Osteitis in Chronic Rhinosinusitis

Additive Effect of Blood and Tissue Eosinophilia on Chronic Rhinosinusitis With Nasal Polyps

PURPOSE

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a highly heterogeneous disease with varied clinical features and treatment effects. This study aimed to investigate the additive effect of blood and tissue eosinophilia on patients with CRSwNP.

METHODS

Based on the blood eosinophil (Beos) count and tissue eosinophil (Teos) count, we divided 144 CRSwNP patients into four groups, analysed their clinical features and histopathologic changes, and investigated their postoperative control.

RESULTS

Patients in the Beos+Teos+ (blood eosinophil count > 0.3 × 109/L, tissue eosinophil count > 10/HPF) group had a higher incidence of allergic rhinitis (AR) and asthma. Lund-Mackay (LM) scores, hyposmia visual analogue scale (VAS) scores and Global Osteitis Scoring Scale (GOSS) scores were higher in the Beos+Teos+ group than those in the other groups. Tissue remodelling, such as connective tissue oedema and basement membrane thickening was more severe in the Beos+Teos+ group compared with other groups. There were more uncontrolled patients after surgery in Beos+Teos+, Beos+Teos- (blood eosinophil count > 0.3 × 109/L, tissue eosinophil count ≤ 10/HPF)and Beos-Teos+ (blood eosinophil count ≤ 0.3 × 109/L, tissue eosinophil count > 10/HPF)groups compared with the Beos-Teos- group.

CONCLUSIONS

Eosinophilic inflammation both in blood and tissue was accompanied by more severe clinical features and tissue remodelling. Eosinophilia in blood or tissue indicated poorer disease control after surgery.

Preliminary study on AI-assisted diagnosis of bone remodeling in chronic maxillary sinusitis

OBJECTIVE

To construct the deep learning convolution neural network (CNN) model and machine learning support vector machine (SVM) model of bone remodeling of chronic maxillary sinusitis (CMS) based on CT image data to improve the accuracy of image diagnosis.

METHODS

Maxillary sinus CT data of 1000 samples in 500 patients from January 2018 to December 2021 in our hospital was collected. The first part is the establishment and testing of chronic maxillary sinusitis detection model by 461 images. The second part is the establishment and testing of the detection model of chronic maxillary sinusitis with bone remodeling by 802 images. The sensitivity, specificity and accuracy and area under the curve (AUC) value of the test set were recorded, respectively.

RESULTS

Preliminary application results of CT based AI in the diagnosis of chronic maxillary sinusitis and bone remodeling. The sensitivity, specificity and accuracy of the test set of 93 samples of CMS, were 0.9796, 0.8636 and 0.9247, respectively. Simultaneously, the value of AUC was 0.94. And the sensitivity, specificity and accuracy of the test set of 161 samples of CMS with bone remodeling were 0.7353, 0.9685 and 0.9193, respectively. Simultaneously, the value of AUC was 0.89.

CONCLUSION

It is feasible to use artificial intelligence research methods such as deep learning and machine learning to automatically identify CMS and bone remodeling in MSCT images of paranasal sinuses, which is helpful to standardize imaging diagnosis and meet the needs of clinical application.

Identifying the Risk Factors for Orbital Complications in Isolated Sphenoid Rhinosinusitis

Background and Objectives: Isolated sphenoid rhinosinusitis may have devastating consequences such as orbital complications due to its anatomical contiguity with vital structures. This study aimed to identify patients with isolated sphenoid inflammatory diseases at high risk for developing orbital complications and requiring aggressive management through investigation of the clinical and computed tomography (CT) characteristics of patients with isolated sphenoid rhinosinusitis. Materials and Methods: The medical records of patients who underwent endoscopic sinus surgery between 2005 and 2022 were retrospectively reviewed. Patients with isolated sphenoid rhinosinusitis were identified based on a manual review of the clinical and histopathological findings. Participants' clinical and CT features were reviewed. Results: Among the 118 patients with isolated sphenoid rhinosinusitis, 15 (12.7%) developed orbital complications, including diplopia, extraocular motility limitation, ptosis, and visual impairment. Headaches and facial pain occurred significantly more frequently in patients with orbital complications than in those without orbital complications (p < 0.001). Patients with diabetes mellitus or malignant neoplasms were more likely to develop orbital complications than those without these comorbidities (p < 0.05). Bony dehiscence on CT images was significantly more common in patients with orbital complications than in those without. In the regression analysis, diabetes mellitus (OR, 4.62), malignant neoplasm (OR, 4.32), and bony dehiscence (OR, 4.87) were significant predictors of orbital complications (p < 0.05). Conclusions: Headaches and facial pain are the most common symptoms of isolated sphenoid rhinosinusitis. Orbital complications of isolated sphenoid rhinosinusitis are more common in patients with comorbidities such as diabetes mellitus or malignancy or in those with bony dehiscence on CT images.

