The incidence and clinical burden of immune thrombocytopenia in pediatric patients in the United States

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.

Epidemiology, Treatment Patterns, and Cost Analysis of Immune Thrombocytopenia in Spain between 2014 and 2020: A Population-based Study

Background  Immune thrombocytopenia (ITP) is characterised by low platelet counts and often leads to bleeding, fatigue, and reduced health-related quality of life. Methods  This observational, retrospective, population-based study using BIG-PAC® database included Spanish paediatric and adult patients with primary ITP diagnosed in primary care and hospitals between 2014 and 2020 (median follow-up: 4 years). Epidemiology, baseline/clinical characteristics, treatment trends, healthcare resources and costs were analysed. Results  The BIG-PAC® database contains records of 1,818,588 patients; 170 adults and 27 children with ITP were included in our analysis. ITP prevalence and annual incidence per 100,000 were estimated in 10.8 (2.8 in chronic ITP [cITP] patients) and 1.5 (0.3 in cITP patients), respectively. Epistaxis was the most common bleeding event, followed by genitourinary and gastrointestinal bleeding; >50%/> 75% of ITP/cITP patients reported fatigue. Chronic patients had lower platelet counts at baseline and required more transfusions. Corticosteroids, immunosuppressants, and thrombopoietin receptor agonists were the most used agents in first-, second- and third-line treatment, respectively. Thirty-five patients, all of them in chronic phase, underwent splenectomy. Patients had on average 13.9, 6.6, and 1.2 visits/year to primary care, haematology/internal medicine, and emergency departments, respectively. More than one-fourth of adult patients took on average 16.3 days of sick leave annually. Mean annual total health care costs were €10,741 (ITP patients) and €19,809 (cITP patients). Conclusion  This is the first study to provide an overall perspective on the situation of the Spanish ITP population in terms of epidemiology, treatment trends, health care resources and costs, highlighting unmet patient needs, and direct and indirect costs/resource use between 2014 and 2020.

Incidence and risk factors of systemic lupus erythematosus in patients with primary immune thrombocytopenia: a systematic review and meta-analysis

Background

Immune disorders and autoantibodies has been noted in both primary immune thrombocytopenia (ITP) and systemic lupus erythematosus (SLE). Whether the two disorders are correlated is unclear. The lack of evidence on the incidence of and risk factors for SLE in primary ITP patients poses a challenge for prediction in clinical practice. Therefore, we conducted this study.

Methods

The protocol was registered with PROSPERO (CRD42023403665). Web of Science, Cochrane, PubMed, and EMBASE were searched for articles published from inception to 30 September 2023 on patients who were first diagnosed with primary ITP and subsequently developed into SLE. Furthermore, the risk factors were analyzed. Study quality was estimated using the Newcastle-Ottawa Scale. The statistical process was implemented using the R language.

Results

This systematic review included eight articles. The incidence of SLE during the follow-up after ITP diagnosis was 2.7% (95% CI [1.3-4.4%]), with an incidence of 4.6% (95% CI [1.6-8.6%]) in females and 0 (95% CI [0.00-0.4%]) in males. Older age (OR = 6.31; 95% CI [1.11-34.91]), positive antinuclear antibody (ANA) (OR = 6.64; 95% CI [1.40-31.50]), hypocomplementemia (OR = 8.33; 95% CI [1.62-42.91]), chronic ITP (OR = 24.67; 95% CI [3.14-100.00]), organ bleeding (OR = 13.67; 95% CI [2.44-76.69]), and female (OR = 20.50; 95% CI [4.94-84.90]) were risk factors for subsequent SLE in ITP patients.

Conclusion

Patients with primary ITP are at higher risk of SLE. Specific follow-up and prevention strategies should be tailored especially for older females with positive ANA, hypocomplementemia, or chronic ITP. In subsequent studies, we need to further investigate the risk factors and try to construct corresponding risk prediction models to develop specific prediction strategies for SLE.

Insidious onset of spontaneous spinal epidural hematoma in immune thrombocytopenic purpura: a case-based review

INTRODUCTION

Spontaneous spinal epidural hematoma (SSEH) can result from various etiologies with a variable degree of neurological deficits. Here, we describe a rare case of SEH secondary to immune thrombocytopenic purpura (ITP) in a child and review the literature of SSEH caused by ITP.

