Remodeling and inflammation in Chinese versus white patients with chronic rhinosinusitis

IL-17A facilitates type 2 inflammation in a modified eosinophilic chronic rhinosinusitis mouse model

BACKGROUND

Eosinophilic chronic rhinosinusitis (ECRS) is predominantly characterized by nasal type 2 inflammation. The pathogenesis of this condition is complex. High levels of IL-17A are associated with eosinophil infiltration in some inflammatory diseases and contribute to the severity and insensitivity of corticosteroid therapy for chronic rhinosinusitis.

METHODS

In the first experiment, we constructed a modified ECRS mouse model using four groups of mice: phosphate-buffered saline (PBS)-sensitized and nasal instillation (control); PBS-sensitized and Staphylococcus aureus enterotoxin B (SEB) nasal instillation after nasal tamponade (SEB group); ovalbumin (OVA)-sensitized and nasal instillation (OVA group); and OVA-sensitized combined with OVA and SEB nasal instillation after nasal tamponade (OVA + SEB group). In the second experiment, we examined the role of IL-17A by dividing the mice into four groups: control group; ECRS group; ECRS + anti-IL-17A group; and ECRS + IL-17A group. The latter two groups received intraperitoneal injections of anti-IL-17A antibody or IL-17A, respectively.

RESULTS

We constructed a modified ECRS mouse model (OVA + SEB group), where the IL-17A levels were upregulated in the nasal sinus of ECRS mice and the IL-17A levels were significantly correlated with eosinophil infiltration. We further demonstrated that IL-17A induced type 2 inflammation and eosinophil infiltration in the ECRS group of mice. In contrast, IL-17A neutralization attenuated type 2 inflammatory cytokine secretion and eosinophil infiltration.

CONCLUSION

OVA sensitization and unilateral nasal tamponade, combined with SEB and OVA alternate nasal instillation (OVA + SEB group), could be used to construct a more typical ECRS mouse model in which IL-17A enhanced the expression of type 2 cytokines and eosinophil infiltration.

Prevalence and risk factors of chronic rhinosinusitis among Chinese: A systematic review and meta-analysis

Background

Chronic rhinosinusitis (CRS) can be seen in people of all ages. CRS heavily affects the quality of a patient's daily life and also causes tremendous economic burdens on patients' families and society. The prevalence of CRS in different countries varies and no systematic review of the prevalence of CRS among Chinese has been published previously. The objective of this systematic review and meta-analysis is to determine the prevalence of CRS among Chinese and to explore the main risk factors of CRS among Chinese.

Methods

Using relevant keywords, data resources including PubMed, Scopus, Web of Science, Google Scholar, Embase, Cochrane Library, Chinese National Knowledge of Infrastructure (CNKI), WANGFANG, VIP, and China Biomedical Literature database (CMB) were searched to obtain literature reporting the prevalence of and risk factors of CRS among Chinese which were clearly diagnosed with CRS from inception to 30 June 2022. The random/fixed effect model was used for meta-analysis, and the I² index was employed to assess heterogeneity among studies. All analyses were performed by using the STATA version 16.0 software. The study was registered with PROSPERO, register number. CRD42022341877.

