Sinonasal epithelial cells synthesize active vitamin D, augmenting host innate immune function

Pathogenesis of Nasal Polyposis: Current Trends

Chronic Rhinosinusitis (CRS) is characterized by edema of the sub-epithelial layers, but, only specific types of CRS are developing polyps. Nasal polyposis may develop under different pathogenetic mechanisms rendering the typical macroscopic classification of CRS, with or without nasal polyps, rather deficient. Currently, we approach nasal polyposis, in terms of diagnosis and treatment, according to its endotype, which means that we focus on the specific cells and cytokines that are participating in its pathogenesis. It appears that the molecular procedures that contribute to polyp formation, initiating with a Th-2 response of the adaptive immune system, are local phenomena occurring in the sub-epithelial layers of the mucosa. Several hypotheses are trying to approach the etiology that drives the immune response towards Th-2 type. Extrinsic factors, like fungi, Staphylococcus superantigens, biofilms, and altered microbiome can contribute to a modified and intense local reaction of the immune system. Some hypotheses based on intrinsic factors like the elimination of Treg lymphocytes, low local vitamin-D levels, high levels of leukotrienes, epithelial to mesenchymal transition (EMT) induced by hypoxia, and altered levels of NO, add pieces to the puzzle of the pathogenesis of nasal polyposis. Currently, the most complete theory is that of epithelial immune barrier dysfunction. Intrinsic and extrinsic conditions can damage the epithelial barrier rendering sub-epithelial layers more vulnerable to invasion by pathogens that trigger a Th-2 response of the adaptive immune system. Th2 cytokines, subsequently, induce the accumulation of eosinophils and IgE together with the remodeling of the stroma in the sub-epithelial layers leading, eventually, to the formation of nasal polyps.

Relationship between the Severity of Inflammatory Changes in Chronic Sinusitis and the Level of Vitamin D before and after the FESS Procedure

There have been a few reports confirming that vitamin D (VD3) deficiency increases inflammation in the paranasal sinuses. The work brings new information that, despite the presence of inflammation before surgery, patients with higher vitamin D levels had less inflammation, and this has been proven on three levels. We show that vitamin D levels clearly correlate with the severity of the disease in chronic sinusitis. These results have been confirmed in imaging studies (Lund MacKay scale), endoscopy (Lund-Kennedy scale) and in the SNOT 20 questionnaire. 40 patients suffering from chronic sinusitis were divided into two equal groups: group 1: with less severe radiological changes (10 or less points on the Lund-Mackay scale), group 2: with a more advanced form (>10 points). The relationship between VD3 and the severity of the disease (clinical and nasal endoscopy) was assessed. The mean VD3 level in patients in group 2 before surgery was lower (23.01 ng/mL) than in group 1 (28.02 ng/mL) (p < 0.05). They presented a higher degree of advanced changes in all the above scales, i.e., before the SNOT 20 procedure, the mean was: group 1: 30.33, group 2: 31.80 (p < NS); Lund-Kennedy: group 1: 3.21, group 2: 6.30 (p < 0.05). After surgery an increase in VD3 levels was observed in both study groups: in group 1 to the value of 37.98 ng/mL (p < 0.002) and in group 2 to 27.67 ng/mL (p < 0.004). Lower VD3 levels were found in patients with a higher stage of the disease. Reduction of inflammation increases the level of VD3 and reduces subjective and objective symptoms of chronic inflammation.

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.

Topical Vitamin D May Modulate Human Sinonasal Mucosal Responses to House Dust Mite Antigen

BACKGROUND

Respiratory epithelium is a key defense against inhaled pathogens. Vitamin D3 (VD) has been suggested to modulate airway inflammation; however, its effect on innate airway defenses, the physical barrier, mucociliary apparatus, and cytokine release remains unclear.

OBJECTIVE

To investigate the outcomes of VD application prior to challenge in an in vitro model of human sinonasal epithelium, through assessment of epithelial transepithelial resistance (TER), cilia beat frequency (CBF), and interleukin (IL)-6 release, and secondarily to determine whether topical VD is beneficial to patients with inflammatory sinonasal pathology.

