Eosinophils: multifaceted biological properties and roles in health and disease

Lactobacillus acidophilus TW01 Mitigates PM2.5-Induced Lung Injury and Improves Gut Health in Mice

Background/Objectives: Exposure to fine particulate matter (PM2.5) causes significant respiratory and gastrointestinal health problems. In our prior research, we identified Lactobacillus acidophilus TW01 as a promising strain for mitigating oxidative damage, enhancing wound healing in intestinal epithelial cells, and protecting bronchial cells from cigarette smoke extract. Building upon these findings, this study examines the protective effects of this strain on lung damage induced by particulate matter (PM) through the gut-lung axis in mouse models. Methods: This study evaluated the protective effects of L. acidophilus TW01 against PM2.5-induced lung injury using two in vivo mouse models (OVA sensitization combined with PM2.5 exposure and DSS-induced colitis). Results: L. acidophilus TW01 exhibited significant protective effects in two in-vivo models, reducing pro-inflammatory cytokines (TNF-α, IL-6, and IL-5), modulating the immune response (IgG subtypes), and improving gut barrier integrity. Importantly, L. acidophilus TW01 increased the abundance of beneficial gut bacteria (Bifidobacterium and Lactobacillus). Conclusions: These findings highlight the significant protective/therapeutic potential of L. acidophilus TW01 in mitigating the adverse health effects of PM2.5 exposure, emphasizing the interplay between the gut and lung microbiomes in overall health. The multi-faceted protective effects of this probiotic suggest a novel, multi-pronged therapeutic strategy for addressing the widespread health consequences of air pollution.

Eosinophils and the Head and Neck

Tissue eosinophilia is a common finding during histopathologic evaluation and recognizing its presence oftentimes aids pathologists in arriving at the correct diagnosis. The head and neck region is an anatomic location where an abundance of eosinophil-rich disorders occur. In this review, we seek to provide an overview of eosinophil morphology, production, regulation, lifecycle, recruitment, function, and mediators. We will also summarize the most commonly diagnosed eosinophil-rich disorders, both non-neoplastic and neoplastic, occurring in the head and neck.

Staphylococcus aureus in Inflammation and Pain: Update on Pathologic Mechanisms

Staphylococcus aureus (S. aureus) is a Gram-positive bacterium of significant clinical importance, known for its versatility and ability to cause a wide array of infections, such as osteoarticular, pulmonary, cardiovascular, device-related, and hospital-acquired infections. This review describes the most recent evidence of the pathogenic potential of S. aureus, which is commonly part of the human microbiota but can lead to severe infections. The prevalence of pathogenic S. aureus in hospital and community settings contributes to substantial morbidity and mortality, particularly in individuals with compromised immune systems. The immunopathogenesis of S. aureus infections involves intricate interactions with the host immune and non-immune cells, characterized by various virulence factors that facilitate adherence, invasion, and evasion of the host's defenses. This review highlights the complexity of S. aureus infections, ranging from mild to life-threatening conditions, and underscores the growing public health concern posed by multidrug-resistant strains, including methicillin-resistant S. aureus (MRSA). This article aims to provide an updated perspective on S. aureus-related infections, highlighting the main diseases linked to this pathogen, how the different cell types, virulence factors, and signaling molecules are involved in the immunopathogenesis, and the future perspectives to overcome the current challenges to treat the affected individuals.

Current Blood Eosinophilia Does Not Predict the Presence of Pulmonary Hypertension in Patients with End-Stage Lung Disease

Objectives: To investigate the role of blood eosinophils in predicting PH in end-stage lung disease. Methods: We conducted a retrospective study of adults with CF, COPD, and ILD who underwent RHC during lung transplant evaluations (2010-2022). Patients were classified by the 2022 ECS/ERS PH guidelines with pulmonary function and laboratory tests, including hemograms. The eosinophil threshold was set at 0.30 G/L. Results: We analyzed 663 patients (n = 89 CF, n = 294 COPD, and n = 280 ILD). Severe PH was more common in ILD (16%) than in CF (4%) and COPD (7%) (p = 0.0002), with higher eosinophil levels in ILD (p = 0.0002). No significant correlation was found between eosinophil levels and hemodynamic parameters (PAPm, PVR, and CI) across CF, COPD, and ILD (PAPm: p = 0.3974, p = 0.4400 and p = 0.2757, respectively; PVR: p = 0.6966, p = 0.1489 and p = 0.1630, respectively; CI: p = 0.9474, p = 0.5705 and p = 0.5945, respectively), nor was a correlation observed in patients not receiving OCS. Linear regression analysis confirmed the lack of association (PAPm: p = 0.3355, p = 0.8552 and p = 0.4146, respectively; PVR: p = 0.6924, p = 0.8935 and p = 0.5459, respectively; CI: p = 0.4260, p = 0.9289 and p = 0.5364, respectively), controlling for 6-MWD, Nt-proBNP, and ICS/OCS dosages. ROC analysis indicated eosinophils were ineffective in distinguishing PH severity levels across these diseases (AUC 0.54, 0.51, and 0.53, respectively). The analysis of eosinophil levels measured 18 ± 6 months prior to baseline found no predictive correlation with the presence of PH either. Eosinophil levels did not differ significantly among PH groups, but eosinophilic COPD was linked to more unclassified PH, higher CO, and greater lung volumes than non-eosinophilic COPD. Conclusions: In our cohort of end-stage CF, COPD, and ILD patients, blood eosinophilia did not predict the presence of PH but was associated with hemodynamic parameters and lung volumes in COPD.

Histopathological, Cytological and Radiological Correlations in Allergy and Public Health Concerns: A Comprehensive Review

Allergies represent a significant and growing public health concern, affecting millions worldwide and burdening healthcare systems substantially. Accurate diagnosis and understanding of allergy is crucial for effective management and treatment. This review aims to explore the historical evolution, current advances, and prospects of histopathological and cytological techniques in allergy diagnosis, highlighting their crucial role in modern medicine. Major biomedical, public health, and imaging databases such as PubMed, Scopus, Web of Science, and EMBASE were used. The search strategy used include specific keywords and Medical Subject Headings (MeSH) terms related to histopathology, cytology, radiology, allergic diseases, and public health. Histopathological and cytological studies play a pivotal role in elucidating the underlying mechanisms of allergies, offering insights into the cellular and tissue-level changes associated with allergic responses. Histopathology reveals characteristic features such as inflammation, tissue remodeling, and the presence of specific immune cells like eosinophils and mast cells. Cytological analysis can detect cellular changes and abnormalities at a finer scale, providing a complementary perspective to histopathological findings. The correlation between histopathological and cytological findings is critical for achieving accurate and reliable diagnoses. Combined histopathological and cytological studies can reveal the extent of airway inflammation, epithelial damage, and immune cell infiltration, providing a robust basis for clinical decision-making. Recent advancements in diagnostic techniques have further revolutionized the field of allergy diagnosis. These technologies offer increased accuracy, speed, and reproducibility, making them invaluable in both clinical and research settings. Despite these advancements, several challenges and limitations persist. By integrating tissue-level and cellular-level analyses, clinicians can achieve more accurate diagnoses, tailor treatments to individual patients, and ultimately improve the quality of care for those suffering from allergies. In conclusion, histopathological and cytological correlation in allergy diagnosis provides a comprehensive framework for understanding and managing allergic conditions.

Eosinophilic inflammation: a key player in COPD pathogenesis and progression

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) remains a significant public health challenge due to its high morbidity and mortality rates. Emerging research has identified eosinophilic inflammation as a crucial factor in the pathogenesis and exacerbation of COPD, warranting a detailed exploration of its underlying mechanisms and therapeutic implications.

OBJECTIVE

This review aims to elucidate the role of eosinophils in COPD, focusing on their contribution to airway remodeling, exacerbation frequency, and the inflammatory cascade.

METHODS

We conducted a comprehensive literature review of recent studies that discuss the pathophysiological role of eosinophils in COPD and the clinical outcomes associated with modulating eosinophilic activity.

