study quality was assessed (QUADAS2), and evidence was synthesized descriptively.

RESULTS

In total, 40 studies (1606 patients) were identified. Nine studies reported sufficient data to determine diagnostic accuracy measures. Anti-platelet IgG antibody testing showed a moderate sensitivity (0·36-0·80 platelet-associated IgG [direct test]; 0·19-0·39 circulating IgG [indirect test]). In studies that reported control data, including patients with non-immune thrombocytopenia, specificity was very good (0·80-1·00). Glycoprotein-specific immunoassays showed comparable sensitivity (three studies) and predominantly identified IgG anti-GP IIb/IIIa antibodies, with few IgG anti-GP Ib/IX antibodies. Anti-platelet IgM antibodies were identified in a substantial proportion of children (sensitivity 0·62-0·64 for direct and indirect tests).

CONCLUSION

The diagnostic evaluation of IgG and IgM anti-platelet antibodies may be useful as a rule-in test for ITP. In children with insufficient platelets for a direct test, indirect tests may be performed instead. A negative test does not rule out the diagnosis of ITP. Future studies should evaluate the value of anti-platelet antibody tests in thrombocytopenic children with suspected ITP.

Anti-platelet antibodies in childhood immune thrombocytopenia: Prevalence and prognostic implications

BACKGROUND

Anti-platelet antibody testing may be useful for the diagnosis and management of childhood immune thrombocytopenia (ITP).

OBJECTIVES

Here we aimed to assess the prevalence and prognostic significance of anti-platelet glycoprotein-specific IgM and IgG antibodies.

METHODS

Children with newly diagnosed ITP were included at diagnosis and randomized to an intravenous immunoglobulins (IVIg) or careful observation group (TIKI trial). In this well-defined and longitudinally followed cohort (N = 179), anti-platelet glycoprotein-specific IgM and IgG antibodies were determined by monoclonal antibody-immobilization of platelet antigens.

RESULTS

The dominant circulating anti-platelet antibody class in childhood ITP was IgM (62% of patients); but IgG antibodies were also found (10%). Children without IgM platelet antibodies were older and more often female. There was weak evidence for an association between IgM anti-GP IIb/IIIa antibodies and an increased bleeding severity (P = .03). The IgM and IgG anti-platelet responses partially overlapped, and reactivity was frequently directed against multiple glycoproteins. During 1-year follow-up, children with IgM antibodies in the observation group displayed a faster platelet recovery compared to children without, also after adjustment for age and preceding infections (P = 7.1 × 10-5 ). The small group of patients with detectable IgG anti-platelet antibodies exhibited an almost complete response to IVIg treatment (N = 12; P = .02), suggesting that IVIg was particularly efficacious in these children.

CONCLUSIONS

Testing for circulating anti-platelet antibodies may be helpful for the clinical prognostication and the guidance of treatment decisions in newly diagnosed childhood ITP. Our data suggest that the development of even more sensitive tests may further improve the clinical value of antibody testing.

Second-line treatment trends and long-term outcomes of 392 children with chronic immune thrombocytopenic purpura: the French experience over the past 25 years

Childhood chronic immune thrombocytopenic purpura (cITP) is a rare disease. In severe cases, there is no evidence for the optimal therapeutic strategy. Our aim was to describe the real-life management of non-selected children with cITP at diagnosis. Since 2004, patients less than 18 years old with cITP have been enrolled in the national prospective cohort, OBS'CEREVANCE. From 1990 to 2014, in 29 centres, 392 children were diagnosed with cITP. With a median follow-up of six years (2·0-25), 45% did not need second-line therapy, and 55% (n = 217) received one or more second lines, mainly splenectomy (n = 108), hydroxychloroquine (n = 61), rituximab (n = 61) or azathioprine (n = 40). The overall five-year further second-line treatment-free survival was 56% [95% CI 49·5-64.1]. The use of splenectomy significantly decreased over time. Hydroxychloroquine was administered to children with positive antinuclear antibodies, more frequently older and girls, and reached 55% efficacy. None of the patients died. Ten years after the initial diagnosis, 55% of the 56 followed children had achieved complete remission. Children with cITP do not need second-line treatments in 45% of cases. Basing the treatment decision on the pathophysiological pathways is challenging, as illustrated by ITP patients with positive antinuclear antibodies treated with hydroxychloroquine.

Fatigue, executive function and psychological effects in children with immune thrombocytopenia: a cross-sectional study

Childhood ITP is often considered to be a relatively mild haematological disorder, with only a minority of patients requiring treatment for troublesome bleeding. Over recent years, wider effects of the condition have been identified in some adults, particularly relating to fatigue and cognitive impairment. In this study, we sought to investigate such effects in a group of children with ITP and further our understanding of their psychological profile. Children attending routine haematology outpatient clinics and their parents were asked to complete standardised questionnaires designed to assess a range of psychological and cognitive factors. Although the majority of children had some scores within the normal range, a significantly high proportion had difficulties with fatigue (70·6%), emotional and behavioural symptoms (25·7%) or executive functioning (19·4%). Quality of life and subjective evaluation of the illness (appraisal) correlated significantly with each of these domains, but bleeding severity and platelet count did not. Our findings provide valuable insight into the broader impact of childhood ITP, which could aid in providing holistic care, potentially contribute to decisions regarding medical treatment, and guide future research.

Why do patients with immune thrombocytopenia (ITP) experience lower bleeding events despite thrombocytopenia?

Immune thrombocytopenia is an autoimmune condition characterized by an isolated thrombocytopenia. Despite the low platelet levels, severe bleeding episodes are relatively rare suggesting that patients with ITP may have a protective factor against bleeding. Platelet microparticles (PMP) are thought to play a role in clot formation and some studies have demonstrated higher levels of circulating PMP in patients with ITP. This article provides a review of the epidemiology, mechanism, clinical presentation, management, and prognosis of ITP as well as a review of the literature and discussion regarding PMP and bleeding risk in ITP patients.

