Value and limitations of targeted next-generation sequencing in idiopathic hypereosinophilia: an integrative diagnostic tool in challenging cases.

Here, we reviewed clinical-morphological data and investigated mutational profiles by NGS in a single-center series of 28 consecutive patients admitted to our hospital between September 2011 and November 2021 for idiopathic hypereosinophilia (HE).Bone marrow (BM) morphology was evaluated in 22 patients: while in six subjects BM was unremarkable, in the remaining cases an increase in BM eosinophils was observed, together with a slight increase in BM fibrosis (MF-1) in 5/22 patients.A total of 4/28 patients had at least one genetic lesion by targeted NGS. In particular, the genes involved were: two each of TET2 and DNMT3A; and one each of JAK2V617F, ASXL1, PPM1D, and ZBTB33. Notably, JAK2V617F and TET2 mutations co-occurred, with the JAK2V617F-mutated sample also carrying TET2 lesions. Median VAF was 21%, with the exception of the oncodriver JAK2V617F, which showed a VAF > 50% in the reported case. Of note, of the four cases bearing lesions, 2/4 had multiple hits in different genes.While in recent years mutational analysis using NGS has proven to be able to differentiate clonal hematopoietic neoplasms from reactive processes in diagnostically difficult cases, we found somatic mutations in only 14.3% of patients who acceded to our hospital for idiopathic HE. More importantly, excluding the JAK2V617F-mutated case with an underlying MPN-Eo diagnosis, NGS was able to identify somatic mutations in only three cases, all older than 70 years. Consequently, the detection of these mutations in idiopathic HE patients should be interpreted with caution and only in the context of other supportive clinical-pathological findings.

Managing Patients with Hypereosinophilic Syndrome: A Statement from the Italian Society of Allergy, Asthma, and Clinical Immunology (SIAAIC).

Hypereosinophilic syndrome (HES) encompasses a heterogeneous and complex group of different subtypes within the wider group of hypereosinophilic disorders. Despite increasing research interest, several unmet needs in terms of disease identification, pathobiology, phenotyping, and personalized treatment remain to be addressed. Also, the prospective burden of non-malignant HES and, more in general, HE disorders is currently unknown. On a practical note, shortening the diagnostic delay and the time to an appropriate treatment approach probably represents the most urgent issue, even in light of the great impact of HES on the quality of life of affected patients. The present document represents the first action that the Italian Society of Allergy, Asthma, and Clinical Immunology (SIAAIC) has finalized within a wider project aiming to establish a collaborative national network on HES (InHES-Italian Network on HES) for patients and physicians. The first step of the project could not but focus on defining a common language as well as sharing with all of the medical community an update on the most recent advances in the field. In fact, the existing literature has been carefully reviewed in order to critically integrate the different views on the topic and derive practical recommendations on disease identification and treatment approaches.

[Severe hypereosinophilia as a paraneoplastic syndrome in a patient with differentiated thyroid cancer] / Hipereosinofilia severa como síndrome paraneoplásico en un paciente con cáncer diferenciado de tiroides.

In solid tumors, hypereosinophilia is a rare phenomenon and is mainly associated with mucin-secreting carcinomas. Thyroid tumors associated with neutrophilia and/or eosinophilia have been described exclusively in patients with anaplastic thyroid cancer. Eosinophilia associated with papillary thyroid cancer is extremely rare and there are very few cases currently described. It has been suggested that three cytokines, namely interleukin-3 (IL-3), interleukin-5 (IL-5), and granulocyte-macrophage colony-stimulating factor (GM-CSF), may act as a peptide potential eosinophilic. To date, only three patients with differentiated thyroid cancer associated with eosinophilia have been reported, two of the papillary type and one of the medullary type. A 48-year-old patient consulted in 2022 due to bilateral cervical lymphadenopathy of 3 years' duration associated with wasting syndrome and hypereosinophilia. PET CT was requested, which showed hypermetabolic focus in the right thyroid lobe and lymph node, lung, bone, and liver metastases; Thyroid ultrasound showing a nodule of high suspicion of malignancy and a conglomerate of lymphadenopathy in the right lobe with positive needle wash for thyroglobulin. Hypereosinophilia was evaluated with initial leukocytosis values of GB 30,310/mm3 (10,608/mm3 of eosinophils) to maximum values of GB 77,090/mm3 (eosinophils 20,814/mm3). It was interpreted as paraneoplastic syndrome and corticosteroid therapy was started at immunosuppressive doses without response. Our observations presented in this article are in line with most studies reflecting that paraneoplastic hypereosinophilia is characterized by more advanced disease and poor prognosis.

