Evaluation of CNPase and TGFß1/Smad Signalling Pathway Molecule Expression in Sinus Epithelial Tissues of Patients with Chronic Rhinosinusitis with (CRSwNP) and without Nasal Polyps (CRSsNP).

Chronic rhinosinusitis with and without nasal polyps (CRSwNP and CRSsNP, respectively) is a chronic inflammatory disease affecting almost 5 to 12% of the population and exhibiting high recurrence rates after functional endoscopic sinus surgery (FESS). TGFß1-related pathways contribute to tissue remodelling, which is one of the key aspects of CRS pathogenesis. Additionally, adenosine signalling participates in inflammatory processes, and CNPase was shown to elevate adenosine levels by metabolizing cyclic monophosphates. Thus, the aim of this study was to assess the expression levels of Smad2, pSmad3, TGFß1, and CNPase protein via immunohistochemistry in sinus epithelial tissues from patients with CRSwNP (n = 20), CRSsNP (n = 23), and non-CRS patients (n = 8). The expression of Smad2, pSmad3, TGFß1, and CNPase was observed in the sinus epithelium and subepithelial area of all three groups of patients, and their expression correlated with several clinical symptoms of CRS. Smad2 expression was increased in CRSsNP patients compared to CRSwNP patients and controls (p = 0.001 and p < 0.001, respectively), pSmad3 expression was elevated in CRSwNP patients compared to controls (p = 0.007), TGFß1 expression was elevated in CRSwNP patients compared to controls (p = 0.009), and CNPase was decreased in CRSsNP patients compared to controls (p = 0.03). To the best of our knowledge, we are the first to demonstrate CNPase expression in the upper airway epithelium of CRSwNP, CRSsNP, and non-CRS patients and point out a putative synergy between CNPase and TGFß1/Smad signalling in CRS pathogenesis that emerges as a novel still undiscovered aspect of CRS pathogenesis; further studies are needed to explore its function in the course of the chronic inflammation of the upper airways.

Evaluation of Changes in the Patency of the Nasal Cavity and Eustachian Tube Depending on the Phase of the Menstrual Cycle: A Pilot Study.

(1) Background: Estrogen and progesterone, hormones specific to females, undergo fluctuations during the menstrual cycle. The aim of this study was to assess subjective and objective changes in nasal cavity and Eustachian tube patency depending on the phase of the menstrual cycle in two groups of women: those in a follicular phase group and those in a luteal phase group. (2) Materials and Methods: The study group consisted of 25 healthy non-pregnant women aged 24 to 32. Based on the phase of the cycle confirmed in sonography, they were divided into follicular phase (FP) and luteal phase (LP) groups. The Eustachian tube and nasal cavity patency examination was carried out using a SNOT-22 Questionnaire, a rhinomanometer, and a tympanometer. (3) Results: We observed that the incidence of nasal obstruction in SNOT-22 was significantly dependent on the cycle phase (p = 0.012) and was lower in the FP compared to the LP. Similar relationships were noticed between the cycle phase and the rhinomanometry outcome, where the LP was associated with a lower flow. We also revealed that the incidence of ear blockage significantly depended on the cycle phase (p = 0.001) and was lower in the FP compared to the LP. Women whose nasal patency deteriorated during the LP also had more negative pressure values in tympanometry. We observed that patients with negative PEAK L and R levels had a lower flow in rhinomanometry. (4) Conclusions: The results highlight the menstrual cycle's substantial impact on both subjective and objective nasal and Eustachian tube patency measurements. The novel finding in this study is that women whose nasal patency deteriorated during the luteal phase also had more negative pressure values in tympanometry. These results suggest that the deterioration of hearing during the menstrual cycle could be a result of swelling of the nasal mucosa and tubes.

Comparative Study of Clinical Features of Patients with Different Types of Benign Paroxysmal Positional Vertigo.