METHODS

Primary human sinonasal epithelial cells from patients with eosinophilic chronic rhinosinusitis (eCRS) and healthy controls were cultured in air-liquid interface (ALI). Well-differentiated cultures from each patient were pretreated for 24 hours with 4 different VD doses. Toxicity was quantified at 24 hours in unchallenged ALI by lactate dehydrogenase (LDH) assay. Innate responses were assessed by measuring TER and CBF before and up to 24 hours after house dust mite Dermatophagoides pteronyssinus challenge. IL-6 release was evaluated 24-hour postchallenge.

RESULTS

Fifteen patients (53 ± 13.5 years, 60% females, 53% eCRS) representing 120 ALI wells were assessed. VD (0, 25, 50, 150 IU/mL) released less LDH than vehicle, indicating noncytotoxicity (0.15 ± 0.02; 0.15 ± 0.00; 0.14 ± 0.02; 0.11 ± 0.01 vs 0.17 ± 0.03, P = .004). VD increased TER for eCRS wells at 5 minutes (50 IU/mL: Δ6.76 ± 3.93 vs Δ3.87 ± 2.46, P = .04) and 24 hours (50 IU/mL: Δ0.88 ± 0.49 vs Δ0.40 ± 0.42, P = .02; 150 IU/mL: Δ1.06 ± 0.58 vs Δ0.47 ± 0.46, P = .01). CBF increased at 1 hour for eCRS wells (50 IU/mL: Δ0.62 ± 0.14 vs Δ0.41 ± 0.13, P = .001; 150 IU/ml: Δ0.60 ± 0.13 vs Δ0.38 ± 0.11, P < .001). IL-6 release was similar between normal and eCRS wells.

CONCLUSION

Topical VD supplementation in eCRS patients may be beneficial for innate epithelial defenses. VD is noncytotoxic and does not adversely affect the physical barrier, mucociliary apparatus, or IL-6 release. Further studies should clarify its potential as a therapeutic agent.

Vitamin D deficiency are associated with subjective disease severity in Chinese patients with chronic rhinosinusitis with nasal polyps

OBJECTIVE

To evaluate the serum vitamin D level in patients with chronic rhinosinusitis with nasal polyps and its correlation with the disease severity.

SETTING

Hospital of Zhejiang University.

STUDY DESIGN

Retrospective analysis of collected data.

SUBJECTS AND METHODS

Patients with chronic rhinosinusitis with or without nasal polyps who underwent endoscopic sinus surgery were recruited. Demographic information including age, gender, body mass index, smoke history, atopic status and asthma was collected. Disease severity was measured by the Lund-Mackay CT score and Sino-Nasal Outcome Test-22 score. Serum 25-hydroxyvitamin D3 was measured by enzyme-linked immunosorbent assay preoperatively.

RESULTS

Serum 25-hydroxyvitamin D3 levels were significantly lower in patients with nasal polyps (CRSwNP, 38.2 ± 9.1 nmol/L; CRSsNP, 48.94 ± 12.1 nmol/L; control, 54.1 ± 17.1 nmol/L. p < 0.001), and the levels were significantly associated with the preoperative Sino-Nasal Outcome Test-22 score (p = 0.013), but not with the Lund-Mackay score (p = 0.126). Furthermore, serum 25-hydroxyvitamin D3 levels were associated with the subjective improvement six months postoperatively (p < 0.001), CONCLUSION: Serum 25-hydroxyvitamin D3 levels are lower in Chinese CRSwNP patients. These 25-hydroxyvitamin D3 levels are associated with SNOT-22 score. Preoperative 25-hydroxyvitamin D3 level may impact on the symptom improvement after surgery.