En los tumores sólidos la hipereosinofilia es un fenómeno raro y se asocia principalmente con carcinomas secretores de mucina. Los tumores tiroideos asociados a neutrofilia y/o eosinofilia se han descrito exclusivamente en pacientes con cáncer anaplásico de tiroides. La eosinofilia asociada con cáncer papilar de tiroides es extremadamente rara y se encuentran muy pocos casos descriptos actualmente. Se ha sugerido que tres citocinas, a saber, la interleucina-3 (IL-3), la interleucina-5 (IL-5) y el factor estimulante de colonias de granulocitos y macrófagos (GM-CSF), pueden actuar como un péptido eosinofílico potencial. Hasta el momento solo se han reportado tres pacientes con cáncer diferenciado de tiroides asociados a eosinofilia, dos de tipo papilar y uno de tipo medular. Paciente de 48 años consultó en el año 2022 por adenopatías cervicales bilaterales de 3 años de evolución asociado a síndrome consuntivo e hipereosinofilia. Se solicitó PET CT que evidenció foco hipermetabólico en lóbulo tiroideo derecho y metástasis ganglionares, pulmonares, óseas y hepáticas; ecografía tiroidea que evidencia en lóbulo derecho nódulo de alta sospecha de malignidad y conglomerado de adenopatías con lavado de aguja positivo para tiroglobulina. Evaluada la hipereosinofilia con valores iniciales de leucocitosis de GB 30310/mm3 (10608/mm3 de eosinófilos) hasta valores máximos de GB 77090/mm3 (eosinófilos 20814/mm3) se interpretó como síndrome paraneoplásico y se inició corticoterapia en dosis inmunosupresoras sin respuesta. Nuestras observaciones presentadas en este artículo están en línea con la mayoría de los estudios que reflejan que la hipereosinofilia paraneoplásica se caracteriza por una enfermedad más avanzada y un mal pronóstico.

[A case of hypereosinophilia with diffuse pulmonary nodules].

We reported a case of a 36-year-old woman who presented with cough, dyspnea, hypereosinophilia, multiple pulmonary nodules and mediastinal lymphadenopathy. The percentage of eosinophils in bronchoalveolar lavage fluid (BALF) was as high as 65%. Pathogenic tests and cytologic examination of BALF were negative. Transbronchial lung biopsy and endobronchial ultrasound-guided transbronchial needle aspiration revealed only eosinophil infiltration. As the patient responded poorly to high-dose corticosteroids, a surgical lung biopsy was performed. The pathological diagnosis was angioimmunoblastic T-cell lymphoma. The patient received chemotherapy and achieved a partial response. Her eosinophil count returned to the normal range, and the pulmonary nodules on chest CT partially resolved.

Case report: eosinophilic myocarditis in hypereosinophilic syndrome: a journey to heart transplantation.

Introduction: Hypereosinophilic Syndrome (HES) is a rare disorder characterized by persistent elevation of eosinophils, leading to multi-organ infiltration and damage. Eosinophilic Myocarditis (EM) is one of its severe complications contributing significantly to morbidity and mortality. Herein, we describe the diagnostic and therapeutic challenges of EM, emphasizing the significance of early recognition and multidisciplinary management. Case presentation: A 51-year-old female with a history of EM, heart failure, and peripheral eosinophilia presented with NYHA class 3b symptoms. Laboratory findings revealed elevated peripheral eosinophil count, NT-Pro BNP, and characteristic electrocardiogram abnormalities. Imaging studies confirmed biventricular thrombi and myocardial abnormalities consistent with EM. Treatment involved Solu-Medrol for HES and heparin for ventricular thrombi, leading to initial clinical improvement. However, refractory heart failure necessitated urgent heart transplantation. Discussion: EM, an under-recognized complication of HES, poses diagnostic and management challenges. Management includes standard heart failure treatments, steroids, and emerging therapies like Mepolizumab. Early diagnosis and aggressive management are pivotal for improving outcomes in this rare and potentially fatal condition. Conclusion: Advancements in the detection of complications, surgical management, and therapeutic options have improved outcomes in HES. Ongoing research is essential to further understand and address the diagnostic and therapeutic challenges of HES and EM.

