The Spectrum of Hypereosinophilia and Associated Clonal Disorders - A Real-World Data Based on Combined Retrospective and Prospective Analysis from a Tropical Setting

Disease Overlap, Healthcare Resource Utilization, and Costs in Patients with Eosinophilic Granulomatosis with Polyangiitis: A REVEAL Sub-study

INTRODUCTION

Eosinophilic granulomatosis with polyangiitis (EGPA) is an eosinophil-associated disease (EAD) characterized by inflammation in small- to medium-sized blood vessels. In the REal-world inVestigation of Eosinophilic-Associated disease overLap (REVEAL) study, overlap among 11 EADs was assessed. In the present sub-study, we evaluated EGPA overlap with other EADs, all-cause EAD- and EGPA-related healthcare resource utilization (HCRU) and costs, and their relationship with blood eosinophil count and treatments received.

METHODS

REVEAL, a retrospective study, used Optum's de-identified Clinformatics® Data Mart Database. In this sub-study, eligibility criteria included an age of ≥ 12 years, ≥ 1 EAD, continuous health-plan eligibility, and compliance with the EGPA/GPA case definition per International Classification of Diseases Ninth/Tenth Revision diagnostic codes between 1 January 2015 and 30 June 2018. Patients were grouped based on whether they had received immunomodulators/cyclophosphamide/mepolizumab (ICM) or not (non-ICM).

RESULTS

Of 701 patients with EGPA, 29.5% were in the ICM group. Overall, 72.2% had ≥ 1 overlapping EAD. The number of overlaps was similar for the ICM and non-ICM groups. In patients with blood eosinophil counts ≥ 300 cells/µL, 22.8% had ≥ 1 overlapping EAD. The mean annual all-cause cost was $98,644, 54.1% of which was from outpatients and 33.6% from inpatients. The mean annual EAD- and EGPA-related costs were $23,820 and $9,306, respectively. Patients in the non-ICM group versus the ICM group had higher all-cause ($101,560 vs $91,684) but lower EAD-related ($22,733 vs $26,412) and EGPA-related ($6,171 vs $16,786) costs. All-cause HCRU and costs increased with increasing overlap.

CONCLUSIONS

EGPA was associated with substantial HCRU and costs, driven by outpatient and inpatient settings. More overlapping EADs were associated with higher HCRU and costs, highlighting the need for treatment to reduce healthcare expenditure in these patients. Infographic available for this article.

Real-World Investigation of Eosinophilic-Associated Disease Overlap (REVEAL): Analysis of a US Claims Database

PURPOSE

The epidemiology of eosinophil-associated diseases (EADs) is not yet fully understood. While some studies have been conducted on stand-alone eosinophilic diseases, there is scarce evidence on the degree of overlap among rarer conditions.

METHODS

The retrospective Real-world inVestigation of Eosinophilic-Associated disease overLap (REVEAL) study used data from the Optum® Clinformatics® insurance claims database to describe and characterize disease overlap among 11 EADs: allergic bronchopulmonary aspergillosis, atopic dermatitis, chronic rhinosinusitis with nasal polyps, eosinophilic gastritis/gastroenteritis, eosinophilic granulomatosis with polyangiitis, eosinophilic esophagitis, bullous pemphigoid, chronic obstructive pulmonary disorder, chronic spontaneous urticaria, and non-cystic fibrosis bronchiectasis. Patient records with EADs of interest were identified between January 1, 2015, and June 30, 2018.

RESULTS

Overall, 1,326,645 patients were included; 74.4% had 1 EAD, 20.5% had ≥ 2 EADs, and 5.1% had ≥ 3 EADs. Higher rates of disease overlap were associated with older age. Higher blood eosinophil counts were also observed in patients with a greater number of overlapping conditions, suggesting a common role for eosinophilic inflammation in the pathogenesis of multiple diseases. Furthermore, greater disease overlap was associated with higher disease severity in most cohorts.

CONCLUSIONS

Results from this study have implications for quantifying unmet needs and can be used to inform treatment guidelines and raise the awareness of eosinophilic inflammation and EAD overlap among healthcare professionals from a range of disease specialties.

Perioperative Respiratory Outcome of Patients with Eosinophilia: A Cohort Study in a Tertiary Care Hospital

Background

A respiratory adverse event is one of the main causes of critical events in the perioperative period. Perioperative distress symptoms like cough and stridor have been reported to occur in patients with hyperreactive airways.

Objective

This study was conducted to determine the relationship between blood eosinophil count and perioperative adverse respiratory events among different age groups of patients who require general anesthesia for different types of surgeries.