RESULTS

Eosinophils contribute to COPD progression by releasing cytotoxic proteins and cytokines that intensify the inflammatory response and airway alterations. Targeting specific eosinophil-related cytokines with monoclonal antibodies or receptor antagonists may potentially reduce eosinophil counts, mitigate exacerbations, and improve patient outcomes.

CONCLUSION

Understanding eosinophilic involvement in COPD can facilitate the development of precision medicine approaches, offering more tailored and effective treatment options. Future research should continue to focus on the integration of eosinophil biomarkers in clinical practice to enhance therapeutic decisions and management strategies for COPD patients.

Dysregulated blood biomarkers in women with acute and chronic respiratory conditions due to air pollutant exposure: An exploratory systematic review

Background

Air pollution exposure poses significant health risks for the general population, but particularly for women with acute and chronic respiratory conditions. Given the increasing global burden of air pollution-related illnesses, understanding these biomarkers is crucial for developing targeted interventions and improving respiratory health outcomes in vulnerable populations. In this systematic review, we aimed to determine potential dysregulated respiratory inflammatory blood biomarker candidates in adult female patients who experience varying levels and sources of inhaled pollutant exposure.

Methods

We searched the Cochrane Library, PubMed, and Web of Science with nuanced search terms to retrieve articles published in English between 1 January 2000 and 12 June 2023, to ensure relevancy. We filtered our findings to generate a focussed narrative analysis and used the Risk of Bias In Non-randomized Studies-of Exposures (ROBINS-E) and Risk-of-bias VISualization (robVIS) tools to ensure the validity of the data and the quality of the conclusions being made.

Results

We identified 916 articles from the databases used in our search, 16 of which met the criteria of our focussed narrative analysis. Among blood biomarkers, platelet-activating factor and eosinophilia could be used to assess the severity of asthma conditions, as a lack or reduction thereof indicates specific conditions. Pro-inflammatory cytokines require further validation, as some studies with a high risk of bias have reported conflicting results compared to more recent research on whether these markers are up-regulated or down-regulated. We found one study to be at a very high risk of bias, two had a high risk of bias, one had some concerns of confounding factors which may not have affected their results, and 12 studies had a low risk of bias.

Conclusions

There were narrowed-down blood biomarker candidates that could be used in future research and avenues of research like generating specific microRNA sequences to test for prognostic/diagnostic tests.

Registration

PROSPERO: 42023435721.

Integrative Cross-Talk in Asthma: Unraveling the Complex Interactions Between Eosinophils, Immune, and Structural Cells in the Airway Microenvironment

Asthma is a chronic inflammatory process that leads to airway narrowing, causing breath loss followed by spasms, wheezing, and shortness of breath. Within the asthmatic lungs, interaction among various immune cells and structural cells plays a significant role in orchestrating an inflammatory response in which eosinophils hold central importance. In these settings, allergens or other environmental exposures commonly drive the immune response to recruit eosinophils to the airways. The appearance of eosinophils in the airways indicates a dynamic interplay of various cell types within lung tissue and does not represent a passive effect of inflammation. The cellular cross-talk causes the persistence of eosinophilic inflammation, and if left untreated, it results in long-term damage to the airway structure and function. Further exacerbation of the condition occurs because of this. We discuss how this complex interplay of eosinophils, immune, and structural cells within the airway microenvironment leads to the distinct pathophysiological features in asthma, the variability in disease severity, and the response to biological treatments.

Complete Blood Count in Children With COVID-19: A Predictor of Disease Severity

Blood count abnormalities are frequent in patients with severe COVID-19 disease and there is still a lack of information in pediatric complete blood count (CBC) results. Thus, this study aims to correlate the CBC in the emergency room of children with COVID-19 between 0 and 10 years old and the clinical severity of the disease. A retrospective cohort study was performed in children with COVID-19 who collected at the emergency room CBC, C-reactive protein (CRP), platelet to lymphocyte ratio (PLR), neutrophil to lymphocyte ratio (NLR), neutrophil to monocyte ratio (NMR), lymphocyte to neutrophil ratio (LNR), lymphocyte to monocyte ratio (LMR), monocyte to neutrophil ratio (MNR) and monocyte to lymphocyte ratio (MLR). In total, demographic data from 93 children with median age of 19 months (0.3-126), 60.2% males, were included. The main changes in the CBC were atypical lymphocytes (51.6%) and eosinopenia (49.5%). From 69 hospitalized children, 21 were considered severe. There was no association between age, gender, and CRP value with clinical severity. The presence of underlying disease was five times higher (odds ratio [OR] = 5.08) in patients who required hospitalization and a higher NLR value was 54% (OR = 1.54) more likely to occur. Eosinopenia was three times more frequent in inpatients with disease severity criteria (OR = 3.05). In conclusion, children younger than 10 years of age with COVID-19 have changes in the CBC collected in the emergency room, mainly atypical lymphocytes and eosinopenia. The presence of a comorbidity or a higher NLR increases the chance of hospitalization. In addition, eosinopenia was a predictor of severity in inpatient children due to COVID-19.

Phenotypic Shift of an Inflammatory Eosinophil Subset into a Steady-State Resident Phenotype after 2 Years of Vaccination against IL-5 in Equine Insect Bite Hypersensitivity

Eosinophils play a key role in allergic diseases such as insect bite hypersensitivity (IBH). Together with Th2 cells, they shape the course of inflammation in associated type I/IVb allergies. Therefore, a virus-like particle (VLP)-based vaccine targeting equine interleukin-5 (eIL-5), eIL-5-CuMV-TT, was developed to interfere with the IL-5 dependency of eosinophils by inducing the production of anti-self-IL-5 antibodies and alleviating clinical signs in IBH-affected horses. A previous study highlighted the presence of two eosinophil subsets, steady-state resident eosinophils (rEos) and inflammatory eosinophils (iEos), circulating in the blood of healthy and IBH-affected horses, distinguishable by the expression of integrin CD49f. Furthermore, eIL-5-CuMV-TT 1st year vaccination showed a significant decrease of total eosinophils and, in particular, iEos. Nevertheless, the very few remaining eosinophils still shared an iEos phenotype, reflected by bigger size and higher granularity. The aim of this study was to follow up on the phenotype of eosinophils in the 2nd year of vaccination of IBH-affected horses with eIL-5-CuMV-TT. Using flow cytometry analysis of the blood of healthy, IBH, IBH-placebo, and IBH-vaccinated horses, the percentage and count of cells were compared between groups with a focus on pair analysis of eosinophils in 1st and 2nd year vaccinated horses. Our data showed comparably low levels of iEos and a significant increase of rEos in 2nd year compared to 1st year vaccinated horses, suggesting a phenotypic shift toward a resident-like eosinophil population, primarily associated with the phenotype of healthy horses. The reduction of size, granularity, and expression of integrin CD49f in the 2nd year suggests a benefit of long-term treatment with the eIL-5-CuMV-TT vaccine.

Flow cytometric immunophenotypic differentiation patterns of bone marrow eosinophilopoiesis

BACKGROUND

Flow cytometry has been widely used to study immunophenotypic patterns of maturation of most hematopoietic lineages in normal human bone marrow aspirates, thus allowing identification of changes in patterns in many myeloid malignancies. Eosinophils play an important role in a wide variety of disorders, including some myeloid neoplasms. However, changes in flow cytometric immunophenotypic patterns during normal and abnormal bone marrow eosinophilopoiesis have not been well studied.

METHODS

Fresh bone marrow aspirates from 15 healthy donors, 19 patients with hypereosinophilic syndromes (HES), and 11 patients with systemic mastocytosis (SM) were analyzed for candidate markers that included EMR-1, Siglec-8, CCR3, CD9, CD11a, CD11b, CD11c, CD13, CD16, CD29, CD34, CD38, CD45, CD44, CD49d, CD49f, CD54, CD62L, CD69, CD117, CD125 (IL-5Rα), HLA-DR, using 10 parameter flow cytometry. Putative CD34-negative immature and mature normal eosinophil populations were first identified based on changes in expression of the above markers in healthy donors, then confirmed using fluorescence-based cell sorting and morphological evaluation of cytospin preparations. The normal immunophenotypic patterns were then compared to immunophenotypic patterns of eosinophilopoiesis in patients with HES and SM.