Result

A total of 12 relevant kinds of literature were qualified for the present systematic review, including 4,033 patients. The results showed that the overall prevalence of CRS among Chinese was 10% (95%CI: 0.06-0.13, I² = 99.6%, P < 0.001). The prevalence of CRS among Chinese who lived in urban cities was 18% (95%CI: -0.07 to 0.43, I² = 99.9%, P < 0.001), which was obviously lower than the prevalence of CRS among Chinese who lived in rural areas (27%, 95%CI: -0.14 to 0.68, I² = 99.8%, P < 0.001). The prevalence of CRS among Chinese before 2010 was 23% (95%CI: -0.05 to 0.50, I² = 99.8%, P < 0.001), which was remarkably higher than the prevalence of CRS among Chinese after 2010 (7%, 95%CI: 0.05-0.09, I² = 99.0%, P < 0.001). The prevalence of CRS among Chinese who were divorced was 17% (95%CI: 0.12-0.22, I² = 0.0%, P = 0.436), while the prevalence of CRS among Chinese who were married, widowed, and unmarried was 9% (95%CI: 0.06-0.11, I² = 88.1%, P = 0.004), 9% (95%CI: 0.06-0.11, I² = 0.0%, P = 0.863), and 9% (95%CI: 0.08-0.10, I² = 0.0%, P = 0.658), respectively. The prevalence of CRS among Han and minority Chinese was 8% (95%CI: 0.07-0.10, I² = 69.6%, P = 0.070) and 12% (95%CI: 0.10-0.15, I² = 38.6%, P = 0.202), respectively. The prevalence of CRS among Chinese who was never exposed to moldy or damp environments was 8% (95%CI: 0.08-0.09, I² = 0.0%, P = 0.351), the prevalence of CRS among Chinese who was occasionally exposed to moldy or damp environments was 16% (95%CI: 0.10-0.22, I² = 78.9%, P = 0.030), and the prevalence of CRS among Chinese who was frequently or every day exposed to moldy or damp environments was up to 20% (95%CI: 0.15-0.24, I² = 0.0%, P = 0.558).

Conclusion

This meta-analysis shows that the prevalence of CRS among Chinese is at a high level. People who have some risk factors, such as occasional or frequent or everyday exposure to moldy or damp environments, have a higher prevalence of CRS. We should attach more importance to the risk factors of CRS in clinical practice and disseminate scientific information and carry out education to lower the prevalence of CRS in China.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=341877, identifier: CRD42022341877.

Activations of group 2 innate lymphoid cells depend on endotypes of chronic rhinosinusitis

OBJECTIVE

Chronic rhinosinusitis (CRS) is a complicated disease with several variants caused by different cellular and molecular mechanisms. The characterization of this heterogeneity supports the definition that the disease consists of many endotypes, such as eosinophilic and neutrophilic CRS, and so on. This study aimed to explore group 2 innate lymphoid cells (ILC2s) in neutrophilic CRS without nasal polyps (CRSsNP) and with nasal polyps (CRSwNP), and evaluate ILC2s across characteristics of the disease.

METHODS

Nasal biopsy samples were obtained from normal subjects or subjects with CRSsNP or CRSwNP during surgery. ILC2s were sorted and purified as CD45⁺Lin^-CD127⁺CD4^-CD8^-CRTH2⁺CD161⁺ cells through flow cytometry, and were compared among three groups of subjects. Then, these samples were cultured in vitro, and inflammatory factors were assessed in tissue cultures. After that, human recombinant (rm) interleukin (IL)-33 or IL-17 were administered into the cultures, and we again examined relevant inflammatory substances.

RESULTS

ILC2s were upregulated in neutrophilic CRSsNP and CRSwNP patients, and there were no statistical differences between them. Eosinophil cation protein (ECP), myeloperoxidase (MPO), IL-25, IL-33, IL-5, IL-13, interferon (IFN)-γ and IL-17 were increased in the cultures, however, only concentrations of MPO, IFN-γ and IL-17 were enhanced in CRSwNP tissues compared to CRSsNP ones. After administration of rmIL-33, ECP, IL-5 and IL-13 were all increased in tissues from CRSsNP and CRSwNP patients, however, there were no significant differences between them. Finally, we evaluated concentrations of several above inflammatory factors after the treatment of rmIL-17, and found that MPO and IFN-γ were enhanced in these two phenotypes of patients, and were elevated significantly in CRSwNP tissue cultures.

CONCLUSION

These findings show that ILC2s might be inactivated in neutrophilic CRSsNP and CRSwNP based on this pilot study.