Role of Vitamin D and Its Receptors in the Pathophysiology of Chronic Rhinosinusitis

OBJECTIVES

Chronic rhinosinusitis (CRS) is a disease that represents a challenging therapeutic problem. Vitamin D and its receptors (VDR) are involved in the regulation of the immune system and may play role in CRS. Objectives of this study were to assess the relationships between the total concentration of vitamin D (25VD3) in sera, vitamin D receptor (VDR) expression, 1α-hydroxylase expression, and clinical data, including age, gender, Sino-Nasal Outcome Test (SNOT-22), computerized tomography (CT) scan, allergy status, and vitamin D supplementation in CRS patients with (CRSwNP) and without nasal polyps (CRSsNP), and in a control group.

METHODS

The studied group comprised 52 patients with CRS without nasal polyps (sNP), 55 with CRS with nasal polyps (wNP), and 59 in the control group. The endpoints were determined by appropriate methods. We conducted immunohistochemical staining of gathered tissue from the ostiomeatal complex for determination of VDR and 1α-hydroxylase. Analytical results were compared with clinical data as already noted.

RESULTS

A decrease in VDR nuclear staining occurred in CRS patients as compared to controls. Insignificant differences were observed in 1α-hydroxylase, expression in all studied groups, while VDR and cytochrome CYP27B1 protein expression (1α-hydroxylase) correlated with clinical data.

CONCLUSIONS

The data provide evidence that indicates that vitamin D and its receptor and enzymes may play a role in CRS.

Physiologic and pathophysiologic roles of extra renal CYP27b1: Case report and review

Although the kidney was initially thought to be the sole organ responsible for the production of 1,25(OH)₂D via the enzyme CYP27b1, it is now appreciated that the expression of CYP27b1 in tissues other than the kidney is wide spread. However, the kidney is the major source for circulating 1,25(OH)₂D. Only in certain granulomatous diseases such as sarcoidosis does the extra renal tissue produce sufficient 1,25(OH)₂D to contribute to the circulating levels, generally associated with hypercalcemia, as illustrated by the case report preceding the review. Therefore the expression of CYP27b1 outside the kidney under normal circumstances begs the question why, and in particular whether the extra renal production of 1,25(OH)₂D has physiologic importance. In this chapter this question will be discussed. First we discuss the sites for extra renal 1,25(OH)₂D production. This is followed by a discussion of the regulation of CYP27b1 expression and activity in extra renal tissues, pointing out that such regulation is tissue specific and different from that of CYP27b1 in the kidney. Finally the physiologic significance of extra renal 1,25(OH)₂D₃ production is examined, with special focus on the role of CYP27b1 in regulation of cellular proliferation and differentiation, hormone secretion, and immune function. At this point the data do not clearly demonstrate an essential role for CYP27b1 expression in any tissue outside the kidney, but several examples pointing in this direction are provided. With the availability of the mouse enabling tissue specific deletion of CYP27b1, the role of extra renal CYP27b1 expression in normal and pathologic states can now be addressed definitively.

The relationship between serum vitamin D and chronic rhinosinusitis: A systematic review

BACKGROUND

An exciting development in upper respiratory tract disease is the pathophysiology of vitamin D (VD3). There now is substantial literature to indicate that VD3 acts as an immunomodulator of adaptive and innate immunity locally within the respiratory epithelium. Chronic rhinosinusitis (CRS) places a relatively large socioeconomic burden on developed nations, yet remains a difficult disease to treat. VD3, therefore, has become an area of clinical interest because it may provide an adjunctive drug therapy option in CRS, thereby potentially improving the quality of life of these patients.

OBJECTIVE

A systematic review of the relationship among serum VD3 levels, CRS phenotype, and disease severity by using outcome assessments.

METHODS

A systematic search was performed by using the PubMed, MEDLINE, and EMBASE databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Studies that measured serum VD3 levels and correlated the measurements to any subtype of CRS (with or without nasal polyps) were included for qualitative analysis.

RESULTS

Seven articles were included (four prospective and three retrospective studies), with a total of 539 patients. There were significantly lower VD3 levels in the polypoid phenotypes of CRS compared with controls. Low VD3 levels were often associated with an increased degree of inflammation.

