Eosinophil cytokines, chemokines, and growth factors: emerging roles in immunity

Aberrant innate immune profile associated with COVID-19 mortality in Pretoria, South Africa

The African continent reported the least number of COVID-19 cases and deaths of all the continents, although the exact reasons for this are still unclear. In addition, little is known about the immunological profiles associated with COVID-19 mortality in Africa. The present study compared clinical and immunological parameters, as well as treatment outcomes in patients admitted with COVID-19 in Pretoria, South Africa, to determine if these parameters correlate with mortality in this population. The in-hospital mortality rate for the cohort was 15.79%. The mortality rate in people living with HIV (PLWH) was 10.81% and 17.16% in people without HIV (p = 0.395). No differences in age (p = 0.099), gender (p = 0.127) or comorbidities were found between deceased patients and those who survived. All four of the PLWH who died had a CD4+ T-cell count <200 cells/mm3, a significantly higher HIV viral load than those who survived (p = 0.009), and none were receiving antiretroviral therapy. Seven of 174 (4%) patients had evidence of auto-antibodies neutralizing Type 1 interferons (IFNs). Two of the them died, and their presence was significantly associated with mortality (p = 0.042). In the adjusted model, the only clinical parameters associated with mortality were: higher fraction of inspired oxygen (FiO2) (OR: 3.308, p = 0.011) indicating a greater need for oxygen, high creatinine (OR: 4.424, p = 0.001) and lower platelet counts (OR: 0.203, p = 0.009), possibly secondary to immunothrombosis. Overall, expression of the co-receptor CD86 (p = 0.021) on monocytes and percentages of CD8+ effector memory 2 T-cells (OR: 0.45, p = 0.027) was lower in deceased patients. Decreased CD86 expression impairs the development and survival of effector memory T-cells. Deceased patients had higher concentrations of RANTES (p = 0.003), eotaxin (p = 0.003) and interleukin (IL)-8 (p < 0.001), all involved in the activation and recruitment of innate immune cells. They also had lower concentrations of transforming growth factor (TGF)-β1 (p = 0.40), indicating an impaired anti-inflammatory response. The immunological profile associated with COVID-19 mortality in South Africa points to the role of aberrate innate immune responses.

Deciphering the Interplay between the Epithelial Barrier, Immune Cells, and Metabolic Mediators in Allergic Disease

Chronic exposure to harmful pollutants, chemicals, and pathogens from the environment can lead to pathological changes in the epithelial barrier, which increase the risk of developing an allergy. During allergic inflammation, epithelial cells send proinflammatory signals to group 2 innate lymphoid cell (ILC2s) and eosinophils, which require energy and resources to mediate their activation, cytokine/chemokine secretion, and mobilization of other cells. This review aims to provide an overview of the metabolic regulation in allergic asthma, atopic dermatitis (AD), and allergic rhinitis (AR), highlighting its underlying mechanisms and phenotypes, and the potential metabolic regulatory roles of eosinophils and ILC2s. Eosinophils and ILC2s regulate allergic inflammation through lipid mediators, particularly cysteinyl leukotrienes (CysLTs) and prostaglandins (PGs). Arachidonic acid (AA)-derived metabolites and Sphinosine-1-phosphate (S1P) are significant metabolic markers that indicate immune dysfunction and epithelial barrier dysfunction in allergy. Notably, eosinophils are promoters of allergic symptoms and exhibit greater metabolic plasticity compared to ILC2s, directly involved in promoting allergic symptoms. Our findings suggest that metabolomic analysis provides insights into the complex interactions between immune cells, epithelial cells, and environmental factors. Potential therapeutic targets have been highlighted to further understand the metabolic regulation of eosinophils and ILC2s in allergy. Future research in metabolomics can facilitate the development of novel diagnostics and therapeutics for future application.

Inflammatory proteins may mediate the causal relationship between gut microbiota and inflammatory bowel disease: A mediation and multivariable Mendelian randomization study

This research investigates the causal relationships among gut microbiota, inflammatory proteins, and inflammatory bowel disease (IBD), including crohn disease (CD) and ulcerative colitis (UC), and identifies the role of inflammatory proteins as potential mediators. Our study analyzed gut microbiome data from 13,266 samples collected by the MiBioGen alliance, along with inflammatory protein data from recent research by Zhao et al, and genetic data on CD and UC from the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC). We used Mendelian randomization (MR) to explore the associations, complemented by replication, meta-analysis, and multivariable MR techniques for enhanced accuracy and robustness. Our analysis employed several statistical methods, including inverse-variance weighting, MR-Egger, and the weighted median method, ensuring comprehensive and precise evaluation. After MR analysis, replication and meta-analysis, we revealed significant associations between 11 types of gut microbiota and 17 inflammatory proteins were associated with CD and UC. Mediator MR analysis and multivariable MR analysis showed that in CD, the CD40L receptor mediated the causal effect of Defluviitaleaceae UCG-011 on CD (mediation ratio 8.3%), and the Hepatocyte growth factor mediated the causal effect of Odoribacter on CD (mediation ratio 18%). In UC, the C-C motif chemokine 4 mediated the causal effect of Ruminococcus2 on UC (mediation ratio 4%). This research demonstrates the interactions between specific gut microbiota, inflammatory proteins, and CD and UC. Furthermore, the CD40L receptor may mediate the relationship between Defluviitaleaceae UCG-011 and CD; the Hepatocyte growth factor may mediate the relationship between Odoribacter and CD; and the C-C motif chemokine 4 may mediate the relationship between Ruminococcus2 and UC. The identified associations and mediation effects offer insights into potential therapeutic approaches targeting the gut microbiome for managing CD and UC.

A single infusion of engineered long-lived and multifunctional T cells confers durable remission of asthma in mice

Asthma, the most prevalent respiratory disease, affects more than 300 million people and causes more than 250,000 deaths annually. Type 2-high asthma is characterized by interleukin (IL)-5-driven eosinophilia, along with airway inflammation and remodeling caused by IL-4 and IL-13. Here we utilize IL-5 as the targeting domain and deplete BCOR and ZC3H12A to engineer long-lived chimeric antigen receptor (CAR) T cells that can eradicate eosinophils. We call these cells immortal-like and functional IL-5 CAR T cells (5TIF) cells. 5TIF cells were further modified to secrete an IL-4 mutein that blocks IL-4 and IL-13 signaling, designated as 5TIF4 cells. In asthma models, a single infusion of 5TIF4 cells in fully immunocompetent mice, without any conditioning regimen, led to sustained repression of lung inflammation and alleviation of asthmatic symptoms. These data show that asthma, a common chronic disease, can be pushed into long-term remission with a single dose of long-lived CAR T cells.

Eosinophils in Colorectal Cancer: Emerging Insights into Anti-Tumoral Mechanisms and Clinical Implications

Eosinophils are myeloid effector cells whose main homing is the gastrointestinal tract. There, they take part in type I and type II immune responses. They also contribute to other non-immunological homeostatic functions like mucus production, tissue regeneration, and angiogenesis. In colorectal cancer (CRC), eosinophils locate in the center of the tumor and in the front of invasion and play an anti-tumoral role. They directly kill tumor cells by releasing cytotoxic compounds and eosinophil extracellular traps or indirectly by activating other immune cells via cytokines. As CRC progresses, the number of infiltrating eosinophils decreases. Although this phenomenon is not fully understood, it is known that some changes in the microenvironmental milieu and microbiome can affect eosinophil infiltration. Importantly, a high number of intratumoral eosinophils is a favorable prognostic factor independent from the tumor stage. Moreover, after immunotherapy, responding patients usually display eosinophilia, so eosinophils could be a good biomarker candidate to monitor treatment outcomes. Finally, even though eosinophils seem to play an interesting anti-tumoral role in CRC, much more research is needed to fully understand their interactions in the CRC microenvironment. This review explores the multifaceted roles of eosinophils in colorectal cancer, highlighting their anti-tumoral effects, prognostic significance, and potential as a biomarker for treatment outcomes.

Eosinophils and Cognitive Impairment in Schizophrenia: A New Perspective

Schizophrenia is a complex psychiatric disorder characterized by a wide array of cognitive impairments. While research has predominantly focused on the neurological aspects of schizophrenia, emerging evidence suggests that the immune system, specifically eosinophils, may play a significant role in the cognitive deficits associated with the disorder. This review presents a novel perspective on the interplay between eosinophils and cognitive impairment in schizophrenia. Eosinophils, traditionally associated with allergic responses and inflammation, have garnered limited attention within the realm of neuropsychiatry. Recent studies have hinted at a potential link between eosinophil activation and the pathogenesis of schizophrenia. In this comprehensive review, we delve into the world of eosinophils, elucidating their nature, functions, and interactions with the immune system. We examine the cognitive deficits observed in individuals with schizophrenia and discuss existing theories on the etiology of these impairments, focusing on immune system involvement. The paper also highlights the evolving body of research that supports the idea of eosinophilic influence on schizophrenia-related cognitive deficits. Furthermore, we explore potential mechanisms through which eosinophils may exert their effects on cognitive function in schizophrenia, including interactions with other immune cells and inflammatory pathways. By discussing the clinical implications and potential therapeutic avenues stemming from this newfound perspective, we underscore the practical significance of this emerging field of research. While this paper acknowledges the limitations and challenges inherent in studying eosinophils within the context of schizophrenia, it serves as a posit for novel thought in this vexing disease space as well as a call to action for future research endeavors. By providing a comprehensive survey of the existing literature and posing unanswered questions, we aim to inspire a reimagining of the relationship between eosinophils and cognitive impairment in schizophrenia, ultimately advancing our understanding and treatment of this debilitating disorder.

