Increased expression of IL-4, IL-5, IFN-gamma, IL-6, IL-8, and TGF-beta mRNAs in maxillary mucosa of patients with chronic sinusitis

Deep learning radiomics-based preoperative prediction of recurrence in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is characterized by poor prognosis and propensity for recurrence even after surgery. Identification of those CRS patients with high risk of relapse preoperatively will contribute to personalized treatment recommendations. In this paper, we proposed a multi-task deep learning network for sinus segmentation and CRS recurrence prediction simultaneously to develop and validate a deep learning radiomics-based nomogram for preoperatively predicting recurrence in CRS patients who needed surgical treatment. 265 paranasal sinuses computed tomography (CT) images of CRS from two independent medical centers were analyzed to build and test models. The sinus segmentation model achieved good segmentation results. Furthermore, the nomogram combining a deep learning signature and clinical factors also showed excellent recurrence prediction ability for CRS. Our study not only facilitates a technique for sinus segmentation but also provides a noninvasive method for preoperatively predicting recurrence in patients with CRS.

A Houttuynia cordata-based Chinese herbal formula improved symptoms of allergic rhinitis during the COVID-19 pandemic

BACKGROUND

The symptoms of coronavirus disease 2019 (COVID-19) such as hyposmia, rhinorrhea, nasal obstruction, and cough are similar to those of chronic allergic rhinitis (AR). Such symptoms can easily lead AR patients to unnecessary anxiety, misdiagnosis, and invasive diagnostic tests in the COVID-19 pandemic. Interleukin-6 (IL-6) is an important mediator for chronic AR and plays a crucial role in the inflammation of COVID-19. Houttuynia cordata (HC) has been shown to reduce nasal congestion and swelling by suppressing the activation of IL-6 and is used to fight COVID-19. A novel HC-based Chinese herbal formula, Zheng-Yi-Fang (ZYF), was developed to test effects on nasal symptoms of patients with AR in the COVID-19 pandemic.

METHODS

Participants aged between 20 and 60 years with at least a 2-year history of moderate to severe perennial AR were enrolled. Eligible participants were randomly allocated to either the intervention group (taking ZYF) or the control group (using regular western medicine) for 4 weeks. The Chinese version of the Rhinosinusitis Outcome Measures was used to evaluate impacts on quality of life and nasal symptoms of participants with AR. In addition, the effect of ZYF on lipopolysaccharide (LPS)-induced IL-6 was investigated.

RESULTS

Participants with AR taking ZYF improved their symptoms of nasal obstruction, nasal secretion, hyposmia, and postnasal drip in comparison with those of the control group. Meanwhile, ZYF exhibited inhibition of IL-6 secretion in the LPS-induced inflammatory model.

CONCLUSION

ZYF has potential effects to relieve nasal symptoms for AR during the COVID-19 pandemic.

High frequency of macrophages expressing elevated level of CD80, PD-Ls and TLR1 in nasal polyps of CRS patients

Identification of the association between tissue biomarkers, their surrogates in blood and clinical features, could provide new diagnostic tools and facilitate adequate choices of therapeutic interventions for selected patients suffering from CRS. The aim of present study was the assessment of macrophages in the polyp tissue and monocytes in the peripheral blood in the course of CRSwNP, and their functional immunophenotype. We analyzed 31 patients with CRSwNP. Nasal mucosa tissue was obtained via functional endoscopic sinus surgery (FESS). The control group included 10 patients with deviated nasal septum (DNS). Fluorochrome stained cells were proceed to acquisition using FACS Canto flow cytometer, and the results were analyzed using the software FACS Diva. In our study, we observed a significantly higher level of CD80, CD274, CD273 and TLR1 in nasal polyps compared to blood samples from patients with CRSwNP. This finding may suggest the importance of the PD-1 pathway as a therapeutic target in CRS and an important role for TLR1 in nasal polyp formation and maintenance. Our results may provide some insight into potential future targets of recurrent nasal polyp treatment and contribute to a better understanding of the inflammatory process in Chronic Rhinosinusitis.

Expression of Interleukin-5, Interleukin-8, and Interleukin-10 mRNA in the Osteomeatal Complex in Nasal Polyposis

Background

Several cytokines are expressed in chronic sinusitis with and without underlying allergy. Their local production and regulation in the osteomeatal complex, the key area of paranasal sinuses, still is not fully understood. This study was performed to investigate differences of cytokine messenger RNA (mRNA) expression between the medial and the lateral part of the middle turbinate and anterior ethmoid mucosa of allergic and nonallergic patients.

