Hematopoietic and eosinophil-specific LNK(SH2B3) deficiency promotes eosinophilia and arterial thrombosis

ABSTRACT

Increased eosinophil counts are associated with cardiovascular disease and may be an independent predictor of major cardiovascular events. However, the causality and underlying mechanisms are poorly understood. Genome-wide association studies have shown an association of a common LNK variant (R262W, T allele) with eosinophilia and atherothrombotic disorders. LNK(TT) reduces LNK function, and Lnk-deficient mice display accelerated atherosclerosis and thrombosis. This study was undertaken to assess the role of eosinophils in arterial thrombosis in mice with hematopoietic Lnk deficiency. Hematopoietic Lnk deficiency increased circulating and activated eosinophils, JAK/STAT signaling in eosinophils, and carotid arterial thrombosis with increased eosinophil abundance and extracellular trap formation (EETosis) in thrombi. Depletion of eosinophils by anti-Siglec-F antibody or by the ΔdbIGata1 mutation eliminated eosinophils in thrombi and markedly reduced thrombosis in mice with hematopoietic Lnk deficiency but not in control mice. Eosinophil depletion reduced neutrophil abundance and NETosis in thrombi without altering circulating neutrophil counts. To assess the role of Lnk specifically in eosinophils, we crossed Lnkf/f mice with eoCre mice. LnkΔeos mice displayed isolated eosinophilia, increased eosinophil activation, and accelerated arterial thrombosis associated with increased EETosis and NETosis in thrombi. DNase I infusion abolished EETs and neutrophil extracellular traps (NETs) in thrombi and reversed the accelerated thrombosis. Human induced pluripotent stem cell-derived LNK(TT) eosinophils showed increased activation and EETosis relative to isogenic LNK(CC) eosinophils, demonstrating human relevance. These studies show a direct link between eosinophilia, EETosis, and atherothrombosis in hematopoietic Lnk deficiency and an essential role of eosinophil LNK in suppression of arterial thrombosis.

Diagnostic significance of peripheral blood indices for eosinophilic chronic rhinosinusitis in Chinese adults

OBJECTIVE

Eosinophilic chronic rhinosinusitis (eCRS) is a refractory subtype of CRS. This study aimed to compare the differences in clinical features and peripheral blood indices between eCRS and non-eCRS Chinese patients and identify the predictive factors for eCRS.

METHODS

In this study, a total of 1352 patients with CRS were enrolled and divided into eCRS and non-eCRS groups based on the degree of eosinophilic infiltration in histopathology, and their demographic and clinical characteristics, as well as peripheral blood indices, were compared. Logistic regression analysis was used to identify the factors associated with eCRS, and the optimal cut-off values of predictors were determined using subject working curves.

RESULTS

As compared to those in the non-eCRS group patients, the proportion of males, age, proportion of smokers, peripheral blood eosinophil count, and erythrocyte count were significantly higher, while the peripheral blood neutrophil count, platelet count, neutrophil/lymphocyte count ratio (NLR), platelet/lymphocyte count ratio (PLR), and neutrophil × platelet/lymphocyte count ratio (SII index) were significantly lower in the eCRS group patients. Logistic regression analysis showed that age, peripheral blood neutrophil count, eosinophil count, and platelet count were independent predictors of eCRS, and eosinophil count > 2.05 × 108/L could be used as a diagnostic marker for eCRS with a sensitivity and specificity of 87.1% and 78.3%, respectively.

CONCLUSIONS

There were significant differences in the clinical features of eCRS and non-eCRS patients. Peripheral blood eosinophil count could early and more accurately predict eCRS.

Traumatic Ulcerative Granuloma with Stromal Eosinophilia on the Tongue

BACKGROUND

Traumatic Ulcerative Granuloma with Stromal Eosinophilia, commonly known as Eosinophilic Ulcer, is a reactive solitary and self-limiting benign lesion. It manifests as a punched-out ulcer with a distinct surrounding indurated border, often raising concerns about malignancy.

METHODS

A 44-year-old male presented with a painless, indurated tongue ulcer evolving over three months. Despite being asymptomatic, the patient underwent an incisional biopsy due to suspicions of oral squamous cell carcinoma.

RESULTS

Histological analysis revealed a disrupted epithelial lining, dense necrotic connective tissue, and a fibrino-purulent pseudomembrane. Proximal to the ulcer, a collar-like projection of reactive epithelial tissue hyperplasia was noted, accompanied by mononuclear cells and a predominantly histiocytic infiltrate in the submucosal layer surrounding skeletal muscle fibers. The final diagnosis was Traumatic Ulcerative Granuloma with Stromal Eosinophilia. Remarkably, the lesion spontaneously healed within 2 weeks post-biopsy, with no recurrence over 6 months.

CONCLUSION

This case emphasizes considering this benign condition in the differential diagnosis of oral ulcers, highlighting the importance of accurate histopathological evaluation to rule out cancer.

Addressing diagnostic dilemmas in eosinophilic esophagitis using esophageal epithelial eosinophil-derived neurotoxin

OBJECTIVES

Eosinophil-derived neurotoxin (EDN) is a viable marker of eosinophilic esophagitis (EoE) disease activity. We studied the utility of measuring EDN from esophageal epithelial brushings for diagnosing EoE, focusing on two scenarios: (1) cases of exclusive distal eosinophilia and (2) cases of discrepancy between endoscopy and histology.

METHODS

Records of patients who underwent esophagogastroduodenoscopy (EGD) with EDN measured via esophageal brushings at Arnold Palmer Hospital for Children in Orlando, Florida from January 2014 to October 2018 were retrospectively reviewed. Demographics, clinical, endoscopic, and histologic data were collected.

RESULTS

We reviewed 231 patient records (66.7% male, mean age 10.3 years, range 1-22 years). EDN values correlated with endoscopic reference score (EREFS) and peak eosinophil count (PEC) (Spearman's rho = 0.756 (p < 0.001) and 0.824 (p < 0.001) respectively). Average PEC, EREFS, and EDN concentrations were higher in patients with active EoE than in controls or patients with EoE in remission (inactive). When grouping patients based on esophageal eosinophilia distribution, EDN mirrored PEC, and EREFS. Patients with exclusive distal eosinophilia had lower EDN concentrations than those with eosinophilia in >1 level of the esophagus (23.8 ± 46.1 mcg/mL vs. 171.3 ± 205.8 mcg/mL respectively, p < 0.001). EDN values were more consistent with EREFS in cases of discrepancies between endoscopic findings and pathology (p < 0.001).

CONCLUSION

EDN measured in esophageal brushing samples reflects disease activity objectively and accurately. It also offers significant value in cases of exclusive distal esophageal eosinophilia and when discrepancies exist between endoscopy and histology.

Association between peripheral eosinophilia, JESREC score, and olfactory dysfunction in patients with chronic rhinosinusitis

Objective

The purpose was to evaluate the relationship between peripheral eosinophilia, Japan Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) score, and olfactory dysfunction in chronic rhinosinusitis (CRS) patients and to explore the accuracy and specific cut points of the JESREC score in predicting olfactory dysfunction.

Methods

In this cross-sectional, retrospective study, olfactory function was assessed by the Sniffin' Sticks 12-item test and multivariate logistic regression analyses were carried out. Receiver operating characteristic curves were plotted to derive accuracy and cutoff values for the JESREC scores of the olfactory dysfunction criterion.

Results

A total of 354 patients [mean (SD) age, 50.0 (14.9) years; 41.8% women] were included in the final analysis. The prevalence of olfactory dysfunction was 46.3%. Individuals who had olfactory dysfunction were more likely to be male (64.6% vs. 52.6%), have eosinophilic chronic rhinosinusitis (ECRS) (39.0% vs. 7.9%), have a longer course of CRS (2.3 years vs. 1.5 years), have higher JESREC scores (8.5 vs. 4.5), and have higher proportions of nasal polyps (78.7% vs. 18.9%) and peripheral eosinophilia (3.3% vs. 1.4%). In logistic analysis, the percentage of eosinophils (1.25, 1.13-1.37), JESREC score (1.31, 1.22-1.40), bilateral lesion (2.06, 1.25-3.41), nasal polyps (15.83, 9.23-27.16), CT shadow (2.73, 1.69-4.43), and ECRS (6.86, 3.68-12.80) were associated with olfactory dysfunction in CRS patients after controlling for covariates, while peripheral neutrophils were not significant. In addition, the area under the curve was 0.778 and the cutoff value for JESREC score for olfactory dysfunction was defined as 5.5.

Conclusions

Peripheral eosinophilia and high JESREC scores were significantly associated with the risk of olfactory dysfunction in CRS patients, and special attention should be paid to patients with a JESREC score ≥6.

Eosinophilic enterocolitis: a case report

BACKGROUND

Eosinophilic enterocolitis is a rare disorder characterized by abnormal eosinophilic infiltration of the small intestine and the colon.