Cerebrospinal fluid eosinophils in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Eosinophils in cerebrospinal fluid (CSF) are an uncommon finding most often associated with parasitic infections, but have also been described in some neuroinflammatory disorders. Eosinophilic infiltration is not thought to be a typical feature of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). We aim to describe the rate of CSF eosinophil positivity in a cohort of pediatric MOGAD patients.

METHODS

Single-center retrospective chart review of pediatric MOGAD patients. Clinical and laboratory data was collected from the electronic medical record and analyzed.

RESULTS

Of 46 pediatric patients with positive serum myelin oligodendrocyte glycoprotein antibody (MOG-IgG) identified, 38 patients fulfilling internationally proposed MOGAD diagnostic criteria were included for analysis. 6 patients with MOGAD were excluded as no CSF data was available, and 2 patients with positive MOG-IgG but diagnosis more consistent with MS were excluded. Median age was 7.3 years, and 19/38 (50 %) were female. Acute disseminated encephalomyelitis (ADEM) was the most common presenting phenotype (23/38, 61 %), and other phenotypes included optic neuritis (10/38, 26 %), transverse myelitis (3/38, 8 %), and neuromyelitis optica spectrum disorder (NMOSD) (2/38, 5 %). 12 of 36 (33 %) patients with all lumbar puncture (LP) data available had CSF eosinophils present, with eosinophil mean of 3 % and range from 1 % to 18 % of CSF while blood cells.

CONCLUSION

CSF eosinophils were present in one third of pediatric MOGAD patients, which is a higher rate than previously reported in either MOGAD or aquaporin-4 antibody positive NMOSD cohorts. Understanding the CSF composition of pediatric MOGAD patients helps to facilitate more prompt diagnosis and treatment and may shed light onto underlying pathologic mechanisms of disease with the goal to inform future therapeutic targets.

The association of blood eosinophil counts and FEV1 decline: a cohort study

BACKGROUND

Accelerated lung function decline is characteristic of COPD. However, the association between blood eosinophil counts and lung function decline, accounting for current smoking status, in young individuals without prevalent lung disease is not fully understood.

METHODS

This is a cohort study of 629 784 Korean adults without COPD or a history of asthma at baseline who participated in health screening examinations including spirometry and differential white blood cell counts. We used a linear mixed-effects model to estimate the annual change in forced expiratory volume in 1 s (FEV1) (mL) by baseline blood eosinophil count, adjusting for covariates including smoking status. In addition, we performed a stratified analysis by baseline and time-varying smoking status.

RESULTS

During a mean follow-up of 6.5 years (maximum 17.8 years), the annual change in FEV1 (95% CI) in participants with eosinophil counts <100, 100-199, 200-299, 300-499 and ≥500 cells·µL-1 in the fully adjusted model were -23.3 (-23.9--22.7) mL, -24.3 (-24.9--23.7) mL, -24.8 (-25.5--24.2) mL, -25.5 (-26.2--24.8) mL and -26.8 (-27.7--25.9) mL, respectively. When stratified by smoking status, participants with higher eosinophil count had a faster decline in FEV1 than those with lower eosinophil count in both never- and ever-smokers, which persisted when time-varying smoking status was used.

CONCLUSIONS

Higher blood eosinophil counts were associated with a faster lung function decline among healthy individuals without lung disease, independent of smoking status. The findings suggest that higher blood eosinophil counts contribute to the risk of faster lung function decline, particularly among younger adults without a history of lung disease.

Monocyte to high-density lipoprotein ratio as a novel-potential biomarker for predicting prognosis of Bell's palsy

OBJECTIVES

In several disorders, the monocyte to high-density lipoprotein ratio (MHR) has been considered a biomarker of systemic inflammation and oxidative stress. However, its role in Bell's palsy (BP) remains unclear. This study investigates the relationship between elevated MHR and poor recovery in BP patients.

METHODS

The clinical data of 729 BP patients were analyzed retrospectively. The House-Brackmann Facial Nerve Grading System (H-B) was utilized to assess the severity of facial motor dysfunction during admission and the follow-up period after discharge. According to the 6 months follow-up data, H-B grades 1-2 were classified as recovered (n = 557), and H-B grades 3-6 as unrecovered (n = 172). The patients were split into MHR ≤ 0.26 (n = 361) and MHR > 0.26 (n = 368) groups based on the median MHR to further analyze the connection between different MHRs and prognosis.

RESULTS

The level of MHR was substantially greater in the unrecovered group of BP patients than in the restored group (medians[interquartile range], 0.32[0.20, 0.49] vs 0.24[0.11, 0.39], P < 0.001). MHR was an independent risk factor for BP prognosis as indicated by the multivariate logistic regression analysis (OR = 4.467, 95% CI = 1.875-10.646, P = 0.001). The area under the curve (AUC) was 0.615 (95% CI = 0.566-0.664, P < 0.001). The initial H-B score did not differ significantly between MHR ≤ 0.26 (n = 361) and MHR > 0.26 (n = 368) groups. However, after 6 months of follow-up, the high-MHR group's H-B score was considerably greater than the low-MHR group's.

CONCLUSIONS

MHR is expected to be an accessible and effective biomarker of BP. In BP patients, elevated MHR is related to an increased chance of poor recovery.

Eosinophils in Oral Disease: A Narrative Review

The prevalence of diseases characterised by eosinophilia is on the rise, emphasising the importance of understanding the role of eosinophils in these conditions. Eosinophils are a subset of granulocytes that contribute to the body's defence against bacterial, viral, and parasitic infections, but they are also implicated in haemostatic processes, including immunoregulation and allergic reactions. They contain cytoplasmic granules which can be selectively mobilised and secrete specific proteins, including chemokines, cytokines, enzymes, extracellular matrix, and growth factors. There are multiple biological and emerging functions of these specialised immune cells, including cancer surveillance, tissue remodelling and development. Several oral diseases, including oral cancer, are associated with either tissue or blood eosinophilia; however, their exact mechanism of action in the pathogenesis of these diseases remains unclear. This review presents a comprehensive synopsis of the most recent literature for both clinicians and scientists in relation to eosinophils and oral diseases and reveals a significant knowledge gap in this area of research.

Longitudinal cytokine and multi-modal health data of an extremely severe ME/CFS patient with HSD reveals insights into immunopathology, and disease severity

Introduction

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) presents substantial challenges in patient care due to its intricate multisystem nature, comorbidities, and global prevalence. The heterogeneity among patient populations, coupled with the absence of FDA-approved diagnostics and therapeutics, further complicates research into disease etiology and patient managment. Integrating longitudinal multi-omics data with clinical, health,textual, pharmaceutical, and nutraceutical data offers a promising avenue to address these complexities, aiding in the identification of underlying causes and providing insights into effective therapeutics and diagnostic strategies.

Methods

This study focused on an exceptionally severe ME/CFS patient with hypermobility spectrum disorder (HSD) during a period of marginal symptom improvements. Longitudinal cytokine profiling was conducted alongside the collection of extensive multi-modal health data to explore the dynamic nature of symptoms, severity, triggers, and modifying factors. Additionally, an updated severity assessment platform and two applications, ME-CFSTrackerApp and LexiTime, were introduced to facilitate real-time symptom tracking and enhance patient-physician/researcher communication, and evaluate response to medical intervention.

Results

Longitudinal cytokine profiling revealed the significance of Th2-type cytokines and highlighted synergistic activities between mast cells and eosinophils, skewing Th1 toward Th2 immune responses in ME/CFS pathogenesis, particularly in cognitive impairment and sensorial intolerance. This suggests a potentially shared underlying mechanism with major ME/CFS comorbidities such as HSD, Mast cell activation syndrome, postural orthostatic tachycardia syndrome (POTS), and small fiber neuropathy. Additionally, the data identified potential roles of BCL6 and TP53 pathways in ME/CFS etiology and emphasized the importance of investigating adverse reactions to medication and supplements and drug interactions in ME/CFS severity and progression.

Discussion

Our study advocates for the integration of longitudinal multi-omics with multi-modal health data and artificial intelligence (AI) techniques to better understand ME/CFS and its major comorbidities. These findings highlight the significance of dysregulated Th2-type cytokines in patient stratification and precision medicine strategies. Additionally, our results suggest exploring the use of low-dose drugs with partial agonist activity as a potential avenue for ME/CFS treatment. This comprehensive approach emphasizes the importance of adopting a patient-centered care approach to improve ME/CFS healthcare management, disease severity assessment, and personalized medicine. Overall, these findings contribute to our understanding of ME/CFS and offer avenues for future research and clinical practice.

