The interleukin-4/interleukin-13 pathway in type 2 inflammation in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is predominantly a type 2 inflammatory disease associated with type 2 (T2) cell responses and epithelial barrier, mucociliary, and olfactory dysfunction. The inflammatory cytokines interleukin (IL)-4, IL-13, and IL-5 are key mediators driving and perpetuating type 2 inflammation. The inflammatory responses driven by these cytokines include the recruitment and activation of eosinophils, basophils, mast cells, goblet cells, M2 macrophages, and B cells. The activation of these immune cells results in a range of pathologic effects including immunoglobulin E production, an increase in the number of smooth muscle cells within the nasal mucosa and a reduction in their contractility, increased deposition of fibrinogen, mucus hyperproduction, and local edema. The cytokine-driven structural changes include nasal polyp formation and nasal epithelial tissue remodeling, which perpetuate barrier dysfunction. Type 2 inflammation may also alter the availability or function of olfactory sensory neurons contributing to loss of sense of smell. Targeting these key cytokine pathways has emerged as an effective approach for the treatment of type 2 inflammatory airway diseases, and a number of biologic agents are now available or in development for CRSwNP. In this review, we provide an overview of the inflammatory pathways involved in CRSwNP and describe how targeting key drivers of type 2 inflammation is an effective therapeutic option for patients.

Pädiatrische Rhinologie. / Pädiatrische Rhinologie.

The following review article highlights key topics in pediatric rhinology that are currently the focus in research and at conferences as well as in the interdisciplinary discussion between otorhinolaryngologists and pediatricians. In particular, congenital malformations such as choanal atresia or nasal dermoid cysts are discussed, followed by statements on the current procedures for sinogenic orbital complications as well as on the diagnosis and therapy of chronic rhinosinusitis in children. Furthermore, updates on the role of the ENT specialist in the care for children with cystic fibrosis and primary ciliary dyskinesia are provided.

The association of COVID-19 pandemic with the increase of sinogenic and otogenic intracranial infections in children: a 10-year retrospective comparative single-center study.

OBJECTIVE: Otitis media and sinusitis are common childhood infections, typically mild with good outcomes. Recent studies show a rise in intracranial abscess cases in children, raising concerns about a link to COVID-19. This study compares a decade of data on these cases before and after the pandemic. METHODS: This retrospective comparative analysis includes pediatric patients diagnosed with otitis media and sinusitis, who later developed intracranial abscesses over the past decade. We collected comprehensive data on the number of cases, patient demographics, symptoms, treatment, and outcomes. RESULTS: Between January 2013 and July 2023, our center identified 10 pediatric patients (median age 11.1years, range 2.2-18.0 years, 60% male) with intracranial abscesses from otitis media and sinusitis. Of these, 7 cases (70%, median age 9.7 years, range 2.2-18.0 years) occurred since the onset of the COVID-19 pandemic, while the remaining 3 cases (30%, median age 13.3 years, range 9.9-16.7 years) were treated before the pandemic. No significant differences were found in otolaryngological associations, surgical interventions, preoperative symptoms, lab findings, or postoperative antibiotics between the two groups. All patients showed positive long-term recovery. CONCLUSION: This study reveals 5-fold increase of pediatric otogenic and sinogenic intracranial abscess cases in the last three-years since the onset of the COVID-19 pandemic. While further investigation is needed, these findings raise important questions about potential connections between the pandemic and the severity of otitis media and sinusitis complications in children. Understanding these associations can improve pediatric healthcare management during infectious disease outbreaks.

[Blood eosinophilia in patients with severe bronchial asthma and chronic polypous rhinosinusitis treated with dupilumab: A review].