CASE PRESENTATION

We report a case of a 29-year-old White man, who presented with an acute bowel obstruction. He had a history of a 2 months non-bloody diarrhea. An abdominal computed tomography (CT) and a MR enterography showed a multifocal extensive ileitis. White blood cell and eosinophilic polynuclei count was elevated (700/mm3). Ileo-colonoscopy showed normal ileum and segmental petechial colitis. Pathology showed a high eosinophilic infiltration in the colon. The patient was treated with steroids, with a clinical, biological and radiological recovery.

CONCLUSION

Eosinophilic enterocolitis should be kept in mind as a rare differential diagnosis in patients presenting with small bowel obstruction.

Myeloid Bmal1 deletion suppresses the house dust mite-induced chronic lung allergy

Asthma is the chronic pulmonary inflammatory response that could lead to respiratory failure when allergic reactions exacerbate. It is featured by type 2 immunity with eosinophilic inflammation, mucus, and IgE production, and Th2 cytokine secretion upon repeated challenge of allergens. The symptom severity of asthma displays an apparent circadian rhythm with aggravated airway resistance in the early morning in patients. Bmal1 is the core regulator of the circadian clock, while the regulatory role of Bmal1 in asthma remains unclear. Here, we investigate whether the myeloid Bmal1 is involved in the pathogenesis of house dust mite (HDM)-induced lung allergy. We found that knockdown of Bmal1 in macrophages suppressed the time-of-day variance of the eosinophil infiltration in the alveolar spaces in chronic asthmatic mice. This was accompanied by decreased bronchial mucus production, collagen deposition, and HDM-specific IgE production. However, the suppression effects of myeloid Bmal1 deletion did not alter the allergic responses in short-term exposure to HDM. The transcriptome profile of alveolar macrophages (AMs) showed that Bmal1-deficient AMs have enhanced phagocytosis and reduced production of allergy-mediating prostanoids thromboxane A2 and prostaglandin F2α synthesis. The attenuated thromboxane A2 and prostaglandin F2α may lead to less induction of the eosinophil chemokine Ccl11 expression in bronchial epithelial cells. In summary, our study demonstrates that Bmal1 ablation in macrophages attenuates eosinophilic inflammation in HDM-induced chronic lung allergy, which involves enhanced phagocytosis and reduced prostanoid secretion.

Two cases of infancy associated eosinophilic pustular folliculitis (I-EPF) comparing the profile of infiltrating cells with classic EPF by immunohistochemical study

Infancy associated eosinophilic pustular folliculitis (I-EPF) is a clinical variant of EPF that develops in childhood. Previous studies have suggested that I-EPF exhibits clinical and histological differences distinct from other variants, including classic EPF. Herein, we report two patients with I-EPF treated with topical indomethacin. These two cases exhibited less perifollicular and more perivascular eosinophilic infiltration, which is different in distribution from that of classic EPF. Immunohistochemical study demonstrated that the infiltrating mononuclear cells were CD4-dominant T cells in classic EPF and I-EPF, whereas the number of CD68-positive cells was significantly higher in classic EPF than in I-EPF. Immunohistochemical staining was also performed for eosinophilic pustular folliculitis (HPGDS), which has been reported to induce eosinophils and is a therapeutic target of indomethacin in classic EPF. HPGDS-positive cells were also observed in I-EPF, which may explain the effectiveness of topical indomethacin. Although clinical and histopathological features of I-EPF are different from other variants, the arachidonic acid pathway could be involved in eosinophil infiltration, not only in classic EPF but also in I-EPF.

Cytopathology of primary sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid: a multi-institutional case series and review of literature

INTRODUCTION

Sclerosing Mucoepidermoid Carcinoma with Eosinophilia (SMECE) of the thyroid is an extremely rare tumor that exhibits unique histologic characteristics and is nearly always associated with lymphocytic thyroiditis (LT). However, the cytomorphologic and clinicopathologic characteristics of SMECE have only been described in rare case reports.

MATERIALS AND METHODS

Authors' institution laboratory information systems were searched for records of SMECE between 2012 and 2023. Literature review was performed using keywords "Sclerosing mucoepidermoid carcinoma with eosinophilia", "thyroid", and "cytopathology" to search through institution electronic library databases for relevant articles.

RESULTS

A total of 19 cases were identified, 3 unpublished in the authors' archives and 16 in the literature which had fine needle aspiration (FNA) material or cytologic features available for review, and were comprised of 3 males and 16 females. The common cytomorphologic characteristics of SMECE included fragments or loose clusters of intermediate-type epidermoid cells in a background of prominent LT and eosinophils. Overt keratinization, mucinous cells, and extracellular mucin were not commonly encountered, resulting in diagnostic challenges, especially if eosinophils associated with epithelial cell clusters were rare. The cases were reported as "Nondiagnostic" (1 case), "Atypia of Undetermined Significance" (4 cases), "Suspicious for Malignancy" (3 case), or "Malignant" (11 cases).

CONCLUSIONS

The clinical course of SMECE of the thyroid varied and distinct cytomorphologic characteristics in a subset of patients who experienced aggressive disease raises the possibility of different prognostic grades. Cases with keratinized squamous cells and necrosis mimic anaplastic (undifferentiated) thyroid carcinoma, but the clinical history and radiologic findings can be helpful to exclude this diagnosis.

The first case of SARS-CoV-2-induced eosinophilic fasciitis

Eosinophilic fasciitis (EF), also known as Shulman syndrome, is a rare auto-immune fibrosing disorder of the fascia. Etiopathogeny of EF is still unclear. Nowadays, it is widely known that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may induce hyper-stimulation of the immune system. Several cases with fasciitis and rhabdomyolysis induced by coronavirus disease 2019 vaccines have been reported in the literature. Herein, we report the first case of EF possibly triggered by SARS-CoV-2 infection. A 45-year-old Tunisian woman, with no medical history, presented to our department with severe widespread muscle pain noticed one month after a SARS-CoV-2 infection. Physical examination showed an induration of the skin and subcutaneous tissue of the arms, forearms and legs with a restricted joint mobility. The level of eosinophils was 430 E/mm3 (6.1%) [1-4%]. Electromyography and creatine kinase levels were normal. Myositis-related antibodies were negative. Magnetic resonance imaging of the left arm showed high-intensity signal and thickness of the fascia without evidence of muscle or bone involvement. A muscular biopsy from the right deltoid showed thickening and inflammation of the fascia. The patient received intraveinous injections of 1000 mg of methylprednisolone for 3 days with an oral relay of 1 mg/kg per day of prednisone equivalent during 4 weeks. At one-month follow-up, a significant improvement of the skin induration and myalgia was observed, with a disappearance of the biological inflammatory syndrome. This brief report suggests a potential link between SARS-CoV-2 infection and new-onset of auto-immune fasciitis.

Eosinophilic Angiocentric Fibrosis of the Orbit: A Clinicopathologic Review of 6 Novel Cases With Review of the Literature

PURPOSE

To describe 6 cases and review the current state of knowledge of eosinophilic angiocentric fibrosis (EAF) involving the orbit.

DESIGN

Retrospective clinicopathologic case series and review of the current literature METHODS: Clinical records and histopathologic data of orbit-involving EAF were gathered between 2004 and 2022 from a single academic institution. The patients' presenting clinical symptoms and signs, laboratory data, radiographic studies, and management documentation were collected.

RESULTS

Retrospective review identified 6 novel cases, totaling 31 cases of EAF involving the orbit described as of this writing. Fourteen patients were male, and the average age of presentation was 49.8 years (range 25-78 years). Eighteen patients had concurrent sinonasal involvement, whereas 13 had primary orbital involvement. The median duration of symptoms prior to evaluation was 24 months, with nasal symptoms, proptosis, periorbital swelling, and pain being the most common presenting symptoms. The majority of patients underwent surgical debulking, as well as treatment with glucocorticoids and steroid-sparing agents, such as rituximab, with varied results.

CONCLUSION

EAF involving the orbit is uncommon. The histopathologic findings include a perivascular, eosinophil-rich infiltrate and a pauci-inflammatory storiform type of fibrosis concentrated around small vessels. Orbital involvement usually results from local extension from adjacent sinuses, but primary orbital involvement has been described. Surgical debulking and immunosuppressive agents such as rituximab have been shown to stabilize disease.

Eosinophils in Traditionally Noneosinophil-Rich Dermatoses

ABSTRACT

The presence or absence of tissue eosinophilia has previously aided in the diagnosis of inflammatory skin conditions. However, recent studies have elucidated the presence of eosinophils in traditionally eosinophil-poor inflammatory skin diseases, such as dermatomyositis (DM), psoriasis, and lichen sclerosus (LS). This systematic review of the literature explores previous studies of tissue eosinophilia in skin biopsies of dermatoses that are believed to be classically poor in eosinophil. We identified 26 studies, the majority of which were retrospective reviews. The percent of specimens with increased eosinophils in psoriasis ranged from 18%-73%, pityriasis rubra pilaris (PRP) 22%-63%, LS 29%-53%, DM 15%-44%, morphea 8%-45%, hypertrophic lichen planus (LP) 0%-21%, and oral LP 0%-4%. These reports of tissue eosinophilia in reputed eosinophil-poor dermatologic conditions present a diagnostic pitfall and suggest that tissue eosinophilia itself should not be used to rule out a diagnosis of one of these conditions.

Myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase fusion genes: A workshop report with focus on novel entities and a literature review including paediatric cases

Myeloid/lymphoid neoplasms with eosinophilia (M/LN-eo) and tyrosine kinase (TK) gene fusions are a rare group of haematopoietic neoplasms with a broad range of clinical and morphological presentations. Paediatric cases have increasingly been recognised. Importantly, not all appear as a chronic myeloid neoplasm and eosinophilia is not always present. In addition, standard cytogenetic and molecular methods may not be sufficient to diagnose M/LN-eo due to cytogenetically cryptic aberrations. Therefore, additional evaluation with fluorescence in-situ hybridisation and other molecular genetic techniques (array-based comparative genomic hybridisation, RNA sequencing) are recommended for the identification of specific TK gene fusions. M/LN-eo with JAK2 and FLT3-rearrangements and ETV6::ABL1 fusion were recently added as a formal member to this category in the International Consensus Classification (ICC) and the 5th edition of the WHO classification (WHO-HAEM5). In addition, other less common defined genetic alterations involving TK genes have been described. This study is an update on M/LN-eo with TK gene fusions with focus on novel entities, as illustrated by cases submitted to the Bone Marrow Workshop, organised by the European Bone Marrow Working Group (EBMWG) within the frame of the 21st European Association for Haematopathology congress (EAHP-SH) in Florence 2022. A literature review was performed including paediatric cases of M/LN-eo with TK gene fusions.

Diagnosis of Adenoid Cystic Carcinoma with Striking Tubular Hypereosinophilia by MYB and EWSR1 Breakapart Fluorescence In Situ Hybridization

BACKGROUND

Adenoid cystic carcinoma (AdCC), associated with MYB/MYBL1 gene rearrangements, shows epithelial and basaloid myoepithelial cells arranged in tubular, cribriform and solid patterns. Variations from this classic morphology make diagnosis challenging, necessitating molecular testing. AdCC with striking tubular hypereosinophilia (AdCC-STE) is one such recently described histological subtype.

METHODS

A 52-year-old female presented with a floor of mouth swelling for two months, diagnosed elsewhere as polymorphous adenocarcinoma (PAC). A biopsy was obtained. With a diagnosis of oncocytic neoplasm, wide excision of the tumor was undertaken. Histological examination, fluorescence in situ hybridization (FISH) and ultrastructural examination were performed. Archival cases of PAC and epithelial myoepithelial carcinoma (EMC) were reviewed, and MYB immunostaining and FISH were performed to identify potential AdCC-STE cases.

RESULTS

The excised tumor from the index patient showed bilayered tubules, micropapillae and cribriform pattern. Luminal cells with hypereosinophilic to clear cytoplasm were surrounded by flattened abluminal cells. Focally, basophilic matrix was seen within sharply demarcated pseudocystic spaces. FISH revealed MYB and EWSR1 gene rearrangements, confirmatory of AdCC-STE. Electron microscopy showed features consistent with AdCC; however, mitochondria were not prominent. Among 14 archival PACs, two showed MYB immunopositivity; one showed MYB rearrangement but was classical AdCC. Among 35 EMC, one case showed MYB immunoreactivity and eosinophilia of luminal cells but lacked MYB/MYBL1 rearrangement.

CONCLUSION

Awareness of unusual histological subtypes of AdCC, such as AdCC-STE, is imperative, as it may be misdiagnosed as PAC and EMC, among others. Presence of basophilic matrix and squamoid morules in a biphasic tumor even with hypereosinophilic rather than basaloid myoepithelial appearance should raise suspicion for AdCC-STE, and prompt molecular testing for confirmation. With wider accessibility, lower cost and significantly shorter turn-around-time when compared to RNA sequencing, FISH can be employed for confirmation of diagnosis, especially in low- and middle-income countries.

Vulval superficial myofibroblastoma with lymphocytic and eosinophilic infiltrate

We present the case of a vulval superficial myofibroblastoma with a lymphocytic and eosinophilic rim in a woman in her late 20s. The tumour presented in pregnancy as a cystic lesion with pain and increasing size. While the histopathology of superficial myofibroblastomas has been well defined in the literature, to our knowledge, there has been no documentation of the presence of an inflammatory infiltrate of lymphocytes and eosinophils surrounding and within the tumour. This may potentially act as a diagnostic or prognostic reference.

Diagnostic Utility of Mucosal Biopsies Taken During Colonoscopy-Guided Colonic Manometry Catheter Placement

OBJECTIVES

The diagnostic utility of mucosal biopsies taken during colonoscopy-guided colonic manometry catheter placement is unknown. The aims of our study were to determine the frequency and histopathology results of mucosal biopsies during these procedures and to assess whether there were any associations between the histology or gross findings with manometry results.

METHODS

We performed a retrospective chart review of children who had a colonic manometry study completed between 2008 and 2020 at a quaternary children's hospital. We captured patient demographics, biopsy locations, histopathology results, gross endoscopy findings, and manometry results. The chi-squared test and when appropriate Fisher exact test was used to evaluate categorical associations.

RESULTS

One hundred forty-eight patients were included. One hundred eighteen (80%) had colonic biopsy and 63 (43%) had ileal biopsy. Colonic histology findings, which patients could have multiple, included lymphonodular hyperplasia (34%), normal (27%), chronic inflammation (24%), melanosis coli (21%), colonic eosinophilia (10%), and acute inflammation (8%). Ileal histology findings included increased Peyer patches (44%), normal (44%), acute inflammation (11%), chronic inflammation (3%), eosinophilia (5%), and eosinophilic ileitis (3%). The majority of acute and chronic inflammation was graded as mild. There were no statistically significant associations of histology to gross endoscopy or manometry findings.

CONCLUSIONS

Colonic biopsies are obtained in the majority of patients presenting for colonic manometry evaluation with ileal biopsies obtained less frequently. Histopathology findings are noted frequently, but the majority are the result of or did not impact clinical care. There were no associations between abnormal histopathology or abnormal gross endoscopy findings with colonic manometry results.

Tissue Eosinophilia is Superior to an Analysis by Polyp Status for the Chronic Rhinosinusitis Transcriptome: An RNA Study

OBJECTIVE

RNA sequencing (transcriptomics) is used to study biological pathways. However, the yield of data depends on comparing well-characterized cohorts. We compared tissue eosinophilia versus nasal polyp (NP) status as the metric to characterize transcriptomic mechanisms at play in eosinophilic and non-eosinophilic chronic rhinosinusitis (CRS) versus controls.

METHODS

RNA sequencing was conducted on sinonasal tissue samples of CRS and controls. Analyses were conducted based on polyp status [with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP)] as well as tissue eosinophil levels per high power field (eos/hpf)[non-eosinophilic (<10 eos/hpf, neCRS) or eosinophilic (≥10 eos/hpf, eCRS)]. The yield of differentially expressed genes (DEGs) and biological pathways through Ingenuity Pathway Analysis (IPA) were compared.

RESULTS

CRS tissue differed from controls by 736 statistically significant DEGs. Both NP status and tissue eosinophilia were effective in differentiating CRS from controls and into two distinct subgroups. Statistically significant DEGs identified when comparing CRS by NP status were 60, whereas 110 DEGs were identified using eosinophil cutoff ≥10 and <10 eos/hpf. Additionally, heatmaps showed greater homogeneity within each CRS subgroup when analyzed by tissue eosinophilia versus NP status. On IPA, the IL-17 signaling pathway was significantly different only by tissue eosinophilia status, not NP status, being higher in CRS <10 eos/hpf.

CONCLUSION

Tissue eosinophilia is superior to an analysis by NP status for the study of CRS transcriptome by RNA sequencing in identifying DEGs. Classification of CRS samples by eosinophil counts agnostic of NP status may offer advantageous insights into CRS pathogenetic mechanisms.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2480-2489, 2023.

Do General Pathologists Assess Gastric and Duodenal Eosinophilia?

CONTEXT.—

Eosinophilic diseases of the gastrointestinal tract (EGIDs), eosinophilic gastritis (EoG), and eosinophilic duodenitis (EoD) are rarely suspected clinically and infrequently detected by pathologists.

OBJECTIVE.—

To determine whether histories of allergic or eosinophilic disorders and requests to rule out EoG and EoD affect pathologists' awareness of eosinophils in gastrointestinal biopsies.

DESIGN.—

Thirty-one community-based pathologists were given 16 sets of biopsies from gastric and duodenal mucosa with elevated eosinophils, Helicobacter pylori gastritis, atrophic gastritis, normal stomach and duodenum, lymphocytosis, and celiac disease. Participants were assigned to 3 groups: group A did not receive histories of allergic or eosinophilic conditions; group B received similar histories plus a clue of possible allergic or eosinophilic conditions; and group C received the same histories as B and was asked to rule out EoG/EoD. A list of gastric and duodenal diagnoses and a space for comments were provided. Results were analyzed descriptively.