Objectives: Even though BPPV is one of the most common causes of vertigo, it is often underdiagnosed and omitted in the diagnosis of patients reporting vertigo. The aim of the study was to establish a diagnostic pattern useful in patients admitted due to vertigo, based on the most common clinical characteristics of patients suffered from posterior canal BPPV (PC-BPPV), horizontal canal BPPV with geotropic (HCG-BPPV) and apogeotropic nystagmus (HCA-BPPV). Methods: The analysis covered the results obtained in 105 patients with a positive result of the Dix-Hallpike maneuver or the supine roll test. The patients were divided into 3 groups based on the BPPV type: gr.1:PC-BPPV (60%); gr.2: HCG-BPPV (27%); gr.3: HCA-BPPV (13%). Patients before the diagnostic maneuvers filled the questionnaire concerning their symptoms and previous diseases. Results: Almost all patients had vertigo during turning over in bed and the character of the symptoms was paroxysmal. The answers to questions about the type of head movement evoked vertigo and how long vertigo lasted were differentiating. The percentages of correct diagnosis speculated by the combined answers were 69.6% in PC-BPPV, 61.8% in HCG-BPPV, and 80% in HCA-BPPV. Conclusions: Basing on those observations there is presented the diagnostic schedule which could be useful in dizziness examination. The above results indicate that a properly collected interview with the patient allows for a high percentage of accurate diagnosis.

Planned Subtotal Resection following Stereotactic Radiosurgery of Koos 3 and 4 Vestibular Schwannomas.

Background/Objectives: Surgical resection of medium to large vestibular schwannomas (VSs, Koos grade 3 and 4) is a widely used approach, although stereotactic radiosurgery (SRS) is increasingly proposed as initial treatment. The quality of life-centered approach is challenged in cases where tumor growth control cannot be achieved with SRS, thus necessitating salvage surgery. We present a series of eight consecutive patients who required surgery due to continued tumor growth after SRS. Methods: Of the 146 patients with VS grades 3 and 4 initially treated with SRS, only eight patients (mean age, 54 ± 7.2 years; range, 42-63 years) required subsequent surgery. Their mean tumor volume was 9.9 ± 3.2 cm3. The mean time from SRS to first tumor progression and planned subtotal resection was 23 ± 5.9 months and 45 ± 17.5 months, respectively. SRS was not performed after the surgery in favor of a "wait and rescan" approach. Tumor residue was monitored on follow-up magnetic resonance imaging. In all patients, tumor growth control after planned subtotal resection was maintained at 63 ± 19.8 months. Results: None of the 146 patients had serious complications after SRS. In the eight patients who required surgery, tumor growth between 22% and 212% (mean, 4 cm3) was reported within 26 to 84 months after SRS. Before salvage surgery, they scored 1 point on the House-Brackmann scale. Subtotal excision was performed, and VIIth nerve function was preserved in all patients. At 63 ± 19.8 months, 3 patients had a House-Brackmann score of 1, four patients had a score of 2, and one patient had a score of 3. Conclusions: Surgical excision of medium to large VS after SRS can be relatively safe, provided that a quality of life-centered approach of subtotal resection is used.

Subtotal resection of vestibular schwannoma with subsequent Gamma Knife irradiation - tumor growth control, facial and cochlear nerve outcome - preliminary results.

<b>Introduction:</b> The choice of treatment of vestibular schwannoma (VS) depends on several factors, including the tumor size, the patient's age and overall health, and the presence and severity of symptoms.<b>Aim:</b> The aim of the study was to assess the effectiveness of intentional subtotal resection (STR) of tumor followed by Gamma Knife surgery (GKS) in patients with larger VS (Koos 3 and 4).<b>Materials and methods:</b> The retrospective analysis was performed on 18 patients. Data of VS volumes measured in MRI, the facial nerve function assessed in the House-Brackmann scoring system (HB), and the results of audiological examination expressed on the Gardner-Robertson scale (GR) were collected preoperatively, postoperatively, and post-GKS.<b>Results:</b> Preoperatively, the main symptom was hearing loss observed in 13 out of 18 patients. The facial nerve function was assessed as HB 1 in 16, whereas HB 2 in 2 patients. The mean volume of the tumor in the initial MRI amounted to 16.81 cm³ . Postoperatively, the facial nerve was assessed as HB 1 or 2 in 16, whereas HB 3 in 2 patients. Serviceable hearing was presented by only 4 persons. The Mean diameter of the tumor after subtotal surgery amounted to 3.16 cm³ , 1.83 cm³ after GKS, and 1.58 cm³ at the last follow-up. The facial nerve function and hearing level remained the same as before GKS in all patients.<b>Conclusions:</b> STR followed by GKS can be a safe and effective method of treatment of large VS concerning the functional outcome of the facial nerve and the tumor volume growth control.

Objective Measurements of Nasal Obstruction and Eustachian Tube Function in Pregnant Women.