CASE REPORT

A 9-year-old female who presented with rapid neurological decline, including bowel and bladder incontinence and paraparesis. A SSEH was observed extending from C2 to T6, causing a mass effect on the spinal cord. Her platelet count was only 7000/µL. Multidisciplinary care was established with neurosurgery, pediatric hematology, and pediatric surgery. The patient was managed emergently with splenectomy and surgical evacuation, with multilevel laminectomy and laminoplasty for evacuation of the hematoma. After a short course of rehabilitation, the patient regained all neurological function.

CONCLUSION

We report the first case of cervicothoracic SSEH secondary to ITP in a child managed with emergent splenectomy and surgical evacuation with multilevel lamoplasty. We also described the methods of timely diagnosis, urgent management, and overall prognosis of patients with this condition.

A single-arm, long-term efficacy and safety study of subcutaneous romiplostim in children with immune thrombocytopenia

Romiplostim is a thrombopoietin (TPO) receptor agonist approved for children and adults with immune thrombocytopenia (ITP) for ≥6 months, recommended as second-line treatment. This phase 3b, single-arm, multicenter study investigated long-term efficacy and safety of romiplostim in children ≥1 to <18 years old with ≥6 months' ITP duration and platelet counts ≤30 × 109/L. Children received weekly subcutaneous romiplostim (1 μg/kg titrated to 10 μg/kg) to maintain platelets within 50 to 200 × 109/L. A subset underwent bone marrow examinations. The primary end point was percentage of time with platelet response during the first 6 months' treatment (counts ≥50 × 109/L without rescue medication within the preceding 4 weeks). Overall, 203 patients (median age, 10.0 years) received ≥1 dose of romiplostim, median treatment duration was ∼3 years, and median average weekly dose was 6.9 μg/kg. Ninety-five (46.8%) discontinued (lack of efficacy, n = 43 [21.2%]). Platelet responses were achieved a median (interquartile range) of 50.0% (16.7%-83.3%) of the time during the first 6 months, increasing to 78.2% (26.7%-90.4%) during the overall 36-month treatment period. Eleven patients (5.4%) achieved sustained responses (consecutive counts ≥50 × 109/L without ITP medications for ≥24 weeks). Treatment-related adverse events (AEs) occurred in 56 patients (27.6%), with 8 (3.9%) experiencing serious treatment-related AEs; all of these led to discontinuation, including 4 cases of neutralizing antibodies (romiplostim, n = 3; TPO, n = 1). Bleeding occurred in 141 patients (69.5%), decreasing over time; grade ≥3 bleeding events occurred in 20 (9.9%). At year 2, eight of 63 evaluable patients (12.7%) had grade 2 reticulin. Long-term romiplostim resulted in sustained on-treatment platelet responses with an overall safety profile consistent with previous studies. This trial was registered at www.clinicaltrials.gov as #NCT02279173.

Assessment of romiplostim immunogenicity in pediatric patients in clinical trials and in a global postmarketing registry

Development of first-generation thrombopoietins (TPOs) was halted due to antibodies that neutralized endogenous TPO, causing protracted thrombocytopenia in some patients. The second-generation TPO receptor agonist romiplostim, having no homology to TPO, was developed to circumvent potential immunogenicity. We examined the development of binding and neutralizing antibodies to romiplostim and TPO among pediatric patients with primary immune thrombocytopenia (ITP) in 5 clinical trials and a global postmarketing registry. In the trials, 25 of 280 (8.9%) patients developed anti-romiplostim binding antibodies. The first positive result was detected 67 weeks (median) after romiplostim treatment was initiated. The median romiplostim dose was 8 µg/kg, and the median platelet count was 87 × 109/L. Most patients who developed anti-romiplostim binding antibodies (18 of 25 [72%]) had ≥90% of platelet assessments showing a response. Anti-romiplostim neutralizing antibodies developed in 8 of 280 (2.9%) patients. The development of anti-romiplostim neutralizing antibodies was unrelated to the romiplostim dose, and most patients who developed the antibodies (7 of 8 [88%]) had platelet response. Nine of 279 (3.2%) patients developed anti-TPO binding antibodies, and 1 (0.4%) developed transient anti-TPO neutralizing antibodies. In 8 patients who developed anti-romiplostim neutralizing antibodies, no TPO cross-reactivity was observed. In the postmarketing registry, 3 of 19 (15.8%) patients developed anti-romiplostim binding antibodies; 1 (5.3%) patient developed anti-romiplostim neutralizing antibodies. These results suggest that immunogenicity to romiplostim occurs infrequently in pediatric patients with ITP and is generally not associated with loss of platelet response or other negative clinical sequelae.