RESULTS.—

Pathologists correctly diagnosed most noneosinophilic gastrointestinal disorders, indicating competence in gastrointestinal pathology. With respect to EoG and EoD, pathologists in group C performed significantly better that those in groups A and B. The combined odds ratio with 95% CI was 12.34 (2.87-53.04), P < .001, for A versus C and 4.02 (1.60-10.09), P < .02, for B versus C.

CONCLUSIONS.—

Most pathologists neither reported gastric/duodenal eosinophilia nor diagnosed EoG/EoD, even when provided histories of eosinophilic disorders. Requests to rule out EoG/EoD resulted in only 4 of 11 participants evaluating and counting eosinophils in some cases. Simple evidence-based histopathologic criteria are needed before pathologists can be expected to consider and diagnose EGIDs.

Pemphigus Vegetans of Hallopeau: A Case Report

Dear Editor, Pemphigus vegetans (PV) of Hallopeau is a rare and indolent variant of pemphigus clinically characterized by vegetating lesions preceded by pustules mainly in flexural areas (1,2). This helps us to differentiate it from PV of Neumann, which is a more extensive and refractory disease, more alike to a pemphigus vulgaris outbreak with blisters which turn into vegetating plaques (3). We report the clinical presentation, course, and therapeutic response in a patient diagnosed with PV of Hallopeau from its early stage during a 3-year follow up. A 62-year-old man, non-smoker, presented at our clinic in July 2018 with hemorrhagic-serous crusts and fissures on the vermilion of the lower lip (Figure 1, a) and two merged circinate, sharply demarcated plaques on the right side of the groin (Figure 1, b). Plaque margins were elevated, with hypertrophic granulation tissue studded with pustules. Mucosal and cutaneous lesions persisted 6 and 4 weeks, respectively. The rest of the mucosa and skin were unaffected; the general state was good. The patient's family history for skin diseases was negative. The medical history included hypertension, atherosclerosis and hypercholesterolemia, hiatus hernia, and recent surgery (3 months prior) of an aortic abdominal aneurysm with reconstruction and synthetic graft placement. He was taking antihypertensives (fixed combination of 3 drugs, among them the ACE-inhibitor perindopril) with well-regulated blood pressure, statins, a pump-proton inhibitor, and acetylsalicylic acid. Differential blood count revealed eosinophilia. Histopathology finding showed acanthosis, suprabasal clefting with a suprabasilar bulla and acantholysis, prominent eosinophilic intraepidermal spongiosis, and heavy dermal infiltration of eosinophils and lymphocytes (Figure 2, a and b). The diagnosis of pemphigus was confirmed by direct immunofluorescence (DIF), which detected C3 deposits on the surface of keratinocytes throughout the epidermis of perilesional skin. Circulating pemphigus antibodies were detected by indirect IF. Only Dsg 3 antibodies were detected using an ELISA assay (233.23 RU/mL). After establishing the diagnosis of PV of Hallopeau, treatment with prednisolone 0.75 mg/kg/day orally in combination with adjuvant immunosuppression (azathioprine 100 mg daily) was started. Appropriate topical therapy with local steroids and antiseptic was applied. The steroid dose was titrated and gradually tapered down to the minimum required to control the disease - 10 mg. One-year remission was achieved. Azathioprine was withdrawn in October 2019 and since then the patient experienced a flare-up twice. The control of pemphigus flare-ups was achieved by a low dose of steroids (30 mg prednisolone orally). It remains debatable whether surgical trauma and radiology procedures such as angiographies (4) well as ACE-inhibitor drugs (5) triggered or aggravated the pemphigus. Early recognition and correct diagnosis of this rare type of pemphigus allows us to treat and control the disease successfully with lower doses of steroids, reducing complications to the minimum.

Endotyping Difficult-to-Treat Chronic Rhinosinusitis with Nasal Polyps by Structured Histopathology

INTRODUCTION

This study aimed to identify the histopathologic characteristics associated with difficult-to-treat chronic rhinosinusitis with nasal polyps (CRSwNPs), enabling physicians to predict the risk of poor outcome after endoscopic sinus surgery (ESS).

METHODS

A prospective cohort study performed at the First Affiliated Hospital of Sun Yat-sen University between January 2015 and December 2018 with CRSwNP patients who underwent ESS. Polyp specimens were collected during surgery and were subjected to structured histopathological evaluation. Difficult-to-treat CRSwNPs were determined at 12-15 months post-operation according to the European Position Paper. Multiple logistic regression model was used to assess the association between histopathological parameters and the difficult-to-treat CRSwNP.

RESULTS

Among 174 subjects included in the analysis, 49 (28.2%) were classified with difficult-to-treat CRSwNP, which had higher numbers of total inflammatory cells, tissue eosinophils, and percentages of eosinophil aggregates and Charcot-Leyden crystals (CLC) formation but a lower number of interstitial glands than the nondifficult-to-treat CRSwNP. Inflammatory cell infiltration (adjusted OR: 1.017), tissue eosinophilia (adjusted OR: 1.005), eosinophil aggregation (adjusted OR: 3.536), and CLC formation (adjusted OR: 6.972) were independently associated with the difficult-to-treat outcome. Furthermore, patients with tissue eosinophil aggregation and CLC formation had an increasingly higher likelihood of uncontrolled disease versus those with tissue eosinophilia.

CONCLUSION

The difficult-to-treat CRSwNP appears to be characterized by increased total inflammatory infiltrates, tissue eosinophilia, eosinophil aggregation, and CLC formation in structured histopathology.

Revisiting idiopathic eosinophilic myositis: towards a clinical-pathological continuum from the muscle to the fascia and skin

OBJECTIVES

Idiopathic inflammatory myopathies are mainly defined by inflammatory infiltrates within the muscle (lymphocytes and macrophages). Eosinophil muscle infiltration has been described in idiopathic eosinophilic myositis (IEM) and rarely in EF. This study aimed to further delineate the nosological frame of idiopathic eosinophil muscle infiltration through the exhaustive analysis of IEM and EF patients.

METHODS

This multicentre retrospective case series included IEM patients diagnosed between 2000 and 2022. IEM inclusion criteria were eosinophilic muscle infiltration with myositis pathological features, after the exclusion of differential diagnoses. An additional group of EF patients diagnosed between 2016 and 2022 was constituted. Inclusion criteria were an EF diagnosis and fascia thickening with inflammatory infiltrate.

RESULTS

A total of 20 IEM cases and 10 EF cases were included. The median (interquartile range) age at diagnosis was 65 (49-70) years; there were 18 males. Data analysis delineated four subgroups: focal EM (FEM, n = 3), diffuse EM (DEM, n = 6), eosinophilic myofasciitis (EMF, n = 11) and EF (n = 10). FEM represented a limited and benign form of myositis. DEM cases presented objective muscle impairment with eosinophilic muscle infiltration. EMF patients presented subjective muscle impairment (myalgia, 55%), fasciitis (on histology and/or imaging), eosinophilic muscle infiltration and frequent hypereosinophilia (55%). EF patients presented myalgia (50%), muscle lesions on histology with fascia-restricted inflammatory infiltrates with (60%) or without (40%) eosinophils.

CONCLUSIONS

The analysis of IEM and EF patient characteristics delineates four subgroups (FEM, DEM, EMF and EF) in terms of clinical, laboratory, imaging, pathological and outcome specificities, and proposes an adapted diagnostic and care management approach.

Abdominal Pain Due to Eosinophilic Gastroenteritis Diagnosed in 25-Year-Old and 27-Year-Old Sisters with a Family History of Asthma

BACKGROUND Eosinophilic gastroenteritis (EG) can be associated with parasitic infections, atopic drug reactions, or atopic diseases, such as asthma. This report describes 25-year-old and 27-year-old sisters with a family history of asthma who presented with abdominal pain due to EG. CASE REPORT Case 1: A 25-year-old woman presented with a 4-month history of chronic left upper quadrant abdominal pain that did not improve with proton pump inhibitor and sucralfate therapy. She has a history of asthma and allergic rhinitis. Endoscopic pathology revealed pangastritis, with eosinophilic infiltration >25 per 1 high power field. Case 2: Her 27-year-old sister was admitted with chronic abdominal discomfort in the form of vomiting and recurrent abdominal pain for the past 2 years. Treatment with proton pump inhibitors and sucralfate did not lead to improvement. She also had intermittent asthma. Pathological findings on her endoscopy showed chronic inflammation of the fundus and antrum, with eosinophilic infiltration >40 per 1 high power field. Association of eosinophilic gastrointestinal diseases in siblings has not been reported previously. CONCLUSIONS This report has highlighted that atopic disease, such as asthma, is often familial, and can be associated with generalized eosinophilia, including EG. In these 2 sisters, the clinical history and histological findings on colonic biopsy were important to confirm the diagnosis.