Loeffler's Endocarditis- A cause of endomyocardial fibrosis in a patient of juvenile idiopathic arthritis: A Case Report.

Endomyocardial fibrosis secondary to hyper-eosinophilic syndrome also known as Loeffler's Endocarditis is a rare cause of restrictive cardiomyopathy. If left untreated, it carries a very high morbidity and mortality rate. The case of a 20 years old girl, a known case of polyarticular juvenile idiopathic arthritis since the age of 13 years was reported at Federal Government Polyclinic Hospital, Islamabad on 14th May 2022. She presented with an acute history of shortness of breath and cough for two weeks. Her initial echocardiogram showed suspicion of Loeffler's Endocarditis, which is attributed to be an adverse effect of etanercept- a tumour necrosis factor (TNF) inhibitor, which she had been prescribed for her arthritis. The patient is currently being managed with high doses of steroids, therapeutic anticoagulation with rivaroxaban, carvedilol for tachycardia and mycophenolate mofetil as an immunosuppressant.

Idiopathic hypereosinophilic syndrome presenting with stroke.

Hypereosinophilic syndrome (HES) is characterized by eosinophilia associated with organ damage. The disorder has substantial clinical heterogeneity and a highly variable prognosis. This report describes an interesting autopsy case of a 62-year-old lady presenting with itching and stroke-like symptoms. She was diagnosed with an "idiopathic" variant of HES after a thorough exclusion of all known causes. Despite adequate measures, she deteriorated rapidly. At autopsy, acute cerebral infarcts were identified in multiple vascular territories including infarcts in watershed areas. Additionally, her heart showed classic pathological features of eosinophilic myocarditis spanning all three stages.

Hypereosinophilic syndrome: a rare cause of ST-elevation myocardial infarction and thrombus formation on the aortic valve.

We present a case of a man in his 30s presenting with ST-segment elevation myocardial infarction and eosinophilia. The patient underwent thrombus aspiration and initially echocardiographic evaluation was normal. The patient was discharged after 2 days, but was hospitalised again after 6 days. Echocardiographic evaluation now revealed a thrombus formation on the aortic valve. Laboratory data revealed increasing eosinophilia, and treatment with high-dosage corticosteroids and hydroxyurea was initiated as eosinophilic disease with organ manifestations could not be precluded. Eosinophils normalised and the patient was discharged again. The combination of hypereosinophilia and absence of infection, rheumatological disorders and malignancy, led to reactive or idiopathic hypereosinophilic syndrome being the most plausible diagnoses. The patient was closely monitored in the cardiology and haematology outpatient clinics. Echocardiographic evaluation, performed 6 weeks after the patient was discharged, showed significant regression in the size of the thrombus mass.

Not just for lymphoid cells: the role of the noncanonical NF-κB signaling pathway in early and late myelopoiesis with a focus on hypereosinophilic disorders.