Background: Hormonal changes during pregnancy have a substantial effect on the swelling of the mucous membrane in the nasal cavity, resulting in rhinitis and Eustachian tube dysfunction. The aim of the study was to assess subjective and objective changes in nasal cavity and Eustachian tube patency in the third trimester of pregnancy. Materials and Methods: The study group included fifty 18-41 year-old women in the third trimester of pregnancy. The control group consisted of 25 females aged 25 to 31 who were not pregnant. The Eustachian tube and nasal cavity patency examination was carried out using a rhinomanometer, a tympanometer and a SNOT-22 Questionnaire. Results: The SNOT-22 showed that subjective nasal obstruction was assessed as strong or worse by 42% of the study group, which was significantly higher than in the control group and confirmed with rhinomanometry. A total of 68% of the study group reported a subjective ear fullness which correlated with the week of pregnancy. The tympanometry showed that all pregnant women exhibited a type A tympanogram, but tympanometry values decreased at higher weeks of pregnancy, and statistical analysis confirmed a significant difference between the study group and the control group in tympanometry for both ears. Conclusions: The results highlight the substantial impact on both subjective and objective measurements of nasal and Eustachian tube patency. Almost every woman in the third trimester of pregnancy experiences nasal obstruction, and nearly 70% struggle with ear fullness. Recognizing and addressing these challenges are pivotal for ensuring the well-being of pregnant individuals and enhancing the quality of antenatal care.

Injury of the Hyoid Bone as a Rare Complication in Cervical Spine Rehabilitation: A Case Report.

Neck pain is a common reason for primary care visits, and its differential diagnosis should consider various conditions. The reported incidence of hyoid bone fractures is extremely low, accounting for only 0.002% of all fractures. The most common causes of hyoid bone fractures include strangulation attempts and motor vehicle accidents. We report a case of an uncommon complication of manual therapy of the cervical spine. A 76-year-old woman complained of neck pain that worsened during speaking and swallowing, originating from a neck physiotherapy session. The otolaryngological examination revealed tenderness on the right side of the neck. Flexible nasal endoscopy demonstrated a shallow right piriform recess and asymmetry of the arytenoid cartilages. Computer tomography scan of the neck showed an isolated fracture of the right greater horn (cornu major) of the hyoid bone. The treatment was nonsurgical, with the use of a Schantz collar and pain relief drugs. Reported symptoms of hyoid bone fractures include dysphagia, odynophagia, and neck pain. In most cases of hyoid fractures, conservative management suffices, involving rest, analgesic and anti-inflammatory treatment, and neck immobilization. Surgical treatment is often necessary in the cases of fractures accompanying other injuries.

The Relationship between Fine Particle Matter (PM2.5) Exposure and Upper Respiratory Tract Diseases.

PM2.5 is one of the most harmful components of airborne pollution and includes particles with diameters of less than 2.5 µm. Almost 90% of the world's population lives in areas with poor air quality exceeding the norms established by the WHO. PM2.5 exposure affects various organs and systems of the human body including the upper respiratory tract which is one of the most prone to its adverse effects. PM2.5 can disrupt nasal epithelial cell metabolism, decrease the integrity of the epithelial barrier, affect mucociliary clearance, and alter the inflammatory process in the nasal mucosa. Those effects may increase the chance of developing upper respiratory tract diseases in areas with high PM2.5 pollution. PM2.5's contribution to allergic rhinitis (AR) and rhinosinusitis was recently thoroughly investigated. Numerous studies demonstrated various mechanisms that occur when subjects with AR or rhinosinusitis are exposed to PM2.5. Various immunological changes and alterations in the nasal and sinonasal epithelia were reported. These changes may contribute to the observations that exposure to higher PM2.5 concentrations may increase AR and rhinosinusitis symptoms in patients and the number of clinical visits. Thus, studying novel strategies against PM2.5 has recently become the focus of researchers' attention. In this review, we summarize the current knowledge on the effects of PM2.5 on healthy upper respiratory tract mucosa and PM2.5's contribution to AR and rhinosinusitis. Finally, we summarize the current advances in developing strategies against PM2.5 particles' effects on the upper respiratory tract.

The midfacial segment pain: little known disorder in need of scientific evaluation.