Primary Thyroid Mucoepidermoid Carcinoma (MEC) Is Clinically, Prognostically, and Molecularly Different from Sclerosing MEC with Eosinophilia: A Multicenter and Integrated Study

Mucoepidermoid carcinoma (MEC) and sclerosing MEC with eosinophilia (SMECE) are rare primary thyroid carcinomas. In this study, we aimed to present our multicenter series of MEC and SMECE and integrated our data with published literature to further investigate the clinicopathological characteristics and prognoses of these tumors. We found 2 MECs and 4 SMECEs in our multicenter archives. We performed fluorescence in situ hybridization (FISH) to determine the MAML2 gene rearrangement. We screened for mutations in BRAF, TERT promoter, and RAS mutations using Sanger sequencing and digital polymerase chain reaction. Histopathologically, MECs and SMECEs were composed of two main cell types including epidermoid and mucin-secreting cells, arranged in cords, nests, and tubules. SMECEs were characterized by a densely sclerotic stroma with abundant eosinophils. We did not detect any MAML2 fusion in any of our cases. Two MEC cases harbored concomitant BRAF p.V600E and TERT C228T mutations. RAS mutations were absent in all cases. Concurrent foci of another thyroid malignancy were more commonly seen in MECs (p < 0.001), whereas SMECEs were associated with chronic lymphocytic thyroiditis (p < 0.001). MECs and SMECEs had equivalent recurrence-free survival (RFS) but MECs conferred significantly dismal disease-specific survival (DSS) as compared to SMECEs (p = 0.007). In conclusion, MECs and SMECEs not only shared some similarities but also demonstrated differences in clinicopathological characteristics, prognoses, and molecular profiles. SMECEs had a superior DSS in comparison to MECs, suggesting that they are low-grade cancers. This could help clinicians better evaluate patient outcomes and decide appropriate treatment plans.

Eosinophilia and elevated IgE serum levels: a red flag: when your diagnosis is not a common atopic eczema or common allergy

OBJECTIVE AND DESIGN

The hallmark of type 2 inflammation is eosinophilia and/or high IgE serum levels, mostly in atopic dermatitis. Nevertheless, many dermatoses may present similar findings. Our aim is to explore the biological and clinical spectrum of cutaneous manifestations involving tissue and/or systemic eosinophilia, and distinct serum levels of IgE, where atopic dermatitis or other primary allergic eczema, not always is the definitive diagnosis.

MATERIALS/METHODS

A total of 37 scientific papers were enrolled in this narrative review.

RESULTS

A diagnostic approach for patients with elevated serum IgE level and a list of conditions not related to atopic dermatitis that runs through inborn errors of immunity, inflammatory disorders, lung disorders, malignancy, infections/infestations are displayed. Regarding to peripheral eosinophilia, differential diagnosis is also explored and clinical patterns of skin diseases associated with tissue eosinophilia are listed, to facilitate our diagnosis.

CONCLUSIONS

We should maintain a high level of suspicion about other differential diagnosis involving eosinophilia and IgE dysregulation, especially in patients very young (when innate errors of the immunity may present) and in middle to elderly patients classified as having atopic dermatitis, due to the possibility of cutaneous hematological malignancies, paraneoplasia or autoimmune blistering diseases.

Mitoquinone mesylate attenuates pathological features of lean and obese allergic asthma in mice

Obesity is associated with severe, difficult-to-control asthma, and increased airway oxidative stress. Mitochondrial reactive oxygen species (mROS) are an important source of oxidative stress in asthma, leading us to hypothesize that targeting mROS in obese allergic asthma might be an effective treatment. Using a mouse model of house dust mite (HDM)-induced allergic airway disease in mice fed a low- (LFD) or high-fat diet (HFD), and the mitochondrial antioxidant MitoQuinone (MitoQ), we investigated the effects of obesity and ROS on HDM-induced airway inflammation, remodeling, and airway hyperresponsiveness (AHR). Obese allergic mice showed increased lung tissue eotaxin, airway tissue eosinophilia, and AHR compared with lean allergic mice. MitoQ reduced airway inflammation, remodeling, and hyperreactivity in both lean and obese allergic mice, and tissue eosinophilia in obese-allergic mice. Similar effects were observed with decyl triphosphonium (dTPP+), the hydrophobic cationic moiety of MitoQ lacking ubiquinone. HDM-induced oxidative sulfenylation of proteins was increased particularly in HFD mice. Although only MitoQ reduced sulfenylation of proteins involved in protein folding in the endoplasmic reticulum (ER), ER stress was attenuated by both MitoQ and dTPP+ suggesting the anti-allergic effects of MitoQ are mediated in part by effects of its hydrophobic dTPP+ moiety reducing ER stress. In summary, oxidative signaling is an important mediator of allergic airway disease. MitoQ, likely through reducing protein oxidation and affecting the UPR pathway, might be effective for the treatment of asthma and specific features of obese asthma.

Multisystemic eosinophilic epitheliotropic disease in three donkeys

Multisystemic eosinophilic epitheliotropic disease (MEED) is a rare condition of equids characterized by eosinophilic infiltration of multiple organs. Clinical signs are variable depending on the affected organs. The most common clinical signs include chronic weight loss, diarrhoea and exfoliative dermatitis. Respiratory distress and raised liver enzymes are less frequently seen. The cause is unknown and the pathogenesis is poorly understood. There are less than 50 reported cases of horses with MEED. We now document the lesions in three donkeys with fluctuating or chronic loss of weight, lethargy, exfoliative dermatitis and peripheral eosinophilia. All three animals were euthanized due to poor prognosis and welfare concerns. Post-mortem examination revealed multiple white to tan, irregular masses composed of eosinophilic infiltrates, including eosinophilic granulomas in several organs, confirming the presence of MEED. To the best of our knowledge, MEED has not previously been reported in donkeys.

Eosinophilic Fasciitis: Current and Remaining Challenges

Eosinophilic fasciitis (EF), defined as diffuse fasciitis with eosinophilia by Shulman in 1974, is a disease with unknown etiology and whose pathogenesis is still being researched. The diagnosis is based on the clinical aspects (skin induration with an "orange peel" appearance), the lab results (eosinophilia, increased inflammatory markers), the skin biopsy with the pathognomonic histopathological result, as well as the typical MRI changes. The treatment includes glucocorticoids and immunosuppressive drugs. Due to severe refractory cases, the treatment remains a challenge. EF is still a disease with potential for further research.

Prognostic Value of Colonic Tissue and Blood Eosinophils in Ulcerative Colitis

BACKGROUND

It has been suggested that eosinophils may be a prognostic marker of disease outcome in ulcerative colitis (UC), but conflicting data exist. The objective was to investigate the extent of mucosal eosinophils and peripheral blood eosinophil count in newly diagnosed UC patients and to investigate its predictive value in short- and long-term disease outcomes.

METHODS

The degree of eosinophilia in baseline colonic biopsies and blood of newly diagnosed UC patients was retrospectively analyzed. It was investigated if tissue and blood eosinophilia could be a marker of a severe phenotype of UC, defined as the need for corticosteroids or immunomodulators in the first year or treatment with therapeutic monoclonal antibodies or colectomy during follow-up. Time to therapeutic monoclonal antibodies and time to colectomy were also evaluated as outcomes.

RESULTS

There were 103 UC patients (median age 26 years) included. Median tissue peak eosinophil count (PEC) was 70.0 and median peripheral blood eosinophil count was 0.3 × 109/L at diagnosis. Tissue PEC (r = -0.161, P = .104) and blood eosinophil count (r = 0.022, P = .877) were not correlated with the severity of histologic inflammation. Logistic regression analyses did not identify PEC and blood eosinophil count as predictors of more severe disease outcomes. Tissue PEC and peripheral blood eosinophil count did not predict the time the initiation of therapeutic monoclonal antibodies or colectomy.

CONCLUSION

Baseline tissue or peripheral blood eosinophils are not markers of disease activity and cannot be used as a predictor of severe disease outcomes in both adults and children with UC.

[Sclerosing mucoepidermoid carcinoma with eosinophilia of thyroid gland]

Sclerosing mucoepidermoid carcinoma with stromal eosinophilia of thyroid gland is represented less than 100 cases in the world literature. We present a rare case of sclerosing mucoepidermoid carcinona with stromal eosinophilia in a 69-year-old woman who has been observed for multinodular goiter for more than 3 years. Cytological examination revealed a picture most of all corresponding to a malignant neoplasm (Bethesda V). The patient underwent a thyroidectomy. Pathomorphological examination revealed a neoplasm of mixed structure with foci of cribriform structures and squamous metaplasia with areas of keratinization. According to the IHC study, the expression of TTF-1, p63, cytokeratins 5/6 were positive, while there were no expression of thyroglobulin with its positive reaction in the thyroid tissue. Additional histochemical staining with Alcian blue revealed a positive reaction with a homogeneous acellular substance of the tumor. A comprehensive morphological study with the use of additional stains made it possible to accurately establish the diagnosis, which will determine the further tactics of managing the patient.