Glucocorticoid-induced TNF receptor family-related protein functions as a costimulatory molecule for murine eosinophils

Eosinophils are typical effector cells associated with type 2 immune responses and play key roles in the pathogenesis of allergic diseases. These cells are activated by various stimuli, such as cytokines, chemokines, and growth factors, but the regulatory mechanisms of eosinophil effector functions remain unclear. Glucocorticoid-induced tumor necrosis factor receptor family-related protein (GITR), a transmembrane protein belonging to the tumor necrosis factor (TNF) receptor superfamily, is a well-known regulatory molecule for T cell activation. Here, we show that GITR is also constitutively expressed on eosinophils and functions as a costimulatory molecule for these cells. Although degranulation was unaffected by GITR engagement of murine bone marrow-derived eosinophils, secretion of inflammatory cytokines such as interleukin (IL)-4, IL-6, and IL-13 from IL-33-activated bone marrow-derived eosinophils was augmented by anti-mouse GITR agonistic antibody (DTA-1). In conclusion, our results provide a new regulatory pathway of cytokine secretion from eosinophils in which GITR functions as a costimulatory molecule.

Association Between Dietary Fiber Intake and Prevalence of Chronic Obstructive Pulmonary Disease in a Middle-Aged and Elderly Population: a Study Based on the National Health and Nutrition Examination Survey Database

Objective

This study aimed to investigate dietary fiber (DF) intake with the prevalence of chronic obstructive pulmonary disease (COPD) in the middle-aged and elderly population through analysis of the National Health and Nutrition Examination Survey (NHANES) data.

Methods

The study utilized data from 3 cycles of the NHANES database (2007-2012). The exposure variable was DF intake, and the outcome variable was COPD prevalence. Weighted logistic regression was utilized to construct relationship models between the 2 variables. Confounding factors were adjusted, and subgroup analysis was to explore the association of DF intake with COPD. Restricted cubic spline (RCS) analysis investigated the nonlinear relationship between DF intake and COPD. Finally, mediation analysis was performed to determine whether the influence of DF intake on COPD prevalence is mediated through the alteration of white blood cell (WBC) counts.

Results

This study included a total of 7301 eligible participants aged >40 years. The results of the study indicated that an increase in DF intake significantly reduced the prevalence of COPD (odds ratio: 0.98, 95% confidence interval: 0.96-0.99, p<0.001), and DF intake was correlated with lung function indicators (e.g., forced expiratory volume in 1 second). Stratified analysis revealed that an increased DF intake significantly reduced the risk of COPD in male individuals, middle-aged individuals (aged 40-59 years), those with a body mass index ≤30 kg/m2, individuals with a history of smoking, and alcohol consumers (p<0.05). Through RCS analysis exploring the nonlinear association between DF intake and COPD prevalence, the critical threshold for the impact of DF intake on COPD prevalence was 15.10 gm. When DF intake was ≥15.10 g/d, it effectively reduced the prevalence of COPD. Mediation analysis results indicated that the WBC count partially mediated the association between DF intake and COPD, with a mediation proportion of 9.89% (p=0.006).

Conclusion

Increased DF intake was linked to decreased prevalence of COPD, particularly in men and middle-aged people. WBC counts may be an important pathway linking DF intake and COPD.

Bilastine in Refractory Chronic Spontaneous Urticaria: Disease Control and Cytokine Modulation in an Open-label Prospective Study

Introduction

The treatment options for chronic spontaneous urticaria (CSU) primarily include second generation non-sedative antihistamine (SGAHs). Bilastine is a newer, nonsedating SGAH approved for urticaria in February 2019 by the Drugs Controller General of India. Its major advantages are in terms of superior efficacy, lack of drug interactions and adverse effects, including sedation, compared to conventional SGAHs. The role of cytokines in the pathogenesis of CSU is well known. However, there is a shortage of data regarding the change in serum levels of proinflammatory cytokines following H1 antihistamines. We conducted this trial to evaluate the role of bilastine in cytokine modulation and autoimmunity, thereby explaining its role in modifying the disease process in CSU.

Materials and Methods

This prospective study was conducted in a tertiary institute in Kolkata on patients aged 12 years and above with a CSU >6 months. These patients had an unsatisfactory response, as per the Urticaria Activity Score 7 (UAS7), to previous antihistamine therapies in standard doses. Treatment effectiveness was determined by comparing the UAS7 at baseline with that at weeks 4, 8 and 12. Also, baseline serum interleukin-6 (IL-6) and IL-17 were compared with those at the end of the study, that is, 12 weeks.

Results

Thirty patients who matched the inclusion criteria and signed informed consent were included in the study. At the end of 12 weeks, 10% of patients (n = 3) achieved a complete treatment response (UAS = 0), whereas 43.33% of patients (n = 13) were labelled as having well-controlled urticaria (UAS <6). At 12 weeks, the mean UAS7 score (6.47 ± 4.45) was statistically significant compared to the baseline score (25.47 ± 7.74). The mean values of serum IL-6 (pg/ml) and IL-17 (pg/ml) at baseline were 5.96 ± 5.24 pg/ml and 6.96 ± 5.97 pg/ml, respectively. At the end of treatment, that is, 3 months, the mean values were reduced to 4.61 ± 4.56 pg/ml and 5.08 ± 3.87 pg/ml. The reduction was statistically significant for both serum IL-6 (P < 0.001) and IL-17 (P < 0.0001).

Conclusion

We conclude that bilastine at a once-daily continuous dose of 40 mg for 3 months is safe and effective in CSU patients who are refractory to treatment at the standard doses of SGAHs. Improved symptomatic control with bilastine was also associated with better control over the inflammatory process, as suggested by the lowering of mean cytokine levels in our study.

Immunofluorescence analysis of human eosinophils

A prominent inflammatory cell type in allergic diseases is the eosinophil, a granulated white blood cell that releases pro-inflammatory cytokines. Eosinophil-derived cytokines, including interleukin-9 (IL-9) and interleukin-13 (IL-13), can skew the immune response towards an allergic phenotype. Unfortunately, it is challenging to immunolabel and collect quantifiable images of eosinophils given their innate autofluorescence and ability to nonspecifically bind to antibodies. Hence, it is important to optimize permeabilization, blocking, and imaging conditions for eosinophils. Here, we show enhanced protocols to ensure that measured immunofluorescence represents specific immunolabelling. To test this, eosinophils were purified from human blood, adhered to glass coverslips, stimulated with or without platelet-activating factor (PAF), fixed with paraformaldehyde, and then permeabilized with Triton X-100 or saponin. Cells were then blocked with goat serum or human serum and incubated with antibodies labelling cytokines (IL-9 and IL-13) and secretory organelles (CD63 for crystalloid granules and transferrin receptor [TfnRc] for recycling endosomes). Carefully selected isotype controls were used throughout, and cells were imaged using Deltavision super-resolution microscopy. Intensities of fluorescent probes were quantified using Volocity software. Our findings show that permeabilization with saponin, blockage with human serum, and using concentrations of antibodies up to 10 μg/ml allowed us to detect marked differences in fluorescence intensities between isotypes and test antibodies. With the achievement of sufficient qualitative and quantitative measures of increased test probe intensity compared to respective isotypes, these results indicate that our protocol allows for optimal immunolabelling of eosinophils. Using this protocol, future studies may provide further insights into trafficking mechanisms within this important inflammatory cell type.

Can the addition of Interleukin-13 affect the cryosurvival of bovine embryos?

In this study, we investigated the impact of incorporating Interleukin-13 (IL-13) into the embryonic culture medium and its influence on cryotolerance and cellular viability of vitrified bovine embryos. Two distinct time points for IL-13 supplementation were explored: during the final hours of culture prior to cryopreservation and during the period of recultivation following cryopreservation and warming. Cryosurvival rates, total cell count, and cell viability were assessed using the TUNEL technique to determine the apoptotic percentage. Re-expansion and hatching rates did not show differences among all groups (P > 0.05), and the total cell number was comparable between the treated and control groups (P > 0.05). However, the group that received IL-13 before vitrification exhibited a higher apoptotic percentage (P < 0.05). This suggests that the anti-inflammatory effect of IL-13 may have impacted the embryo's defense capacity against the stress induced by cryopreservation, leading to an increased percentage of apoptosis, although it did not influence the developmental resumption capability.

Human uterine natural killer cells regulate differentiation of extravillous trophoblast early in pregnancy

In humans, balanced invasion of trophoblast cells into the uterine mucosa, the decidua, is critical for successful pregnancy. Evidence suggests that this process is regulated by uterine natural killer (uNK) cells, but how they influence reproductive outcomes is unclear. Here, we used our trophoblast organoids and primary tissue samples to determine how uNK cells affect placentation. By locating potential interaction axes between trophoblast and uNK cells using single-cell transcriptomics and in vitro modeling of these interactions in organoids, we identify a uNK cell-derived cytokine signal that promotes trophoblast differentiation at the late stage of the invasive pathway. Moreover, it affects transcriptional programs involved in regulating blood flow, nutrients, and inflammatory and adaptive immune responses, as well as gene signatures associated with disorders of pregnancy such as pre-eclampsia. Our findings suggest mechanisms on how optimal immunological interactions between uNK cells and trophoblast enhance reproductive success.

Symptomatic intracranial hemorrhage mediates the association between eosinophils and 90-day outcomes after mechanical thrombectomy for acute ischemic stroke

BACKGROUND

Decreased eosinophil level is associated with poor outcomes after mechanical thrombectomy in patients with acute ischemic stroke (AIS), but the underlying mechanism of this association is elusive. We aimed to assess the mediation effect of symptomatic intracranial hemorrhage (sICH) on the aforementioned association.