CONCLUSION

The available evidence indicated that there is a significant relationship between low VD3 levels and polypoid CRS phenotypes. The association between VD3 levels and disease severity and VD3 potential for drug therapy remains unclear, which warrants further research in the area.

Evaluation of vitamin D levels in children with primary epistaxis

OBJECTIVE

This study aimed to investigate whether there is a relationship between 25-hydroxy vitamin D [25(OH)D 3] values and incidences of primary epistaxis among children.

METHODS

A total of 42 cases and 55 matched controls were included in our study. The study group and control group were well matched for age and gender. Age, gender, activated partial thromboplastin time (APTT) with reference to the international normalized ratio (INR), prothrombin time (PT), and 25(OH)D 3, parathormone (PTH), alkaline phosphatase (ALP), calcium (Ca), magnesium (Mg), and phosphorus (P) values were recorded for each participant.

RESULTS

Serum 25(OH) D values were found to be statistically significantly (P = 0.03) lower in children with primary epistaxis than in the healthy control group. Our study also revealed that 25(OH) D values were considerably (P < 0.001) lower in the group with primary epistaxis and upper respiratory tract infections (RTI) than in the group with primary epistaxis without upper RTI. Univariate logistic regression analyses demonstrated that 25(OH)D 3 < 20 ng/ml [odds ratio (OR) 1.117, 95% confidence interval (CI) (1.019-1.225); P = 0.019] and serum albumin level [OR 3.499, 95% CI (1072-11,426); P = 0.038] ratio were significantly related to primary epistaxis. Furthermore, multivariate logistic regression analyses revealed that 25(OH)D 3 < 20 ng/ml [OR 1.141, 95% CI (1047-1242); P = 0.003] and serum albumin level [OR 3.340, 95% CI (1068-10,446); P = 0.038] ratio were significantly related to primary epistaxis.

CONCLUSIONS

Many studies have revealed that vitamin D is a preventive and therapeutic agent for inflammation and infection, thereby providing benefits for children with primary epistaxis. In line with this, our study suggested that a patient's vitamin D status could also be important for the prevention of childhood primary epistaxis, although further studies are required to validate our findings.

New insights into upper airway innate immunity

BACKGROUND

Protecting the upper airway from microbial infection is an important function of the immune system. Proper detection of these pathogens is paramount for sinonasal epithelial cells to be able to prepare a defensive response. Toll-like receptors and, more recently, bitter taste receptors and sweet taste receptors have been implicated as sensors able to detect the presence of these pathogens and certain compounds that they secrete. Activation of these receptors also triggers innate immune responses to prevent or counteract infection, including mucociliary clearance and the production and secretion of antimicrobial compounds (e.g., defensins).

OBJECTIVE

To provide an overview of the current knowledge of the role of innate immunity in the upper airway, the mechanisms by which it is carried out, and its clinical relevance.

METHODS

A literature review of the existing knowledge of the role of innate immunity in the human sinonasal cavity was performed.

RESULTS

Clinical and basic science studies have shown that the physical epithelial cell barrier, mucociliary clearance, and antimicrobial compound secretion play pivotal innate immune roles in defending the sinonasal cavity from infection. Clinical findings have also linked dysfunction of these defense mechanisms with diseases, such as chronic rhinosinusitis and cystic fibrosis. Recent discoveries have elucidated the significance of bitter and sweet taste receptors in modulating immune responses in the upper airway.

CONCLUSION

Numerous innate immune mechanisms seem to work in a concerted fashion to keep the sinonasal cavity free of infection. Understanding sinonasal innate immune function and dysfunction in health and disease has important implications for patients with respiratory ailments, such as chronic rhinosinusitis and cystic fibrosis.