Tumor-associated tissue eosinophilia promotes angiogenesis and metastasis in head and neck squamous cell carcinoma

Eosinophils are terminally differentiated leukocytes that participate in the process of chronic inflammation and allergy and are able to release multiple cytokines into the surrounding tissue environment. Tumor-associated tissue eosinophilia (TATE) is the presence of eosinophils in the tumor or in the neighboring stroma and has been observed in various types of cancer. In head and neck squamous cell carcinoma (HNSCC), the clinical relevance of TATE has not been concluded yet because of the inconsistent results in different studies. In our study, we focus on the prognostic effects of TATE on HNSCC and how TATE can influence tumor behavior and tumor microenvironment. We first showed that in both the TCGA-HNSC cohort and our cohort of patients with HNSCC who had received curative surgery, TATE is correlated with worse overall survival. To investigate the underlying mechanism of how TATE leads to poor clinical outcomes, we showed that activated eosinophils produce a variety of cytokines and chemokines, and activated TATE-derived culture medium promotes tumor migration mainly through CCL2. We also showed that eosinophils are capable of inducing angiogenesis and that HNSCC samples enriched with TATE are highly correlated with tumor angiogenesis. Furthermore, HNSCC enriched with TATE had more aggressive pathological features, including regional lymph node metastasis, perineural invasion, lymphovascular invasion, and tumor growth. Lastly, we showed that HNSCC enriched with TATE is associated with immunosuppressive tumor microenvironment. Taken together, our results suggest that TATE promotes cancer metastasis and angiogenesis which results in a poor clinical outcomes in HNSCC.

Wells Syndrome Presenting as Atypical Periorbital Cellulitis

A 62-year-old man presented with diffuse, painless, left-sided preseptal edema, erythema, and woody induration extending to the left temple. The induration generated an orbital compartment syndrome with markedly elevated intraocular pressure necessitating lateral canthotomy and cantholysis. Although atypical for an infectious etiology, empiric broad-spectrum intravenous antibiotics were initiated with no improvement. A tissue biopsy demonstrated extensive perivascular and interstitial eosinophils with focal flame figures, and the patient was diagnosed with a severe hypersensitivity reaction or eosinophilic cellulitis (Wells syndrome). The disease process remitted rapidly upon initiation of oral prednisone. Wells syndrome is a rare inflammatory eosinophilic dermatosis, most often presenting in the limbs and trunk, with few reports of facial and periorbital involvement. This case highlights the importance of considering Wells syndrome in the differential diagnosis of atypical periorbital cellulitis that is nonresponsive to antibiotics and reviews the clinicopathologic nature of this disease.

Importance of eosinophilic infiltration of the colonic mucosa in ulcerative colitis patients who are refractory to maintenance therapy: A prospective, single-center study

Eosinophilic infiltration is sometimes observed histologically in ulcerative colitis (UC), but the effect of the degree of infiltration on the treatment course for UC is not completely understood. We investigated whether short-term steroid administration in UC patients refractory to maintenance therapy, with high eosinophilic infiltration in the colonic mucosa, contributed to the clinical and endoscopic improvement. Ten patients with endoscopically active and pathologically high eosinophilic infiltration, based on pathological examination using endoscopic biopsy, were examined for the clinical background when starting steroid treatment. The clinical and endoscopic improvement before and after steroid use were assessed prospectively. The average initial steroid dosage and duration of use were 21.0 mg and 102.7 days, respectively. The mean values before and after steroid use of the clinical activity index, the Mayo endoscopic subscore, and the UC endoscopic index of severity were 2.4 and 1.0, 1.8 and 0.7, and 3.9 and 1.1, respectively. All scores improved significantly after steroid use (P = .042, P = .002, P = .002, respectively). Steroids were discontinued in all patients; no patients required steroid re-administration. There may be cases of UC with eosinophilic infiltration into the colonic mucosa and resistance to maintenance treatment, suggesting that short-term steroid administration may contribute to clinical and endoscopic improvements.

A Case Of Precursor B-Acute Lymphoblastic Leukaemia Masquerading As Hypereosinophilia And Space Occupying Lesion In A 14-Year-Old Boy

Peripheral blood eosinophilia is associated with a variety of benign and neoplastic conditions. Rarely, marked eosinophilia can mask an underlying Acute Leukaemia, delaying the correct diagnosis and treatment. Here, we report a case of 14-year-old boy, who presented with marked eosinophilia and space occupying lesion in the brain. Bone marrow biopsy and biopsy of brain lesion were performed to assess the underlying disorder, revealing the unexpected diagnosis of Precursor B- Acute Lymphoblastic Leukaemia in this patient. Cytogenetic studies revealed a normal male karyotype. This case highlights the significance of considering the rare possibility of Acute Lymphoblastic Leukaemia among the differential diagnosis of persistent eosinophilia in order to facilitate prompt and appropriate treatment.

Airway remodelling rather than cellular infiltration characterizes both type2 cytokine biomarker-high and -low severe asthma

BACKGROUND

The most recognizable phenotype of severe asthma comprises people who are blood eosinophil and FeNO-high, driven by type 2 (T2) cytokine biology, which responds to targeted biological therapies. However, in many people with severe asthma, these T2 biomarkers are suppressed but poorly controlled asthma persists. The mechanisms driving asthma in the absence of T2 biology are poorly understood.

OBJECTIVES

To explore airway pathology in T2 biomarker-high and -low severe asthma.

METHODS

T2 biomarker-high severe asthma (T2-high, n = 17) was compared with biomarker-intermediate (T2-intermediate, n = 21) and biomarker-low (T2-low, n = 20) severe asthma and healthy controls (n = 28). Bronchoscopy samples were processed for immunohistochemistry, and sputum for cytokines, PGD2 and LTE4 measurements.

RESULTS

Tissue eosinophil, neutrophil and mast cell counts were similar across severe asthma phenotypes and not increased when compared to healthy controls. In contrast, the remodelling features of airway smooth muscle mass and MUC5AC expression were increased in all asthma groups compared with health, but similar across asthma subgroups. Submucosal glands were increased in T2-intermediate and T2-low asthma. In spite of similar tissue cellular inflammation, sputum IL-4, IL-5 and CCL26 were increased in T2-high versus T2-low asthma, and several further T2-associated cytokines, PGD2 and LTE4 , were increased in T2-high and T2-intermediate asthma compared with healthy controls.

CONCLUSIONS

Eosinophilic tissue inflammation within proximal airways is suppressed in T2 biomarker-high and T2-low severe asthma, but inflammatory and structural cell activation is present, with sputum T2-associated cytokines highest in T2 biomarker-high patients. Airway remodelling persists and may be important for residual disease expression beyond eosinophilic exacerbations. Registered at ClincialTrials.gov: NCT02883530.

Significance and potential role of eosinophils in non-cystic fibrosis bronchiectasis

Bronchiectasis is a complex and heterogeneous disease with a myriad of pulmonary and extrapulmonary etiologies. Bronchiectasis has a predominantly neutrophilic inflammatory profile. However, eosinophilic inflammation has also been documented in both the airways and the systemic circulation. Various diseases (eg, asthma, allergic bronchopulmonary aspergillosis, chronic rhinosinusitis with nasal polyps) characterized by heightened type 2 airway inflammatory responses, including blood or sputum eosinophilia, may coexist with bronchiectasis. Apart from those eosinophilic etiologies or comorbidities related to bronchiectasis, around 20% of patients with bronchiectasis have peripheral eosinophilia (at least 3% or 300 eosinophils/μL) with no identified concomitant disease (also termed "eosinophilic bronchiectasis"), whose roles have not been fully understood. The two key points regarding these observations are that eosinophils confer both bactericidal and antiviral properties against common pathogenic microorganisms that are usually detected in bronchiectasis, and that eosinophilic bronchiectasis has been associated with better therapeutic response to inhaled corticosteroids and other anti-T_H2 profile treatments. In this review, we summarize the most significant evidence regarding the role of eosinophils in patients with bronchiectasis, including the association of bronchiectasis with eosinophilic diseases (as etiologies or comorbidities), and existing data on eosinophilic bronchiectasis not related to eosinophilic disorders.

Mucosal color changes on narrow-band imaging in esophageal eosinophilic infiltration

This study aimed to examine the range of beige colored mucosa (BCM) in patients with esophageal eosinophilic infiltration (EEI) using narrow-band imaging (NBI). In this retrospective study, EEI was confirmed histologically in 12 consecutive patients from January 2014 to December 2017. The BCM tone on NBI without magnifying endoscopy was evaluated, and red, green, and blue (RGB) values of BCM and normal mucosa were measured. BCM was macroscopically classified into 2 groups (bright and dark) using cluster analysis. Histopathological analysis was performed in 1 patient who underwent biopsy for both normal mucosa and BCM. All 12 patients presented with BCM. Endoscopy revealed fixed rings, longitudinal furrows, mucosal edema, and exudate in 3, 12, 10, and 8 patients, respectively. Strictures were absent. Five patients had findings suggestive of gastroesophageal reflux disease. In the cluster analysis, 5 and 7 patients had bright and dark BCM, respectively. Consistent results were noted when we categorized patients according to their macroscopic characteristics. RGB values of the BCM and normal mucosa were measured-normal mucosa: R: 99.8 ± 16.5, G: 121.7 ± 23.1, and B: 93.4 ± 19.2; BCM: R: 152.0 ± 31.3, G: 123.9 ± 35.0, and B: 97.5 ± 29.5. BCM had significantly higher R values than normal mucosa (P = .0001). All parameters were significantly lower in the dark BCM group than in the bright BCM group (P < .001). Histopathological analysis revealed expansion of the epithelial intercellular space, eosinophilic infiltration, and basal cell hyperplasia at the BCM sites. BCM was observed in all cases of EEI. RGB values differed between bright and dark BCM. Assessing BCM tone using NBI is a potentially novel diagnostic method for EEI.