Relative Dose Intensity of Chemotherapy and Survival in Patients with Advanced Stage Solid Tumor Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Chemotherapy-induced toxicities lead to therapy dose reduction or delay, affecting patient outcomes. This systematic review and meta-analysis evaluated the impact of relative dose intensity (RDI) on survival in adult patients with solid tumor cancer on nonadjuvant-based chemotherapy regimens.

METHODS

PubMed, Embase, and Web of Science databases were searched for peer-reviewed English journal articles or congress abstracts evaluating association between RDI and survival; observational studies, case series of ≥20 patients, and clinical trials published between 2013 and 2020 were eligible. Meta-analyses were conducted to quantify the association between RDI levels and overall survival (OS) among studies reporting a hazard ratio (HR) for OS by similar tumor types, regimens, and RDI. Forest plots represented summary HR and 95% confidence interval (CI); Cochran's Q and I2 tests evaluated study heterogeneity.

RESULTS

Overall, 919 articles were reviewed and 22 included; seven were eligible for meta-analysis. Significantly shorter OS at RDI <80% versus ≥80% and <85% versus ≥85% was observed upon meta-analysis of four carboplatin-based studies for breast, non-small cell lung, or ovarian cancer (HR 1.17; 95% CI: 1.07-1.27) and three FOLFOX-, FOLFIRI-, or FOLFIRINOX-based studies for colorectal or pancreatic cancer (HR 1.39; 95% CI: 1.03-1.89). Grade 3 or higher hematologic toxicities were higher for carboplatin-based regimens (thrombocytopenia: 14%-22%; anemia: 15%-19%; neutropenia: 24%-58%) than FOLFOX-, FOLFIRI-, or FOLFIRINOX-based regimens (thrombocytopenia: 1%-4%; anemia: 5%-19%; neutropenia: 19%-47%).

CONCLUSION

The results suggested longer OS with RDI ≥80% or ≥85% for both regimens, indicating that management of toxicities across treatment modalities may contribute to maintenance of higher RDI and benefit survival for patients with advanced solid tumors.

IMPLICATIONS FOR PRACTICE

Chemotherapy-induced toxicities lead to dose reduction and/or treatment delay, thus affecting patient outcomes. Results of this systematic review and meta-analysis, evaluating the impact of relative dose intensity (RDI) on survival of patients with solid tumors on nonadjuvant-based chemotherapy regimens, demonstrate a longer overall survival with RDI levels of at least 80% for patients with solid tumors on carboplatin-based and FOLFOX-, FOLFIRI-, or FOLFIRINOX-based chemotherapy regimens, suggesting a protective effect of maintaining RDI ≥80% or ≥ -85%. Although grade 3 or higher hematologic toxicities occurred more in carboplatin-based studies, managing toxicities across treatment regimens may contribute to maintenance of higher RDI and ultimately benefit overall survival.

U.S. Population-Based background incidence rates of medical conditions for use in safety assessment of COVID-19 vaccines

The Coronavirus Disease 2019 (COVID-19) pandemic has had a devastating impact on global health, and has resulted in an unprecedented, international collaborative effort to develop vaccines to control the outbreak, protect human lives, and avoid further social and economic disruption. Mass vaccination campaigns are underway in multiple countries and are expected worldwide once more vaccine becomes available. Some early candidate vaccines use novel platforms, such as mRNA encapsulated in lipid nanoparticles, and relatively new platforms, such as replication-deficient viral vectors. While these new vaccine platforms hold promise, limited safety data in humans are available. Serious health outcomes linked to vaccinations are rare, and some outcomes may occur incidentally in the vaccinated population. Knowledge of background incidence rates of these medical conditions is a critical component of vaccine safety monitoring to aid in the assessment of adverse events temporally associated with vaccination and to put these events into context with what would be expected due to chance alone. A list of 22 potential adverse events of special interest (AESI), including neurologic, autoimmune, and cardiovascular disorders, was compiled by subject matter experts at the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention. The most recently available U.S. background rates for these medical conditions, overall and by age, sex, and race/ethnicity (when available), were sourced from reported statistics (data published by medical panels/ associations or federal government reports), and literature reviews in PubMed. This review provides estimates of background incidence rates for medical conditions that may be monitored or studied as AESI during safety surveillance and research for COVID-19 vaccines and other new vaccines.

Pediatric Hematologic and Oncologic Emergencies

Pediatric hematologic and oncologic emergencies are in 3 major categories: complications of hematologic disorders, emergencies associated with the new onset of cancers, and treatment-associated oncologic emergencies. The overall number of these patients remains low; however, the mortality associated with these diseases remains high despite significant advances in management. This article presents a review of the most commonly encountered pediatric hematologic and oncologic complications that emergency physicians and providers need to know.