Chronic rhinosinusitis pathogenesis

There are a variety of medical conditions associated with chronic sinonasal inflammation, including chronic rhinosinusitis (CRS) and cystic fibrosis. In particular, CRS can be divided into 2 major subgroups based on whether nasal polyps are present or absent. Unfortunately, clinical treatment strategies for patients with chronic sinonasal inflammation are limited, in part because the underlying mechanisms contributing to disease pathology are heterogeneous and not entirely known. It is hypothesized that alterations in mucociliary clearance, abnormalities in the sinonasal epithelial cell barrier, and tissue remodeling all contribute to the chronic inflammatory and tissue-deforming processes characteristic of CRS. Additionally, the host innate and adaptive immune responses are also significantly activated and might be involved in pathogenesis. Recent advancements in the understanding of CRS pathogenesis are highlighted in this review, with special focus placed on the roles of epithelial cells and the host immune response in patients with cystic fibrosis, CRS without nasal polyps, or CRS with nasal polyps.

Regenerative potential of human schneiderian membrane: progenitor cells and epithelial-mesenchymal transition

An innate osteogenic potential of the Schneiderian membrane (SM) is progressively assessed in studies ranging from non-human species to human subjects. It has relevance for endosteal placement and osseointegration. Nestin-expressing osteogenic progenitor cells are allegedly involved in bone formation and remodelling. Nestin phenotype was not assessed previously in human SM. We therefore aimed to fill that particular gap in the literature. Bioptic samples of human adult SM were obtained during surgery from eight adult patients, operated for non-malignant pathologies. Immunohistochemistry on paraffin-embedded tissue samples used primary antibodies against nestin, CD45, CD146, cytokeratin 7 (CK7), and alpha-smooth muscle actin (α-SMA). Nestin expression was consistently found in endothelial cells, and was scarcely encountered in pericytes, putative stromal stem/progenitor cells, as well as in glandular epithelial cells. Moreover, woven bone formation in the periosteal layer of the SM can also be regarded as evidence of the osteogenic potential of this membrane. Nestin and CD45 expression in cells of the primary bone supports the osteogenic potential of SM nestin-expressing cells and a possible involvement of hematopoietic stem cells in maxillary sinus floor remodeling. CD146, a known inducer of epithelial-mesenchymal transition (EMT), was expressed in epithelia, as was CK7. Isolated stromal cells were found expressing CD146, CK7 and α-SMA, suggesting that regenerative processes happening in the SM may also involve processes of EMT which generate stem/progenitor cells. This study provides additional evidence for the regenerative potential of the Schneiderian membrane and identifies potential roles for cells of its stem niche in osteogenesis.

Association of Vitamin D Status and Acute Rhinosinusitis: Results From the United States National Health and Nutrition Examination Survey 2001-2006

Although vitamin D status may be a modifiable risk factor for various respiratory ailments, limited data exists regarding its role in sinonasal infections. Our goal was to investigate the association of 25-hydroxyvitamin D (25OHD) levels with acute rhinosinusitis (ARS) in a large, nationally representative sample of non-institutionalized individuals from the United States. In this cross-sectional study of individuals ≥ 17 years from the National Health and Nutrition Examination Survey 2001-2006, we used multivariable regression analysis to investigate the association of 25OHD levels with ARS, while adjusting for season, demographics (age, sex, race, and poverty-to-income ratio), and clinical data (smoking, asthma, chronic obstructive pulmonary disease, diabetes mellitus, and neutropenia). A total of 3921 individuals were included in our analyses. Median 25OHD level was 22 (interquartile range 16-28) ng/mL. Overall, 15.8% (95% confidence interval [CI] 14.4-17.7) of participants reported ARS within the 24 hours leading up to their survey participation. After adjusting for season, demographics, and clinical data, 25OHD levels were associated with ARS (odds ratio 0.88, 95% CI 0.78-0.99 per 10 ng/mL). When vitamin D status was dichotomized, 25OHD levels < 20 ng/mL were associated with 33% higher odds of ARS (odds ratio 1.33, 95% CI 1.03-1.72) compared with levels ≥ 20 ng/mL. Our analyses suggest that 25OHD levels are inversely associated with ARS. Randomized, controlled trials are warranted to determine the effect of optimizing vitamin D status on the risk of sinonasal infections.