Torasemide-induced Vascular Purpura in the Course of Eosinophilic Granulomatosis with Polyangiitis

Torasemide is a loop diuretic with a molecule that is chemically similar to the sulphonamides described as eosinophilic granulomatosis with polyangiitis (EGPA) triggering drugs. The presented case is probably the first description of torasemide-induced vascular purpura in the course of EGPA. Any diagnosis of vasculitis should be followed by an identification of drugs that may aggravate the disease. A 74-year-old patient was admitted to the Department of Dermatology with purpura-like skin lesions on the upper, and lower extremities, including the buttocks. The lesions had appeared around the ankles 7 days before admission to the hospital and then started to progress upwards. The patient complained on lower limb paresthesia and pain. Other comorbidities included bronchial asthma, chronic sinusitis, ischemic heart disease, mild aortic stenosis, arterial hypertension, and degenerative thoracic spine disease. The woman had previously undergone nasal polypectomy twice. She was on a constant regimen of oral rosuvastatin 5 mg per day, spironolactone 50 mg per day, metoprolol 150 mg per day, inhaled formoterol 12 μg per day, and ipratropium bromide 20 μg per day. Ten days prior to admission, she was commenced on torasemide at a dose of 50 mg per day prescribed by a general practitioner due to high blood pressure. Doppler ultrasound upon admission to the hospital excluded deep venal thrombosis. The laboratory tests revealed leukocytosis (17.1 thousand per mm3) with eosinophilia (38.6%), elevated plasma level of C-reactive protein (119 mg per L) and D-dimers (2657 ng per mm3). Indirect immunofluorescent test identified a low titer (1:80) of antinuclear antibodies, but elevated (1:160) antineutrophil cytoplasmic antibodies (ANCA) in the patient's serum. Immunoblot found them to be aimed against myeloperoxidase (pANCA). A chest X-ray showed increased vascular lung markings, while high-resolution computed tomography revealed peribronchial glass-ground opacities. Microscopic evaluation of skin biopsy taken from the lower limbs showed perivascular infiltrates consisting of eosinophils and neutrophils, fragments of neutrophil nuclei, and fibrinous necrosis of small vessels. Electromyography performed in the lower limbs because of their weakness highlighted a loss of response from both sural nerves, as well as slowed conduction velocity of the right tibial nerve and in both common peroneal nerves. Both clinical characteristics of skin lesions and histopathology suggested a diagnosis of EGPA, which was later confirmed by a consultant in rheumatology. The patient was commenced on prednisone at a dose of 0.5 mg per kg of body weight daily and mycophenolate mofetil at a daily dose of 2 g. The antihypertensive therapy was modified, and torasemide was replaced by spironolactone 25 mg per day. The treatment resulted in a gradual regression of skin lesions within a few weeks. The first report of EGPA dates back to 1951. Its authors were Jacob Churg and Lotte Strauss. They described a case series of 13 patients who had severe asthma, fever, peripheral blood eosinophilia, and granulomatous vasculitis in microscopic evaluation of the skin. Three histopathological criteria were then proposed, and Churg-Strauss syndrome was recognized when eosinophilic infiltrates in the tissues, necrotizing inflammation of small and medium vessels, and the presence of extravascular granulomas were observed together in a patient (1). Only 17.4% of patients met all three histopathological criteria, and the diagnosis of the disease was frequently delayed despite of its overt clinical picture (2). In 1984, Lanham et al. proposed new diagnostic criteria which included the presence of bronchial asthma, eosinophilia in a peripheral blood smear >1.5 thousand per mm3, and signs of vasculitis involving at least two organs other than the lungs (3). Lanham's criteria could also delay the recognition of the syndrome before involvement of internal organs, and the American College of Rheumatology therefore established classification criteria in 1990. These included the presence of bronchial asthma, migratory infiltrates in the lungs as assessed by radiographs, the presence of abnormalities in the paranasal sinuses (polyps, allergic rhinitis, chronic inflammation), mono- or polyneuropathy, peripheral blood eosinophilia (>10% of leukocytes must be eosinophils), and extravascular eosinophilic infiltrates in a histopathological examination. Patients who met 4 out of 6 criteria were classified as having Churg-Strauss syndrome (4). The term EGPA was recommended to define patients with Churg-Strauss syndrome in 2012 (5). EGPA is a condition with low incidence (0.11-2.66 cases per million) and morbidity. It usually occurs in the fifth decade of life (6,7), although 65 cases reports of EGPA in people under 18 years of age could be found in the PubMed and Ovid Medline Database at the end of 2020 (8). The etiopathogenesis of the disease has not been fully explained so far. Approximately 40-60% of patients are positive to pANCA (9), but the role of these antibodies in the pathogenesis of EGPA remains unclear. They are suspected to mediate binding of the Fc receptor to MPO exposed on the surface of neutrophils. Subsequently, this may active neutrophils and contribute to a damage of the vascular endothelium (9,10). Glomerulonephritis, neuropathy, and vasculitis are more common in patients with EGPA who have detectable pANCA when compared with seronegative patients. There are at least several drugs which potentially may EGPA. The strongest association with the occurrence of EGPA was found with the use of leukotriene receptor antagonists (montelukast, zafirlukast, pranlukast), although they are commonly used in the treatment of asthma, which is paradoxically one of the complications of the syndrome (13). Although no relationship has been demonstrated so far between the occurrence of EGPA and the intake of drugs from the groups used by the presented patient, a clear time relationship can be observed between the commencement of torasemide and the onset of symptoms in our patient. To date, only three cases of leukocytoclastic vasculitis have been reported after the administration of torasemide. Both of them developed cutaneous symptoms of the disease within 24 hours of the administration of torasemide in patients with no previous history of drug hypersensitivity, but they disappeared quickly within 8-15 days after drug discontinuation (14,15). The chemical structure of torasemide is similar to the molecule of sulfonamides which were previously found to be a triggering factors for EGPA (12). This drug belongs to the group of loop diuretics classified as sulfonamide derivatives. A comparison of the chemical structure of torasemide and sulphanilamide molecules is presented in Figure 1. The clear time relationship between starting the administration of torasemide and the occurrence of purpura-like lesions suggests that it was an aggravating factor for EGPA in our patient. A coexistence of several disorders (asthma, nasal polyps, symptoms of peripheral neuropathy) in our patient suggest EGPA could have developed in her years before oral intake of torasemide. The sudden onset of skin symptoms shows torasemide to be possible inducing factor for the development of vascular purpura in patients suffering from EGPA but without previous cutaneous involvement.

Sustained Eosinophilic Cholangitis Due to a Mite Allergy Mimicking Sclerosing Cholangitis

Eosinophilic cholangiopathy (EC) presents with thickening and stenosis of the bile duct wall that is histologically characterized by eosinophil infiltration. The diagnosis is often difficult. We herein report a patient who had been followed up with a diagnosis of primary sclerosing cholangitis but had a final diagnosis of EC based on eosinophilia, histological findings of bile duct and liver biopsy specimens, and a review of a previous surgical specimen of the gallbladder. Antigen tests, isolation from her house, and accidental re-exposure to the antigen revealed that the causative antigen was the mite Dermatophagoides pteronyssinus.

Duodenal eosinophilia is associated with symptomatic erosive gastro-oesophageal reflux disease, presence of co-morbidities, and ethnicity but not undifferentiated functional dyspepsia: A retrospective Malaysian study

BACKGROUND

Duodenal eosinophilia is postulated to play a key role in the pathogenesis of functional dyspepsia, a common condition responsible for considerable impairment of quality of life. Our objective was to evaluate the relative strength of the associations between duodenal eosinophilia, functional dyspepsia, symptomatic erosive gastroesophageal reflux disease (GERD), the presence of co-morbidities, and a number of other variables.

METHODS

Eosinophil counts of archived endoscopic duodenal biopsies of 289 subjects were determined by a pathologist blinded to the clinical data. Duodenal eosinophilia was defined by a count of more than 15 per 5 high power fields. Clinical charts were reviewed by a gastroenterologist blinded to the histology review.

RESULTS

In the study sample, the primary diagnosis was functional dyspepsia (undifferentiated by subtypes) in 45, symptomatic erosive GERD in 29, gall stone disease in 17, irritable bowel syndrome in 23, and an alternative or undetermined diagnosis in 175 subjects, respectively. On logistic regression analyses, eosinophil counts were positively associated with symptomatic erosive GERD (Odds Ratio, OR 1.03, 95% Confidence Interval, 95%CI: 1.00, 1.05; p=0.035) but not functional dyspepsia. Pre-defined duodenal eosinophilia was associated with symptomatic erosive gastro-oesophageal reflux disease (OR 3.36, 95%CI 1.18,-9.60; p=0.023), the presence of co-morbidities (OR 2.00, 95%CI 1.10, 3.62; p=0.022), and Chinese (as compared to Malay and Indian) ethnicity but not with either functional dyspepsia, irritable bowel syndrome, gallstone disease, Helicobacter pylori infection, or gender.