Tissue Interleukin-33: A Novel Potential Regulator of Innate Immunity and Biomarker of Disease Severity in Chronic Rhinosinusitis with Nasal Polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a disease of real interest for researchers due to its heterogenicity and complex pathophysiological mechanisms. Identification of the factors that ensure success after treatment represents one of the main challenges in CRSwNP research. No consensus in this direction has been reached so far. Biomarkers for poor outcomes have been noted, but nonetheless, their prognostic value has not been extensively investigated, and needs to be sought. We aimed to evaluate the correlation between potential prognostic predictors for recalcitrant disease in patients with CRSwNP.

METHODS

The study group consisted of CRSwNP patients who underwent surgical treatment and nasal polyp (NP) tissue sampling. The preoperative workup included Lund-Mackay assessment, nasal endoscopy, eosinophil blood count, asthma, and environmental allergy questionnaire. Postoperatively, in subjects with poor outcomes, imagistic osteitis severity was evaluated, and IL-33 expression was measured.

RESULTS

IL-33 expression in NP was positively and significantly correlated with postoperative osteitis on CT scans (p = 0.01). Furthermore, high osteitis CT scores were related to high blood eosinophilia (p = 0.01). A positive strong correlation was found between postoperative osteitis and the Lund-Mackay preoperative score (p = 0.01), as well as the nasal endoscopy score (p = 0.01).

CONCLUSIONS

Our research analyzed the levels of polyp IL-33, relative to blood eosinophilia, overall disease severity score, and osteitis severity, in patients with CRSwNP. These variables are prognostic predictors for poor outcomes and recalcitrant disease. Considering the importance of bone involvement in CRSwNP, this research aims to provide a better insight into the correlations of osteitis with clinical and biological factors.

The Impact of Spray Cryotherapy on Lesion-Induced Osteitis in a New Murine Experimental Model

Background and Objectives: Endoscopic sinus surgery is considered the gold management strategy for difficult-to-treat chronic rhinosinusitis. The inflammatory bony process is incriminated as being involved in the unfavorable evolution and recurrence of the disease. Osteitis is significantly increased in patients that have been previously submitted to surgery, and it is more often present in patients with extended radiological disease and in patients undergoing revision surgery. The aim of the research is to demonstrate the presence of inflammations and neo-osteogenesis associated with nasal mucosal surgical injury and the correlation between their severity and to evaluate the efficacy of low-pressure spray cryotherapy in reducing inflammation and bone remodeling. Materials and Methods: The experimental murine model was conducted over a period of 80 days and included a total of 60 adult female Wistar rats, with three periods of withdrawal of 20 individuals each from the experiment. After inducing a bilateral mechanical injury by brushing, low-pressure spray cryotherapy application was performed unilaterally, and tissue samples were prepared specifically for histological analysis. The scores for inflammation and osteitis were compared over time and between the two nasal fossae. Results: Osteitis and inflammation were induced by a simple mucosal brushing lesion, similar to surgical injury. We identified the presence of inflammation in 95% of the specimens, and it was present over time. Moreover, criteria for bone remodeling were clearly highlighted in a percentage of 72% of the specimens. There was a direct correlation between the severity of inflammation and neo-osteogenesis, with a statistical significance of p = 0.050. Low-pressure spray cryotherapy was safe and effective in reducing inflammation (p = 0.020) and osteitis (p = 0.000) with a safety profile. Conclusions: Low-pressure cryotherapy reduces the severity of mucosal inflammation and osteitis in lesion-induced neo-osteogenesis.

The Impact of Osteitis on Quality of Life in Patients with Chronic Rhinosinusitis