Methods

A cohort study was conducted on 197 patients of either gender, aged 3 years and above, belonging to ASA classes I-II, who were scheduled to undergo surgery requiring general anesthesia and intubation. Patients were stratified according to absolute eosinophil count into two groups: Group A (AEC 0 to 499/mm³) and Group B (AEC 500 to 1000/mm³). Patients were monitored for 24 hours in the perioperative period for adverse respiratory events such as bronchospasm, laryngospasm, a fall in SPO2 < 95%, and cough and stridor.

Results

A total of 197 patients were evaluated, with a median age of 37 ± 14.4 years. The percentage range of adverse respiratory events across different age groups was 35% in adults to 60% in children. Major complications noted were a fall in SPO2 < 95% (62.5%) and cough (27.7%) as per CTCAE v5.0 (November 27, 2017). The Naranjo score of adverse respiratory events was categorized as possible with mild level 1 severity. Adverse respiratory events were managed with humidified oxygen, antitussives, and bronchodilators.

Conclusions

Eosinophilia is seen in one-third of the patients undergoing surgical interventions. Patients with a blood eosinophil count of ≥400/mm³ had an increased risk of exacerbations of respiratory adverse events in the perioperative period.

An intriguing case of a paravertebral extramedullary erythropoiesis presenting as tumor-mimicking lesion in a patient with eosinophilia with FIP1L1-PDGFRA rearrangement

Extramedullary hematopoiesis in the posterior mediastinum is rare. Our case interested a 28-year-old man with a history of eosinophilia with FIP1L1-PDGFRA fusion gene who had a mediastinal mass surgically excised. Pathological examination concluded to an extramedullary erythropoiesis. This case is original by its location and the presence of only the erythroblastic line rearrangement.

Clinical Profile and Treatment in Hypereosinophilic Syndrome Variants: A Pragmatic Review

BACKGROUND

Hypereosinophilic syndrome (HES) is a group of rare hematologic disorders leading to eosinophil-driven tissue damage and dysfunction. Better understanding of HES variants may facilitate improved patient management.

OBJECTIVE

To describe disease characteristics, treatment, and outcomes of patients with idiopathic (I-HES), myeloproliferative (M-HES), lymphocytic (L-HES), and chronic eosinophilic leukemia, not otherwise specified (CEL-NOS) among HES case reports and aggregate data where available.

METHODS

Relevant articles published between January 1, 2000, and March 20, 2020, were retrieved via PubMed; those reporting secondary, associated/reactive, overlap/single-organ, or familial HES were excluded.

RESULTS

Of 188 articles included, 171 contained data on 347 separate HES cases (152 I-HES, 121 M-HES, 62 L-HES, 12 CEL-NOS). Based on individual data, mean age at diagnosis was 43 to 48 years for patients with all HES variants. Males accounted for 90% to 91% of M-HES/CEL-NOS and 55% to 65% of I-HES/L-HES cases. Cardiac symptoms were frequently observed for all HES variants (13%-22% of patients). Respiratory symptoms (I-HES), splenomegaly (M-HES and CEL-NOS), and skin conditions (L-HES) were also frequently observed. Bone marrow, heart, lung, spleen, liver, skin, and lymph nodes were commonly involved. Most patients with I-HES, L-HES, and CEL-NOS received corticosteroids (65%-85%), whereas most with M-HES received imatinib (81%); those with CEL-NOS also received interferon alpha (42%).

CONCLUSIONS

Collective analysis of HES case reports supports and extends current understanding of HES variants, highlighting differences in signs and symptoms, organ involvement, and treatment approaches. Improved characterization of HES variants may facilitate the development of novel treatments.

Pediatric hypereosinophilia and toxoplasma: Peregrination beyond facileness

Evaluation of pediatric hypereosinophilia (HE) is challenging, especially in the tropical developing countries, as appropriate diagnostic facilities may be lacking, parasitic/helminthic infections are common, and existing data on the etiology of severe eosinophilia are sparse. Second, data on long-term follow-up of these children including the temporal course of eosinophilia are also scarce. Besides, questions regarding the coexistence of multiple etiologies and their association with the severity of HE are largely unexplored. These challenges and questions often lead to diagnostic and therapeutic dilemmas. We highlight these difficulties utilizing a real-life clinical description. We emphasize the need for long-term follow-up of such children as HE may be the combinatorial effect of multiple etiologies, rather than a single cause. We also describe an unusual association of severe eosinophilia in a child with toxoplasmosis that was treated successfully with 8-week combination therapy with azithromycin and cotrimoxazole (sulfadiazine and pyrimethamine were not available).