METHODS

A total of 328 consecutive AIS patients undergoing mechanical thrombectomy between May 2017 and March 2021 were analyzed. SICH was defined as any evidence of brain hemorrhage on CT scan with neurological deterioration. Regression analysis was used to assess the effect of eosinophils on sICH, and its effect on poor outcome. Mediation analysis was performed to assess the proportion of total effect by sICH on the association between eosinophils and poor outcome.

RESULTS

Multivariate analysis revealed an independent association between eosinophil count and sICH after adjusting for potential confounders (odds ratio, 0.00; 95% CI, 0.00-0.01; P = 0.0141), which is consistent with the result of eosinophil count (dichotomous) as a categorical variable (odds ratio, 0.22; 95% CI, 0.11-0.46; P < 0.0001). Eosinophil count was negatively associated with poor outcome (odds ratio, 0.00; 95% CI, 0.00-0.02; P = 0.0021). Mediation analysis revealed that sICH partially mediated the negative relationship between eosinophil count and poor outcome (indirect effect=-0.1896; 95%CI: -0.3654 - -0.03, P < 0.001).

CONCLUSION

This study showed an important effect of sICH on the association between eosinophils and poor outcome.

Eosinophils-from cradle to grave: An EAACI task force paper on new molecular insights and clinical functions of eosinophils and the clinical effects of targeted eosinophil depletion

Over the past years, eosinophils have become a focus of scientific interest, especially in the context of their recently uncovered functions (e.g. antiviral, anti-inflammatory, regulatory). These versatile cells display both beneficial and detrimental activities under various physiological and pathological conditions. Eosinophils are involved in the pathogenesis of many diseases which can be classified into primary (clonal) and secondary (reactive) disorders and idiopathic (hyper)eosinophilic syndromes. Depending on the biological specimen, the eosinophil count in different body compartments may serve as a biomarker reflecting the underlying pathophysiology and/or activity of distinct diseases and as a therapy-driving (predictive) and monitoring tool. Personalized selection of an appropriate therapeutic strategy directly or indirectly targeting the increased number and/or activity of eosinophils should be based on the understanding of eosinophil homeostasis including their interactions with other immune and non-immune cells within different body compartments. Hence, restoring as well as maintaining homeostasis within an individual's eosinophil pool is a goal of both specific and non-specific eosinophil-targeting therapies. Despite the overall favourable safety profile of the currently available anti-eosinophil biologics, the effect of eosinophil depletion should be monitored from the perspective of possible unwanted consequences.

An Emerging Role of Extracellular Traps in Chronic Rhinosinusitis

PURPOSE OF REVIEW

Chronic rhinosinusitis (CRS) is a complicated, heterogeneous disease likely caused by inflammatory and infectious factors. There is clear evidence that innate immune cells, including neutrophils and eosinophils, play a significant role in CRS. Multiple immune cells, including neutrophils and eosinophils, have been shown to release chromatin and granular proteins into the extracellular space in response to triggering extracellular traps (ETs). The formation of ETs remains controversial due to their critical function during pathogen clearance while being associated with harmful inflammatory illnesses. This article summarizes recent research on neutrophil extracellular traps (NETs) and eosinophil extracellular traps (EETs) and their possible significance in the pathophysiology of CRS.

RECENT FINDINGS

A novel type of programmed cell death called ETosis, which releases ETs, has been proposed by recent study. Significantly more NETs are presented in nasal polyps, and its granule proteins LL-37 induce NETs production in CRS with nasal polyps (CRSwNP) patients. Similar to NETs, developed in the tissue of nasal polyps, primarily in subepithelial regions with epithelial barrier defects, and are associated with linked to elevated tissue levels of IL-5 and S. aureus colonization. This article provides a comprehensive overview of NETs and EETs, as well as an in-depth understanding of the functions of these ETs in CRS.

Inflammatory markers in exhaled breath condensate in nonasthmatic children with food allergy

Allergy is a systemic inflammation; therefore, although the allergic symptom may be seen in a specific organ system, the effects of this inflammation may be seen in other organs. interleukin (IL) IL4, IL5 and IL13 are the major Th2 cytokines and e-cadherin is an epithelial barrier protein. The objective of this research was to assess indicators of inflammation specific to Th2 responses and proteins related to the protective barrier of the airway's inner lining. These assessments were conducted using exhaled breath condensate (EBC), which provides insights into peripheral airway conditions of children suffering from food allergies. The study had 24 patients with food allergy and 24 control individuals younger than three years of age with no history of food reaction. The diagnosis of food allergy was based on food allergen-specific IgE and skin prick test positivity in our clinic and oral food testing in selected cases. EBC samples were obtained by Ecoscreen (Jaegar, Hoechberg, Germany). IL4, IL5, IL13 and E-cadherin levels were measured in these samples by enzyme linked immunoassay. The group of children with food allergies, consisting mainly of 14 girls, had a median age of 16 months, whereas the control group, which included 11 girls, had a median age of 15 months (p= 0.89). Comparing the two groups, children with food allergies exhibited notably lower levels of IL-13 in the EBC compared to the control group (median values of 59.14 and 76.36, respectively,p= 0.02). Conversely, the concentration of IL-4 in the EBC was significantly higher in children with food allergies (median values of 1.94 and 1.29, respectively,p= 0.003). However, the levels of IL-5 and e-cadherin showed no significant differences between the two groups (withp-values of 0.74 and 0.09, respectively) as shown in table1. High level of IL-4 despite the low level of IL-13 in the EBC of children having food allergy may be indicative of an early inflammatory phase that is not yet in the effector phase. Studies about the evolution of this process later in life are needed to assess the role of airway inflammation in children with food allergy who develop asthma.

Basis of preventive and non-pharmacological interventions in asthma

Asthma is one of the most common atopic disorders in all stages of life. Its etiology is likely due to a complex interaction between genetic, environmental, and lifestyle factors. Due to this, different non-pharmacological interventions can be implemented to reduce or alleviate the symptoms caused by this disease. Thus, the present narrative review aimed to analyze the preventive and non-pharmacological interventions such as physical exercise, physiotherapy, nutritional, ergonutritional, and psychological strategies in asthma treatment. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Asthma is an immune-mediated inflammatory condition characterized by increased responsiveness to bronchoconstrictor stimuli. Different factors have been shown to play an important role in the pathogenesis of asthma, however, the treatments used to reduce its incidence are more controversial. Physical activity is focused on the benefits that aerobic training can provide, while physiotherapy interventions recommend breathing exercises to improve the quality of life of patients. Nutritional interventions are targeted on implement diets that prioritize the consumption of fruits and vegetables and supplementation with antioxidants. Psychological interventions have been proposed as an essential non-pharmacological tool to reduce the emotional problems associated with asthma.

[Eosinophilic chronic obstructive pulmonary disease: A review]

Over the past decades, chronic obstructive pulmonary disease (COPD) has become a major public health problem due to increasing morbidity and mortality. COPD is characterized by airflow limitation due to inflammation of the bronchial tree and remodeling of the small airways. In 20-40% of patients with COPD, eosinophilic inflammation of the airways is observed, as in bronchial asthma. Eosinophilic COPD has recently been shown to be a distinct disease and is associated with more pronounced airway remodeling. Although the role of eosinophils in the pathogenesis of COPD is not fully understood, the level of eosinophils can be used in the prognosis and administration of corticosteroids, and their effectiveness is higher in eosinophilia. Currently, monoclonal antibodies directed against interleukins (IL-5, IL-4 and IL-13) or their receptors are being tested in the T2 endotype of COPD. This review focuses on the mechanisms of eosinophilia in COPD, the use of blood and sputum eosinophils as a biomarker, and the advisability of using monoclonal antibodies in the treatment of eosinophilic COPD.

Micronized Acellular Matrix Biomaterial Leverages Eosinophils for Postinfarct Cardiac Repair

After ischemic injury, immune cells mediate maladaptive cardiac remodeling. Extracellular matrix biomaterials may redirect inflammation toward repair. Pericardial fluid contains pro-reparative immune cells, potentially leverageable by biomaterials. Herein, we explore how pericardial delivery of a micronized extracellular matrix biomaterial affects cardiac healing. In noninfarcted mice, pericardial delivery increases pericardial and myocardial eosinophil counts. This response is sustained after myocardial infarction, stimulating an interleukin 4 rich milieu. Ultimately, the biomaterial improves postinfarct vascularization and cardiac function; and eosinophil-knockout negates these benefits. For the first time, to our knowledge, we demonstrate the therapeutic potential of pericardial biomaterial delivery and the eosinophil's critical role in biomaterial-mediated postinfarct repair.

Eosinophilic Enteritis Flare-Up Mimicking Acute Gastroenteritis: A Rare Case

Eosinophilic enteritis is a rare subset of eosinophilic gastrointestinal disorders. It typically presents with chronic symptoms of abdominal pain, nausea, vomiting, diarrhea, and ascites. However, the clinical presentation can vary due to acute flare-ups. Here, we present a case of eosinophilic enteritis in a young female patient with intractable vomiting and diarrhea, mimicking acute gastroenteritis in the absence of other gastrointestinal symptoms. This case illustrates the challenge of diagnosing acute and diverse presentations of eosinophilic enteritis. It also highlights the importance of promptly treating and confirming the diagnosis through urgent tissue histopathology in adolescents with unexplained vomiting and diarrhea.