Introduction: Chronic rhinosinusitis (CRS) is a significant health problem worldwide with an estimated prevalence of 5-12% in the general population. Osteitis refers to inflammation of bone characterized by bone remodeling, neo-osteogenesis and thickening of adjacent mucosa. These changes are evidenced by specific radiological appearance on Computerized Tomography (CT) which may be localized or diffuse dependent on extent of disease. Osteitis act as a marker of severity in chronic rhinosinusitis and can significantly affect the patient's Quality of Life (QOL) proportional to its severity. Aim: To analyze the impact of osteitis on quality of life in patients with chronic rhinosinusitis as evidenced by pre-operative Sinonasal Outcome Test-22(SNOT-22) scores. Materials & Methods: 31 patients diagnosed to have chronic rhinosinusitis with co-existing osteitis were enrolled in this study based on computerized tomography scan Paranasal Sinuses (PNS) findings and graded as per the calculated Global Osteitis Scoring Scale. Accordingly, patients were categorised into those without significant osteitis, with mild, moderate and severe osteitis. Baseline quality of life in these patients was assessed using the Sinonasal Outcome Test-22 (SNOT-22) and its association with the severity of osteitis analysed. Results: There is a very strong correlation between severity of osteitis and quality of life in the study population based on the Sinonasal Outcome Test-22 scores (p = 0.000). The mean Global Osteitis score was 21.65 with standard deviation 5.66. Maximum score obtained was 38 and minimum score 14. Conclusion: • Osteitis has a significant impact on quality of life in patients with chronic rhinosinusitis. • Severity of osteitis has a direct relation to quality of life in chronic rhinosinusitis.

Eosinophil-derived interferon-γ drives transmembrane protein 119-induced new bone formation in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory sinonasal disease characterized by eosinophilic infiltration and new bone formation. These changes indicate the severity and prognosis of CRSwNP and may be closely linked to each other.

METHODS

We performed RNA sequencing to screen specific osteogenic molecules and validated transmembrane protein 119 (TMEM119) expression by quantitative polymerase chain reaction (qPCR) and immunohistochemistry analyses. TMEM119 knockdown was performed to observe the downregulation of bone mineralization. We validated the bone-forming activity of interferon-γ (IFN-γ) and its signaling pathways in cultured primary sinus bone cells. Cellular sources of IFN-γ were identified using immunohistochemistry and immunofluorescence analyses. Interleukin-4-eosinophil-IFN-γ axis and the effect of dupilumab were investigated in Eol-1 cells.

RESULTS

We observed elevated IFN-γ levels and eosinophils in the nasal fluid and predominantly eosinophil-derived IFN-γ in the sinus mucosa of patients with CRSwNP. TMEM119 expression and bone-forming activities were increased in the osteitic and primary sinus bone cells of CRSwNP. IFN-γ treatment enhanced bone mineralization and TMEM119 expression via signal transducer and activator of transcription 1 (STAT1) signaling. Moreover, TMEM119 knockdown inhibited sinus bone cell mineralization and dupilumab attenuated IFN-γ secretion by IL4-stimulated Eol-1 cells.

CONCLUSION

Eosinophil-derived IFN-γ promotes the bone-forming activities of sinus bone cells via the STAT1-TMEM119 signaling pathway. Interleukin-4-eosinophil-IFN-γ axis may be crucial for TMEM119-mediated new bone formation in CRSwNP.

Tips and tricks for management of the dysfunctional maxillary sinus

PURPOSE OF REVIEW

To review the various factors associated with the most common cause of maxillary sinus dysfunction; recalcitrant chronic maxillary sinusitis (RCMS). In addition, available medical and surgical management options are discussed along with various tips and tricks for optimal management.

RECENT FINDINGS

Defects in mucociliary clearance, immunodeficiency, anatomic factors, and infectious etiologies have been implicated in dysfunction of the maxillary sinus leading to RCMS. Medical management including oral antibiotics or topical drugs have shown varying degrees of success. Endoscopic modified medial maxillectomy (EMMM) has been shown to significantly improve symptoms in patients with RCMS.

SUMMARY

A dysfunctional maxillary sinus presents a clinical challenge. A thorough evaluation of any potential contributing factors must be done in addition to an assessment of the adequacy of prior surgical treatment of the maxillary sinus. Beyond the middle meatal antrostomy, EMMM can be used to effectively address RCMS. In cases that fail EMMM, removal of the condemned mucosa to encourage auto-obliteration of the sinus can be considered.