Chronic rhinosinusitis phenotypes

OBJECTIVE

To review the current knowledge surrounding different chronic rhinosinusitis (CRS) presentations and the relative roles of nasal polyps, eosinophilia, and allergies in discerning phenotypes.

DATA SOURCES

PubMed literature review.

STUDY SELECTIONS

Articles discussing the various phenotypes of CRS with emphasis on pathologic and immune mechanistic studies that distinguish disease.

RESULTS

Current guidelines primarily separate CRS based on the presence or absence of nasal polyps. This is largely driven by the tendency of eosinophilic disease to present with nasal polyps (NPs) in contrast to noneosinophilic presentations, which less often lead to the development NPs. Further separations have been proposed based on expression of aeroallergen sensitization.

CONCLUSION

The presence of NPs may only poorly predict the presence of an underlying eosinophilic process and as such may have poor utility in forming the basis for recommending eosinophil-target therapies. Similarly, there is little evidence to support a significant role for aeroallergen exposure in contributing to the presence, severity, or natural history of CRS. Appropriate separation of CRS into specific phenotypes will allow therapeutic approaches to be individualized to each distinct presentation.

Pediatric Severe Chronic Upper Airway Disease (P-SCUAD)

The term SCUAD (severe chronic upper airway disease) has been previously introduced to describe cases with upper airway disorders and symptoms not adequately controlled despite correct diagnosis and management. It has been so far applied mainly in adults and no specific focus has been given on the pediatric population. When the term SCUAD is considered for children specifically, a series of issues may arise. These issues involve accurate definition, epidemiology, clinical characteristics, pathophysiology, and socioeconomic implications. These issues seem to clearly differentiate adult from pediatric SCUAD. We attempt to shed light on these issues in an effort to provide directions for future guideline development and research. In this context, P-SCUAD (pediatric severe chronic upper airway disease) is hereby introduced.

Rhinitis Subtypes, Endotypes, and Definitions

Rhinitis is often seen as posing a small burden. However, rhinitis is a complex disease that is underpinned by a plethora of different mechanisms and causes. Rhinitis is frequently associated with other comorbid conditions but, by itself, is a source of considerable morbidity for patients and creates a significant financial burden on health systems worldwide. This article approaches this condition from both a phenotypic and mechanistic standpoint, focusing on the complexity of characterizing these subtypes. Developing a clearer demarcation of the currently obscure rhinitis phenotypes and endotypes will substantially improve their future prevention and treatment.

Increased phosphorylation of STAT5b, but not STAT5a, in nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a recurrent, benign, extensively proliferating disease that is triggered by inflammation. The signaling pathways in sinusitis and the regulation by intracellular signaling peptides and proteins are not fully understood. Signal transducer and activator of transcription (STAT) 5a and STAT5b are two closely related phosphokinases involved in the regulation of diverse cellular functions, including proliferation and apoptosis.

OBJECTIVE

The objective of the study was to investigate the expression, activation, and distribution of STAT5 Transcription factor in CRSwNP.

METHODS

We studied these transcription factors in tissue samples of nasal polyps and inferior turbinates from a total of 35 patients with CRSwNP and compared them with healthy nasal mucosa. The samples were analyzed by using a DNA microarray, quantitative real-time polymerase chain reaction, a protein array, immunoblot, immunoprecipitation and immunohistochemistry.

RESULTS

We found equivalent overall expression of STAT5a in all tissue types. We observed an increase in the expression of STAT5b protein in both polyps and turbinates of patients with CRSwNP. In addition, STAT5b, but not STAT5a, was activated by phosphorylation in nasal polyps. Phosphorylated STAT5a/b was not detectable in the epithelium of turbinates from either patients with CRSwNP or patients with healthy mucosa, but it was clearly expressed in the epithelium of nasal polyps.

CONCLUSION

Analysis of these data indicates distinct expression and activation of STAT5a and STAT5b in nasal polyps, particularly the activation of STAT5b. It is possible that STAT5b may contribute to the development of nasal polyps.