Eosinophils as potential biomarkers in respiratory viral infections

Eosinophils are bone marrow-derived granulocytes that, under homeostatic conditions, account for as much as 1-3% of peripheral blood leukocytes. During inflammation, eosinophils can rapidly expand and infiltrate inflamed tissues, guided by cytokines and alarmins (such as IL-33), adhesion molecules and chemokines. Eosinophils play a prominent role in allergic asthma and parasitic infections. Nonetheless, they participate in the immune response against respiratory viruses such as respiratory syncytial virus and influenza. Notably, respiratory viruses are associated with asthma exacerbation. Eosinophils release several molecules endowed with antiviral activity, including cationic proteins, RNases and reactive oxygen and nitrogen species. On the other hand, eosinophils release several cytokines involved in homeostasis maintenance and Th2-related inflammation. In the context of SARS-CoV-2 infection, emerging evidence indicates that eosinophils can represent possible blood-based biomarkers for diagnosis, prognosis, and severity prediction of disease. In particular, eosinopenia seems to be an indicator of severity among patients with COVID-19, whereas an increased eosinophil count is associated with a better prognosis, including a lower incidence of complications and mortality. In the present review, we provide an overview of the role and plasticity of eosinophils focusing on various respiratory viral infections and in the context of viral and allergic disease comorbidities. We will discuss the potential utility of eosinophils as prognostic/predictive immune biomarkers in emerging respiratory viral diseases, particularly COVID-19. Finally, we will revisit some of the relevant methods and tools that have contributed to the advances in the dissection of various eosinophil subsets in different pathological settings for future biomarker definition.

Evaluation of hypereosinophilia in a case of FLT3-mutant acute myeloid leukemia treated with gilteritinib

Acute myeloid leukemias (AMLs) frequently harbor activating mutations in Fms-like tyrosine kinase 3 (FLT3). The use of FLT3 inhibitors (FLT3i) is the standard of care for treatment of newly diagnosed and relapsed patients with AML. Differentiation responses including clinical differentiation syndrome have been previously reported with FLT3i when used as single agents in relapsed disease. We present a case of hypereosinophilia in a patient on FLT3i therapy with persistent FLT3 polymerase chain reaction (PCR) positivity in peripheral blood. We sorted mature leukocytes by lineage to determine if the eosinophils were leukemia-derived. FLT3 PCR and next-generation sequencing analysis demonstrated monocytic differentiation of the FLT3-ITD leukemic clone with reactive hypereosinophilia that was derived from a preleukemic SF3B1, FLT3 wild-type clone. Our case is the first to definitively demonstrate the emergence of clonal FLT3-ITD monocytes with FLT3i and the first to demonstrate a differentiation response following decitabine, venetoclax, and gilteritinib triplet therapy.

Depletion of Mcpip1 in murine myeloid cells results in intestinal dysbiosis followed by allergic inflammation

MCPIP1 (called also Regnase-1) is a negative regulator of inflammation. Knockout of the Zc3h12a gene, encoding Mcpip1 in cells of myeloid origin (Mcpip1^MKO), has a pathological effect on many organs. The aim of this study was to comprehensively analyze pathological changes in the skin caused by Mcpip1 deficiency in phagocytes with an emphasis on its molecular mechanism associated with microbiome dysbiosis. Mcpip1^MKO mice exhibited spontaneous wound formation on the skin. On a molecular level, the Th2-type immune response was predominantly characterized by an increase in Il5 and Il13 transcript levels, as well as eosinophil and mast cell infiltration. Irritation by DNFB led to a more severe skin contact allergy in Mcpip1^MKO mice. Allergic reactions on the skin were strongly influenced by gut dysbiosis and enhanced systemic dissemination of bacteria. This process was followed by activation of the C/EBP pathway in peripheral macrophages, leading to local changes in the cytokine microenvironment that promoted the Th2 response. A reduced bacterial load inhibited allergic inflammation, indicating the role of intestinal dysbiosis in the development of skin diseases. Our results clearly show that MCPIP1 in phagocytes is an essential negative regulator that controls the gut-skin axis.

Loss of Gata1 decreased eosinophils, macrophages, and type 2 cytokines in regenerating nerve and delayed axon regeneration after a segmental nerve injury

The immune system has garnered attention for its role in peripheral nerve regeneration, particularly as it pertains to regeneration across segmental injuries. Previous work demonstrated that eosinophils are recruited to regenerating nerve and express interleukin-4, amongst potential cytokines. These results suggest a direct role for eosinophils in promoting nerve regeneration. Therefore, we further considered eosinophils roles in nerve regeneration using a segmental nerve injury and Gata1 knockout (KO) mice, which are severely eosinophil deficient, compared to wild-type BALB/c mice (WT). Mice receiving a sciatic nerve gap injury demonstrated distinct cytokine expression and leukocytes within regenerating nerve. Compared to controls, Gata1 KO regenerated nerves contained decreased expression of type 2 cytokines, including Il-5 and Il-13, and decreased recruitment of eosinophils and macrophages. At this early time point during ongoing regeneration, the macrophages within Gata1 KO nerves also demonstrated significantly less M2 polarization compared to controls. Subsequently, motor and sensory axon regeneration across the gap injury was decreased in Gata1 KO compared to WT during ongoing nerve regeneration. Over longer observation to allow for more complete nerve regeneration, behavioral recovery measured by grid-walk assessment was not different comparing groups but modestly delayed in Gata1 KO compared to WT. The extent of final axon regeneration was not different amongst groups. Our data provide additional evidence suggesting eosinophils contribute to nerve regeneration across a nerve gap injury, but are not essential to regeneration in this context. Our evidence also suggests eosinophils may regulate cytokines that promote distinct macrophage phenotypes and axon regeneration.

Experimental observation of the effect of immunotherapy on CD4+ T cells and Th1/Th2 cytokines in mice with allergic rhinitis

The present study aims to investigate the effect of immunotherapy in a mouse model of allergic rhinitis (AR) and to explore the possible molecular mechanisms of action. An animal model of AR was established by sensitization and challenge of BALB/c mice with house dust mite (HDM) extract. The mice were injected subcutaneously with HDM for immunotherapy. AR nasal symptoms were evaluated according to the frequencies of nose rubbing and sneezing and the degree of rhinorrhea. The nasal mucosa and lung tissue architecture and inflammatory status by histological analysis; the infiltration of eosinophils in nasal lavage fluid (NALF) of mice was observed by Diff-Quik stain; ELISA-based quantification of serum HDM-specific IgE and TH1/TH2 cytokine concentration; and flow cytometry detected the number of serum CD4+/CD8+ cells to evaluate the mechanism of immunotherapy. It was found that after immunotherapy, the AR symptom score was reduced, the number of eosinophils in NALF was reduced, and the infiltration of inflammatory cells and tissue damage in the nasal mucosa and lung tissue were alleviated. Immunotherapy can increase the number of CD4+ T cells in the peripheral blood, increase the ratio of CD4+/CD8+ cells, increase the expression of Th1 cytokines such as IL-2 and IFN-γ, reduce the expression of Th2 cytokines such as IL-4 and IL-5. The results showed that repeated intraperitoneal injection of crude extract of HDM for sensitization, followed by nasal drops can effectively construct a mouse model of AR, and subcutaneous injection of immunotherapy in mice can reduce allergic inflammation in model mice and improve the inflammatory infiltration of the nasal cavity in allergic rhinitis. Immunotherapy can reduce the expression of inflammatory factors in AR, improve Th1/Th2 balance, and may play a role in the treatment of AR by improving the function of immune cells.

MiR-223-3p regulates the eosinophil degranulation and enhances the inflammation in allergic rhinitis by targeting FBXW7

OBJECTIVES

MiR-223-3p is a multifunctional microRNA regulated by multiple transcription factors and plays a critical role in inflammation. This paper was designed to investigate the regulatory role and mechanism of miR-223-3p in eosinophils degranulation and allergic rhinitis (AR) inflammation.

METHODS

OVA sensitized AR mouse model and EOL-1 cells model were established. RT-qPCR and FISH were performed to detect the miR-223-3p expression. ELISA and WB were utilized to evaluate mRNA and protein expression. HE staining and transmission electron microscopy were applied to observe the morphological changes in nasal mucosa. Flow cytometry and immunofluorescence staining were performed to measure the proportion of eosinophils and eosinophilic major basic protein expression. The targeting relationship between miR-223-3p and FBXW7 was verified by bioinformatic analysis and dual-luciferase reporter gene assay. The expression of FBXW7 was detected by immunohistochemistry.

RESULTS

The level of miR-223-3p in nasal mucosa was significantly up-regulated in AR group. The expression of miR-223-3p, ECP, MBP, and EPO were increased in EOL-1 cells, further increasing the miR-223-3p level could promote the ECP and EPO mRNA expression. Upregulation of miR-223-3p increased eosinophils granule protein expression, aggravated mucosal destruction and enhanced AR inflammation. Luciferase assay verified miR-223-3p directly target the 3'-UTR of FBXW7. In vitro, overexpression of FBXW7 could reverse the increase in MBP expression caused by the up-regulation of miR-223-3p. In vivo, knockdown of FBXW7 could reverse the down-regulation in granule protein level caused by the down-regulation of miR-223-3p, thereby aggravating AR inflammation.