Construction and analysis of a ceRNA network and patterns of immune infiltration in chronic rhinosinusitis with nasal polyps: based on data mining and experimental verification

Recent studies have revealed the significant role of the competing endogenous RNA (ceRNA) network in human diseases. However, systematic analysis of the ceRNA mechanism in chronic rhinosinusitis with nasal polyps (CRSwNP) is limited. In this study, we constructed a competitive endogenous RNA (ceRNA) network and identified a potential regulatory axis in CRSwNP based on bioinformatics analysis and experimental verification. We obtained lncRNA, miRNA, and mRNA expression profiles from the Gene Expression Omnibus. After analysis of CRSwNP patients and the control groups, we identified 565 DE-lncRNAs, 23 DE-miRNAs, and 1799 DE-mRNAs by the DESeq2 R package or limma R package. Enrichment analysis of 1799 DE-mRNAs showed that CRSwNP was associated with inflammation and immunity. Moreover, we identified 21 lncRNAs, 8 miRNAs and 8 mRNAs to construct the lncRNA-miRNA-mRNA ceRNA network. A potential MIAT/miR-125a/IRF4 axis was determined according to the degree and positive correlation between a lncRNA and its competitive endogenous mRNAs. The GSEA results suggested that IRF4 may be involved in immune cell infiltration. The validation of another dataset confirmed that MIAT and IRF4 were differentially expressed between the CRSwNP and control groups. The area under the ROC curve (AUC) of MIAT and IRF4 was 0.944. The CIBERSORT analysis revealed that eosinophils and M2 macrophages may be involved in the CRSwNP process. MIAT was correlated with dendritic cells and M2 macrophages, and IRF4 was correlated with dendritic cells. Finally, to validate the key genes, we performed in-silico validation using another dataset and experimental validation using immunohistochemistry, immunofluorescence, and Western blot. In summary, the constructed novel MIAT/miR-125a/IRF4 axis may play a critical role in the development and progression of CRSwNP. We believe that the ceRNA network and immune cell infiltration could offer further insight into novel molecular therapeutic targets for CRSwNP.

Osteitis in Eosinophilic Chronic Rhinosinusitis

OBJECTIVES

Eosinophilic chronic rhinosinusitis (ECRS) is an allergic inflammatory disease characterized by chronic inflammation of the sinus mucosa, and sometimes, osteitis. This study aimed to investigate the pattern of osteitis in ECRS and the relationship between bony thickening of the middle turbinate and recurrence of ECRS.

METHODS

A total of 246 patients with paranasal diseases were included in the study. The patients' data on bone thickening level, mucosal thickening, polyp score, clinical severity, and laboratory data were retrospectively evaluated.

RESULTS

In total, 38, 186, and 22 patients had ECRS, non-ECRS (NECRS), and odontogenic sinusitis, respectively. The Lund-Mackey (LM) score and Global Osteitis Scoring Scale (GOSS) scores in patients with ECRS were higher than those in patients with other paranasal diseases. There was a significant positive correlation between the GOSS score and ECRS clinical disease severity. Postoperative recurrence was significantly increased in patients with ECRS associated with bony thickening of the middle turbinate.

CONCLUSION

Both mucosal inflammation and osteitis were more severe in patients with ECRS than in patients with other diseases, and clinical disease severity was correlated with osteitis. Furthermore, the postoperative recurrence rate tended to increase in patients with ECRS who had bony thickening of the middle turbinate.

Alleviation of Surgery-Induced Osteitis in Sinonasal Cavity by Dexamethasone-Loaded Poly(lactic-co-glycolic acid) (PLGA) Microparticles with Strong Calcium-Binding Affinity

For the treatment of sinus surgery-induced osteitis in chronic rhinosinusitis (CRS), oral or intranasal administration of corticoids is generally used, although it has critical limitations and unavoidable side effects. To overcome these limitations, we designed dexamethasone (Dex)-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles with bone-specific binding affinity, which could release the encapsulated Dex in a sustained manner on the exposed bone after the surgical wound in the nasal cavity. In a previous report, we prepared poly(butyl methacrylate-co-methacryloyloxyethyl phosphate) (PBMP) with both calcium-binding phosphomonoester groups and PLGA-binding butyl groups to introduce strong calcium-binding property to PLGA particles. In this study, after successful encapsulation of Dex in the PBMP-coated PLGA particles, we applied the Dex-PLGA/PBMP to the treatment of post-operative osteitis in the sinonasal cavity. The Dex-PLGA/PBMP showed more than 5-times higher binding affinity to the hydroxyapatite (HA) surface compared to the non-coated PLGA particles, without altering the morphology and encapsulation efficiency. After establishing the neo-osteogenesis mouse model by mechanical injury of the nasal mucosa, the activity of intranasally administered Dex-PLGA/PBMP was examined to inhibit the formation of undesirable new woven bone during the wound healing process. In addition, significantly lower osteocalcin activity was observed in the group treated with Dex-PLGA/PBMP, indicating decreased activation of osteoblasts. Overall, these results demonstrate that the PLGA/PBMP microparticle strategy has great potential for the treatment of CRS-related osteitis by localized corticoid delivery on the exposed bones with minimal side effects.

