Pediatric Eosinophilia: A Review and Multiyear Investigation into Etiologies.

OBJECTIVES: To identify the etiology of peripheral eosinophilia in a large pediatric population and to develop a diagnostic algorithm to help guide diagnosis and management of peripheral eosinophilia in the outpatient pediatric population. STUDY DESIGN: We performed a retrospective chart review of children presenting to Texas Children's Hospital in Houston with peripheral eosinophilia between January 1, 2011 and December 31, 2019. Eosinophilia was classified as mild (absolute eosinophil count [AEC] >500 and <1500 cells/µL), moderate (AEC >1500 and <4500 cells/µL), or severe (AEC >4500 cells/µL). Demographic information and diagnostic workup data were collected. RESULTS: A total of 771 patients aged <18 years were evaluated. The most common cause of eosinophilia was allergy (n = 357; 46%), with atopy (n = 296) and drug reaction (n = 54) the most common subcauses. This was followed by unknown etiology (n = 274; 36%), infectious causes (n = 72; 9%), and eosinophilic disorders (n = 47; 6%). Many patients with an unknown cause (n = 202; 74%) had limited or no follow-up testing. CONCLUSIONS: More information on the etiology of pediatric eosinophilia and workup data could help identify the causes. This study provides important information on the evaluation of eosinophilia in the US pediatric population, including a diagnostic algorithm to guide primary care pediatricians.

Pediatric autoimmune myelofibrosis: Experience from a large pediatric tertiary care center.

Autoimmune myelofibrosis (AIMF) is a rare disorder characterized by cytopenias and autoimmunity, with characteristic bone marrow findings that include lymphocytic infiltration and fibrosis. AIMF is described predominantly in adult populations who have systemic lupus erythematosis (SLE), with scant pediatric cases described mainly in older adolescents with SLE. Here, we described the largest single-center pediatric experience of pediatric autoimmune myelofibrosis (PAIMF) series, demonstrating both similarities and distinctions from the adult experience. Patients overall respond well to steroid therapy, but these patients were significantly younger, infrequently carried a diagnosis of SLE, and causative genetic lesions were identified in many cases.

Pediatric refractory immune thrombocytopenia: A systematic review.

Pediatric immune thrombocytopenia (ITP) is an acquired disorder associated with autoimmune destruction and impairment of platelet production in children. Some children exhibit poor or transient response to ITP-directed treatments and are referred to as having refractory ITP (rITP). There is currently no consensus on the definition of rITP, nor evidence-based treatment guidelines for patients with rITP. After a survey of pediatric ITP experts demonstrated lack of consensus on pediatric rITP, we pursued a systematic review to examine the reported clinical phenotypes and treatment outcomes in pediatric rITP. The search identified 253 relevant manuscripts; following review, 11 studies proposed a definition for pediatric rITP with no consensus amongst them. Most definitions included suboptimal response to medical management, while some outlined specific platelet thresholds to define this suboptimal response. Common attributes identified in this study should be used to propose a comprehensive definition, which will facilitate outcome comparisons of future rITP studies.

Refractory autoimmune cytopenias in pediatric Evans syndrome with underlying systemic immune dysregulation.

Evans syndrome is a rare but challenging disorder in children; and despite rapidly growing evidence for targetable systemic immune dysregulation driving these "idiopathic" autoimmune cytopenias, precision diagnosis and management remains sub-optimal among these patients. We analyzed retrospective clinical data for 60 pediatric ES patients followed at 3 large tertiary referral centers in the United States over a recent 6-year period and found that definable underlying systemic immune dysregulation was identified in only 42% of these patients throughout the course of clinical care. Median time from ES diagnosis to identification of the underlying systemic immune dysregulation disorder was 1.3 years (<1 month for rheumatologic disease, 2.3 years for CVID, 3.4 years for ALPS, and 7.4 years for monogenic disorders of immune regulation). Notably, a significantly higher percentage of patients in whom a definitive immune dysregulation disorder was ultimately identified required ≥3 cytopenia-directed therapies (92%) and also second- and third-line immunomodulatory agents (84%), vs those in whom no unifying immune dysregulation was diagnosed (65%, and 35%, respectively)-indicating that autoimmune cytopenias as a manifestation of systemic immune dysregulation are more treatment-refractory and severe. These data underline the importance of identifying the underlying systemic immune dysregulation and providing targeted therapy in pediatric ES.

Immune thrombocytopenia following multisystem inflammatory syndrome in children (MIS-C) - a case series.

Patients with coronavirus disease 2019 (COVID-19) from novel coronavirus (SARS-CoV-2) infection may present with immune thrombocytopenia (ITP). Multisystem inflammatory syndrome in children (MIS-C) is a serious complication of SARS-CoV-2 causing systemic organ dysfunction. This case series presents the first reported cases of patients who developed ITP following MIS-C, while completing corticosteroid tapers. These patients responded to standard of care therapies for ITP and had appropriate platelet count recovery. We emphasize the importance of careful monitoring of those recovering from COVID-19 or MIS-C, to proactively identify clinical and laboratory abnormalities, in addition to long-term cardiovascular sequelae.

Association of a positive direct antiglobulin test with chronic immune thrombocytopenia and use of second line therapies in children: A multi-institutional review.