CONCLUSION

Collected evidence elucidated that miR-223-3p could regulate the eosinophil degranulation and enhances the inflammation in AR by targeting FBXW7. The miR-223-3p/FBXW7 axis may provide a novel approach for AR treatment.

Eosinophil: A New Circulating Biomarker for Risk of Poor Outcome in Stroke Patients Undergoing Mechanical Thrombectomy

Objective

Acute ischemic stroke (AIS), caused by occlusion of large vessel, is a serious life-threatening disease. This study aimed to comprehensively investigate the association of 14 common and readily available circulating biomarkers with the 90-day modified Rankin Scale (mRS) score in patients undergoing mechanical thrombectomy (MT).

Methods

This study included patients with anterior circulation large vessel occlusive stroke treated with MT from 05/2017 to 12/2021. Baseline comparisons of poor outcome were performed among enrolled patients. Factors that may be associated with the mRS score were assessed using correlation analysis. Univariate and multivariate logistic regression analyses were used to evaluate the predictive value of circulating biomarkers and poor outcome.

Results

The mRS score has a strong correlation with neutrophil to lymphocyte ratio (NLR) and eosinophil levels (all r_s>0.4 in absolute value and all P<0.001) in addition to a high correlation with National Institute of Health Stroke Scale (NIHSS) score (r_s=0.40, P<0.001). There was also a high correlation between NLR and eosinophil (r_s=-0.58, P<0.001). In the multivariate regression analysis, only neutrophil (adjusted OR=1.301, 95% CI: 1.155-1.465, P<0.001), eosinophil (adjusted OR<0.001, 95% CI: <0.001-0.016, P<0.001), and NLR (adjusted OR=1.158, 95% CI: 1.082-1.241, P<0.001) were independently associated with poor outcome.

Conclusion

This study evaluated a series of circulating biomarkers and found that neutrophil, eosinophil, and NLR independently predicted poor outcome after MT in AIS patients. There was a significant negative correlation between eosinophil and NLR levels.

Perillyl alcohol (PA) mitigates inflammatory, oxidative, and histopathological consequences of allergic asthma in rats

Allergic asthma is an inflammatory and chronic condition, which is the most common asthma phenotype. It is usually defined by sensitivity to environmental allergens and leads to the narrowing of the airways. Around 300 million individuals are suffering from asthma worldwide. The purpose of the current research was to evaluate the effect of perillyl alcohol (PA) on oxidative stress and inflammation parameters in rats with allergic asthma. Experimental asthma was induced by ovalbumin (OVA) sensitization and inhalation in five groups of rats including control, asthma, asthma + vehicle, asthma + PA, and asthma + dexamethasone (Dexa). PA (50 mg/kg) or Dexa (2.5 mg/kg) were administered intraperitoneally for seven consecutive days following asthma induction. Histopathological evaluation was performed via hematoxylin and eosin (H&E) and Masson's trichrome staining. The enzyme-linked immunosorbent assay (ELISA) was used for the evaluation of the cytokine levels, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-17, and IL-10, as well as oxidative stress biomarkers including reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (TAC), and glutathione peroxidase (GPx) in the lung tissue and bronchoalveolar lavage fluid (BALF). Real-time polymerase chain reaction (PCR) was utilized for assessing the mRNA expression of FOXP3 and GATA3 and western blot analysis was used for the measurement of nuclear factor kappa B (NF-κB) protein expression. PA and Dexa decreased the pathological alterations and the expression levels of inflammatory factors (cytokines, GATA3, and NF-κB) in the lung tissue and BALF of asthmatic rats. PA restored GPx, SOD, and TAC levels and reduced ROS, MDA, nitrite, and total protein in the lung and BALF. Overall, our findings demonstrated that PA can be used as a therapeutic agent in asthma patients, but it is essential to monitor its effects in future clinical studies.

Proposed refined diagnostic criteria and classification of eosinophil disorders and related syndromes

Eosinophilia and eosinophil activation are recurrent features in various reactive states and certain hematologic malignancies. In patients with hypereosinophilia (HE), HE-induced organ damage is often encountered and may lead to the diagnosis of a hypereosinophilic syndrome (HES). A number of known mechanisms and etiologies contribute to the development of HE and HES. Based on these etiologies and the origin of eosinophils, HE and HES are divided into primary forms where eosinophils are clonal cells, reactive forms where an underlying reactive or neoplastic condition is detected and eosinophils are considered to be "non-clonal" cells, and idiopathic HE and HES in which neither a clonal nor a reactive underlying pathology is detected. Since 2012, this classification and the related criteria have been widely accepted and regarded as standard. However, during the past few years, new developments in the field and an increasing number of markers and targets have created a need to update these criteria and the classification of HE and HES. To address this challenge, a Working Conference on eosinophil disorders was organized in 2021. In this conference, a panel of experts representing the relevant fields, including allergy, dermatology, hematology, immunology, laboratory medicine, and pathology, met and discussed new markers and concepts as well as refinements in definitions, criteria and classifications of HE and HES. The outcomes of this conference are presented in this article and should assist in the diagnosis and management of patients with HE and HES in daily practice and in the preparation and conduct of clinical trials.

Bioinformatics analysis and verification of key candidate genes influencing the pathogenesis of chronic rhinosinusitis with nasal polyps

OBJECTIVES

Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) is a prominent public health issue. Furthermore, the prognosis of eosinophilic CRSwNP is poor, with a high recurrence rate. The underlying molecular mechanisms of eosinophilic CRSwNP remain unclear. Therefore, in this study, we sought to determine the crucial genes underlying eosinophil infiltration in eosinophilic CRSwNP pathogenesis.

METHODS

We used the Gene Expression Omnibus database (GEO) (GSE36830 and GSE23552 datasets) to mine gene expression profiles of CRSwNP patients and normal subjects. Differentially expressed genes (DEGs) between normal and CRSwNP tissues were identified and subjected to the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses. Co-expression networks were established using a weighted gene co-expression network analysis (WGCNA) and single-sample gene set enrichment analysis (GSEA). Protein-protein interaction networks were developed to detect functional protein modules. Based on the common DEGs, candidate miRNAs and related lncRNAs were predicted using the mirTarBase and StarBase databases. Finally, we generated immune cell subtypes of CRSwNP.

RESULTS

A total of 146 DEGs were identified. Of these, 131 genes were upregulated, whereas 15 were downregulated. GO analysis indicated that DEGs primarily participated in leukocyte chemotaxis and migration as well as cell chemotaxis. KEGG pathway analysis suggested that DEGs participated in the interactions between cytokines and viral proteins, osteoclast differentiation, and cytokine-cytokine receptor interactions. Real-time quantitative polymerase chain reaction analysis showed that Complement C5a Receptor 1 (C5AR1), C-C Motif Chemokine Receptor 3 (CCR3), Complement C3a Receptor 1 (C3AR1), and C-C Motif Chemokine Ligand 13 (CCL13) expression levels were significantly upregulated in nasal polyps, whereas C-C Motif Chemokine Ligand 4 (CCL4) expression levels were significantly downregulated.

CONCLUSIONS

The candidate genes identified in this study may influence the activation and accumulation of eosinophils, cell chemotaxis, and inflammatory responses, thereby potentially representing molecular targets for future studies of CRSwNP.

IL-5 and GM-CSF, but Not IL-3, Promote the Proliferative Properties of Inflammatory-like and Lung Resident-like Eosinophils in the Blood of Asthma Patients

Blood eosinophils can be described as inflammatory-like (iEOS-like) and lung-resident-like (rEOS-like) eosinophils. This study is based on the hypothesis that eosinophilopoetins such as interleukin (IL)-3 and IL-5 and granulocyte-macrophage colony-stimulating factor (GM-CSF) alter the proliferative properties of eosinophil subtypes and may be associated with the expression of their receptors on eosinophils. We investigated 8 individuals with severe nonallergic eosinophilic asthma (SNEA), 17 nonsevere allergic asthma (AA), and 11 healthy subjects (HS). For AA patients, a bronchial allergen challenge with Dermatophagoides pteronyssinus was performed. Eosinophils were isolated from peripheral blood using high-density centrifugation and magnetic separation methods. The subtyping of eosinophils was based on magnetic bead-conjugated antibodies against L-selectin. Preactivation by eosinophilopoetins was performed by incubating eosinophil subtypes with IL-3, IL-5, and GM-CSF, and individual combined cell cultures were prepared with airway smooth muscle (ASM) cells. ASM cell proliferation was assessed using an Alamar blue assay. The gene expression of eosinophilopoetin receptors was analyzed with a qPCR. IL-5 and GM-CSF significantly enhanced the proliferative properties of iEOS-like and rEOS-like cells on ASM cells in both SNEA and AA groups compared with eosinophils not activated by cytokines (p < 0.05). Moreover, rEOS-like cells demonstrated a higher gene expression of the IL-3 and IL-5 receptors compared with iEOS-like cells in the SNEA and AA groups (p < 0.05). In conclusion: IL-5 and GM-CSF promote the proliferative properties of iEOS-like and rEOS-like eosinophils; however, the effect of only IL-5 may be related to the expression of its receptors in asthma patients.