RESULTS

The eosinophilic lineage was first verified using the human eosinophil-specific antibody EMR-1 in combination with anti-IL-5Rα antibody. Then, a combination of Siglec-8, CD9, CD11b, CCR3, CD49d, and CD49f antibodies was used to delineate normal eosinophilic maturational patterns. Early stages (eosinophilic promyelocytes/myelocytes) were identified as Siglec-8 dim/CD11b dim to moderate/CD9 dim/CCR3 dim/CD49d bright/CD49f dim, intermediate stages (eosinophilic myelocytes/metamyelocytes) as Siglec-8 moderate/CD11b moderate to bright/CD9 moderate/CCR3 moderate/CD49d moderate/CD49f moderate and mature bands/segmented eosinophils as Siglec-8 bright/CD11b bright/CD9 bright/CCR3 bright/CD49d dim/CD49f bright. Overall maturational patterns were also similar in patients with HES and SM; however, the expression levels of several surface markers were altered compared to normal eosinophils.

CONCLUSION

A novel flow cytometric antibody panel was devised to detect alterations in immunophenotypic patterns of bone marrow eosinophil maturation and evaluated in normal, HES and SM samples. This approach will allow us to elucidate changes in immunophenotypic patterns of bone marrow eosinophilopoiesis in other hematological diseases.

Eosinophil extracellular traps in respiratory ailment: Pathogenic mechanisms and clinical translation

Background

Eosinophilic extracellular traps (EETs) are reticular complexes comprising deoxyribonucleic-Acid (DNA) fibers and granule proteins.

Aims

EETs play a crucial role in antimicrobial host responses and are pathogenic when overproduced or under degraded. EETs created by eosinophils appear to enable vital immune responses against extra-cellular pathogens, nevertheless, trap overproduction is evident in pathology.

Materials & Methods

As considerably research is performed, new data affirmed that EETs can alter the outcome of respiratory ailment.

Results

We probe into the disclosure and specificity of EETs produced in reaction to various stimuli and propose a role for those frameworks in ailment pathogenesis and the establishment of chronic, unresolved inflammation.

Discussion

Whether EETs can be used as a prospective brand-new target for the diagnosis, treatment and prognosis of respiratory ailments is a scientific theme worth studying.

Conclusion

We probe into the disclosure and specificity of EETs produced in reaction to various stimuli and propose a role for those frameworks in ailment pathogenesis and the establishment of chronic, unresolved inflammation.

Considerations on the evolutionary biology and functions of eosinophils: what the "haeckel"?

The origins and evolution of the eosinophilic leukocyte have received only scattered attention since Paul Ehrlich first named this granulocyte. Studies suggest that myeloperoxidase, expressed by granulocytes, and eosinophil peroxidase diverged some 60 to 70 million years ago, but invertebrate to vertebrate evolution of the eosinophil lineage is unknown. Vertebrate eosinophils have been characterized extensively in representative species at light microscopic, ultrastructural, genetic, and biochemical levels. Understanding of eosinophil function continues to expand and includes to date regulation of "Local Immunity And/Or Remodeling/Repair" (the so-called LIAR hypothesis), modulation of innate and adaptive immune responses, maintenance of tissue and metabolic homeostasis, and, under pathologic conditions, inducers of tissue damage, repair, remodeling, and fibrosis. This contrasts with their classically considered primary roles in host defense against parasites and other pathogens, as well as involvement in T-helper 2 inflammatory and immune responses. The eosinophils' early appearance during evolution and continued retention within the innate immune system across taxa illustrate their importance during evolutionary biology. However, successful pregnancies in eosinophil-depleted humans/primates treated with biologics, host immune responses to parasites in eosinophil-deficient mice, and the absence of significant developmental or functional abnormalities in eosinophil-deficient mouse strains under laboratory conditions raise questions of the continuing selective advantages of the eosinophil lineage in mammals and humans. The objectives of this review are to provide an overview on evolutionary origins of eosinophils across the animal kingdom, discuss some of their main functions in the context of potential evolutionary relevance, and highlight the need for further research on eosinophil functions and functional evolution.

Prediction of Osteoporotic Hip Fracture Outcome: Comparative Accuracy of 27 Immune-Inflammatory-Metabolic Markers and Related Conceptual Issues

Objectives: This study, based on the concept of immuno-inflammatory-metabolic (IIM) dysregulation, investigated and compared the prognostic impact of 27 indices at admission for prediction of postoperative myocardial injury (PMI) and/or hospital death in hip fracture (HF) patients. Methods: In consecutive HF patient (n = 1273, mean age 82.9 ± 8.7 years, 73.5% females) demographics, medical history, laboratory parameters, and outcomes were recorded prospectively. Multiple logistic regression and receiver-operating characteristic analyses (the area under the curve, AUC) were used to establish the predictive role for each biomarker. Results: Among 27 IIM biomarkers, 10 indices were significantly associated with development of PMI and 16 were indicative of a fatal outcome; in the subset of patients aged >80 years with ischaemic heart disease (IHD, the highest risk group: 90.2% of all deaths), the corresponding figures were 26 and 20. In the latter group, the five strongest preoperative predictors for PMI were anaemia (AUC 0.7879), monocyte/eosinophil ratio > 13.0 (AUC 0.7814), neutrophil/lymphocyte ratio > 7.5 (AUC 0.7784), eosinophil count < 1.1 × 109/L (AUC 0.7780), and neutrophil/albumin × 10 > 2.4 (AUC 0.7732); additionally, sensitivity was 83.1-75.4% and specificity was 82.1-75.0%. The highest predictors of in-hospital death were platelet/lymphocyte ratio > 280.0 (AUC 0.8390), lymphocyte/monocyte ratio < 1.1 (AUC 0.8375), albumin < 33 g/L (AUC 0.7889), red cell distribution width > 14.5% (AUC 0.7739), and anaemia (AUC 0.7604), sensitivity 88.2% and above, and specificity 85.1-79.3%. Internal validation confirmed the predictive value of the models. Conclusions: Comparison of 27 IIM indices in HF patients identified several simple, widely available, and inexpensive parameters highly predictive for PMI and/or in-hospital death. The applicability of IIM biomarkers to diagnose and predict risks for chronic diseases, including OP/OF, in the preclinical stages is discussed.

All-cause mortality and related factors in patients with varying degrees of peripheral blood eosinophilia

The aim of this study was to investigate all-cause mortality rates and related factors in patients with different levels of eosinophilia. This retrospective cohort study was conducted between January 2020 and December 2022 in the Internal Medicine Department of Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkiye. A total of 161 patients with eosinophilia (at least 3 times) were included and divided into groups with absolute eosinophil counts of 500-999/µL (mild), 1000-1500/µL (moderate), and >1500/µL (severe). The mean age of patients was 65.67 ± 16.64 years at the time of admission, and 45 patients (57.8%) were male. The rates of mortality, oncological disease, and organ involvement were significantly higher in the severe group (P < .05). Increased serum total immunoglobulin E and vitamin B12, hematocrit value, eosinophil-to-lymphocyte ratio, and leukocyte were observed in eosinophilic patients. Decreased lymphocyte count, hemoglobin and hematocrit values were higher in deceased patients than in survivors (P < .05). Increased eosinophil-to-lymphocyte ratio, C-reactive protein, vitamin B12, and lactate dehydrogenase (LDH) activity were observed in participants who died compared to those who survived (P < .05). Multivariable logistic regression revealed that advanced age and higher LDH activity were independently associated with greater mortality risk while receiving non-steroid anti-inflammatory drugs or proton-pump inhibitors were associated with reduced mortality risk (P < .05). Advanced age and increased LDH activity were independently associated with greater risk for mortality, whereas absolute eosinophil counts was not. Considering the literature on this topic, our results show the need for further clinical and fundamental research to understand the role of eosinophils in human disease.

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.