Differential release and deposition of S100A8/A9 proteins in inflamed upper airway tissue

Intracellular Ca2+-binding S100A8/A9 proteins gain novel functions when released during inflammation. The exact outcome of their extracellular function depends on the local tissue environment in which they are released; both anti-inflammatory and pro-inflammatory responses are described, modulating the immune system by binding Toll-like receptor (TLR)-4 or the receptor for advanced glycation end-products (RAGE). However, the contribution of the proteins in the pathophysiology of chronic rhinosinusitis (CRS) remains unclear.

Homomeric S100A8 and S100A9, and heteromeric S100A8/A9 proteins were evaluated in CRS with/without nasal polyps (CRSw/sNP) and controls. Functional responses were assessed in polyp tissue stimulated with S100 proteins in the presence of TLR-4 and RAGE blocking antibodies.

S100A8, S100A9 and S100A8/A9 protein levels were significantly higher in CRSwNP patients, showing increased deposition on extracellular matrix (ECM) structures of CRSwNP tissue in contrast to CRSsNP and controls. In the presence ofStaphylococcus aureus, S100A8/A9 is released from neutrophils and from the ECM. Extracellular S100A8 and S100A9 proteins induced increased levels of diverse inflammatory mediatorsviaTLR-4 engagement.

The inflammatory/remodelling characteristics of CRSwNP specifically allow increased retention of S100A8, S100A9 and S100A8/A9 proteins in the ECM of CRSwNP tissue. Upon release, homodimeric proteins act as a local danger signal inducing inflammatory mediators, predominantlyviaTLR-4 activation.

Severe Chronic Upper Airway Disease (SCUAD) in children. Definition issues and requirements

OBJECTIVES

Upper airway diseases are extremely common, and a significant proportion of patients are not adequately controlled by contemporary treatment algorithms. The term SCUAD (Severe Chronic Upper Airway Disease) has been previously introduced to describe such cases. However, this term has not been adequately focused on children.

METHODS

This study aims to address the necessity of the term, as well as further details specifically for children. For this purpose, a review was performed of the current literature, with specific focus on issues regarding SCUAD in children.

RESULTS

Paediatric SCUAD represents a heterogeneous group of patients and has significant clinical and socioeconomic implications. Relevant literature is generally lacking and questions regarding definition and pathogenesis remain unanswered.

CONCLUSIONS

Accurate definition and acknowledgement of paediatric SCUAD cases may lead to better design of future clinical and molecular research protocols. This may provide improved understanding of the underlying disease processes, more accurate data regarding socioeconomic burden, and, above all, more successful treatment and prevention strategies.

Aquaporin expression profiles in normal sinonasal mucosa and chronic rhinosinusitis

BACKGROUND

Thickened secretions, mucosal edema, and polyp formation are pathological features in chronic rhinosinusitis (CRS) that could theoretically be caused by aberrant water flow through sinonasal mucosa. Aquaporins (AQPs) are a family of proteins with roles in water transport, with tissue-specific expression profiles. This study aims to determine if AQP expression in sinonasal mucosa is different between normal controls and patients with CRS, either with (CRSwNP) or without (CRSsNP) nasal polyps.

METHODS

During endoscopic sinus surgery or transsphenoidal surgery, sinonasal tissue was collected and classified as CRSwNP (n = 13), CRSsNP (n = 10), or normal (n = 10). Messenger RNA (mRNA) expression of human AQP0 to AQP12b was determined using quantitative real-time polymerase chain reaction (qRT-PCR). Cellular localization of AQP1, AQP3, AQP4, AQP5, AQP7, and AQP11 was determined by immunohistochemistry.