Imaging After Sinonasal Surgery

Posttreatment imaging evaluation of sinuses encompasses a wide gamut of procedures, ranging from endoscopic procedures for sinonasal inflammatory diseases to markedly radical surgeries for malignant neoplasms (with or without reconstructions), as well as providing access for surgeries involving the anterior and central skull base. Advances in both techniques and devices have expanded the use of endoscopic approaches in managing both benign and malignant lesions, in addition to being the primary surgical method for treating all medically refractive sinonasal inflammatory disorders. Familiarity with the complex anatomy in the sinonasal region and knowledge of the various procedures is indispensable in interpreting these imaging studies.

Value of Hounsfield Units in the Evaluation of Isolated Sphenoid Sinus Lesions

Radiologic findings of fungal sinus disease are generally opacification in paranasal computed tomography (CT) images. The Hounsfield unit (HU) is a standardized objective unit that is also suitable for measuring remodeling and opacifications on CT scans of bone sections of patients with chronic rhinosinusitis. We hypothesized that HU values could provide valuable information in isolated sphenoid sinus lesions before surgery. Between 2012 and 2019, 35 patients underwent functional endoscopic sinus surgery for sphenoid sinus lesions. Tissues obtained from the sphenoid sinus were divided into two groups, fungal and nonfungal, according to the findings of histopathologic examinations. HU values were measured in sphenoid sinus sections on paranasal CT scans of these two groups. Differences in mean and maximum HU values between the two groups were statistically significant (p < .05). The maximum HU values calculated from the sphenoid sinus were 435.08 and 196.23 (p ≤ .05) in the fungal group and nonfungal group, respectively. The mean HU values calculated from the sphenoid sinus were 64.31 and 29 (p ≤ .05) in the fungal and nonfungal groups, respectively. At the maximum cutoff value of 241, the sensitivity and specificity of the HU maximum were 84.6% and 77.3%, respectively. At the mean cutoff value of 41.5, the sensitivity and specificity of the HU mean were 76.9% and 86.4%, respectively. HU is an objective value used in radiographic density measurement. The HU values were higher in fungal lesions than in nonfungal inflammations, and they are useful in preoperative measurement.

Endotype-related recurrence pattern of chronic rhinosinusitis in revision functional endoscopic sinus surgery

OBJECTIVE

The recurrence of chronic rhinosinusitis (CRS) after functional endoscopic sinus surgery (FESS) is influenced by various factors, potentially including the endotype based on the molecular pathophysiology of CRS. This study investigated differences in the recurrence pattern of CRS by endotype after primary FESS.

METHODS

This retrospective study enrolled patients who had undergone revision FESS for recurrent CRS. Based on their clinical diagnosis, the patients were divided into two endotype groups: recurrent eosinophilic CRS (rECRS) and recurrent non-eosinophilic CRS (rNECRS). We compared and analyzed preoperative computed tomography (CT) findings, including typical anatomical findings of recurred CRS such as lateralized middle turbinate and retained uncinate process, the sinus where recurrence took place, and previous surgical completeness of the sinuses, between the rECRS and rNECRS groups.

RESULTS

In total, 142 patients were enrolled (48 rECRS, 94 rNECRS). No significant difference was found in the typical anatomic findings of recurrent CRS between the rECRS and rNECRS groups. The rates of the completeness of previous surgeries was significantly higher in rECRS than in rNECRS(P=.031). Despite the completeness of previous surgeries, the recurrence rate of frontal and ethmoidal sinuses was higher in the rECRS than rNECRS(P=.012, P<.001, respectively). In subgroup analysis according to the severity of ECRS, the number of involved sinuses and the rates of CRS recurrence and surgical completeness in frontal and anterior ethmoidal sinuses increased with ECRS severity.

CONCLUSIONS

CT findings of revision FESS cases differed by CRS endotype. The rECRS group showed higher recurrence in the frontal and ethmoidal sinuses despite a higher surgical completeness rate. Incomplete surgery was more often found in the rNECRS group.

Computed Tomography Evaluation of Unilateral Chronic Maxillary Sinusitis With Osteitis

BACKGROUND

Computed tomography (CT) is the preferred noninvasive method for the evaluation of osteitis in chronic sinusitis. Some scholars believe that the bone changes associated with chronic sinusitis always show high attenuation (high density) and are positively correlated with the severity of the disease. However, sinus bone remodeling is a complex process that may cause high or low attenuation. There have been few reports on the spread of osteitis. Therefore, additional research on sinus CT is necessary.