Despite its inclusion in the International Classification of Orofacial Pain, tension-type orofacial pain has little support in the scientific literature. However, a similar-in-phenotype orofacial pain perceived in the middle segment of the face has been described by few case series from mostly ear, nose and throat clinics. The authors of these descriptions used the term 'midfacial segment pain'. Patients had no significant sinonasal disorder in these studies, but experienced symmetrical pain perceived mostly over the maxillary and ethmoid sinuses. No aura or autonomic symptoms were present apart from mild nasal congestion or rhinorrhoea in some individuals. This description appears similar to tension-type headache, but with midfacial location. In this viewpoint, we indicate a need to fill this gap in scientific knowledge and propose a multicentre interdisciplinary study that would give a detailed description of this type of orofacial pain.

HMGB1 Carried by Small Extracellular Vesicles Potentially Plays a Role in Promoting Acquired Middle Ear Cholesteatoma.

Cholesteatoma is a specific medical condition involving the abnormal, non-cancerous growth of skin-like tissue in the middle ear, potentially leading to a collection of debris and even infections. The receptor for advanced glycation (RAGE) and its ligand, high-mobility box 1 (HMGB1), are both known to be overexpressed in cholesteatoma and play a potential role in the pathogenesis of the disease. In this study, we investigated the role of small extracellular vesicles (sEVs) in carrying HMGB1 and inducing disease-promoting effects in cholesteatoma. No significant differences in the concentration of isolated sEVs in the plasma of cholesteatoma patients (n = 17) and controls (n = 22) were found (p > 0.05); however, cholesteatoma-derived sEVs carried significantly higher levels of HMGB1 (p < 0.05). In comparison to sEVs isolated from the plasma of controls, cholesteatoma-derived sEVs significantly enhanced keratinocyte proliferation and IL-6 production (p < 0.05), potentially by engaging multiple activation pathways including MAPKp44/p42, STAT3, and the NF-κB pathway. Thus, HMGB1(+) sEVs emerge as a novel factor potentially promoting cholesteatoma progression.

Susac syndrome - A review of current knowledge and own experience.

Susac syndrome is a rare connective tissue disorder. The pathology affects the small vessels of the brain, retina, and inner ear, and therefore the main symptoms of the disease include encephalopathy, visual disturbances, and sensorineural hearing loss. The aim of this article is to review the current medical knowledge on Susac syndrome and to present our clinical experience regarding this disease entity. In the paper, we are also presenting a case of a 25-year-old patient who was diagnosed with Susac syndrome on the basis of clinical presentation and additional test results. Susac syndrome should be differentiated from multiple sclerosis and other causes of multifocal brain damage as early diagnosis and treatment play a key role in later prognosis.

Change in the Characteristics of Patients Qualified for Hearing Aids over the Last 25 Years in Poland.

Hearing loss is one of the most common causes of disability worldwide. The aim of the study was to compare the demographic structure and the results of hearing tests in people qualified for hearing aids over the last 25 years. The material covered 1246 patients qualified for hearing aids in the years 1996-2001 and 2016-2021. Patients were divided into two groups according to the time of qualifying for hearing aids. Group 1 (G1) consisted of 759 people qualified in the years 1996-2001, and Group 2 (G2) comprised 487 people qualified in the years 2016-2021. Statistical analysis was performed on the results of pure tone threshold audiometry and the demographic structure in both groups. Patients in G1 had statistically significantly elevated hearing thresholds (HT) in the air conduction range at frequencies from 2000 to 8000 Hz in relation to G2 patients. The opposite situation was observed for the bone conduction threshold. G2 patients had significantly elevated bone conduction HT at frequencies from 250 to 1000 Hz compared to G1 patients. The age structure in both groups was similar; however, the gender distribution was statistically significantly different. In G1 women accounted for 40%, and in G2, they became the dominant gender (53%). Over the last twenty years, there has been a change in the structure of patients qualified for hearing aids. Although the age has remained similar, today, patients decide to use hearing aids at an earlier stage of hearing loss than 25 years ago. Modern women began to use hearing aids much more often.

A Relation between Obstructive Sleep Apnea in Pregnancy and Delivering Small for Gestational Age Infant-A Systematic Review.