RESULTS

mRNA of AQP0 to AQP11 was identified in all samples. AQP12b mRNA was not detected. Significant differences in the mRNA expression levels of AQP4 and AQP11 were identified between normal and CRSwNP patients (p < 0.05). Differences in the cellular localization of AQPs were observed in both CRSsNP and CRSwNP patients vs normal controls. More intense localization to the cell cytoplasm was observed for AQP5 in glandular epithelium (CRSwNP; p < 0.05) and surface epithelium (CRSsNP; p < 0.05), and AQP4 in glandular epithelium (CRSsNP; p < 0.05).

CONCLUSION

This study characterized AQP mRNA expression and protein localization in normal human sinonasal tissue. Significant differences in mRNA expression were found for AQP4 and AQP11 in CRSwNP and differences in protein localization patterns of AQP4 and AQP5 were identified in both types of CRS.

Effect of prednisone on nasal symptoms and peripheral blood T-cell function in chronic rhinosinusitis

BACKGROUND

Systemic corticosteroids are the most effective anti-inflammatory drugs used for controlling chronic rhinosinusitis (CRS) symptoms. The potential mechanisms for their beneficial effects include increasing the number and function of T regulatory cells (Tregs), as reported in the local tissue post-intranasal steroid treatment. We investigated the effect of systemic corticosteroids on peripheral blood (PB) Tregs in subjects with CRS.

METHODS

Twenty CRS subjects and 19 controls were recruited. PB mononuclear cells (PBMCs) were isolated from CRS subjects before and after systemic corticosteroid administration in the course of clinical treatment. Control subjects received no treatment and were studied at one visit. Nasal symptoms were recorded. CD4(+) CD25(+) Foxp3(+) cells (Tregs) were analyzed by flow cytometry. Messenger RNA (mRNA) levels for interferon γ (IFN-γ), interleukin 4 (IL-4), IL-10, IL-13, IL-17A, transforming growth factor β1 (TGF-β1), forkhead box P3 (FoxP3), and GATA-binding factor 3 (GATA-3) were measured in PBMCs using real-time polymerase chain reaction (PCR).

RESULTS

CRS subjects reported improved nasal symptoms (p = 0.005) and significantly reduced PB Tregs after treatment with corticosteroids (p = 0.042). The transcript levels of IL-4 and GATA-3 were significantly higher in the CRS subjects at their first visit when compared to controls (p = 0.019 and p = 0.05, respectively). Corticosteroid treatment lowered the transcript levels of immunoregulatory transcription factors [FoxP3 (p = 0.048) and GATA-3 (p = 0.012)] and IFN-γ (p = 0.036) in PB.

CONCLUSION

In contrast to prior work in local nasal tissue, our study reports reduced PB Tregs and decreased T helper 1 (T(H)1) and T(H)2 function after treatment with systemic corticosteroids. These data indicate that corticosteroid effects on Tregs in CRS are complex involving local signals in the tissue that are distinct from those in circulating cells.

Increased activation and differentiated localization of native and phosphorylated STAT3 in nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial disease; the underlying mechanisms of cell signalling are not fully understood. STAT3 (signal transducer and activator of transcription 3) is a phosphokinase and a key signalling molecule implicated in cell cycle regulation. We studied the distribution and expression of STAT3 to examine the role of STAT3 in the pathogenesis of CRSwNP.

METHODS

We investigated tissue samples of the nasal polyps and inferior turbinate of patients with CRSwNP as well as samples of the inferior turbinate of subjects without chronic sinusitis. The expression levels of STAT3 and its activated form pSTAT3 were analysed using Western blotting, protein array, DNA microarray and immunohistochemistry.

RESULTS

No significant differences were found in STAT3-mRNA levels between the samples of nasal polyps and inferior turbinates of the same patient. However, the amount of pSTAT3 was increased in the polyp tissue compared to the inferior turbinates from both CRSwNP patients and control subjects (p < 0.01), indicating an activation of STAT3 in polyps. We identified a varying distribution pattern of pSTAT3; pSTAT3 was primarily found in superficial epithelial cells but not in the basal layer of the epithelium of the turbinate, whereas pSTAT3 was located in all layers of the epithelium of the polyp and mostly noted in the basal layer.