OBJECTIVE

To observe bony changes in chronic maxillary sinusitis (CMS) by CT and reveal the mechanism.

METHODS

A retrospective study was conducted in 45 patients with unilateral CMS with bony changes in the sinus walls. The patients' clinical data and CT results were analyzed and compared between the affected and normal sides. We propose the location, involvement, attenuation, and thickness method to evaluate CMS with osteitis.

RESULTS

Of the 45 patients, 40 (88.9%), 2, 12, and 7 had posterior external, medial, anterior, and superior lesions, respectively. The nasal region, sphenoid bone, palatine bone, and zygomatic arch were involved in 3, 12, 8, and 18 (40%) patients, respectively. Computed tomography indicated high attenuation in 30 (75.0%) and low attenuation in 10 (25.0%) patients; 6 (15.0%) showed new bone marrow cavities. The bone thickness was significantly different between the affected and normal sides in 40 patients (P < .001), including members of both the high- and low-attenuation groups (high-attenuation group: P < .001; low-attenuation group: P < .01). However, there was no significant difference in the thickness of the affected side between the high- and low-attenuation groups (P > .05).

CONCLUSIONS

Chronic rhinosinusitis with bony changes may occur in the maxillary sinus walls and spread to adjacent bones. Both increased and decreased attenuation may occur in these circumstances. Analyzing the CT features of bone changes in unilateral CMS can improve the accuracy of disease diagnosis.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Advances in the Knowledge of the Underlying Airway Remodeling Mechanisms in Chronic Rhinosinusitis Based on the Endotypes: A Review

Chronic rhinosinusitis (CRS) is a chronic inflammatory condition of the nasal and paranasal sinus mucosa that affects up to 10% of the population worldwide. CRS is the most representative disease of the upper respiratory tract where airway remodeling occurs, including epithelial damage, thickening of the basement membrane, fibrosis, goblet cell hyperplasia, subepithelial edema, and osteitis. CRS is divided into two phenotypes according to the presence or absence of nasal polyps: CRS with nasal polyp (CRSwNP) and CRS without nasal polyps (CRSsNP). Based on the underlying pathophysiologic mechanism, CRS is also classified as eosinophilic CRS and non-eosinophilic CRS, owing to Type 2 T helper (Th2)-based inflammation and Type 1 T helper (Th1)/Type 17 T helper (Th17) skewed immune response, respectively. Differences in tissue remodeling in CRS are suggested to be based on the clinical phenotype and endotypes; this is because fibrosis is prominent in CRSsNP, whereas edematous changes occur in CRSwNP, especially in the eosinophilic type. This review aims to summarize the latest information on the different mechanisms of airway remodeling in CRS according to distinct endotypes.

A Computed Tomographic Assessment of Osteitis of Sinus Bony Structures in Horses With Sinonasal Disorders

Background: Computed tomographic (CT) imaging has shown some horses with sinonasal diseases to have changes in their sinus bony structures. Scintigraphic and clinical evidence of sinus osteitis have also been reported. However, no study has objectively examined for the presence and degree of osteitis in equine sinonasal disease.

Objectives: To assess for the presence and extent of osteitis of sinus-related bony structures by examination of CT images of horses with clinically and sinoscopically confirmed unilateral sinonasal disease.

Study Design: Retrospective examination of CT images of horses with confirmed, mainly chronic (>2 month duration) unilateral sinus disease of different etiologies.

Methods: Bone thickness at designated sites of the maxillary bone (n = 3), frontal bone (n = 1), infraorbital canal (n = 2), and bony nasolacrimal duct (n = 1) were measured, as were the maximal diameters of the infraorbital canal and the bony nasolacrimal duct on both affected and control sides. Maxillary bone density (in Hounsfield Units) was also assessed bilaterally. Bone thickness was compared between affected and controlled sides using paired statistical tests.

Results: Bone was significantly thicker in the affected sinuses compared to the control sides at the three maxillary bone sites (all, P < 0.001) and at both infraorbital bone sites (both, P < 0.001), but not at the two most dorsal sites examined, i.e. frontal bone (P = 0.188) and bony nasolacrimal duct (P = −0.260) sites. Infraorbital canal and bony nasolacrimal duct diameters were significantly wider in the affected as compared to the control sides (P < 0.001 and P = 0.002, respectively). Maxillary bone density did not differ significantly between the affected (mean = 1,075 HU, SD = 230.01) and control (mean = 1,100, SD = 200.71) sides (t₍₅₈₎ = −1.03, P = 0.306).

Main Limitations: Possible variation in selecting measurement sites. Variation in the severity and chronicity of sinonasal disease between horses.