An increased relative eosinophil count as a predictive dynamic biomarker in non-small cell lung cancer patients treated with immune checkpoint inhibitors

BACKGROUND

An increased relative eosinophil count (REC) has potential as a predictive biomarker for a beneficial clinical response and outcome to cancer immunotherapies. Therefore, the present study investigated the impact of an increased posttreatment REC on the prognosis of non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs).

METHODS

We retrospectively reviewed all 151 patients diagnosed with NSCLC and treated with ICI monotherapy and blood test data between March 2016 and August 2021 at National Hospital Organization Kochi Hospital and Tokushima University.

RESULTS

A total of 151 patients with a mean age of 69 years were included. REC after 4 weeks of initial ICI monotherapy was higher than pretreatment REC in 87 patients but not in 64. REC after 4 weeks of the ICI treatment with and without an increased REC were 4.4 and 1.8%, respectively (p < 0.001). Disease control rates (DCR) were significantly higher in patients with than in those without an increased REC (84% vs. 47%, p < 0.001). The median overall survival (OS) of lung cancer patients with or without an increased REC were 674 and 234 days, respectively. A Kaplan-Meier univariate analysis revealed a significant difference in OS between the two groups (p < 0.001). A Cox proportional regression analysis identified an increased REC as an independent predictor of OS (p = 0.003).

CONCLUSION

ICI-treated NSCLC patients with an increased REC after 4 weeks of treatment had a better DCR and prognosis than the other patients examined.

Cell type-specific molecular mechanisms and implications of necroptosis in inflammatory respiratory diseases

Necroptosis is generally considered as an inflammatory cell death form. The core regulators of necroptotic signaling are receptor-interacting serine-threonine protein kinases 1 (RIPK1) and RIPK3, and the executioner, mixed lineage kinase domain-like pseudokinase (MLKL). Evidence demonstrates that necroptosis contributes profoundly to inflammatory respiratory diseases that are common public health problem. Necroptosis occurs in nearly all pulmonary cell types in the settings of inflammatory respiratory diseases. The influence of necroptosis on cells varies depending upon the type of cells, tissues, organs, etc., which is an important factor to consider. Thus, in this review, we briefly summarize the current state of knowledge regarding the biology of necroptosis, and focus on the key molecular mechanisms that define the necroptosis status of specific cell types in inflammatory respiratory diseases. We also discuss the clinical potential of small molecular inhibitors of necroptosis in treating inflammatory respiratory diseases, and describe the pathological processes that engage cross talk between necroptosis and other cell death pathways in the context of respiratory inflammation. The rapid advancement of single-cell technologies will help understand the key mechanisms underlying cell type-specific necroptosis that are critical to effectively treat pathogenic lung infections and inflammatory respiratory diseases.

Which inflammatory marker, between systemic immune-inflammation index and neutrophil to eosinophil ratio, is associated with Peyronie's disease and are there any implications for a better understanding of its mechanisms?

BACKGROUND

Peyronie's disease affects up to 9% of men and is often accompanied by pain and/or erectile dysfunction. It is characterized by an inflammatory process that is the grassroots of the subsequent fibrosis stage. There is an unmet need to evaluate its onset and progression. Among the newly proposed biomarkers of inflammation, authors developed a novel systemic immune-inflammation index (SII) based on lymphocyte, neutrophil, and platelet counts. Similarly, a recent study reported that a neutrophil-to-eosinophil ratio (NER) represents systemic inflammation.

RESULTS

A 49-patient group with Peyronie's disease as confronted with 50 well-matched for age and BMI controls. As laboratory evaluation of inflammation, SII, NER and the eosinophil to neutrophil ratio (ENR) were studied. As a likely risk factor for the presence of Peyronie's disease, a higher prevalence of hypercholesterolemia, hyperglycemia and hypertension was discovered in the patients compared to controls. A significant difference was found in the median values of the NER between the two selected groups, i.e., 32.5 versus 17.3 (p = 0.0021). As expected, also ENR was significantly different. The receiver operating characteristic curves for SII, ENR and NER were 0.55, 0.32 and 0.67, respectively, highlighting the best performance of NER. The cut-off for NER was 12.1, according to the Youden test.

CONCLUSIONS

According to our results, any evaluation of circulating eosinophil, evaluated as NER, beyond being a signature of immuno-inflammatory response, help assess tissue homeostasis, since eosinophils are now considered multifunctional leukocytes and give a picture of the inflammatory process and repair process belonging to Peyronie's disease.

Integrative analysis of immune-related signature profiles in eosinophilic chronic rhinosinusitis with nasal polyposis

Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is a subtype of chronic rhinosinusitis (CRS) that is associated with the nasal cavity and sinus polyps, elevated levels of eosinophils, and dysregulated immune responses to environmental triggers. The underlying cause of ECRSwNP is not well understood, and few studies have focused on the unique features of this subtype of CRS. Our study integrated proteomic and transcriptomic data with multi-omic bioinformatics analyses. We collected nasal polyps from three ECRSwNP patients and three control patients and identified 360 differentially expressed (DE) proteins, including 119 upregulated and 241 downregulated proteins. Functional analyses revealed several significant associations with ECRSwNP, including focal adhesion, hypertrophic cardiomyopathy, and extracellular matrix (ECM)-receptor interactions. Additionally, a protein-protein interaction (PPI) network revealed seven hub proteins that may play crucial roles in the development of ECRSwNP. We also compared the proteomic data with publicly available transcriptomic data and identified a total of 1077 DE genes. Pathways enriched by the DE genes involved angiogenesis, positive regulation of cell motility, and immune responses. Furthermore, we investigated immune cell infiltration and identified biomarkers associated with eosinophil and M2 macrophage infiltration using CIBERSORT and Weighted Gene Correlation Network Analysis (WGCNA). Our results provide a more complete picture of the immune-related mechanisms underlying ECRSwNP, which could contribute to the development of more precise treatment strategies for this condition.

Blood CD62Llow inflammatory eosinophils are related to the severity of asthma and reduced by mepolizumab

BACKGROUND

Eosinophils have been divided into different subpopulations with distinct phenotypes based on CD62L expression. No data are available regarding the correlation between eosinophils subphenotypes and clinical severity of asthma, as well as the effect of anti-IL-5 therapy on these cells. The study investigates the correlation between blood CD62Llow inflammatory eosinophils (iEos) and clinical severity of severe eosinophilic asthma (SEA) and evaluates the impact of mepolizumab on iEos.

METHODS

112 patients were screened and were divided in two groups: biological-naive (n = 51) and biological-treated patients (n = 61). The Biological-naive patients were analyzed before treatment (Group A) and 19 out of 51 patients, were longitudinally analyzed before and after treatment with mepolizumab 100 mg s.c/4 weeks (Group B); 32 patients were excluded because they were being treated with other biological therapies. Blood eosinophils were analyzed by FACS and correlated with clinical scores. In vitro effect of IL-5 and mepolizumab on CD62L expression was assessed.

RESULTS

A significant correlation between blood CD62Llow cells and clinical scores of asthma and nasal polyps, as well as the number of asthma exacerbations in the last year was shown in untreated patients. In longitudinally studied patients we observed a marked reduction of CD62Llow cells paralleled by an increase in the proportion of CD62Lbright cells, associated with clinical improvement of asthma control. In vitro, CD62L expression on eosinophils is modulated by IL-5 and anti-IL-5.

CONCLUSION

A positive correlation between CD62Llow iEos and the baseline clinical features of SEA with CRSwNP was shown. Furthermore mepolizumab restores the healthy balance among eosinophils sub-phenotypes in SEA patients.

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.

Elevated eosinophils proportion as predictor of immune-related adverse events after ipilimumab and nivolumab treatment of advanced and metastatic renal cell carcinoma

OBJECTIVES

Ipilimumab and nivolumab treatment against advanced and metastatic renal cell carcinoma (RCC) causes severe and lethal immune-related adverse events (irAEs). Predicting irAEs might improve clinical outcomes, however no practical biomarkers exist. This study examined whether eosinophils could be effective biomarkers for ≥grade 2 irAEs in RCC.