The noncanonical NF-κB pathway is involved in lymphoid organ development, B-cell maturation, and cytokine production. However, new research has demonstrated that this pathway is also key for the orderly and sequential maturation of myeloid cells, including neutrophils and eosinophils. When this pathway is disrupted or constitutively activated, aberrations in hematopoietic stem and progenitor cell survival and proliferation, as well as subsequent granulopoiesis and eosinophilopoiesis, are affected. Disturbance of such a coordinated and delicate process can manifest in devastating clinical disease, including acute and chronic myeloid leukemias, preleukemic processes such as myelodysplastic syndrome, or hyperinflammatory conditions like hypereosinophilic syndrome. In this review, we discuss the molecular machinery within the noncanonical NF-κB pathway, crosstalk with the canonical NF-κB pathway, murine models of noncanonical signaling, and how aberrations in this pathway manifest in leukemic or hyperinflammatory disease with a focus on hypereosinophilic syndrome. Potential and promising drug therapies will also be discussed, emphasizing the noncanonical NF-κB pathway as a potential target for improved treatment for patients with leukemia or idiopathic hypereosinophilic syndrome. The hope is that review of such mechanisms and treatments may eventually result in findings that aid physicians in rapidly diagnosing and more accurately classifying patients with such complex and overlapping hematopoietic diseases.

A Case of Chronic Eosinophilic Leukemia with CSF3R-Mutant Clone and Transformed to Secondary Acute Myeloid Leukemia.

BACKGROUND: Chronic eosinophilic leukemia (CEL) is a rare invasive disease characterized by non-specific cytogenetic abnormalities or elevated mother cells, poor prognosis, and a high risk of conversion to acute leukemia. METHODS: We described the data of a patient with CEL-NOS. RESULTS: This case is a CEL-NOS with four mutations in CSF3R-T618I, DNMT3A Q816, ASXL1, and IDH2. CONCLUSIONS: The patient rapidly evolves into secondary acute myeloid leukemia (AML).

Involvement of the JAK-STAT pathway in the molecular landscape of tyrosine kinase fusion-negative hypereosinophilic syndromes: A nationwide CEREO study.

We investigated using a custom NGS panel of 149 genes the mutational landscape of 64 consecutive adult patients with tyrosine kinase fusion-negative hypereosinophilia (HE)/hypereosinophilic syndrome (HES) harboring features suggestive of myeloid neoplasm. At least one mutation was reported in 50/64 (78%) patients (compared to 8/44 (18%) patients with idiopathic HE/HES/HEUS used as controls; p < .001). Thirty-five patients (54%) had at least one mutation involving the JAK-STAT pathway, including STAT5B (n = 18, among which the hotspot N642H, n = 13), JAK1 (indels in exon 13, n = 5; V658F/L, n = 2), and JAK2 (V617F, n = 6; indels in exon 13, n = 2). Other previously undescribed somatic mutations were also found in JAK2, JAK1, STAT5B, and STAT5A, including three patients who shared the same STAT5A V707fs mutation and features consistent with primary polycythemia. Nearly all JAK-STAT mutations were preceded by (or associated with) myelodysplasia-related gene mutations, especially in RNA-splicing genes or chromatin modifiers. In multivariate analysis, neurologic involvement (hazard ratio [HR] 4.95 [1.87-13.13]; p = .001), anemia (HR 5.50 [2.24-13.49]; p < .001), and the presence of a high-risk mutation (as per the molecular international prognosis scoring system: HR 6.87 [2.39-19.72]; p < .001) were independently associated with impaired overall survival. While corticosteroids were ineffective in all treated JAK-STAT-mutated patients, ruxolitinib showed positive hematological responses including in STAT5A-mutated patients. These findings emphasize the usefulness of NGS for the workup of tyrosine kinase fusion-negative HE/HES patients and support the use of JAK inhibitors in this setting. Updated classifications could consider patients with JAK-STAT mutations and eosinophilia as a new "gene mutated-entity" that could be differentiated from CEL, NOS, and idiopathic HES.

Extracellular sombrero vesicles are hallmarks of eosinophilic cytolytic degranulation in tissue sites of human diseases.