Immune thrombocytopenia (ITP) is the most common autoimmune cytopenia in children. Approximately, 25% of patients develop chronic disease, which may be unpredictable and challenging to treat. It is not currently possible to predict at the time of presentation which patients will have chronic disease or will experience symptoms requiring second-line therapy defined as treatment beyond corticosteroids, intravenous immunoglobulin, or Rh immune globulin. A multi-institutional retrospective review of 311 pediatric patients with ITP was performed with the goal of identifying clinical characteristics associated with disease course. In a cohort of 216 patients tested and for whom disease status was known, a positive direct antiglobulin test (DAT) was associated with chronic ITP vs spontaneous resolution of disease (29.2% vs 8.1%, P < 0.001) as well as the need for treatment with second line agents (38.5% vs 11.4%, P < 0.001) in 241 patients. Controlling for the effect of Evans syndrome, defined as having two immune cytopenias, a positive DAT was independently associated with chronic ITP (OR = 2.7, 95% CI: 1.0-7.2, P = 0.041) and use of second-line agents (OR: 3.6, 95% CI: 1.7-7.7, P = 0.001) by multivariate logistic regression model. These findings demonstrate an association with positive DAT and chronic disease, as well as refractory disease requiring second-line agents.

Molecular Diagnosis Is Vital to the Accurate Classification and Management of Thrombotic Thrombocytopenic Purpura in Children.

Thrombotic thrombocytopenic purpura (TTP) is a rare but potentially life-threatening hematologic disease, presenting a myriad of diagnostic and management challenges in children. Here, we provide a review of this disorder and discuss 2 exemplary cases of TTP occurring in adolescents, emphasizing the need for consideration of late-onset congenital TTP (cTTP). We demonstrate the importance of early confirmation of ADAMTS13 enzyme deficiency and the presence or absence of ADAMTS13 inhibitor in order to rapidly initiate the appropriate life-saving therapies. Ultimately, molecular testing is paramount to distinguishing between congenital and acquired immune-mediated TTP.

Untargeted metabolomic profiling in a patient with glycogen storage disease Ib receiving empagliflozin treatment.

Glycogen storage disease type Ib (GSD-Ib) is a rare inborn error of glycogen metabolism uniquely associated with neutropenia and neutrophil dysfunction, causing severe infections, inflammatory bowel disease (IBD), and impaired wound healing. Recently, kidney sodium-glucose co-transporter-2 (SGLT2) inhibitors such as empagliflozin known to reduce plasma levels of 1,5-anhydroglucitol (1,5-AG) and its toxic derivatives in neutrophils, have been described as a new treatment option in case reports of patients with GSD-Ib from Europe and Asia. We report our experience with an 11-year-old girl with GSD-Ib presenting with short fasting hypoglycemia, neutropenia with neutrophil dysfunction, recurrent infections, suboptimal growth, iron-deficiency anemia, and IBD. Treatment with daily empagliflozin improved neutrophil counts and function with a significant reduction in G-CSF needs. Significant improvement in IBD has led to weight gain with improved nutritional markers and improved fasting tolerance. Reduction of maximum empagliflozin dose was needed due to arthralgia. No other significant side effects of empagliflozin were observed. This report uniquely highlights the novel use of untargeted metabolomics profiling for monitoring plasma levels of 1,5-AG to assess empagliflozin dose responsiveness and guide dietary management and G-CSF therapy. Clinical improvement correlated to rapid normalization of 1,5-AG levels in plasma sustained after dose reduction. In conclusion, empagliflozin appeared to be a safe treatment option for GSD-Ib-associated neutropenia and neutrophil dysfunction. Global untargeted metabolomics is an efficient method to assess biochemical responsiveness to treatment.

Romiplostim for the Treatment of Immune Thrombocytopenia: Spotlight on Patient Acceptability and Ease of Use.

Immune thrombocytopenia (ITP) is an immune-mediated disorder resulting in platelet destruction and subsequent thrombocytopenia. Bleeding symptoms range from mild cutaneous bleeding to life-threatening hemorrhage. Romiplostim, a peptide-antibody fusion product, is a thrombopoietin receptor agonist (TPO-RA) indicated for use in patients with ITP. Romiplostim is US Food and Drug Administration (FDA) approved in children ≥1 year of age with ITP of >6 months' duration who have had an inadequate response to first-line therapies or splenectomy. FDA approval in adults with chronic ITP was expanded in October 2019 to include adults with newly diagnosed (<3 months' duration) and persistent (3-12 months' duration) ITP who demonstrated an inadequate response to first-line therapies, including corticosteroids and immunoglobulins, or splenectomy. The newly published 2019 American Society of Hematology ITP Guidelines place TPO-RAs, including romiplostim, as second-line therapies in both children and adults. Here, we review the use of romiplostim as second-line therapy with a spotlight on health-related quality of life, ease of use, and patient preference.

Pediatric ITP: is it different from adult ITP?

Immune thrombocytopenia (ITP) has historically been thought to occur in 2 distinct forms: childhood ITP and adult ITP. This division is based largely on the presumption that childhood ITP is often benign and self-limited, whereas ITP in adults tends to be more chronic and difficult to treat. Although data exist to justify a different approach to the diagnosis and treatment in young children and the elderly, ITP in older children, adolescents, and younger adults is likely to share more similar pathology. This article will highlight the most recent data describing the natural history, diagnostic approach, management strategies, and disease-related outcomes in children and adults with ITP. These data reveal many unexpected similarities between the 2 groups, while confirming some of the more well-described differences. Discussion of these findings aims to highlight similarities and differences between ITP in children and adults, which will underscore important areas of future research and/or changes in management guidelines.