METHODS

We retrospectively analyzed 75 patients with RCC treated with ipilimumab and nivolumab between August 2018 and March 2021 in a multicenter study. Eosinophils were examined before and 2 weeks after treatment, and immediately after irAEs development. The optimal cut-off value for ≥grade 2 irAEs was determined by a receiver operating characteristic (ROC) curve. Univariate and multivariate analyses were undertaken to identify predictors of ≥grade 2 irAEs.

RESULTS

Two weeks after treatment, eosinophils were significantly upregulated in patients who had experienced ≥grade 2 irAEs than in those who had not experienced irAEs (mean, 5.7% vs. 3.2%; p < 0.05). The optimal cut-off value for eosinophils against ≥grade 2 irAEs was 3.0% (area under the curve = 0.69). In multivariate analyses, an eosinophil level ≥ 3.0% was a risk factor for ≥grade 2 irAEs (odds ratio 4.18, 95% confidence interval 1.16-15.1). The eosinophil level 2 weeks after treatment was upregulated by the onset of any type of irAEs including endocrine, gastrointestinal, pulmonary and skin disorders.

CONCLUSIONS

An increased eosinophil level 2 weeks after treatment might be an effective biomarker for ≥grade 2 irAEs in patients with RCC treated with ipilimumab and nivolumab.

Cationic proteins from eosinophils bind bone morphogenetic protein receptors promoting vascular calcification and atherogenesis

AIMS

Blood eosinophil count and eosinophil cationic protein (ECP) concentration are risk factors of cardiovascular diseases. This study tested whether and how eosinophils and ECP contribute to vascular calcification and atherogenesis.

METHODS AND RESULTS

Immunostaining revealed eosinophil accumulation in human and mouse atherosclerotic lesions. Eosinophil deficiency in ΔdblGATA mice slowed atherogenesis with increased lesion smooth muscle cell (SMC) content and reduced calcification. This protection in ΔdblGATA mice was muted when mice received donor eosinophils from wild-type (WT), Il4-/-, and Il13-/- mice or mouse eosinophil-associated-ribonuclease-1 (mEar1), a murine homologue of ECP. Eosinophils or mEar1 but not interleukin (IL) 4 or IL13 increased the calcification of SMC from WT mice but not those from Runt-related transcription factor-2 (Runx2) knockout mice. Immunoblot analyses showed that eosinophils and mEar1 activated Smad-1/5/8 but did not affect Smad-2/3 activation or expression of bone morphogenetic protein receptors (BMPR-1A/1B/2) or transforming growth factor (TGF)-β receptors (TGFBR1/2) in SMC from WT and Runx2 knockout mice. Immunoprecipitation showed that mEar1 formed immune complexes with BMPR-1A/1B but not TGFBR1/2. Immunofluorescence double-staining, ligand binding, and Scatchard plot analysis demonstrated that mEar1 bound to BMPR-1A and BMPR-1B with similar affinity. Likewise, human ECP and eosinophil-derived neurotoxin (EDN) also bound to BMPR-1A/1B on human vascular SMC and promoted SMC osteogenic differentiation. In a cohort of 5864 men from the Danish Cardiovascular Screening trial and its subpopulation of 394 participants, blood eosinophil counts and ECP levels correlated with the calcification scores of different arterial segments from coronary arteries to iliac arteries.

CONCLUSION

Eosinophils release cationic proteins that can promote SMC calcification and atherogenesis using the BMPR-1A/1B-Smad-1/5/8-Runx2 signalling pathway.

Demographic, environmental and physiological predictors of gastrointestinal parasites in urban raccoons

Raccoons are host to diverse gastrointestinal parasites, but little is known about the ecology of these parasites in terms of their interactions with each other during coinfections, their interactions with host physiology and environmental factors, and their impact on raccoon health and survival. As a first step, we investigated the patterns of parasite infection and their demographic distribution in an urban-suburban population of raccoons trapped in the summers and autumns of 2018 and 2019. We collected faecal samples, demographic data, morphometric measurements, and blood smears, and used GPS data to classify trapping location by land cover type. Faecal floats were performed to detect and quantify gastrointestinal nematode eggs and coccidia oocysts, and white blood cell differentials were performed on blood smears to characterise white blood cell distributions. Data were analysed cross-sectionally and, where possible, longitudinally, using generalised linear models. Overall, 62.6% of sampled raccoons were infected with gastrointestinal nematodes, and 82.2% were infected with gastrointestinal coccidia. We analysed predictors of infection status and faecal egg count for three different morphotypes of nematode-Baylisascaris, strongyle, and capillariid nematodes-and found that infection status and egg count varied with Year, Month, Age class, Land cover, and coinfection status, though the significance of these predictors varied between nematode types. Gastrointestinal coccidia prevalence varied with Year, Month, Age class, strongyle infection status, and capillariid infection status. Coccidia oocyst counts were lower in adults and in October, but higher in females and in raccoons trapped in areas with natural land cover; furthermore, coccidia oocysts were positively associated with capillariid faecal egg counts. We found no evidence that gastrointestinal parasites influenced raccoon body condition or overwinter mortality, and so conclude that raccoons, though harbouring diverse and abundant gastrointestinal parasites, may be relatively tolerant of these parasites.

Effects of Lidocaine-Derived Organic Compounds on Eosinophil Activation and Survival

Lidocaine, a local anesthetic, is known to possess anti-inflammatory properties. However, its clinical use is limited by inconveniences, such as its local synesthetic effects. This study evaluated lidocaine analogs designed and synthesized to overcome the disadvantages of lidocaine, having anti-inflammatory properties. Interleukin 5 (IL-5)-induced eosinophil activation and survival were evaluated using 36 lidocaine analogs with modified lidocaine structure on the aromatic or the acyl moiety or both. Eosinophil survival was evaluated using a CellTiter 96® aqueous cell proliferation assay kit. Superoxide production was determined using the superoxide dismutase-inhibitable reduction of cytochrome C method. Eosinophil cationic protein (ECP), IL-8, and transcription factor expression were determined using enzyme-linked immunosorbent assay. The platelet-activating factor (PAF)-induced migration assay was performed using a Transwell insert system. Compounds EI137 and EI341 inhibited IL-5-induced eosinophil survival and superoxide and ECP production in a concentration-dependent manner. These compounds also significantly reduced IL-8 production. Although compounds EI137 and EI341 significantly reduced phosphorylated ERK 1/2 expression, they did not influence other total and phosphorylated transcription factors. Moreover, 1000 µM of compound EI341 only inhibited PAF-induced migration of eosinophils. Lidocaine analogs EI137 and EI341 inhibited IL-5-mediated activation and survival of eosinophils. These compounds could be new therapeutic agents to treat eosinophilic inflammatory diseases.

Correlating Salivary Levels of Immunoglobin E and Human Eosinophil Cationic Protein in the Aseer Cohort with Recurrent Apthous Stomatitis

Background

Repeated Aphthous Stomatitis (RAS) is the most prevalent inflammatory disorder of the oral mucosa, characterized by recurrent emergence of single or numerous painful ulcers. RAS usually affects healthy people without systemic illnesses. There is evidence linking atopy to the progression of this illness. Immunoglobulin E (IgE) and human eosinophil cationic protein (HECP) levels in the saliva of individuals with aphthous stomatitis were assessed as allergy-related indicators.

Materials and Methods

Sixty people were assessed for this study. 30 patients with RAS were included in the patient group, while 30 healthy individuals made up for the control group. Sixty participants' non-stimulated saliva was taken and IgE and HECP were evaluated using enzyme-linked immunosorbent assay (ELISA). Data were analyzed in SPSS 20 through the Mann-Whitney test and p<0.05 was considered significant.

Results

The salivary level of HECP was significantly (p 0.05) higher among cases (0.83 0.70) compared to controls (0.170 0.15), whereas the salivary level of IgE was not significantly (p = 0.41) higher among cases (35.60 11.19) compared to controls (67.42 18.34).