Eosinophil sombrero vesicles are large tubular carriers resident in the cytoplasm of human eosinophils, identifiable by transmission electron microscopy, and important for immune mediator transport. Increased formation of sombrero vesicles occurs in activated eosinophils in vitro and in vivo. In tissue sites of eosinophilic cytolytic inflammation, extracellular eosinophil sombrero vesicles are noted, but their frequency and significance in eosinophil-associated diseases remain unclear. Here, we performed comprehensive quantitative transmission electron microscopy analyses and electron tomography to investigate the numbers, density, integrity, and 3-dimensional structure of eosinophil sombrero vesicles in different biopsy tissues from 5 prototypic eosinophil-associated diseases (eosinophilic chronic rhinosinusitis/nasal sinuses, ulcerative colitis/intestines, hypereosinophilic syndrome/skin, dermatitis/skin, and schistosomiasis/rectum). The morphology of extracellular eosinophil sombrero vesicles was also compared with that of cytoplasmic eosinophil sombrero vesicles, isolated by subcellular fractionation from peripheral blood eosinophils. We demonstrated that (i) eosinophil cytolysis, releasing intact sombrero vesicles and membrane-bound granules, is a consistent event in all eosinophil-associated diseases; (ii) eosinophil sombrero vesicles persist intact even after complete disintegration of all cell organelles, except granules (late cytolysis); (iii) the eosinophil sombrero vesicle population, composed of elongated, curved, and typical sombreros, and the eosinophil sombrero vesicle 3-dimensional architecture, diameter, and density remain unchanged in the extracellular matrix; (iv) free eosinophil sombrero vesicles closely associate with extracellular granules; and (v) free eosinophil sombrero vesicles also associate with externalized chromatin during eosinophil ETosis. Remarkably, eosinophil sombrero vesicles appeared on the surface of other cells, such as plasma cells. Thus, eosinophil cytolysis/ETosis can secrete intact sombrero vesicles, alongside granules, in inflamed tissues of eosinophil-associated diseases, potentially serving as propagators of eosinophil immune responses after cell death.

Biologic therapy in rare eosinophil-associated disorders: remaining questions and translational research opportunities.

Rare eosinophil-associated disorders (EADs), including hypereosinophilic syndrome, eosinophilic granulomatosis with polyangiitis, and eosinophilic gastrointestinal disorders, are a heterogeneous group of conditions characterized by blood and/or tissue hypereosinophilia and eosinophil-related clinical manifestations. Although the recent availability of biologic therapies that directly and indirectly target eosinophils has the potential to dramatically improve treatment options for all EADs, clinical trials addressing their safety and efficacy in rare EADs have been relatively few. Consequently, patient access to therapy is limited for many biologics, and the establishment of evidence-based treatment guidelines has been extremely difficult. In this regard, multicenter retrospective collaborative studies focusing on disease manifestations and treatment responses in rare EADs have provided invaluable data for physicians managing patients with these conditions and helped identify important questions for future translational research. During the Clinical Pre-Meeting Workshop held in association with the July 2023 biennial meeting of the International Eosinophil Society in Hamilton, Ontario, Canada, the successes and limitations of pivotal multicenter retrospective studies in EADs were summarized and unmet needs regarding the establishment of guidelines for use of biologics in rare EADs were discussed. Key topics of interest included (1) clinical outcome measures, (2) minimally invasive biomarkers of disease activity, (3) predictors of response to biologic agents, and (4) long-term safety of eosinophil depletion. Herein, we report a summary of these discussions, presenting a state-of-the-art overview of data currently available for each of these topics, the limitations of the data, and avenues for future data generation through implementation of multidisciplinary and multicenter studies.

Idiopathic Hypereosinophilic Syndrome in a Professional Athlete.

OBJECTIVE: To present the case of an athlete with hypereosinophilic syndrome (HES). CASE REPORT: We present a 25-year-old female athlete, with no significant past medical history, who had a two-month history of progressive dry cough, wheezing, exertional dyspnea, and chest pain. Physical examination revealed patient to be febrile to 101.6 degrees Fahrenheit and tachycardic to 120 beats per minute with new leukocytosis of 35.9x109/L and eosinophilia of 24,000/µL. She was also found to have elevated troponins ~1.5 ng/mL and creatine kinase (CK) 203 U/L. Her overall clinical picture was concerning for hypereosinophilic syndrome with multiorgan system involvement. CONCLUSION: Findings endorse the diagnosis of HES. HES is a rare condition that is difficult to diagnose. Early clinical diagnostic signs of HES may include fatigue, cough, breathlessness, and fever.