CONCLUSION

Duodenal eosinophilia was associated with symptomatic erosive GERD, the presence of co-morbidities, and Chinese ethnicity but not with undifferentiated functional dyspepsia.

Colonic mucosal eosinophilia and immunohistochemical expression of COX-2 and NF-kB in patients with irritable bowel syndrome

BACKGROUND

There is growing evidence that eosinophilic infiltration can release mediators which are harmful to the intestinal epithelium in patients with irritable bowel syndrome (IBS). Although cyclooxygenase 2 (COX-2) and nuclear factor-kappa beta (NF-kB) expression had been previously reported to increase in many inflammatory conditions, there is a paucity in data investigating their expressions in IBS. Our aim was to evaluate colonic mucosal eosinophilia and immunohistochemical expression of COX-2 and NF-kB in patients with irritable bowel syndrome.

METHODS

A total of 80 patients who met the inclusion criteria of IBS based on Rome IV symptoms questionnaire were subjected to abdominal ultrasound, laboratory investigations, serum immunoglobulin E (IgE) level assessment and colonoscopic examination. Immunohistochemistry was performed to detect COX-2 and NF-kB expression in colonic biopsies obtained from IBS patients.

RESULTS

Histopathological examination showed that 60 colonic biopsy specimens (75%) showed few mixed inflammatory cells ≤3 cells/ HPF, 12 biopsy specimens (15%) showed eosinophilic infiltration ≥25 eosinophils/HPF and 8 biopsy specimens (10%) showed severe lymphocytic infiltration and aggregation. Colonic eosinophilic infiltrate was significantly higher among patients presented with IBS-D subtype. Serum IgE was significantly higher among patients with colonic eosinophilic infiltrate than the others. In IBS-D patients, colonic mucosa showed positive expression of COX-2 and NF-kB in 52.1% and 81.25% of cases, respectively.

CONCLUSION

Patients with IBS -particularly IBS-D subtype- should undergo colonoscopy and biopsy to exclude underlying inflammatory pathology. Moreover, patients with positive COX-2 and NF-kB need further evaluation and follow-up.

Quantification of Mucosal Eosinophils for the Histopathologic Diagnosis of Eosinophilic Gastritis and Duodenitis: A Primer for Practicing Pathologists

Eosinophilic gastrointestinal diseases, specifically eosinophilic gastritis and duodenitis, are chronic inflammatory conditions characterized by persistent gastrointestinal (GI) symptoms and elevated levels of activated eosinophils in the GI tract. Both clinical and endoscopic findings are nonspecific, no clinical or histopathologic diagnostic guidelines are published, and disease awareness is low, both among clinicians and amongst pathologists, who tend to overlook mild or moderate increases in the density of eosinophils in GI biopsy specimens. Yet, evaluating and, at times, counting eosinophils in GI biopsies may have important clinical implications: the numbers of tissue eosinophils correlate with clinical manifestations, can be used as determinants of effective management, and are used to assess the effects of treatment. A most persuasive argument for providing a count rather than a value judgment is that patients read reports, understand numbers, and use them to help to understand the course of their disease. The objective of this primer is to provide pathologists with the tools to incorporate a quantitative assessment of eosinophilia in the diagnosis of gastric and duodenal biopsy specimens and to develop a systematic approach to their evaluation, counting, and reporting. To achieve this aim, we present our general approach to the biopsy (where to count), followed by details on the characteristics of a countable eosinophil (what to count), and provide with a set of suggestions on the counting methods (how to count). We conclude with suggestions on how to report GI tissue eosinophilia in a manner that alerts clinicians and prompts pertinent management steps.

Eosinophilic gastrointestinal disorders in children and adolescents: A single-center experience

BACKGROUND

To date, few studies have been conducted in Italy on pediatric eosinophilic gastrointestinal diseases (EGIDs).

AIMS

To assess clinical features of pediatric patients with EGIDs who are followed in a tertiary pediatric center.

METHODS

From January 2015 to December 2019, we retrospectively enrolled patients with EGIDs, and collected clinical, endoscopic, and histological data.

RESULTS

We enrolled 112 patients, 75.8% were male. Mean age was 9.3 ± 4.8 years. Diagnosis of EGIDs has increased in the last two years, with non-esophageal EGIDs more prevalent than eosinophilic esophagitis (EoE) (5.1% vs. 4.4%). Approximately 30% of patients had allergic comorbidities, which prevailed in children with EoE. Autism spectrum disorders were common in patients with non-esophageal EGIDs (p = 0.007), a statistically significant finding. In addition, esophageal atresia was associated with EoE (p = 0.04). Most EGIDs patients had normal findings or an inflammatory endoscopic phenotype. Patients with EoE were mainly treated with proton pump inhibitors (PPIs) alone or in combination with swallowed steroids. PPIs, oral steroids, and food-elimination diets were prescribed to patients with non-esophageal EGIDs.

CONCLUSION

This is the first Italian study revealing an increased frequency of EGIDs in a pediatric population. Further studies are needed to characterize patients with these emerging diseases.

Plasma membrane lesion type total intestinal eosinophilic enteritis: A case report

BACKGROUND

Eosinophilic gastroenteritis is a rare gastrointestinal disease that is characterized by diffuse or localized eosinophil infiltration in the gastrointestinal tract, and is accompanied by increased peripheral blood eosinophils. Herein, a case of plasma membrane lesion-type total intestinal eosinophil enteritis is reported.

CASE PRESENTATION

We report on a 20-year-old male patient who was admitted to the hospital with "abdominal distension for 15 days". The infiltration of a large number of eosinophils was found by conducting an intestinal biopsy, routine ascites examination, blood routine, smear test, and a bone marrow puncture. A special feature of this patient was that a large number of eosinophils were found in the duodenum, small intestine, and colon. The final diagnosis was plasma membrane lesion type total intestinal eosinophilic enteritis. After four weeks of prednisone treatment, the symptoms disappeared completely and the entire intestinal mucosa was endoscopically observed as smooth.

CONCLUSION

Clinical practitioners must pay attention to gastrointestinal endoscopy and biopsy pathology results for patients presenting with abdominal distention and ascites. Combined with an abnormal increase of eosinophils in ascites, bone marrow, and peripheral blood, clinical practitioners must be highly vigilant against plasma membrane lesion type total intestinal eosinophilic enteritis.

Comprehensive characterization of central BCL-2 family members in aberrant eosinophils and their impact on therapeutic strategies

Purpose

Hypereosinophilia represents a heterogenous group of severe medical conditions characterized by elevated numbers of eosinophil granulocytes in peripheral blood, bone marrow or tissue. Treatment options for hypereosinophilia remain limited despite recent approaches including IL-5-targeted monoclonal antibodies and tyrosine kinase inhibitors.

Methods

To understand aberrant survival patterns and options for pharmacologic intervention, we characterized BCL-2-regulated apoptosis signaling by testing for BCL-2 family expression levels as well as pharmacologic inhibition using primary patient samples from diverse subtypes of hypereosinophilia (hypereosinophilic syndrome n = 18, chronic eosinophilic leukemia not otherwise specified n = 9, lymphocyte-variant hypereosinophilia n = 2, myeloproliferative neoplasm with eosinophilia n = 2, eosinophilic granulomatosis with polyangiitis n = 11, reactive eosinophilia n = 3).

Results

Contrary to published literature, we found no difference in the levels of the lncRNA Morrbid and its target BIM. Yet, we identified a near complete loss of expression of pro-apoptotic PUMA as well as a reduction in anti-apoptotic BCL-2. Accordingly, BCL-2 inhibition using venetoclax failed to achieve cell death induction in eosinophil granulocytes and bone marrow mononuclear cells from patients with hypereosinophilia. In contrast, MCL1 inhibition using S63845 specifically decreased the viability of bone marrow progenitor cells in patients with hypereosinophilia. In patients diagnosed with Chronic Eosinophilic Leukemia (CEL-NOS) or Myeloid and Lymphatic Neoplasia with hypereosinophilia (MLN-Eo) repression of survival was specifically powerful.

Conclusion

Our study shows that MCL1 inhibition might be a promising therapeutic option for hypereosinophilia patients specifically for CEL-NOS and MLN-Eo.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03827-9.

Fever, rash, and eosinophilia - early signs of angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is an uncommon lymphoma of elderly adults with a poor prognosis. AITL patients show systemic symptoms, lymphadenopathy, and not infrequently, skin rash with various dysimmune phenomena rashes. The case is presented of a 68-year-old male with skin rash, lymphadenopathy and hypereosinophilia who, after investigations, was diagnosed with AITL. Despite the treatment used, the patient's condition gradually deteriorated and died due to heart and kidney failure. The diagnosis of AITL is often established only after several weeks or months because of transient physical findings, non-specific symptoms, and a broad range of serologic or radiologic abnormalities. Some patients with AITL experience non-specific dermatitis and eosinophilia. The presented case should raise awareness of the presentations of AITL which is important for physicians to reach an accurate diagnosis.