Conclusion

Even though this study found a positive correlation between elevated HECP levels and RAS, additional research with larger sample sizes is required to identify the biological mechanisms responsible for the observed associations and to include salivary HECP levels in the RAS patient's evaluation.

TIME Is Ticking for Cervical Cancer

Cervical cancer (CC) is a major health problem among reproductive-age females and comprises a leading cause of cancer-related deaths. Human papillomavirus (HPV) is the major risk factor associated with CC incidence. However, lifestyle is also a critical factor in CC pathogenesis. Despite HPV vaccination introduction, the incidence of CC is increasing worldwide. Therefore, it becomes critical to understand the CC tumor immune microenvironment (TIME) to develop immune cell-based vaccination and immunotherapeutic approaches. The current article discusses the immune environment in the normal cervix of adult females and its role in HPV infection. The subsequent sections discuss the alteration of different immune cells comprising CC TIME and their targeting as future therapeutic approaches.

Effect of Functional Nanoporous TiO2 Film Obtained on Ti6Al4V Implant Alloy to Improve Resistance in Biological Solution for Inflammatory Conditions

The metallic titanium-based biomaterials are sensitive to corrosion-induced degradation in biological fluids in the presence of inflammatory conditions containing reactive oxygen species (ROS). Excess ROS induces oxidative modification of cellular macromolecules, inhibits protein function, and promotes cell death. In addition, ROS could promote implant degradation by accelerating the corrosive attack of biological fluids. The functional nanoporous titanium oxide film is obtained on titanium alloy to study the effect on implant reactivity in biological fluid with reactive oxygen species such as hydrogen peroxide, which are present in inflammations. The TiO₂ nanoporous film is obtained by electrochemical oxidation at high potential. The untreated Ti6Al4V implant alloy and nanoporous titanium oxide film are comparatively evaluated for corrosion resistance in biological solution by Hank's and Hank's doped with hydrogen peroxide by electrochemical methods. The results showed that the presence of the anodic layer significantly improved the resistance of the titanium alloy to corrosion-induced degradation in biological solutions under inflammatory conditions.

Living Leukocyte-Based Drug Delivery Systems

Leukocytes play a vital role in immune responses, including defending against invasive pathogens, reconstructing impaired tissue, and maintaining immune homeostasis. When the immune system is activated in vivo, leukocytes accomplish a series of orderly and complex regulatory processes. While cancer and inflammation-related diseases like sepsis are critical medical difficulties plaguing humankind around the world, leukocytes have been shown to largely gather at the focal site, and significantly contribute to inflammation and cancer progression. Therefore, the living leukocyte-based drug delivery systems have attracted considerable attention in recent years due to the innate and specific targeting effect, low immunogenicity, improved therapeutic efficacy, and low reverse effect. In this review, the recent advances in the development of living leukocyte-based drug delivery systems including macrophages, neutrophils, and lymphocytes as promising treatment strategies for cancer and inflammation-related diseases are introduced. The advantages, current challenges, and limitations of these delivery systems are also discussed, as well as perspectives on the future development of precision and targeted therapy in the clinics are provided. Collectively, it is expected that such kind of living cell-based drug delivery system is promising to improve or even revolutionize the treatments of cancers and inflammation-related diseases in the clinics.

Clinical and laboratory differences between pediatric hospitalized patients with sickle cell disease infected or not by SARS-CoV-2

OBJECTIVE

The aim of this study was to identify clinical and complete blood count differences between pediatric hospitalized patients with sickle cell disease infected or not by SARS-CoV-2 and compare the complete blood count of patients with sickle cell disease infected by SARS-CoV-2 before hospitalization and on admission.

METHODS

This study was a single-center prospective cohort. Data were collected from medical records of pediatric inpatients with sickle cell disease under 18 years old infected or not with SARS-CoV-2 from the first visit to the hospital until discharge and from the last medical appointment. All patients were tested for SARS-CoV-2 by the real-time reverse transcription polymerase chain reaction.

RESULTS

Among 57 pediatric patients with sickle cell disease hospitalized from March to November 2020 in a Brazilian academic hospital, 11 (19.3%) had a positive result for SARS-CoV-2. Patients infected by SARS-CoV-2 had a higher prevalence of comorbidities than the ones who were not infected (63.6 vs. 30.4%; p=0.046). During hospital stay, no clinical or complete blood count differences between groups were found. There was a decrease in eosinophil count on hospital admission in patients with sickle cell disease infected by SARS-CoV-2 (p=0.008).

CONCLUSIONS

Pediatric hospitalized patients with sickle cell disease infected by SARS-CoV-2 had more comorbidities and had a decrease in eosinophil count between hospital admission and the last medical appointment.

Sexual Dimorphic Innate Immune Response to a Viral-Bacterial Respiratory Disease Challenge in Beef Calves

The potential for sexually dimorphic innate immune responses to respiratory disease was evaluated, where eight steers and seven heifers (280 ± 4 kg) were subjected to a viral−bacterial respiratory disease challenge utilizing bovine herpesvirus-1 (BoHV-1; intranasal; 1 × 108 PFU/nostril) and Mannheimia haemolytica (MH; intratracheal; 1.3 × 107 CFU/head) administered 72 h later. Body temperature was lesser in heifers than steers (p < 0.01). There was a sex × time interaction (p = 0.05) for white blood cells where heifers had reduced concentrations compared with steers at −72 and 0 h but greater concentrations from 36 to 60 h post-MH. Concentrations of neutrophils were lesser in heifers compared to steers from 0 to 4 h, and from 8 to 12 h (p = 0.03). Lymphocytes were greater in heifers compared to steers at 12 h and from 36 to 60 h post-MH (p < 0.01). The neutrophil−lymphocyte ratio was lesser in heifers compared to steers from 2 to 24 h and at 48 h post-MH (p < 0.01). Monocytes were greater in heifers compared to steers from 24 to 60 h post-MH (p < 0.01), while eosinophils were greater in heifers compared to steers at 48 and 60 h (p < 0.01). Serum IL-4 was lesser in heifers compared to steers at 0 h and from 2 to 72 h post-MH challenge (p = 0.02). Non-esterified fatty acid concentrations were lesser (p < 0.01) in heifers compared to steers from 2 to 4 h post-MH challenge. Urea nitrogen concentrations were greater (p < 0.01) in heifers than steers at 36 h post-MH challenge. Data from this study reveal distinct differences in the acute phase response following a respiratory disease challenge where steers produced an early response, while the response in heifers appeared to be delayed.

Rethinking blood eosinophil counts: Epidemiology, associated chronic diseases, and increased risks of cardiovascular disease

Background

The distribution and determinants of blood eosinophil counts in the general population are unclear. Furthermore, whether elevated blood eosinophil counts increase risk for cardiovascular disease (CVD) and other chronic diseases, other than atopic conditions, remains uncertain.

Objective

We sought to describe the distribution of eosinophil counts in the general population and determine the association of eosinophil count with prevalent chronic disease and incident CVD.

Methods

A population-based adult cohort was followed from January 1, 2006, to December 31, 2020. Electronic health record data regarding demographic characteristics, prevalent clinical characteristics, and incident CVD were extracted. Associations between blood eosinophil counts and demographic characteristics, chronic diseases, laboratory values, and risks of incident CVD were assessed using chi-square test, ANOVA, and Cox proportional hazards regression.

Results

Blood eosinophil counts increased with age, body mass index, and reported smoking and tobacco use. The prevalence of chronic obstructive pulmonary disease, hypertension, cardiac arrhythmias, hyperlipidemia, diabetes mellitus, chronic kidney disease, and cancer increased as eosinophil counts increased. Eosinophil counts were significantly associated with coronary heart disease (hazard ratio [HR], 1.44; 95% CI, 1.12-1.84) and heart failure (HR, 1.62; 95% CI, 1.30-2.01) in fully adjusted models and with stroke/transient ischemic attack (HR, 1.37; 95% CI, 1.16-1.61) and CVD death (HR, 1.49; 95% CI, 1.10-2.00) in a model adjusting for age, sex, race, and ethnicity.