Bronchial asthma and chronic polypous rhinosinusitis are diseases associated with a T2-inflammatory immune response. These nosologies can be combined, creating the preconditions for a more severe course of multimorbidity, requiring the use of genetic engineering biological therapy. Dupilumab is a monoclonal antibody that can specifically bind to the alpha subunit of the interleukin-4 receptor and block the action of interleukins 4 and 13, which play a key role in the development of T2 inflammation. Numerous studies have demonstrated the high effectiveness of this medicament. The use of dupilumab in some cases may be accompanied by an increase in eosinophils in the blood. This article presents scientific base and our own experience in treating patients with dupilumab-associated eosinophilia, in addition we describe an algorithm for examining this group of patients for the purpose of timely diagnosis of diseases such as eosinophilic granulomatosis with polyangiitis, eosinophilic pneumonia, etc. It should be noted that in the most cases eosinophilia during targeted therapy with dupilumab is temporary and does not cause clinical manifestations.

Evaluation of sinonasal involvement in patients with asthma and chronic obstructive pulmonary disease.

Background: Asthma and chronic obstructive pulmonary disease (COPD) are the most common obstructive diseases. Based on the similarities, we aimed to evaluate sinonasal symptoms in patients with asthma or COPD, and compare the two diseases with regard to upper-airway involvement. Methods: Patients with asthma or with COPD who were followed up at Ankara University Immunology and Allergy or Chest Diseases Departments were included in the study. The participants went through pulmonary function tests, skin-prick tests, and disease severity assessment of either disease. Nasal endoscopic evaluations of all the patients were performed in the Department of Otorhinolaryngology. Lund-Mackay scoring was performed on the computed tomography of the paranasal sinus. Chronic rinosinusitis (CRS) diagnosis was made as recent guidelines. Results: A total of 112 subjects (number of women/men: n = 67/45; median age, 49 years [The range for IQR was 22 years]) were included in the study. Fifty-five patients had asthma, 33 had COPD, and 24 were healthy controls. Nasal symptoms were more frequent in the patients with asthma (patients with asthma, n = 52 [98%]; patients with COPD, n = 17 [52%]; controls, n = 9 [38%]) (p < 0.001). The median (IQR) 22-item Sino-Nasal Outcome Test (SNOT-22) questionnaire score was higher in the patients with asthma (33 [20-50]) than in the patients with COPD (8 [1.5-18.7]) and the control group (3.5 [0-18.7]) (p < 0.01). Patients with asthma had significantly higher prevalence rates of rhinosinusitis than did those in the COPD and the control groups (36%, 15.6%, 8.3%, respectively; p < 0.01). The SNOT-22 optimal cutoff score was calculated as ≥11 to detect the score limit for CRS prediction with the best sensitivity and specificity. Conclusion: As a result, patients with both asthma and COPD may have upper-airway symptoms. CRS, was primarily seen in the patients with asthma. Accordingly, SNOT-22 scores were higher in the patients with asthma than in those in the COPD and the control groups. A referral to the Ear Nose Throat department for further evaluation with nasal endoscopy and computed tomography of the paranasal may be required in a subgroup of patients.

The oxidant-antioxidant imbalance was involved in the pathogenesis of chronic rhinosinusitis with nasal polyps.

Background: Although oxidative stress is involved in the pathophysiological process of chronic rhinosinusitis with nasal polyps (CRSwNP), the specific underlying mechanism is still unclear. Whether antioxidant therapy can treat CRSwNP needs further investigation. Methods: Immunohistochemistry, immunofluorescence, western blotting and quantitative polymerase chain reaction (qPCR) analyses were performed to detect the distribution and expression of oxidants and antioxidants in nasal polyp tissues. qPCR revealed correlations between oxidase, antioxidant enzymes and inflammatory cytokine levels in CRSwNP patients. Human nasal epithelial cells (HNEpCs) and primary macrophages were cultured to track the cellular origin of oxidative stress in nasal polyps(NPs) and to determine whether crocin can reduce cellular inflammation by increasing the cellular antioxidant capacity. Results: The expression of NOS2, NOX1, HO-1 and SOD2 was increased in nasal epithelial cells and macrophages derived from nasal polyp tissue. Oxidase levels were positively correlated with those of inflammatory cytokines (IL-5 and IL-6). Conversely, the levels of antioxidant enzymes were negatively correlated with those of IL-13 and IFN-γ. Crocin inhibited M1 and M2 macrophage polarization as well as the expression of NOS2 and NOX1 and improved the antioxidant capacity of M2 macrophages. Moreover, crocin enhanced the ability of antioxidants to reduce inflammation via the KEAP1/NRF2/HO-1 pathway in HNEpCs treated with SEB or LPS. Additionally, we observed the antioxidant and anti-inflammatory effects of crocin in nasal explants. Conclusion: Oxidative stress plays an important role in the development of CRSwNP by promoting various types of inflammation. The oxidative stress of nasal polyps comes from epithelial cells and macrophages. Antioxidant therapy may be a promising strategy for treating CRSwNP.