Cytokines in Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO), also known as thyroid eye disease (TED) or Graves' orbitopathy (GO), is a complex autoimmune condition causing visual impairment, disfigurement, and harm to patients' physical and mental health. The pathogenesis of TAO has not been fully elucidated, and the mainstream view is that coantigens shared by the thyroid and orbit trigger remodeling of extraocular muscles and orbital connective tissues through an inflammatory response. In recent years, cytokines and the immune responses they mediate have been crucial in disease progression, and currently, common evidence has shown that drugs targeting cytokines, such as tocilizumab, infliximab, and adalimumab, may be novel targets for therapy. In this review, we summarize the research development of different cytokines in TAO pathogenesis in the hope of discovering new therapeutic targets.

The Predictive Value of Eosinophil Indices for Major Cardiovascular Events in Patients with Acute Decompensated HFrEF

Background and Objectives: Heart failure is a chronic disease with a high risk of mortality and morbidity. In these patients, inflammatory markers have been shown to be associated with cardiovascular adverse outcomes and disease progression. To investigate the relationships between eosinophil indices and major cardiovascular events (MACE) in patients with acute decompensated heart failure (ADHF) with reduced ejection fraction. Materials and Methods: A total of 395 consecutive patients admitted to the intensive care unit (ICU) with ADHF and reduced ejection fraction between January 2017 and December 2021 were enrolled in this retrospective study. MACE was defined as the composite of death and re-hospitalization for ADHF within 6 months of index hospitalization. All-cause mortality and MACE were assessed with respect to relationships with eosinophil indices, including neutrophil-to-eosinophil ratio (NER), leukocyte-to-eosinophil ratio (LER), eosinophil-to-lymphocyte ratio (ELR), and eosinophil-to-monocyte ratio (EMR). Results: NER and LER were significantly higher in subjects with MACE. Absolute eosinophil, lymphocyte and basophil count, hemoglobin, serum Na+, albumin, and CRP, and EMR and ELR were significantly lower in subjects with MACE compared to those without. NT-proBNP (OR: 1.682, 95% CI: 1.106−2.312, p = 0.001), Na+ (OR: 0.932, 95% CI: 0.897−0.969, p < 0.001), NER (OR: 2.740, 95 % CI: 1.797−4.177, p < 0.001), LER (OR: 2.705, 95% CI: 1.752−4.176, p < 0.001), EMR (OR:1.654, 95% CI 1.123−2.436, p = 0.011), ELR (OR: 2.112, 95% CI 1.424−3.134, p < 0.001), and eosinophil count (OR: 1.833, 95% CI 1.276−2.635) were independent predictors for development of MACE. Conclusions: Patients with ADHF and reduced ejection fraction who developed MACE within the first six months of index hospitalization had lower levels of absolute eosinophil and lymphocyte counts, and EMR and ELR values, whereas NER and LER were higher compared to those without MACE. The eosinophil indices were independently associated with mortality and MACE development. The eosinophil indices may be used to estimate MACE likelihood with acceptable sensitivity and specificity.

Eosinophilic inflammation: An Appealing Target for Pharmacologic Treatments in Severe Asthma

Severe asthma is characterized by different endotypes driven by complex pathologic mechanisms. In most patients with both allergic and non-allergic asthma, predominant eosinophilic airway inflammation is present. Given the central role of eosinophilic inflammation in the pathophysiology of most cases of severe asthma and considering that severe eosinophilic asthmatic patients respond partially or poorly to corticosteroids, in recent years, research has focused on the development of targeted anti-eosinophil biological therapies; this review will focus on the unique and particular biology of the eosinophil, as well as on the current knowledge about the pathobiology of eosinophilic inflammation in asthmatic airways. Finally, current and prospective anti-eosinophil therapeutic strategies will be discussed, examining the reason why eosinophilic inflammation represents an appealing target for the pharmacological treatment of patients with severe asthma.

Solving the Conundrum of Eosinophils in Alloimmunity

Eosinophils are bone-marrow-derived granulocytes known for their ability to facilitate clearance of parasitic infections and their association with asthma and other inflammatory diseases. The purpose of this review is to discuss the currently available human observational and animal experimental data linking eosinophils to the immunologic response in solid organ transplantation. First, we present observational human studies that demonstrate a link between transplantation and eosinophils yet were unable to define the exact role of this cell population. Next, we describe published experimental models and demonstrate a defined mechanistic role of eosinophils in downregulating the alloimmune response to murine lung transplants. The overall summary of this data suggests that further studies are needed to define the role of eosinophils in multiple solid organ allografts and points to the possibility of manipulating this cell population to improve graft survival.

Mucosal Eosinophil Abundance in Non-Inflamed Colonic Tissue Is Associated with Response to Vedolizumab Induction Therapy in Inflammatory Bowel Disease

Vedolizumab is used as a treatment for patients with inflammatory bowel disease (IBD), but induction therapy leads to clinical response and remission in approximately 55% and 30% of patients with IBD, respectively. In this study, we aimed to explore the predictive value of mucosal eosinophils and serum eotaxin-1 regarding response to vedolizumab induction therapy. Eighty-four (84) patients with IBD (37 Crohn’s disease [CD], 47 ulcerative colitis [UC]) were included. For 24 patients with IBD, histopathology was assessed for eosinophil counts in non-inflamed colonic tissue prior to vedolizumab treatment. For 64 patients with IBD, serum eotaxin-1 levels were quantified prior to (baseline) and during vedolizumab treatment. Serum samples of 100 patients with IBD (34 CD, 66 UC) from the GEMINI 1 and 2 trials were used for external validation. Baseline mucosal eosinophil numbers in non-inflamed colonic tissue were significantly higher in responders to vedolizumab induction therapy when compared to primary non-responders (69 [34−138] vs. 24 [18−28] eosinophils/high-power field, respectively, p < 0.01). Baseline serum eotaxin-1 levels in the discovery cohort were significantly elevated in responders, compared to primary non-responders (0.33 [0.23−0.44] vs. 0.20 [0.16−0.29] ng/mL, p < 0.01). Prediction models based on mucosal eosinophil counts and serum eotaxin-1 showed an area under the curve (AUC) of 0.90 and 0.79, respectively. However, the predictive capacity of baseline serum eotaxin-1 levels could not be validated in the GEMINI cohort. Mucosal eosinophil abundance in non-inflamed colonic tissue was associated with response to vedolizumab induction therapy in patients with IBD. Future studies are warranted to further validate the potential value of mucosal eosinophils and serum eotaxin-1 as biomarkers for response to vedolizumab therapy.

Cytokine‐ and chemokine‐induced inflammatory colorectal tumor microenvironment: Emerging avenue for targeted therapy

Colorectal cancer (CRC) is a predominant life‐threatening cancer, with liver and peritoneal metastases as the primary causes of death. Intestinal inflammation, a known CRC risk factor, nurtures a local inflammatory environment enriched with tumor cells, endothelial cells, immune cells, cancer‐associated fibroblasts, immunosuppressive cells, and secretory growth factors. The complex interactions of aberrantly expressed cytokines, chemokines, growth factors, and matrix‐remodeling enzymes promote CRC pathogenesis and evoke systemic responses that affect disease outcomes. Mounting evidence suggests that these cytokines and chemokines play a role in the progression of CRC through immunosuppression and modulation of the tumor microenvironment, which is partly achieved by the recruitment of immunosuppressive cells. These cells impart features such as cancer stem cell‐like properties, drug resistance, invasion, and formation of the premetastatic niche in distant organs, promoting metastasis and aggressive CRC growth. A deeper understanding of the cytokine‐ and chemokine‐mediated signaling networks that link tumor progression and metastasis will provide insights into the mechanistic details of disease aggressiveness and facilitate the development of novel therapeutics for CRC. Here, we summarized the current knowledge of cytokine‐ and chemokine‐mediated crosstalk in the inflammatory tumor microenvironment, which drives immunosuppression, resistance to therapeutics, and metastasis during CRC progression. We also outlined the potential of this crosstalk as a novel therapeutic target for CRC. The major cytokine/chemokine pathways involved in cancer immunotherapy are also discussed in this review.

Eosinophils, Stroke-Associated Pneumonia, and Outcome After Mechanical Thrombectomy for Acute Ischemic Stroke

Background

Eosinophils contribute to antibacterial defense by releasing mitochondrial DNA, which are decreased in patients with acute ischemic stroke (AIS). However, the impact of eosinophils on stroke-associated pneumonia (SAP) among patients with AIS remains unclear. Moreover, whether SAP is in the path of the association between eosinophils and clinical outcomes also remains unclear. We aimed to assess the relationships between eosinophils, SAP, and clinical outcome after mechanical thrombectomy in patients with AIS.

Methods

A total of 328 consecutive patients with AIS who underwent mechanical thrombectomy between May 2017 and March 2021 were analyzed. Their baseline data and peripheral eosinophil counts were recorded on admission. Regression analysis was used to assess the effect of eosinophils on SAP, and its effect on poor outcome is defined as a modified Rankin Scale score of 3–6 at month 3 after admission. Mediation analysis was utilized to assess the proportion of the total effect of SAP on the association between eosinophils and poor outcomes.

Results

Multivariate analysis revealed that eosinophils was independently associated with SAP after adjusting for potential confounders (odds ratio, 0.00; 95% CI, 0.00–0.38; P = 0.0267), which are consistent with the result of eosinophils (dichotomous) as a categorical variable (odds ratio, 0.54; 95% CI, 0.31–0.96; P = 0.0342). A non-linear relationship was detected between eosinophils and SAP, whose inflection point was 0.06. Subgroup analyses further confirmed these associations. Eosinophils were also associated with poor outcomes (odds ratio, 0.00; 95% CI, 0.00–0.14; P = 0.0124). Additionally, mediation analysis found that SAP partially mediated the negative relationship between eosinophils and poor outcome (indirect effect = −0.169; 95% CI:−0.339 –−0.040, P < 0.001).