Obstructive sleep apnea (OSA) during pregnancy can negatively affect both the mother and the baby. Our main goal is to show whether there is an association between OSA during pregnancy and delivering small for gestational age (SGA) infants. This systematic review was conducted according to the PRISMA 2020 statement using three databases: MEDLINE via PubMed, Scopus, and Cochrane Library. All databases were last accessed on 1 June 2023. The implemented systematic literature search identified 744 articles. After excluding reviews, meta-analyses, book chapters, case reports, and letters, 47 studies were analyzed, 18 of which finally met the inclusion criteria. The included studies mainly indicate that OSA during pregnancy may not significantly impact SGA, but some of them have shown the existence of this relation. Nevertheless, it is recommended that all pregnant women should be screened for symptoms of OSA and that sleep tests should be performed on those who show signs of it. Detecting and treating OSA early in pregnancy can help reduce the condition's negative effects. However, more extensive studies are still needed to gather clear evidence on the impact of an OSA diagnosis on mothers and babies.

Expression and Regulatory Mechanisms of MicroRNA in Cholesteatoma: A Systematic Review.

Cholesteatoma is a temporal bone disease characterized by dysfunctions of keratinocytes. MicroRNAs (miRNAs) are evolutionary conserved noncoding RNAs that regulate mRNA expression. They can be packaged into exosomes and transported to target cells that can be used in the future therapy of cholesteatoma. This study aimed to collect knowledge on the role of miRNAs and exosomal miRNAs in cholesteatoma and was conducted according to the PRISMA guidelines for systematic reviews. Four databases were screened: Pubmed/MEDLINE, Web of Science, Scopus, and the Cochrane Library. The last search was run on the 6th of June 2023. We included full-text original studies written in English, which examined miRNAs in cholesteatoma. The risk of bias was assessed using the Office of Health Assessment and Translation (OHAT) Risk of Bias Rating Tool, modified for the needs of this review. We identified 118 records and included 18 articles. Analyses revealed the downregulation of exosomal miR-17 as well as miR-10a-5p, miR-125b, miR-142-5p, miR34a, miR-203a, and miR-152-5p and the overexpression of exosomal miR-106b-5p as well as miR-1297, miR-26a-5p, miR-199a, miR-508-3p, miR-21-3p, miR-584-5p, and miR-16-1-3p in cholesteatoma. The role of differentially expressed miRNAs in cholesteatoma, including cell proliferation, apoptosis, the cell cycle, differentiation, bone resorption, and the remodeling process, was confirmed, making them a potential therapeutic target in this disease.

The Latest Craniofacial Reconstructive Techniques Using Anchored Implants after Surgical Treatment of Nasal and Paranasal Sinuses Tumors.

Reconstructive surgery after surgical treatment of neoplasms in the head and neck region is always a challenge. Many factors are responsible for the success of reconstruction. The anatomy of the facial region is complex, which significantly influences the aesthetic effect of the reconstruction. Moreover, many patients undergo postoperative radiotherapy after surgical treatment, which affects the range of reconstructive techniques. The aim of this study is to review current reconstructive methods in the craniofacial region, using bone-anchored implants to attach nasal prostheses. The article also comprises the authors' own experience with successful single-stage, Vistafix 3 osseointegrated implants for the attachment of an external nasal prosthesis in a 51-year-old man after surgical removal of squamous cell carcinoma of the nose and paranasal sinuses. The literature search for articles regarding implants in craniofacial reconstructions was performed using the three following databases: Scopus, Web of Science and MEDLINE (through PubMed), and follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). A systematic literature search was set for 2018-2023 and retrieved 92 studies. From them, 18 articles were included in the review.

Extracellular Vesicle-Based Drug Delivery Systems for Head and Neck Squamous Cell Carcinoma: A Systematic Review.

It is estimated that there are over 890,000 new cases of head and neck squamous cell carcinoma (HNSCC) worldwide each year, accounting for approximately 5% of all cancer cases. Current treatment options for HNSCC often cause significant side effects and functional impairments, thus there is a challenge to discover more acceptable treatment technologies. Extracellular vesicles (EVs) can be utilized for HNSCC treatment in several ways, for example, for drug delivery, immune modulation, as biomarkers for diagnostics, gene therapy, or tumor microenvironment modulation. This systematic review summarizes new knowledge regarding these options. Articles published up to 11 December 2022, were identified by searching the electronic databases PubMed/MEDLINE, Scopus, Web of Science, and Cochrane. Only full-text original research papers written in English were considered eligible for analysis. The quality of studies was assessed using the Office of Health Assessment and Translation (OHAT) Risk of Bias Rating Tool for Human and Animal Studies, modified for the needs of this review. Of 436 identified records, 18 were eligible and included. It is important to note that the use of EVs as a treatment for HNSCC is still in the early stages of research, so we summarized information on challenges such as EV isolation, purification, and standardization of EV-based therapies in HNSCC.