Intracranial hemorrhage in primary immune thrombocytopenia (ITP): 20 years' experience in pediatrics

Incidence of intracranial hemorrhage (ICH) among children with primary immune thrombocytopenia (ITP) varies among different studies. We published data during the period of 1997-2007 of ICH in children with primary ITP, addressing risk factors and outcome. The aim of this study is to assess changes in incidence, risk factors, and outcome of ICH in children with ITP from last decade and to report the overall 20 years' experience. We compared 2008-2018 with the decade before it. Data of children with ITP and ICH during study period and ITP control cases were analyzed. Neurosurgical intervention and outcome were also reported. A total of 4340 children with primary ITP were evaluated. Twenty-five (0.63%) ICH events were reported over 2 decades. Head trauma, hematuria, and platelet counts < 10 × 109/L were the risk factors mostly associated with ICH. Overall mortality was 24%, and a further 28% had neurologic sequelae. Neurosurgical intervention was done in 12% of cases with good outcome.Conclusion: Persistent platelet counts < 10 × 109/L were a significant risk factor for ICH in both time periods, while head trauma and hematuria were more reported in the period of 2008-2018 as significant risk factors for ICH. Outcome was comparable in both periods. What is Known: • ICH is a rare complication of ITP; however, early recognition of risk factors and aggressive treatment might lead to complete recovery without sequalae. Platelet counts less than < 10 × 109/L are the main risk factor for ICH. Few studies reported other significant risk factors. What is New: • Hematuria and head trauma are significant risk factors for ICH in ITP, in addition to having a persistently low platelet count < 10 × 109/L. (more than 90 days in chronic ITP, 45 days in persistent and 21 days in acute ITP) • Combined treatment with IVIG and HDMP followed by platelet transfusion was associated with complete recovery without sequelae in almost 50% of patients.

Incidence and prevalence of immune thrombocytopenia under the copayment waiver policy for pediatric patients in Korea: Data from the National Health Claims Database

The purpose of this study was to investigate the epidemiology of immune thrombocytopenia (ITP) under the copayment waiver policy for pediatric patients in Korea. The data were collected from the National Health Insurance Claims Database of Korea. ITP was identified based on the diagnostic code D69.38 from the Korean Standard Classification of Diseases. Patients between one and 18 years old, who had at least one health insurance claim for ITP as a final diagnosis, from 1 January 2016, to 31 December 2017, were analyzed. Prevalent cases were defined as patients who used, at least one time, any medical services coded as D69.38. Incident cases were defined as patients who did not use D69.38 coded medical services during the prior year and were newly registered in 2017. The prevalence and incidence of ITP were 24.53 and 13.39 per 100,000 persons. The peak rates were observed in 1-year-old patients. The gender-specific prevalence of ITP was significantly higher in one-year-old males than females. According to the change-point analysis, we found that the prevalence and incidence diminished rapidly at the ages of four and three, respectively. This Korean population-based epidemiological study of ITP provided meaningful insights into the current epidemiology of ITP and demonstrated the implications of interpreting epidemiologic studies to reflect age categorizing and health care system characteristics.

Hypovitaminosis D Influences the Clinical Presentation of Immune Thrombocytopenia in Children with Newly Diagnosed Disease

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by isolated thrombocytopenia defined as platelet count in peripheral blood <100 × 10⁹/L. Hypovitaminosis D is very common in children with autoimmune diseases. To analyze whether hypovitaminosis D is associated with the clinical presentation of ITP in children, medical records of 45 pediatric patients with newly diagnosed immune thrombocytopenia in the coastal region of Croatia were evaluated. The severity of bleeding was assessed using two bleeding scores. Children with lower 25-hydroxyvitamin D (25(OH)D) values had higher values of the skin-mucosa-organ-gradation (SMOG) bleeding score and respectively more severe bleeding on diagnosis of ITP. With further analysis of the main domains of that score, we found that patients with a lower 25(OH)D value had more severe bleeding in the skin and organs. When 25(OH)D and ITP Bleeding Scale (IBLS) score were analyzed, a negative correlation was found, but it was not significant. Our findings suggest that hypovitaminosis D influences the severity of the clinical presentation of ITP in children on initial diagnosis of the disease. Therefore, therapy with 25(OH)D could be a new potential option for treatment of ITP. To investigate the connection between 25(OH)D and the incidence and severity of ITP, further studies, especially randomized controlled studies, are needed.