Manifestation and associated factors of systemic and local allergy among patients with allergic fungal rhinosinusitis: An observational study.

Allergic fungal rhinosinusitis (AFRS) is a subtype of chronic rhinosinusitis, characterized by excessive immune responses to environmental molds or fungi. The diagnosis and classification of AFRS into systemic and local types remain clinically challenging due to overlapping characteristics. This study investigated the prevalence of AFRS, its manifestation and associated factors in systemic and local AFRS. A total of 200 patients diagnosed with fungal rhinosinusitis underwent both skin provocation tests (SPT) and nasal provocation tests (NPT) to confirm AFRS and classify systemic and local types. Patients were considered to have AFRS if either the SPT or NPT was positive. Among these, patients with systemic AFRS were those who had a SPT positive. Local AFRS was when patients had a negative SPT and a positive NPT. Medical history, serum total IgE level, nasal endoscopy examinations, and CT scans were also recorded. Most patients were female (65.8%), with a mean age of 55.6 years (SD = 14.4). Based on the SPT and NPT results, 31% of patients (n = 62) were diagnosed with AFRS. Among these, 54.8% (n = 34) had systemic AFRS, while 45.2% (n = 28) had local AFRS. Patients with AFRS exhibited significantly higher levels of total IgE, eosinophils, and more pronounced signs and symptoms compared to those without AFRS. However, no statistically significant differences were observed between patients with systemic AFRS and those with local AFRS. AFRS was prevalent in our study. Among patients with AFRS, both systemic AFRS and local AFRS were also prevalent. While allergic indicators and clinical presentations can aid in AFRS diagnosis, minimal distinctions were observed between systemic and local AFRS. A comprehensive assessment incorporating both local and systemic allergic responses through provocation tests, such as a combination of skin and nasal tests, is imperative for optimizing AFRS diagnosis and management.

A multi-view fusion lightweight network for CRSwNPs prediction on CT images.

Accurate preoperative differentiation of the chronic rhinosinusitis (CRS) endotype between eosinophilic CRS (eCRS) and non-eosinophilic CRS (non-eCRS) is an important topic in predicting postoperative outcomes and administering personalized treatment. To this end, we have constructed a sinus CT dataset, which comprises CT scan data and pathological biopsy results from 192 patients of chronic rhinosinusitis with nasal polyps (CRSwNP), treated at the Second Affiliated Hospital of Shantou University Medical College between 2020 and 2022. To differentiate CRSwNP endotype on preoperative CT and improve efficiency at the same time, we developed a multi-view fusion model that contains a mini-architecture with each network of 10 layers by modifying the deep residual neural network. The proposed model is trained on a training set and evaluated on a test set. The multi-view deep learning fusion model achieved the area under the receiver-operating characteristics curve (AUC) of 0.991, accuracy of 0.965 and F1-Score of 0.970 in test set. We compared the performance of the mini-architecture with other lightweight networks on the same Sinus CT dataset. The experimental results demonstrate that the developed ResMini architecture contribute to competitive CRSwNP endotype identification modeling in terms of accuracy and parameter number.

Study protocol: the biologics in severe chronic rhinosinusitis with nasal polyps survey.