Concomitant use of Tyrosine-kinase Inhibitor and Mepolizumab in Asthma secondary to Chronic Myeloid Leukemia with hypereosinophilia

INTRODUCTION

Asthma and hypereosinophilia have been treated with different therapeutics in the past. Some of them appear to be more effective in symptoms resolution and decreasing eosinophilic count.

CASE PRESENTATION

We report here an unusual case of asthma with hypereosinophilia secondary to Chronic Myeloid Leukemia (CML) with high prevalence of eosinophilic infiltrate, treated simultaneously with an anti-IL-5 antibody (Mepolizumab) and Tyrosine-kinase Inhibitors (TKI: Imatinib and Bosutinib) for three years. The patient showed a promising reduction of pulmonary exacerbations and good control of CML without developing side effects.

CONCLUSION

We hope that this finding could inspire further studies on the efficacy and safety of the concomitant use of anti-IL-5 and TKI.

Hyper-eosinophilic syndrome: An uncommon cause of chronic abdominal pain in an elderly male

Hypereosinophilia is defined as an absolute eosinophil count of ≥1.5 × 10⁹/L, and its presence with involvement of at least one organ system defines the hypereosinophilic syndrome. It may occur with parasitic infestation, connective tissue disorder or rarely in clonal disorders such as eosinophilic leucaemia. Organ systems that may be involved include the cardiovascular, central nervous, respiratory and gastrointestinal systems. In the latter, a wide spectrum of clinical presentation may be seen from trivial, to debilitating or rarely fatal. We report an elderly male with a history of bronchial asthma, obstructive sleep apnoea and food allergy who presented with chronic abdominal pain and weight loss. Abdominal examination and routine evaluation were essentially normal other than a peripheral hyper-eosinophilia. We witnessed a brisk and lasting response to an elimination diet and corticosteroids.

Paratrabecular myelofibrosis and occult mastocytosis are strong morphological clues to suspect FIP1L1-PDGFRA translocation in hypereosinophilia

To study the clinico-haematological and histopathological characteristics of FIP1L1-PDGFRA rearranged hypereosinophilia/hypereosinophilic syndrome (F/P+ve HE/HES), a retrospective analysis of patients with F/P+ve HE diagnosed over a period of 43 months was performed. Peripheral blood smears, bone marrow aspirate (BMA) and biopsies (BMB) were reviewed in each case and; reticulin stain and immunohistochemistry for mast cell tryptase (MCT) and CD117 was performed. F/P+ve HE was diagnosed in a total of ten patients during study period. All patients were males with a median age of 36 years (23-44 years). The median duration of presenting complaints was 7 months (2 months-3 years) which included specific symptoms related to various organs (80% of cases). Anaemia, thrombocytopenia and splenomegaly were seen in 60%, 50% and 90% of the cases respectively. Mastocytosis was not obvious in BMA but identified by MCT on BMB in all cases. Myelofibrosis (grade ≥ 1) was seen in 80% of the cases and includes multifocal paratrabecular fibrosis in 50% of the biopsies. Our study shows that bone marrow mastocytosis and myelofibrosis are very useful morphological indicators to suspect F/P+ve HE and suggests the routine use of reticulin staining and MCT immunohistochemistry in all BMBs performed for the evaluation of HE/HES.

Eosinophilic disorders: evaluation of current classification and diagnostic criteria, proposal of a practical diagnostic algorithm

Eosinophilic disorders represent a group of pathologic conditions with highly heterogeneous pathophysiology and clinical presentation and variable prognosis, ranging from asymptomatic or mild, to severe and complex cases, with fatal outcome. Interest in this group of disorders has increased during the last two decades, with consistent progress made regarding understanding of molecular mechanisms, refining of diagnostic criteria, classification and evaluation of therapeutic options. There are still many gaps and difficulties in evaluating eosinophilic syndromes and diseases in medical practice. The disease prognosis depends mainly on the cause and mechanism of eosinophilia, on severity of organ dysfunction and on accurate diagnosis and response to treatment. Besides primary hypereosinophilic syndromes and secondary (reactive) eosinophilias, many associated or idiopathic forms have been described, making this topic a complex and difficult medical entity. An important aim of the experts in the field is to agree upon a more clear and practically useful classification, a better characterization of various phenotypes and endotypes of eosinophilic diseases and to identify novel biomarkers and more effective therapies. The aim of this paper is to review recent data from the literature regarding definition, classification and diagnosis criteria of eosinophilic diseases and to propose a revised and updated diagnostic algorithm useful in clinical practice.