Methods

Using the LightCycler system for real-time reverse-transcription polymerase chain reaction, we investigated the content of interleukin (IL)-5, IL-8, and IL-10 mRNA in tissue samples from middle turbinates and anterior ethmoids of 18 patients with chronic sinusitis and nasal polyps. Inferior turbinate mucosa of six control subjects without sinusitis and allergy served as control.

Results

IL-5 mRNA was detectable in 32 (60%) of 54 samples (two of six controls) in significant different amounts between the various locations (p ≤ 0.001). Anterior ethmoid mucosa (0.96 ± 0.99) expressed the highest amount of IL-5 mRNA followed by the lateral (0.37 ± 0.54) and the medial portion of the middle turbinate (0.12 ± 0.29) with no difference between allergic and nonallergic subgroups. IL-8 was detected in significant higher amounts in all three origins with no significant difference in concentrations between the examined locations as compared with controls. Patients expressed either IL-5 or IL-8 or both cytokine mRNA. IL-10 was expressed in all three specimens from five of eight allergic patients. All five individuals with clinical symptoms of allergy at the time of operation expressed IL-10 in at least one specimen.

Conclusions

IL-5 cytokine expression in the osteomeatal complex is linked to the presence of nasal polyps, whereas IL-8 is up-regulated without distinct correlation to nasal polyps. IL-10 expression was detectable in five of eight allergic patients.

LL-37 causes cell death of human nasal epithelial cells, which is inhibited with a synthetic glycosaminoglycan

LL-37 is an immune peptide that regulates innate and adaptive immune responses in the upper airways. Elevated levels of LL-37 have been linked to cell death and inflammatory diseases, such as chronic rhinosinusitis (CRS). Glycosaminoglycans (GAGs) are polysaccharides that are found on respiratory epithelial cells and serve important roles in mucosal surface repair. Recent findings suggest that a synthetic glycosaminoglycan (GM-0111) can protect against LL-37-induced sinonasal mucosal inflammation and cell death in a murine model of acute RS. Herein, we elucidated the mechanisms by which LL-37 causes sinonasal inflammation and how GM-0111 can prevent these mechanisms. When challenged with LL-37, human nasal epithelial cells (HNEpCs) and mouse macrophages (J774.2) demonstrated increased release of adenosine triphosphate (ATP) and interleukin (IL)-6 and -8, as well as cell death and lysis. These cellular responses were all blocked dose-dependently by pre-treatment with GM-0111. We identified that LL-37-induced cell death is associated with caspase-1 and -8 activation, but not activation of caspase-3/7. These responses were again blocked by GM-0111. Our data suggest that LL-37 causes cellular death of HNEpCs and macrophages through the pro-inflammatory necrotic and/or pyroptotic pathways rather than apoptosis, and that a GM-0111 is capable of inhibiting these pro-inflammatory cellular events.

IL-13 regulates human nasal epithelial cell differentiation via H3K4me3 modification

Introduction

Epigenetic regulation has been shown to play an important role in the development of inflammatory diseases, including chronic rhinosinusitis and nasal polyps. The latter are characterized by epithelial mis-differentiation and infiltration of inflammatory cytokines. H3K4me3 has been shown to be involved in regulating lineage commitment. However, the underlying mechanisms, especially in human nasal epithelial cells (HNEpC), remain underexplored. The objective of this study was to investigate the role of H3K4me3 in HNEpC differentiation treated with the Th2 cytokine IL-13.

Patients and methods

The expression levels of mRNA and proteins were investigated using reverse transcription-polymerase chain reaction (RT-PCR) assays and Western blot in nasal polyp tissues and human nasal epithelial cells respectively. We measured these levels of H3K4me3, MLL1 and targeted genes compared with control subjects.

Results

We demonstrate that expression of H3K4me3 and its methyltransferase MLL1 was significantly upregulated in IL-13-treated HNEpC. This elevation was also observed in nasal polyps. Expression of cilia-related transcription factors FOXJ1 and DNAI2 decreased, while goblet cell-derived genes CLCA1 and MUC5a increased upon IL-13 treatment. Mechanistically, knockdown of MLL1 restored expression of these four genes induced by IL-13.

Conclusion

These findings suggest that H3K4me3 is a critical regulator in control of nasal epithelial cell differentiation. MLL1 may be a potential therapeutic target for nasal inflammatory diseases.