Conclusions: Osteitis and enlargement of paranasal bony structures commonly occurs in horses with sinonasal disease and can explain the clinical presence of ipsilateral diffuse soft tissue facial swelling, epiphora, and scintigraphic evidence of bone inflammation in sinonasal disease.

Crosstalk Between Mucosal Inflammation and Bone Metabolism in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a multifactorial and highly heterogeneous upper airway disease that affects approximately 12% of the general population. There is increasing evidence supporting the impact of osteitis on the pathophysiology of CRS. Osteitis is frequently observed in patients with CRS, and is associated with severe sinonasal inflammation and recalcitrant cases. The overlying inflammatory sinonasal mucosa plays a critical role in the initiation of osteitis; however, the underlying molecular mechanisms and functional significance remain unclear. Increasingly many studies have suggested that immune cells play a crucial role in the bone remodeling process in CRS. The purpose of this review is to summarize the current state of knowledge regarding the specific role of sinonasal inflammation in bone remodeling in CRS patients.

A Comparison of Sphenoid Sinus Osteoneogenesis in Aspirin-Exacerbated Respiratory Disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is characterized by excessive leukotriene production, diffuse polyp burden and osteitic bone changes. These bony changes have not been previously characterized.

OBJECTIVE

The aim of this radiographic study is to characterize the bony changes noted on computed tomography (CT) scans of the sphenoid sinus in patients with AERD compared to other diseased sinonasal inflammatory states and non-diseased controls.

METHODS

A retrospective review of 43 patients with clinically confirmed AERD were included and compared to 22 non-diseased, 9 allergic fungal sinusitis, and 43 chronic rhinosinusitis controls (23 without polyps and 18 with polyps). Comparative measurements were performed using fine-cut CT scans. Sites of comparison were the intersinus septum, the left and right lateral sphenoid wall, the roof, and left and right floor of the sphenoid sinus. Standardized measurements were averaged by two separate rhinologists.

RESULTS

Patients with AERD had an average statistically significant increase in bone thickness compared to healthy and diseased controls in nearly every site with the most pronounced changes in the intersinus septum (p < 0.05).

CONCLUSION

Patients with AERD have significantly increased thickness of the sphenoid bone compared to control groups with the most pronounced difference in the intersinus septum. These findings may help clinicians increase suspicion for a diagnosis of AERD who clinically have diffuse nasal polyposis.

The impact of asthma on quality of life and symptoms in patients with chronic rhinosinusitis. Curr Med Res Opin 2020;36:1043-1048. [PMID: 32270714 DOI: 10.1080/03007995.2020.1754189]

Objective: The study aims to evaluate how asthma influences on clinical symptoms, imaging scores and HRQL in CRS patients.Methods: The study enrolled CRS patients and collected data about asthma status, clinical symptoms, allergic sensitization, computed tomography (CT) and 22-item SinoNasal Outcome questionnaire (SNOT-22). Matching pairs of asthmatic and non-asthmatic CRS patients were defined based on age, gender and nasal polyp presence. The difference between pairs in clinical symptoms, CT and SNOT-22 was then analyzed. The study enrolled mild to moderate asthma patients.Results: From 250 CRS patients 65 (26%) had asthma. We found 60 CRS asthma and CRS non-asthma pairs based on age, gender and nasal polyp presence. There was no difference in total SNOT-22 score between asthma (46.5) and non-asthma (43.5) CRS groups (p < .357). There were more patients with allergy positive medical history in asthma group (66.1%) when we stratified for CRS phenotypes, gender and age. Comparing visual analogue scale (VAS) scores for clinical symptoms, smell (p < .013) was the only symptom significantly worse in CRS asthma group. Although there was no difference in Lund-Mackay score, there was a slightly higher osteitis score in CRS asthma group (5.21 vs. 3.45; p = .059).Conclusion: CRS patients with asthma have significantly worse impairment of smell and taste when compared to non-asthmatic CRS patients. This is the only significant difference which is independent of nasal polyp presence, gender, age and allergy.

Risk factors for neo-osteogenesis in cystic fibrosis and non-cystic fibrosis chronic rhinosinusitis

BACKGROUND

The purpose of this retrospective review was to determine how patient-related factors and culture data affect neo-osteogenesis in patients with chronic rhinosinusitis (CRS) and patients with cystic fibrosis (CF) with CRS.