INTRODUCTION: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a frequent condition affecting approximately 2% of the population. Medical treatment consists long-term use of intranasal corticosteroids and short-term use of oral corticosteroids, in adjunct with saline solution rinses. Surgical management is proposed in patients who failed after medical treatment. In France, two biologics are reimbursed in case of severe uncontrolled CRSwNP despite medical treatment and endoscopic sinus surgery. Waiting for head-to-head biologics comparison, studies should report the efficacy and safety of biologics in large real-life cohorts. This study protocol describes the aims and methods of a prospective, observational, national, multicentric cohort of patients with CRSwNP treated with biologics. METHODS AND ANALYSIS: The BIOlogics in severe nasal POlyposis SurvEy is a French multicentre prospective observational cohort study. The main aim is to assess the efficacy and tolerance of biologics in patients with CRSwNP, with or without association with other type 2 diseases, and to determine the strategies in case of uncontrolled disease under biologics. Patients over 18 years old requiring biologics for CRSwNP in accordance with its marketing approval in France (ie, severe nasal polyposis, with lack of control under nasal corticosteroid, systemic corticosteroids and surgery) are invited to participate. Collected data include topical history of surgical procedures and biologics, medication and use of systemic corticosteroids, visual analogical scales for specific symptoms, Sino-Nasal Outcome Test-22 questionnaire, nasal polyp score, asthma control test, Lund-Mackay score on CT scan and IgE concentration and eosinophilic count on blood sample. TRIAL REGISTRATION: NCT05228041/DRI_2021/0030.

Nasolacrimal Duct Obstruction Secondary to Eosinophilic Chronic Rhinosinusitis: A Case Report.

A 47-year-old Japanese woman presented with a 1-year history of right-sided epiphora. On initial consultation, the patient had a high right tear meniscus height. CT images revealed bilateral soft tissue opacification in the nasal cavity and maxillary, frontal, and ethmoid sinuses. The lesion in the right nasal cavity and maxillary sinus involved the right lacrimal sac and nasolacrimal duct. Blood test results showed elevated eosinophil count. Endoscopic sinus surgery and excisional biopsy of the nasolacrimal duct were performed. Histopathological examinations of the excised right nasolacrimal duct and nasal polyps from the nasal cavity and maxillary sinus showed high levels of eosinophilic inflammatory infiltrates. The definite diagnosis of eosinophilic chronic rhinosinusitis was made, based on clinical, radiological, and histopathological findings. At 1.5-year follow-up, tear meniscus height was normal, the lacrimal drainage system remained patent, and the rhinosinusitis did not recur.

[A comparative study of the effectiveness of azoximer bromide and surgery on the quality of the life of patients with chronic rhinosinusitis without nasal polyps]. / Sravnitel'naya otsenka vliyaniya azoksimera bromida i khirurgicheskogo lecheniya na kachestvo zhizni patsientov s khronicheskim rinosinusitom bez polipov.

OBJECTIVE: The aim of this study was to compare the effects of azoximer bromide and surgery on the quality of life of patients with chronic rhinosinusitis (CRS) without polyps. We also wanted to examine changes in the patient's emotional state and the nature of their complaints. MATERIAL AND METHODS: The results of using the Visual Analogue Scale (VAS) and the Sino-Nasal Outcome Test-22 (SNOT-22) questionnaire in patients with CRS without severe or moderate-severe polyps, before treatment and 3 months after treatment, are presented. Patients, depending on their choice, were treated with functional endoscopic intervention or a course of 6 mg/ml azoximer bromide (1 ml per day, a course of at least 10 days). RESULTS: The median [interquartile range] score for VAS in patients before azoximer bromide treatment was 6.7 [6.3; 7.05] points, after treatment 4.2 [3.50; 4.70] points. The median [interquartile range] of VAS scores in patients before surgical treatment was 6.4 [6.1; 6.9] points, and after 4.8 [4.50; 5.30] points. The median [interquartile range] of the SNOT-22 score before azoximer bromide treatment was 33 [32; 36] points, after treatment - 24 [22; 25] points. The median [interquartile range] of the SNOT-22 score before surgery was 34 [32; 36] points, after treatment - 19 [18; 21.25] points. CONCLUSION: Azoximer bromide treatment and surgery improve the quality of life of patients with CRS (according to the visual analog scale and all SNOT-22 domains) during a control survey after 3 months (p<0.001). Surgical treatment has a stronger impact on the quality of life, which is more noticeable in the influence on the domains "Rhinological symptoms", "Extranasal symptoms", "Ear/facial symptoms" (p<0.05). According to the domains "Psychological dysfunction", "Sleep dysfunction", surgical intervention had no advantages in affecting the quality of life, compared with taking azoximer bromide (p<0.05).