Conclusions

Blood eosinophil counts differ by demographic and clinical characteristics as well as by prevalent chronic disease. Moreover, elevated eosinophil counts are associated with risk of CVD. Further prospective investigations are needed to determine the utility of eosinophil counts as a biomarker for CVD risk.

Immunopathologic Role of Eosinophils in Eosinophilic Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a diverse chronic inflammatory disease of the sinonasal mucosa. CRS manifests itself in a variety of clinical and immunologic patterns. The histological hallmark of eosinophilic CRS (ECRS) is eosinophil infiltration. ECRS is associated with severe disease severity, increased comorbidity, and a higher recurrence rate, as well as thick mucus production. Eosinophils play an important role in these ECRS clinical characteristics. Eosinophils are multipotential effector cells that contribute to host defense against nonphagocytable pathogens, as well as allergic and nonallergic inflammatory diseases. Eosinophils interact with Staphylococcus aureus, Staphylococcal enterotoxin B, and fungi, all of which were found in the tissue of CRS patients. These interactions activate Th2 immune responses in the sinonasal mucosa and exacerbate local inflammation. Activated eosinophils were discovered not only in the tissue but also in the sinonasal cavity secretion. Eosinophil extracellular traps (EETs) are extracellular microbes trapping and killing structures found in the secretions of CRS patients with intact granule protein and filamentous chromatic structures. At the same time, EET has a negative effect by causing an epithelial barrier defect. Eosinophils also influence the local tissue microenvironment by exchanging signals with other immune cells and structural cells. As a result, eosinophils are multifaceted leukocytes that contribute to various physiologic and pathologic processes of the upper respiratory mucosal immune system. The goal of this review is to summarize recent research on the immunopathologic properties and immunologic role of eosinophils in CRS.

Communication is key: Innate immune cells regulate host protection to helminths

Parasitic helminth infections remain a significant global health issue and are responsible for devastating morbidity and economic hardships. During infection, helminths migrate through different host organs, which results in substantial tissue damage and the release of diverse effector molecules by both hematopoietic and non-hematopoietic cells. Thus, host protective responses to helminths must initiate mechanisms that help to promote worm clearance while simultaneously mitigating tissue injury. The specialized immunity that promotes these responses is termed type 2 inflammation and is initiated by the recruitment and activation of hematopoietic stem/progenitor cells, mast cells, basophils, eosinophils, dendritic cells, neutrophils, macrophages, myeloid-derived suppressor cells, and group 2 innate lymphoid cells. Recent work has also revealed the importance of neuron-derived signals in regulating type 2 inflammation and antihelminth immunity. These studies suggest that multiple body systems coordinate to promote optimal outcomes post-infection. In this review, we will describe the innate immune events that direct the scope and intensity of antihelminth immunity. Further, we will highlight the recent progress made in our understanding of the neuro-immune interactions that regulate these pathways and discuss the conceptual advances they promote.

The Dual Role of Innate Immune Response in Acetaminophen-Induced Liver Injury

Acetyl-para-aminophenol (APAP), a commonly used antipyretic analgesic, is becoming increasingly toxic to the liver, resulting in a high rate of acute hepatic failure in Europe and the United States. Excessive APAP metabolism in the liver develops an APAP-protein adduct, which causes oxidative stress, MPTP opening, and hepatic necrosis. HMGB-1, HSP, nDNA, mtDNA, uric acid, and ATP are DMAPs released during hepatic necrosis. DMAPs attach to TLR4-expressing immune cells such KCs, macrophages, and NK cells, activating them and causing them to secrete cytokines. Immune cells and their secreted cytokines have been demonstrated to have a dual function in acetaminophen-induced liver injury (AILI), with a role in either proinflammation or pro-regeneration, resulting in contradicting findings and some research confusion. Neutrophils, KCs, MoMFs, NK/NKT cells, γδT cells, DCs, and inflammasomes have pivotal roles in AILI. In this review, we summarize the dual role of innate immune cells involved in AILI and illustrate how these cells initiate innate immune responses that lead to persistent inflammation and liver damage. We also discuss the contradictory findings in the literature and possible protocols for better understanding the molecular regulatory mechanisms of AILI.

The regulatory role of eosinophils in viral, bacterial, and fungal infections

Eosinophils are innate immune cells typically associated with allergic and parasitic diseases. However, in recent years, eosinophils have also been ascribed a role in keeping homeostasis and in fighting several infectious diseases. Indeed, these cells circulate as mature cells in the blood and can be quickly recruited to the infected tissue. Moreover, eosinophils have all the necessary cellular equipment such as pattern recognition receptors (PRRs), pro-inflammatory cytokines, anti-bacterial proteins, and DNA traps to fight pathogens and promote an efficient immune response. This review summarizes some of the updated information on the role of eosinophils' direct and indirect mediated interactions with pathogens.

Construction and Validation of an Immune-Related Risk Score Model for Survival Prediction in Glioblastoma

Background

As one of the most important brain tumors, glioblastoma (GBM) has a poor prognosis, especially in adults. Immune-related genes (IRGs) and immune cell infiltration are responsible for the pathogenesis of GBM. This study aimed to identify new tumor markers to predict the prognosis of patients with GBM.

Methods

The Cancer Genome Atlas (TCGA) database and ImmPort database were used for model construction. The Wilcoxon rank-sum test was applied to identify the differentially expressed IRGs (DEIRGs) between the GBM and normal samples. Univariate Cox regression analysis and Kaplan–Meier analysis was performed to investigate the relationship between each DEIRG and overall survival. Next, multivariate Cox regression analysis was exploited to further explore the prognostic potential of DEIRGs. A risk-score model was constructed based on the above results. The area under the curve (AUC) values were calculated to assess the effect of the model prediction. Furthermore, the Chinese Glioma Genome Atlas (CGGA) dataset was used for model validation. STRING database and functional enrichment analysis were used for exploring the gene interactions and the underlying functions and pathways. The CIBERSORT algorithm was used for correlation analysis of the marker genes and the tumor-infiltrating immune cells.

Results

There were 198 DEIRGs in GBM, including 153 upregulated genes and 45 downregulated genes. Seven marker genes (LYNX1, PRELID1P4, MMP9, TCF12, RGS14, RUNX1, and CCR2) were filtered out by sequential screening for DEIRGs. The regression coefficients (0.0410, 1.335, 0.005, −0.021, 0.123, 0.142, and −0.329) and expression data of the marker genes were used to construct the model. The AUC values for 1, 2, and 3 years were 0.744, 0.737, and 0.749 in the TCGA–GBM cohort and 0.612, 0.602, and 0.594 in the CGGA-GBM cohort, respectively, which indicated a high predictive power. The results of enrichment analysis revealed that these genes were enriched in the activation of T cell and cytokine receptor interaction pathways. The interaction network map demonstrated a close relationship between the marker genes MMP9 and CCR2. Infiltration analysis of the immune cells showed that dendritic cells (DCs) could identify GBM, while LYNX1, RUNX1, and CCR2 were significantly positively correlated with DCs expression.

Conclusion

This study analyzed the expression of IRGs in GBM and identified seven marker genes for the construction of an immune-related risk score model. These marker genes were found to be associated with DCs and were enriched in similar immune response pathways. These findings are likely to provide new insights for the immunotherapy of patients with GBM.

Immune System in Action

Tumor exists as a complex network of structures with an ability to evolve and evade the host immune surveillance mechanism. The immune milieu which includes macrophages, dendritic cells, natural killer cells, neutrophils, mast cells, B cells, and T cells is found in the core, the invasive margin, or the adjacent stromal or lymphoid component of the tumor. The immune infiltrate is heterogeneous and varies within a patient and between patients of the same tumor histology. The location, density, functionality, and the crosstalk between the immune cells in the tumor microenvironment influence the nature of immune response, prognosis, and treatment outcomes in cancer patients. Therefore, an understanding of the characteristics of the immune cells and their role in tumor immune surveillance is of paramount importance to identify immune targets and to develop novel immune therapeutics in the war against cancer. In this chapter, we provide an overview of the individual components of the human immune system and the translational relevance of predictive biomarkers.