CONCLUSIONS

Our results of the activation and varying localisation of STAT3 and its phosphorylated form in nasal polyps suggest that pSTAT3 plays a crucial role in the proliferative development of nasal polyps.

Peripheral blood and tissue T regulatory cells in chronic rhinosinusitis

BACKGROUND

The pathogenesis of chronic rhinosinusitis (CRS) has not been fully elucidated. Increased inflammatory cell infiltration and decreased numbers and/or impaired function of T regulatory cells (Tregs) have been reported. This study aimed to determine the role of Tregs in CRS in peripheral blood (PB) and sinus tissue.

METHODS

Sinus tissue was obtained from 16 CRS subjects and 5 controls. PB from additional 16 CRS subjects and total 20 controls was obtained. Immunohistochemical analysis (CD3(+), CD4(+), CD8(+), and Treg [CD4(+)-FoxP3(+) and CD25(+)-FoxP3(+)] cells) of sinus tissue was performed. Percentage of PB Tregs (CD4(+)-CD25(+)-FoxP3(+) cells) was analyzed by flow cytometry. Spontaneous and phytohemagglutinin (PHA)-induced release of cytokines (IL-6, IL-4, IL-10, interferon gamma, transforming growth factor [TGF] beta1, and TNF-alpha) from PB mononuclear cells (PBMCs) was determined.

RESULTS

PB flow cytometric analysis revealed a lower percentage of Tregs in subjects with CRS compared with healthy controls (p = 0.0003). Although no differences in the PB Treg counts were observed between the CRS subjects with nasal polyposis (CRSwNP) and without nasal polyposis (CRSsNP), immunohistochemical analysis performed on sinus tissue revealed a higher proportion of Tregs in CRSwNP subjects compared with CRSsNP (p < 0.05). Additionally, we failed to detect any Tregs from control sphenoid sinus tissue. Lower levels of regulatory cytokines (IL-10 and TGF-β1) and higher levels of proinflammatory cytokines (TNF-α and IL-6) were found from PBMCs from CRS subjects compared with controls (p < 0.05).

CONCLUSION

Our findings suggest that CRS subjects exhibit a decreased percentage of PB Tregs compared with normal controls. PBMCs from CRS subjects show a more proinflammatory and less regulatory phenotype.

Endotypes and phenotypes of chronic rhinosinusitis: a PRACTALL document of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology

Chronic rhinosinusitis (CRS) is a complex disease consisting of several disease variants with different underlying pathophysiologies. Limited knowledge of the mechanisms of these disease subgroups is possibly the greatest obstacle in understanding the causes of CRS and improving treatment. It is generally agreed that there are clinically relevant CRS phenotypes defined by an observable characteristic or trait, such as the presence or absence of nasal polyps. Defining the phenotype of the patient is useful in making therapeutic decisions. However, clinical phenotypes do not provide full insight into all underlying cellular and molecular pathophysiologic mechanisms of CRS. Recognition of the heterogeneity of CRS has promoted the concept that CRS consists of multiple groups of biological subtypes, or "endotypes," which are defined by distinct pathophysiologic mechanisms that might be identified by corresponding biomarkers. Different CRS endotypes can be characterized by differences in responsiveness to different treatments, including topical intranasal corticosteroids and biological agents, such as anti-IL-5 and anti-IgE mAb, and can be based on different biomarkers that are linked to underlying mechanisms. CRS has been regarded as a single disease entity in clinical and genetic studies in the past, which can explain the failure to identify consistent genetic and environmental correlations. In addition, better identification of endotypes might permit individualization of therapy that can be targeted against the pathophysiologic processes of a patient's endotype, with potential for more effective treatment and better patient outcomes.