Screening for Genetic Mutations for the Early Diagnosis of Common Variable Immunodeficiency in Children With Refractory Immune Thrombocytopenia: A Retrospective Data Analysis From a Tertiary Children's Center

Aim: This study aimed to identify common variable immunodeficiency (CVID) by high-throughput next-generation sequencing (NGS) in children with refractory immune thrombocytopenia (RITP) to facilitate early diagnosis. Methods: CVID-related genetic mutations were explored in patients with RITP during 2016-2019. They were tested consecutively through NGS by the ITP team of the tertiary children hospital in China. An evaluation system was devised based on the phenotype, genetic rule, and serum immunoglobulins (Igs) of all patients with RITP. The patients were divided into highly suspicious, suspicious, and negative groups using the evaluation system. Results: Among 176 patients with RITP, 16 (9.1%) harbored CVID-related genetic mutations: 8 (4.5%) were highly suspicious of CVIDs. Five had mutations in tumor necrosis factor receptor superfamily 13B (TNFRSF13B), one in lipopolysaccharide responsive beige-like anchor protein (LRBA), one in nuclear factor kappa-B2 (NF-κB2), and one in caspase recruitment domain11 (CARD11). Others were classified into the suspicious group because the clinical phenotype and pedigree were suggestive, yet insufficient, for diagnosis. Repeated infection existed in all patients. Two had an allergic disease. Positive autoimmune serologies were noted in 62.5%. Five had a definite positive family history. The median serum immunoglobulin (Ig)A, IgG, and IgM levels were 0.3875, 6.14, and 0.522 g/L, respectively. Nearly 85.7% of patients had insufficient serum IgA levels, while 37.5% had low IgG and IgM levels. Conclusions: High-throughput NGS and a thorough review of the medical history are beneficial for the early diagnosis of patients without any significant clinical characteristics, distinguishing them from those with primary pediatric ITP. The cases suspicious of CVID need further investigation and follow-up to avoid deterioration.

First Line Treatments for Newly Diagnosed Primary Immune Thrombocytopenia in Children: A Systematic Review and Network Meta-analysis

BACKGROUND

The first-line interventions in immune thrombocytopenia (ITP) include intravenous polyclonal immunoglobulins (IVIg), corticosteroids and anti-D immunoglobulin (anti-D).

OBJECTIVE

We aimed to compare the effectiveness and safety of first line treatments for newlydiagnosed primary ITP in children to increase the platelet count.

METHODS

We searched MEDLINE, EMBASE, LILACS and the Cochrane Central register of Controlled Trials (CENTRAL); and included the clinical trials. We performed the statistical analysis in R.

RESULTS

We included 12 studies for meta-analysis. Compared with IVIG 2g/kg, response rates were lower for prednisone 2mg/kg at 72 hours [RR 0.04 (95% CI 0.0 to 0.68)] and at 7 days [RR 0.23 (95% CI 0.08 to 0.67)]; at 48 hours, methylprednisolone 30mg/kg also showed lower response rates [RR 0.72 (95% CI 0.52 to 0.99)]. IVIG 2g/kg and 2.5g/kg had less adverse effects than Anti- D, methylprednisolone and IVIG 0.8g/kg. For rising platelet count, no statistical differences were found at 24 hours or in 7 days; at 48 hours, IVIG 2g/kg showed better results than Anti-D 75μg/kg [MD -58.84 (95% CI -87.02 to -25.66)]. After a month, platelet count with IVIG 2g/kg was higher than Anti-D 50 and 75μg/kg [-82.03 (95% CI -102.60 to -61.46) and -78.77 (95% CI -97.80 to - 59.74), respectively], but lower than methylprednisolone 50mg/kg [MD 118 (95% CI 3.88 to 232.12)].

CONCLUSION

The total platelet count rises higher in early and late phases with IVIG than Anti-D, but in long term it is higher with methylprednisolone. Additionally, IVIG causes less adverse effects than Anti-D and corticosteroids.

Association of Immune Thrombocytopenia and T-Lymphoblastic Lymphoma in a Pediatric Patient

Immune thrombocytopenia (ITP) is characterized by isolated thrombocytopenia of unclear etiology. We present a unique case of an 8-year-old girl with chronic ITP who was subsequently diagnosed with T-lymphoblastic lymphoma at age 11. The clinical course was complicated by the occurrence of nonepileptiform events with bizarre behavior changes following the administration of nelarabine and intrathecal and high-dose systemic methotrexate. This case highlights an unusual co-occurrence of hematologic malignancy and chronic ITP in an otherwise healthy child. We speculate that underlying genetic or immunologic lesions may predispose a subset of pediatric ITP patients to the development of hematologic malignancies.

Inborn Errors of Immunity With Immune Dysregulation: From Bench to Bedside

Inborn errors of immunity are genetic disorders with broad clinical manifestations, ranging from increased susceptibility to infections to significant immune dysregulation, often leading to multiple autoimmune phenomena, lymphoproliferation, and malignancy. The treatment is challenging as it requires careful balancing of immunosuppression in subjects at increased risk of infections. Recently, the improved ability to define inborn errors of immunity pathophysiology at the molecular level has set the basis for the development of targeted therapeutic interventions. Such a "precision medicine" approach is mainly bases on the use of available small molecules and biologics to target a specific cell function. In this article, we summarize the clinical and laboratory features of various recently described inborn errors of immunity associated with immune dysregulation and hyperinflammation in which mechanism-based therapeutic approaches have been implemented.