METHODS

Information from a database associated with a large tertiary medical center was used to assess adult patients with CF CRS and non-CF CRS (total, n = 102; CF CRS, n = 31; non-CF CRS, n = 71). Radiologic evidence of neo-osteogenesis was measured using the Global Osteitis Scoring Scale (GOSS), and mucosal disease was assessed using the Lund-Mackay score (LMS) by 2 independent reviewers who were blinded to the patient's disease state. Bacterial cultures were obtained endoscopically. Multiple logistic regression models were used to evaluate the effect of age, sex, number of previous surgeries, CF, and culture species on the odds of neo-osteogenesis.

RESULTS

Fifty-one of the 102 patients (50%) met radiologic criteria for neo-osteogenesis. Sixty-nine patients (67.6%) with CF CRS and non-CF CRS had culture data. In the multiple logistic regression model, male gender was significantly associated with neo-osteogenesis (odds ratio [OR], 5.2; 95% confidence interval [CI], 1.68-17.86; p = 0.006). Pseudomonas aeruginosa was not associated with neo-osteogenesis (OR, 3.12; 95% CI, 0.84-12.80; p = 0.097). Age, number of surgeries, CF, Staphylococcus aureus, and coagulase-negative Staphylococcus were not statistically significant.

CONCLUSION

To our knowledge, this is the first study to assess risk factors associated with neo-osteogenesis and patients with CF CRS. Interestingly, male gender was the only significant predictor of neo-osteogenesis.

Increased nasal matrix metalloproteinase-1 and -9 expression in smokers with chronic rhinosinusitis and asthma

A potential mechanism underlying cigarette smoke-induced airway disease is insufficient tissue repair via altered production of matrix metalloproteinases (MMPs). Osteitis is a signature feature of recalcitrant chronic rhinosinusitis (CRS) and often results in revision surgery. The present study aimed to investigate MMP expression in the nasal tissues of asthmatic patients with CRS and any association with cigarette smoking and osteitis. Thirteen smokers with CRS and asthma, 16 non-smokers with CRS and asthma, and seven non-smoker asthmatic patients without CRS were prospectively recruited. The expression of MMPs and associated immunological factors in surgically-obtained nasal tissues was evaluated via real-time PCR and western blotting. Maximal bone thickness of the anterior ethmoid (AE) partition was measured in axial sinus computed tomography (CT) sections. MMP-1 and MMP-9 expression was increased in the nasal tissues of smokers with asthma and CRS via real-time PCR and western blot. Maximal AE partition bone thickness was greater in smokers with CRS and asthma than in non-smokers with CRS and asthma. MMP-1 and MMP-9 levels were correlated with maximal AE bone thickness. Cigarette smoking was associated with the up-regulation of MMP-1 and MMP-9 in the nasal tissues of patients with airway inflammatory diseases, and with AE osteitis, and with therapeutic resistence.

Interleukin (IL)-13 and IL-17A contribute to neo-osteogenesis in chronic rhinosinusitis by inducing RUNX2

Background

There is increasing evidence supporting the impact of neoosteogenesis in the pathophysiology of chronic rhinosinusitis (CRS), especially in the recalcitrant group of patients. Runt-related transcription factor 2 (RUNX2), a member of the RUNX family, controls osteoblast differentiation and bone formation. However, the role and regulation of RUNX2 in CRS patients with neoosteogenesis remain unclear. The aim of the study is to determine the role of RUNX2 in neoosteogenesis of CRS patients.

Methods

Sinonasal bone and overlying mucosa samples were obtained from CRS patients with or without neoosteogenesis (n = 67) and healthy controls (n = 11). Double immunofluorescence, immunohistochemistry, and immunoblotting were used to evaluate RUNX2 expression in CRS patients with and without neoosteogenesis. In addition, the osteogenic activity of pro-inflammatory cytokines was examined by measuring alkaline phosphatase (ALP) activity and bone mineralisation in vitro.

Findings

RUNX2 was highly expressed in osteoblasts of CRS patients with neoosteogenesis compared with tissues from control subjects and those with CRS without neoosteogenesis. Mucosal extracts from CRS patients with neoosteogenesis showed increased RUNX2 expression and ALP activity in C2C12 cells, whereas those from patients without neoosteogenesis did not. Expression of interleukin (IL)-13 and IL-17A was upregulated in CRS patients with neoosteogenesis. ALP activity and Alizarin Red staining showed IL-13 and IL-17A dose-dependent osteoblast differentiation and mineralisation in vitro.

Interpretation

These findings suggested that IL-13- or IL-17A-induced RUNX2 contributed to new bone formation in CRS patients through its effect on the activity of osteoblasts. RUNX2 may be a novel target for preventing neoosteogenesis in CRS patients.