[Clinical observation of the course of eosinophilic otitis media against the background of biological therapy of chronic polypous rhinosinusitis]. / Klinicheskoe nablyudenie techeniya eozinofil'nogo srednego otita na fone provedeniya biologicheskoi terapii khronicheskogo polipoznogo rinosinusita.

Eosinophilic otitis media (EoOM) is a variant of exudative otitis media characterized by a persistent persistent course, the presence of a very viscous effusion in the tympanic cavity, comorbidally associated with chronic polypous rhinosinusitis and bronchial asthma. The disease is characterized by a persistent progressive course, which can lead to a gradual decrease in hearing up to complete deafness. Conservative treatment methods for EoOM include local and systemic administration of glucocorticosteroids. Encouraging data on the effectiveness of biological therapy have appeared in recent publications. The above clinical observation examines the course of EoOM in a patient who received biological therapy with dupilamab.

[Problems of polypragmasia and drug interaction in the treatment of uncomplicated acute rhinosinusitis]. / Problemy polipragmazii i lekarstvennogo vzaimodeistviya v terapii neoslozhnennogo ostrogo rinosinusita.

This publication discusses polypragmasia and drug interactions in the treatment of uncomplicated acute rhinosinusitis in children and adults. Treatment of rhinosinusitis on an outpatient basis in multimorbid patients may be accompanied by multiple prescriptions, which increases the risk of drug interactions. The article reflects the most significant inappropriate combinations of both medicines and biologically active additives, herbal preparations. The advantages of using drugs with proven effectiveness, in particular intranasal glucocorticosteroids, are considered.

Effectiveness of the piezoelectric knife as a tool for nasal beak reduction in patients with chronic rhinosinusitis - a pilot study.

AIM: The aim of this study was to evaluate the safety and efficacy of the piezoelectric knife as a new tool for frontal beak surgery in patients with chronic rhinosinusitis (CRS) both in terms of imaging and perception of symptoms' outcomes. MATERIALS AND METHODS: The study involved 28 patients with CRS who underwent endoscopic sinus surgery (ESS) using a piezoelectric knife in the frontal recess region. Assessment of sinus imaging and patients' quality of life (QoL) was performed before and after surgery with the Lund-Kennedy and Lund-Mackay systems and the 22-item Sino-Nasal Outcomes Test (SNOT-22). RESULTS: Median scores on the Lund-Kennedy and Lund-Mackay systems decreased within 24 weeks after surgery with piezo knife assistance by 4 and 5 points, respectively. QoL improved with SNOT-22 scores decreasing by 35.5 points. CONCLUSIONS: ESS with the piezoelectric knife used for frontal beak reduction turned out to be a safe procedure. In the studied group of patients, the improvement was observed in terms of imaging, patients' perceptions of symptoms, and QoL outcomes. Therefore, the piezoelectric knife might be a valuable supporting tool in ESS in patients with CRS, although further observation is needed.

Choanephora infundibulifera Rhinosinusitis in Man with Acute Lymphoblastic Leukemia, Tennessee, USA.

Choanephora infundibulifera is a member of the Mucorales order of fungi. The species is associated with plants as a saprophyte or parasite and may be responsible for spoilage or disease but is an uncommon cause of human infection. We describe C. infundibulifera rhinosinusitis in a young man with leukemia in Tennessee, USA.