The Impact of the Angular Head Movement's Velocity during Diagnostic Maneuvers on Proper Benign Positional Paroxysmal Vertigo Diagnosis and Therapy.

Based on the current state of the BPPV field, there are no guidelines that specify an angular head movement's velocity (AHMV) during diagnostic maneuvers of BPPV. The aim of this study was to evaluate the impact of AHMV during diagnostic maneuvers on proper BPPV diagnosis and therapy. The analysis covered the results obtained in 91 patients with a positive result of the Dix-Hallpike (D-H) maneuver or the roll test. The patients were divided into four groups based on values of AHMV (high 100-200°/s and low 40-70°/s) and the BPPV type (posterior: PC-BPPV or horizontal: HC-BPPV). The parameters of the obtained nystagmuses were analyzed and compared to AHMV. There was a significant negative correlation between AHMV and latency of nystagmus in all study groups. Furthermore, there was a significant positive correlation between AHMV and both maximum slow phase velocity and average frequency of nystagmus in the PC-BPPV groups, whereas it was not observed in the HC-BPPV patients. Complete relief of symptoms was reported after 2 weeks and was better in patients diagnosed with maneuvers performed with high AHMV. High AHMV during the D-H maneuver allows the nystagmus to be more visible, increasing the sensitivity of diagnostic tests and is crucial for a proper diagnosis and therapy.

Susac syndrome - the current review of knowledge and own experience presentation.

Susac syndrome is a rare autoimmune vasculopathy involving the small precapillary arterioles of the brain, retina, and inner ear. It is characterized by a triad of symptoms: encephalopathy, visual disturbances due to obstruction of retinal artery branches, and sensorineural hearing loss. The study aimed to review the current medical knowledge on Susac syndrome and present our clinical experience regarding this disease entity. The paper also presents a case of a 25-year-old patient who was diagnosed with Susac's syndrome based on the clinical picture and the results of additional tests. This syndrome should be considered in the differential diagnosis of multiple sclerosis and other multifocal lesions of the central nervous system because early diagnosis of the disease and immunosuppressive treatment significantly alleviates its course and improves the prognosis.

Perspectives in Therapy of Chronic Rhinosinusitis.

The recent classification of chronic rhinosinusitis (CRS) focusses on investigating underlying immunopathophysiological mechanisms. Primary CRS is subdivided based on endotype dominance into type 2 (that relates mostly to the Th2 immune response with high levels of IL-5, IL-13, and IgE), or non-type 2 (that corresponds to the mix of type 1 and type 3). The treatment selection of CRS is dependent on endotype dominance. Currently, the majority of patients receive standardized care-traditional pharmacological methods including local or systemic corticosteroids, nasal irrigations or antibiotics (for a selected group of patients). If well-conducted drug therapy fails, endoscopic sinus surgery is conducted. Aspirin treatment after aspirin desensitization (ATAD) with oral aspirin is an option for the treatment in nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) patients. However, in this review the focus is on the role of biological treatment-monoclonal antibodies directed through the specific type 2 immune response targets. In addition, potential targets to immunotherapy in CRS are presented. Hopefully, effective diagnostic and therapeutic solutions, tailored to the individual patient, will be widely available very soon.

Immunological Aspects of Chronic Rhinosinusitis.

Chronic rhinosinusitis (CRS) is related to persistent inflammation with a dysfunctional relationship between environmental agents and the host immune system. Disturbances in the functioning of the sinus mucosa lead to common clinical symptoms. The major processes involved in the pathogenesis of CRS include airway epithelial dysfunctions that are influenced by external and host-derived factors which activate multiple immunological mechanisms. The molecular bases for CRS remain unclear, although some factors commonly correspond to the disease: bacterial, fungal and viral infections, comorbidity diseases, genetic dysfunctions, and immunodeficiency. Additionally, air pollution leads increased severity of symptoms. CRS is a heterogeneous group of sinus diseases with different clinical courses and response to treatment. Immunological pathways vary depending on the endotype or genotype of the patient. The recent knowledge expansion into mechanisms underlying the pathogenesis of CRS is leading to a steadily increasing significance of precision medicine in the treatment of CRS. The purpose of this review is to summarize the current state of knowledge regarding the immunological aspects of CRS, which are essential for ensuring more effective treatment strategies.