Some Polymorphisms in Epstein-Barr Virus–induced Gene 3 Modify the Risk for Chronic Rhinosinusitis

Background

Forkhead box protein 3 (FOXP3), a transcription factor required for development and function of regulatory T cell, and Epstein-Barr virus–induced gene 3 (EBI3), a downstream target of FOXP3, may be important in the development of chronic rhinosinusitis (CRS) with or without sinonasal polyposis (CRSwNP and CRSsNP, respectively). Our objective was therefore to examine the presence of any associations between specific single nucleotide polymorphisms (SNPs) in/around the FOXP3 and EBI3 genes and risk for CRS in Chinese subjects. A population-based case–control association analysis was performed.

Methods

DNA extracted from peripheral blood leukocytes from 667 subjects with CRS (360 CRSwNP and 306 CRSsNP) and 330 healthy controls was assessed for SNPs selected and complemented with tagging SNPs. A total of seven SNPs (4 in FOXP3 and 3 in EBI3 genes) were genotyped and genetic association tests were performed.

Results

In the single-locus analyses of CRS risk, the allele frequencies of rs428253 (p = 0.0191) in EBI3 gene and rs2232365 (p = 0.0307) and rs3761548 (p = 0.0221) in FOXP3 gene were significantly different between the CRS cases and the controls. Furthermore, genotype association analysis showed a significant protective effect only between EBI3_rs428253 (CG/CC; p = 0.029) and CRS after adjustment. Similarly, stratified analysis of CRS risk on category showed rs428253 of the EBI3 gene to play a protective role among both CRSwNP (CG/CC; p = 0.002) and CRSsNP (GG/CC; p = 0.023) subjects. Haplotype analysis of the FOXP3 gene region further indicated that CRS risk was higher in individuals carrying the haplotype GG in rs2294018–rs2232365 block, compared with wild-type AG haplotype, and AG in rs3761548–4824747 block, compared with wild-type CG haplotype.

Conclusion

The findings of this study suggest that SNPs in FOXP3 and EBI3 genes modify the risk for development of CRS.

Regulation of transforming growth factor-β1 activation and expression in the tissue remodeling involved in chronic rhinosinusitis

Transforming growth factor-β1 (TGF-β1) plays a key role in the tissue remodeling processes involved in chronic rhinosinusitis (CRS), with the biological functions of secreted TGF-β1 regulated by multiple proteins. Among these regulators, latency-associated peptide and latent TGF-β-binding protein inhibit TGF-β1 function, whereas different proteases and integrins activate it. Progress in understanding the factors responsible for the bioactivity and expression of TGF-β1 has revealed that the dysregulation of TGF-β1 activation and expression is closely associated with the chronic respiratory inflammatory diseases involved in CRS. This review of the regulation of TGF-β1 activation and expression provides insight into the mechanism responsible for the different CRS subtypes, which will help further the investigation of novel therapy targets for the treatment of CRS.

Rhinosinusitis and asthma: a link for asthma severity

The term rhinosinusitis describes an inflammation of the mucosal lining of the nose and sinuses; however, recent evidence points to the need to differentiate patients with chronic rhinosinusitis without nasal polyps from those with nasal polyps. Asthma comorbidity is especially common in nasal polyp disease and may be associated with aspirin-exacerbated respiratory disease. Of interest, asthma comorbidity is uncommon in some parts of the world but common in others. A further analysis of the inflammatory patterns also revealed that nasal polyps do not represent one single entity; interleukin (IL)-5-positive nasal polyps can be differentiated from IL-5-negative forms by different inflammatory patterns (predominance of eosinophils vs neutrophils). Staphylococcus aureus superantigens frequently colonize IL-5-positive nasal polyps and may amplify the eosinophilic inflammation, induce a polyclonal local IgE formation, and increase the risk of asthma comorbidity. Recent findings in severe asthma patients confirm the role of superantigens in lower airway disease.