Correlation among post-surgery recurrence of CRSwNP and TCM syndromes and tissue inflammatory cell infiltration type: a study protocol.

BACKGROUND: Functional endoscopic sinus surgery is a principal option for treating chronic rhinosinusitis with nasal polyps (CRSwNP) after medication failures. Unfortunately, some patients still have unsatisfactory postoperative recovery. The type of inflammatory cell infiltration in nasal polyp tissue has been reported available for recurrence prediction. As it is invasive and time-consuming, this technique is hard to promote clinically under the existing technical conditions. And during the course of clinical treatment, we have noted that differences in the postoperative recurrence rate of patients present among different traditional Chinese medicine syndrome types. METHODS AND ANALYSIS: This is a non-randomized, single-center, and prospective cohort study started in Chengdu Sichuan Province, People's Republic of China, in January 2021. A total of 200 participants will be recruited from patients who are diagnosed with CRSwNP and prepared for functional endoscopic sinus surgery. We collect preoperative data which includes general information, medical history, TCM syndromes, visual analogue scale (VAS) of subjective symptoms, Lund-Kennedy endoscopic score, and Lund-Mackay score of computed tomography (CT) scanning of sinuses. We acquire the VAS score and Lund-Kennedy score of subjective symptoms through multiple planned follow-up after surgery. After 1 year of follow-up, the recurrence rate will be calculated, and the curative effect will be assessed. Meanwhile, the patients' pathological sections will be sorted out, and inflammatory cell infiltration will be analyzed. Statistical analysis will be carried out to evaluate the correlation among CRSwNP recurrence and TCM syndrome types and tissue inflammatory cell infiltration types. Then we will establish a predictive model for CRSwNP recurrence. Analyses of survey data include descriptive and inferential statistical approaches. DISCUSSION: This is the first prospective cohort study on investigating the correlation of CRSwNP recurrence with TCM syndrome types and tissue inflammatory cell infiltration types. Through this study, we hope to discover a new and simple, effective, and noninvasive way to predict the recurrence rate rapidly after CRSwNP and provide reference for the intervention timing of traditional Chinese medicine application, thereby achieving customized diagnosis and treatment, minimizing risks of surgical events, and delaying postoperative recurrence of CRSwNP. SYSTEMATIC REVIEW REGISTRATION: PROSPERO ChiCTR2100041646.

Bacterial and fungal communities in chronic rhinosinusitis with nasal polyps.

OBJECTIVE: Multiple inflammatory mechanisms dynamically interact in the development of chronic rhinosinusitis with nasal polyps (CRSwNP). Disruption of the relationship between host and environmental factors on the mucosal surface leads to the development of inflammation. Microorganisms constitute the most important part of environmental factors. METHODS: 28 volunteers (18 CRSwNP patients and 10 healthy individuals) were included in the study. Eight patients were recurrent nasal polyposis cases, and the remaining were primary cases. Swab samples were taken from the middle meatus under endoscopic examination from all participants. After DNA extraction, a library was created with the Swift Amplicon 16S + ITS kit and sequenced with Illumina Miseq. Sequence analysis was performed using QIIME, UNITE v8.2 database for ITS and Silva v138 for 16S rRNA. RESULTS: The predominant bacteria in all groups were Firmicutes, Proteobacteria, Actinobacteria as phyla and Staphylococcus, Corynebacterium, Sphingomonas as genera. Comparison of bacterial communities of CRSwNP patients and control group highlighted Corynebacterium, as the differentiating taxa for control group and Streptococcus, Moraxella, Rothia, Micrococcus, Gemella, and Prevotella for CRSwNP patients. The predominant fungal genus in all groups was Malassezia. Staphylococcus; showed a statistically significant negative correlation with Dolosigranulum. Corynebacterium had a positive correlation with Anaerococcus, and a negative correlation with Neisseria, Prevotella, Fusobacterium and Peptostreptococcus. CONCLUSION: Nasal microbiome of CRSwNP patients shows greater inter-individual variation than the control group. Corynebacterium is less abundant in patients with CRSwNP compared to the control group. Malassezia is the predominant fungus in the nasal cavity and paranasal sinuses and correlates positively with the abundance of Corynebacterium.