Conclusion

Our findings suggested that a lower eosinophil level was associated with higher SAP and poorer outcome, and SAP might play an important effect in the association between eosinophils and poor outcomes.

Eosinophils in the Gastrointestinal Tract: Key Contributors to Neuro-Immune Crosstalk and Potential Implications in Disorders of Brain-Gut Interaction

Eosinophils are innate immune granulocytes actively involved in defensive responses and in local and systemic inflammatory processes. Beyond these effector roles, eosinophils are fundamental to maintaining homeostasis in the tissues they reside. Gastrointestinal eosinophils modulate barrier function and mucosal immunity and promote tissue development through their direct communication with almost every cellular component. This is possible thanks to the variety of receptors they express and the bioactive molecules they store and release, including cytotoxic proteins, cytokines, growth factors, and neuropeptides and neurotrophines. A growing body of evidence points to the eosinophil as a key neuro-immune player in the regulation of gastrointestinal function, with potential implications in pathophysiological processes. Eosinophil–neuron interactions are facilitated by chemotaxis and adhesion molecules, and the mediators released may have excitatory or inhibitory effects on each cell type, with physiological consequences dependent on the type of innervation involved. Of special interest are the disorders of the brain–gut interaction (DBGIs), mainly functional dyspepsia (FD) and irritable bowel syndrome (IBS), in which mucosal eosinophilia and eosinophil activation have been identified. In this review, we summarize the main roles of gastrointestinal eosinophils in supporting gut homeostasis and the evidence available on eosinophil–neuron interactions to bring new insights that support the fundamental role of this neuro-immune crosstalk in maintaining gut health and contributing to the pathophysiology of DBGIs.

Diagnosis and Management of Pediatric Hypereosinophilic Syndrome

Hypereosinophilic syndrome (HES) is a diverse group of disorders characterized by peripheral blood eosinophilia of 1.5 × 10⁹/L (1,500/μL) or greater with evidence of end-organ damage attributable to eosinophilia and no other cause of the end-organ damage. The HES is rare, especially in children. This review aims to provide best practices in diagnosis and treatment of HES in children, including how to differentiate between primary and secondary causes of hypereosinophilia; how to distinguish the differences in clinical presentation, treatment, and prognosis of HES in children and adults; and how to identify key steps in the evaluation and management of HES in children.

Dendrobium nobile Lindley Administration Attenuates Atopic Dermatitis-like Lesions by Modulating Immune Cells

Atopic dermatitis (AD) is a chronic inflammatory skin disease that can significantly affect daily life by causing sleep disturbance due to extreme itching. In addition, if the symptoms of AD are severe, it can cause mental disorders such as ADHD and suicidal ideation. Corticosteroid preparations used for general treatment have good effects, but their use is limited due to side effects. Therefore, it is essential to minimize the side effects and study effective treatment methods. Dendrobium nobile Lindley (DNL) has been widely used for various diseases, but to the best of our knowledge, its effect on AD has not yet been proven. In this study, the inhibitory effect of DNL on AD was confirmed in a DNCB-induced Balb/c mouse. In addition, the inhibitory efficacy of inflammatory cytokines in TNF-α/IFN-γ-induced HaCaT cells and PMACI-induced HMC-1 cells was confirmed. The results demonstrated that DNL decreased IgE, IL-6, IL-4, scratching behavior, SCORAD index, infiltration of mast cells and eosinophils and decreased the thickness of the skin. Additionally, DNL inhibited the expression of cytokines and inhibited the MAPK and NF-κB signaling pathways. This suggests that DNL inhibits cytokine expression, protein signaling pathway, and immune cells, thereby improving AD symptoms in mice.

Impacts of eosinophil percentage on prognosis acute type A aortic dissection patients

Background

Eosinophils are pro-inflammatory cells involved in thrombosis and have been proposed as a prognosis marker in acute ischemic stroke and ST-elevation myocardial Infarction. Here, we sought to clarify the prognostic value of eosinophil percentage (EOS%) in patients with acute type A aortic dissection (AAAD).

Methods

We examined 183 consecutive AAAD patients. Based on the optimum cut-off value of EOS% determined by X-tile software, patients were classified into the low EOS% (EOS% ≤ 0.1) and high EOS% groups (EOS% > 0.1). We performed multivariate regression analysis and Kaplan–Meier (KM) survival curves to assess the association between EOS% and mortality. Eosinophil accumulation in aortic dissection intraluminal thrombus was confirmed using hematoxylin–eosin (H&E) staining. An external cohort from Medical Information Mart for Intensive Care IV was performed to validate the results.

Results

Relative to surviving patients, those who died during hospitalization had significantly lower EOS% (p = 0.001) but significantly higher WBC (p = 0.002) and neutrophil (p = 0.001) counts. Multivariate regression analysis identified EOS% as an independent predictor of in-hospital and 1-year mortality. KM curves revealed that 1-year cumulative mortality was significantly higher in the low EOS% group, although it was mainly attributed to the higher 30-day mortality. H&E staining revealed massive infiltration of eosinophils in all 20 thrombus specimens. The external validation confirmed that relative to survivors, patients with in-hospital mortality (p = 0.010) had significantly lower EOS%. Moreover, multivariate regression analyses identified that decreased EOS% was independently significantly associated with in-hospital mortality.

Conclusions

Low EOS% is significantly related to increased mortality rates in AAAD patients.

Proposed Pathogenesis of Diffuse Alveolar Hemorrhage in Idiopathic Pulmonary Hemosiderosis

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease that causes diffuse alveolar hemorrhage (DAH). The latest data suggests an immunologic origin of IPH, and a new name, immune mediated pulmonary hemosiderosis (ImPH), has been proposed. However, the exact immunologic mechanism has remained elusive for nearly eight decades despite extensive research, including detailed histopathologic analysis. Although several hypotheses have been proposed to describe the pathobiology of IPH, none of them explain the clinical and histopathologic findings conclusively. In this manuscript, we have presented a new hypothesis for the pathogenesis of DAH in IPH. We hypothesize that DAH in IPH is not immunocomplex mediated but due to histamine, eosinophilic cationic protein (ECP), and possibly vascular endothelial growth factor (VEGF). These bioactive proteins induce endothelial and alveolar epithelial damage, leading to the peri-capillary and intraalveolar escape of RBCs. The deformability of the RBC likely also plays a role. The supranormal secretion of histamine, ECP and VEGF occurs in genetically predisposed individuals with an aberrant immunologic response. The histamine is released from the basophils and possibly the mast cells in response to cytokines secreted by activated lymphocytes. The lymphocyte activation occurs after exposure to a known (gluten) or unknown antigen. The same lymphocyte-derived cytokines also induce eosinophilic degranulation of ECP and VEGF in the pulmonary circulation. We believe that our hypothesis unifies the observed clinical variabilities and histopathologic findings in IPH, and we hope that would promote future research in the field of IPH.

Chronic obstructive pulmonary disease and atherosclerosis: common mechanisms and novel therapeutics

Chronic obstructive pulmonary disease (COPD) and atherosclerosis are chronic irreversible diseases, that share a number of common causative factors including cigarette smoking. Atherosclerosis drastically impairs blood flow and oxygen availability to tissues, leading to life-threatening outcomes including myocardial infarction (MI) and stroke. Patients with COPD are most likely to die as a result of a cardiovascular event, with 30% of all COPD-related deaths being attributed to cardiovascular disease (CVD). Both atherosclerosis and COPD involve significant local (i.e. lung, vasculature) and systemic inflammation and oxidative stress, of which current pharmacological treatments have limited efficacy, hence the urgency for the development of novel life-saving therapeutics. Currently these diseases must be treated individually, with no therapies available that can effectively reduce the likelihood of comorbid CVD other than cessation of cigarette smoking. In this review, the important mechanisms that drive atherosclerosis and CVD in people with COPD are explained and we propose that modulation of both the oxidative stress and the inflammatory burden will provide a novel therapeutic strategy to treat both the pulmonary and systemic manifestations related to these diseases.

Overview on Molecular Biomarkers for Laryngeal Cancer: Looking for New Answers to an Old Problem

Laryngeal squamous cell cancer (LSCC) accounts for almost 25-30% of all head and neck squamous cell cancers and is clustered according to the affected districts, as this determines distinct tendency to recur and metastasize. A major role for numerous genetic alterations in driving the onset and progression of this neoplasm is emerging. However, major efforts are still required for the identification of molecular markers useful for both early diagnosis and prognostic definition of LSCC that is still characterized by significant morbidity and mortality. Non-coding RNAs appear the most promising as they circulate in all the biological fluids allowing liquid biopsy determination, as well as due to their quick and characteristic modulation useful for non-invasive detection and monitoring of cancer. Other critical aspects are related to recent progress in circulating tumor cells and DNA detection, in metastatic status and chemo-refractoriness prediction, and in the functional interaction of LSCC with chronic inflammation and innate immunity. We review all these aspects taking into account the progress of the technologies in the field of next generation sequencing.