Distinct Immunological Features of Inflammatory Demyelinating Diseases of the Central Nervous System

OBJECTIVE

The immunological features between neuromyelitis optica spectrum disorder (NMOSD), multiple sclerosis (MS), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), lacked systemic comparisons. Accordingly, we aimed to investigate immunological differences between NMOSD, MS, and MOGAD.

METHODS

Patients with MOGAD, MS, and NMOSD who received immunological tests including cytokine profiles and cytometry analysis of the lymphocyte subgroups were retrospectively reviewed and divided into training and validation sets. Discriminatory models based on immunological data were established to identify optimal classifiers using orthogonal partial least square discriminant analysis (OPLS-DA). Constructed models were tested in another independent cohort.

RESULTS

OPLS-DA of the immunological data from 50 patients (26 NMOSD, 14 MS, and 10 MOGAD) demonstrated the discriminatory values of a relatively low level of T-lymphocyte subsets, especially the CD4+ T cells, in MOGAD; a decreased NK cell, eosinophil, and lymphocyte level; an elevated neutrophil-to-lymphocyte ratio in NMOSD; and a declined IFN-γ-producing CD4+ T cells/Th with an increased IL-8 concentration in MS. All the models (NMOSD vs. MS, NMOSD vs. MOGAD, and MS vs. MOGAD) exhibited a significant predictive value and accuracy (>85%).

CONCLUSIONS

NMOSD, MS, and MOGAD may be different in pathogenesis, and several immunological biomarkers can serve as potential classifiers clinically.

Splenic Transcriptional Responses in Severe Visceral Leishmaniasis: Impaired Leukocyte Chemotaxis and Cell Cycle Arrest

Structural changes in the spleen have been reported in several infectious diseases. In visceral leishmaniasis (VL), a severe parasitic disease caused by Leishmania spp., the loss of white pulp accompanies a severe clinical presentation. Hamster model reproduces aspects of human VL progression. In the early stages, a transcriptomic signature of leukocyte recruitment was associated with white pulp hyperplasia. Subsequently, impaired leukocyte chemotaxis with loss of T lymphocytes in the periarteriolar lymphoid sheath occurred. This differential gene expression was subsequently corroborated by transcriptomic profiling of spleens in severe human VL. At the latest stage, spleen disorganization was associated with increasing clinical signs of VL. White pulp disruption was accompanied by decreased DLK1 expression. The expression of CXCL13, CCR5, CCL19, CCR6, CCR7 and LTA decreased, likely regulated by CDKN2A overexpression. Our findings enlighten a pathway implying cell cycle arrest and decreased gene expression involved in spleen organization.

The Immunological Mechanisms and Immune-Based Biomarkers of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) has become one of the major challenges of drug safety all over the word. So far, about 1,100 commonly used drugs including the medications used regularly, herbal and/or dietary supplements, have been reported to induce liver injury. Moreover, DILI is the main cause of the interruption of new drugs development and drugs withdrawn from the pharmaceutical market. Acute DILI may evolve into chronic DILI or even worse, commonly lead to life-threatening acute liver failure in Western countries. It is generally considered to have a close relationship to genetic factors, environmental risk factors, and host immunity, through the drug itself or its metabolites, leading to a series of cellular events, such as haptenization and immune response activation. Despite many researches on DILI, the specific biomarkers about it are not applicable to clinical diagnosis, which still relies on the exclusion of other causes of liver disease in clinical practice as before. Additionally, circumstantial evidence has suggested that DILI is mediated by the immune system. Here, we review the underlying mechanisms of the immune response to DILI and provide guidance for the future development of biomarkers for the early detection, prediction, and diagnosis of DILI.

Nasal polyp fibroblasts (NPFs)-derived exosomes are important for the release of vascular endothelial growth factor from cocultured eosinophils and NPFs

OBJECTIVE

Significant eosinophil infiltration and tissue remodeling are common characteristics of conditions associated with chronic airway inflammation, such as chronic rhinosinusitis with nasal polyp and bronchial asthma. This study was designed to elucidate the role of eosinophil-fibroblast interactions in tissue remodeling during chronic airway inflammation.

METHODS

Peripheral blood eosinophils or EoL-1 eosinophilic leukemia cells were cocultured with nasal polyp fibroblasts (NPFs). Coculture-induced release of exosomes, major components of extracellular vesicles (EVs), and a profibrotic cytokine, vascular endothelial growth factor (VEGF), were evaluated by enzyme-linked immunosorbent assay.

RESULTS

Eosinophil-NPF interactions stimulated the release of exosomes and VEGF into culture supernatants. Coculture-induced release of exosomes was stimulated earlier than VEGF release, at 3 h of incubation. The average size of the EVs released by NPFs was 133 ± 3.6 nm. NPF-derived EVs (exosome concentration: 25 pg/mL) significantly stimulated VEGF release from EoL-1 cells. Pretreatment of NPFs with exosome inhibitor, GW4869 or DMA attenuated the release of exosomes and VEGF from cocultured EoL-1 cells and NPFs.

CONCLUSION

The results of this study indicate that eosinophil-fibroblast interactions are important in the pathophysiology of tissue remodeling in eosinophil-predominant airway inflammation and that NPF-derived exosomes play a crucial role in the release of VEGF.

Role of Eosinophils in Intestinal Inflammation and Fibrosis in Inflammatory Bowel Disease: An Overlooked Villain?

Eosinophils are leukocytes which reside in the gastrointestinal tract under homeostatic conditions, except for the esophagus which is normally devoid of eosinophils. Research on eosinophils has primarily focused on anti-helminth responses and type 2 immune disorders. In contrast, the search for a role of eosinophils in chronic intestinal inflammation and fibrosis has been limited. With a shift in research focus from adaptive to innate immunity and the fact that the eosinophilic granules are filled with inflammatory mediators, eosinophils are becoming a point of interest in inflammatory bowel diseases. In the current review we summarize eosinophil characteristics and recruitment as well as the current knowledge on presence, inflammatory and pro-fibrotic functions of eosinophils in inflammatory bowel disease and other chronic inflammatory conditions, and we identify research gaps which should be covered in the future.

Baicalin relieves Mycoplasma pneumoniae infection‑induced lung injury through regulating microRNA‑221 to inhibit the TLR4/NF‑κB signaling pathway

Mycoplasma pneumoniae (MP) is a common pathogen that can cause respiratory infections. MP pneumonia (MPP) leads to numerous complications, including lung injury and even death. The present study aimed to investigate the protective effects of Baicalin treatment on MP infection‑induced lung injury and the molecular mechanism underlying these effects. Briefly, after mice were infected intranasally by MP and treated with Baicalin (80 mg/kg), serum levels of MP‑immunoglobulin M (IgM) were detected by ELISA. The expression levels of C‑reactive protein (CRP) in lung tissue were detected by immunohistochemistry and the bronchoalveolar lavage fluid (BALF) was examined by ELISA. Inflammatory factors and inflammatory cells in the BALF were assessed. The expression levels of microRNA (miR)‑221 in lung tissue were examined by reverse transcription‑quantitative PCR and pathological changes in lung tissue were detected by H&E staining. Cell apoptosis was evaluated by TUNEL assay and the protein expression levels of TLR4, MyD88 and NF‑κB were detected by western blotting. Baicalin treatment significantly reduced serum levels of MP‑IgM and CRP expression in lung tissue during MP infection. In addition, Baicalin decreased the levels of IL‑1β, IL‑6, IL‑18 and TNF‑α in the BALF, and the number of inflammatory cells. Baicalin also reduced the inflammatory infiltration in lung tissue induced by MP infection, improved the pathological changes detected in lung tissue, reduced apoptosis, and downregulated the protein expression levels of TLR4, MyD88 and NF‑κB. Furthermore, Baicalin treatment downregulated the expression of miR‑221 and the protective effects of Baicalin were attenuated by miR‑221 overexpression. In conclusion, Baicalin has a therapeutic effect on mice with MP infection‑induced lung injury, which may be related to inhibition of miR‑221 expression and regulation of the TLR4/NF‑κB signaling pathway.