[The preliminary application of mNGS in the diagnosis of invasive fungal sinusitis].

Objective: By conducting a retrospective analysis of the clinical data of 14 patients diagnosed with invasive fungal rhinosinusitis (IFRS) confirmed by metagenomics next generation sequencing (mNGS) technology, we aim to explore the rapid diagnosis value of mNGS in IFRS. Methods: The clinical data of 14 IFRS patients admitted to TianJin First Central Hospital were retrospectively analyzed from February 2021 to October 2023. The study cohort comprised 8 males and 6 females, with ages ranging from 14 to 77 years. All patients were diagnosed as IFRS by performing mNGS sequencing technology of nasal sinus lesion biopsy specimens. Clinical data such as laboratory examination, imaging examination, histopathological examination results, treatment plan and prognosis were summarized and analyzed. Results: All 14 patients were diagnosed as IFRS, with mNGS detecting pathogens such as Rhizopus (7 cases), Aspergillus (5 cases), Trichoderma (1 case), and Scedosporium apiospermum (1 case). Follow-up evaluations were conducted for a period ranging from 2 months to 2 years post-treatment. At the end of follow-up, 11 out of 14 IFRS patients achieved a complete cure with no signs of recurrence, while the symptoms of the remaining 3 patients significantly improved with comprehensive treatment. Conclusion: mNGS emerges as a highly effective diagnostic tool for IFRS, providing valuable microbiological evidence for clinical diagnosis and demonstrating promising clinical utility.

Macrophages in CRSwNP: Do they deserve more attention?

Chronic rhinosinusitis (CRS) represents a heterogeneous disorder primarily characterized by the persistent inflammation of the nasal cavity and paranasal sinuses. The subtype known as chronic rhinosinusitis with nasal polyposis (CRSwNP) is distinguished by a significantly elevated recurrence rate and augmented challenges in the management of nasal polyps. The pathogenesis underlying this subtype remains incompletely understood. Macrophages play a crucial role in mediating the immune system's response to inflammatory stimuli. These cells exhibit remarkable plasticity and heterogeneity, differentiating into either the pro-inflammatory M1 phenotype or the anti-inflammatory and reparative M2 phenotype depending on the surrounding microenvironment. In CRSwNP, macrophages demonstrate reduced production of Interleukin 10 (IL-10), compromised phagocytic activity, and decreased autophagy. Dysregulation of pro-resolving mediators may occur during the inflammatory resolution process, which could potentially hinder the adequate functioning of anti-inflammatory macrophages in facilitating resolution. Collectively, these factors may contribute to the prolonged inflammation observed in CRSwNP. Additionally, macrophages may enhance fibrin cross-linking through the release of factor XIII-A (FAXIII), promoting fibrin deposition and plasma protein retention. Macrophages also modulate vascular permeability by releasing Vascular endothelial growth factor (VEGF). Moreover, they may disrupt the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs), which favors extracellular matrix (ECM) degradation, edema formation, and pseudocyst development. Accumulating evidence suggests a close association between macrophage infiltration and CRSwNP; however, the precise mechanisms underlying this relationship warrant further investigation. In different subtypes of CRSwNP, different macrophage phenotypic aggregations trigger different types of inflammatory features. Increasing evidence suggests that macrophage infiltration is closely associated with CRSwNP, but the mechanism and the relationship between macrophage typing and CRSwNP endophenotyping remain to be further explored. This review discusses the role of different types of macrophages in the pathogenesis of different types of CRSwNP and their contribution to polyp formation, in the hope that a better understanding of the role of macrophages in specific CRSwNP will contribute to a precise and individualized understanding of the disease.