ICON: chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a public health problem that has a significant socio-economic impact. Moreover, the complexity of this disease due to its heterogeneous nature based on the underlying pathophysiology - leading to different disease variants - further complicates our understanding and directions for the most appropriate targeted treatment strategies. Several International/national guidelines/position papers and/or consensus documents are available that present the current knowledge and treatment strategies for CRS. Yet there are many challenges to the management of CRS especially in the case of the more severe and refractory forms of disease. Therefore, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), a collaboration between EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus (ICON) on Chronic Rhinosinusitis. The purpose of this ICON on CRS is to highlight the key common messages from the existing guidelines, the differences in recommendations as well as the gaps in our current knowledge of CRS, thus providing a concise reference. In this document we discuss the definition of the disease, its relevance, pharmacoeconomics, pathophysiology, phenotypes and endotypes, genetics and risk factors, natural history and co-morbidities as well as clinical manifestations and treatment options in both adults and children comprising pharmacotherapy, surgical interventions and more recent biological approaches. Finally, we have also highlighted the unmet needs that wait to be addressed through future research.

Nasal and Exhaled Nitric Oxide in Chronic Rhinosinusitis with Polyps

Background

The ciliary epithelial cells in the paranasal sinuses produce nasal nitric oxide (NO) continuously and plays a variety of roles in the paranasal sinuses. The purpose of this study was to assess whether we can use the levels of nasal NO (nNO) and exhaled NO (eNO) as a tool for evaluation in chronic rhinosinusitis (CRS) with nasal polyp patients.

Methods

We used chemiluminescent NO analyzer to measure nNO and eNO among normal controls (32) and CRS with polyp (30) and CRS with polyp and allergic rhinitis patients (27) and compared it with various clinical symptoms, laboratory data, and computed tomography (CT) scores.

Results

Levels of nNO were significantly lower in patients with CRS with polyps (88.5 ± 54.7 ppb) compared with controls (241.0 ± 89.5 ppb). Levels of nNO in CRS with polyps and allergic rhinitis (167.0 ± 47.6 ppb) were significantly higher than CRS with polyps and lower than controls. A significant inverse relationship was observed between nNO and sinus CT scores, severity of nasal obstruction, and purulent rhinorrhea in CRS with polyps. Low values of nNO separated well patients with CRS with polyps, and the cutoff value of <163 ppb was associated with the best com nation of specificity (93%) and sensitivity (81%). A significant positive relationship was observed between eNO and CT scores.

Conclusion

The nNO could be used for another screening of CRS with polyps for the more severe phenotypes, which may eventually have to be treated with surgery.

Primary human sinonasal epithelial cell culture model for topical drug delivery in patients with chronic rhinosinusitis with nasal polyposis

OBJECTIVES

The primary human sinonasal epithelial cell culture (HSNEC) allows for in-vitro modelling of mucosal responses to topical therapy. Cultures grown from healthy donors may underestimate changes in individuals with chronic sinonasal disease thereby yielding inaccurate results with respect to this large patient population. The purpose of this study was to analyse HSNECs derived from patients with chronic rhinosinusitis with nasal polyposis (CRSwNP) to determine whether expected disease dependent variables salient to topical drug delivery persist in culture.

METHODS

Cultures were grown from patients with CRSwNP. Ciliary beat frequency (CBF) (basal and stimulated), permeability (trans and paracellular), inflammatory response, and glucocorticoid dose response were measured and compared with healthy controls.

KEY FINDINGS

Methylcholine stimulated CBF was greater in CRSwNP versus controls (ΔCBF(60 min) 7.25 ± 1.02 vs 0.89 ± 1.04 Hz, respectively). Paracellular permeability was greater in CRSwNP versus controls (basolateral dextran(120 min) 18.97 ± 3.90 vs 11.31 ± 4.35 µg/ml, respectively). Lipopolysaccharide (0.1 mg/ml) stimulated interleukin-6 (IL-6) and IL-8 secretion was increased in CRSwNP versus controls (IL-6 Δbaseline 1738.72 ± 654.82 vs 1461.61 ± 533.51%, respectively; IL-8 Δbaseline 137.11 ± 0.83 vs 111.27 ± 0.67%, respectively). CRSwNP cultures were more sensitive than controls to dexamethasone (1 µg/ml) dependent IL-6 and IL-8 suppression.

CONCLUSIONS

HSNECs derived from patients with CRSwNP retained their primary phenotype with respect to ciliary function, epithelial permeability, irritant induced inflammatory cytokine secretion, and glucocorticoid dose response.

Pro-inflammatory effects of ochratoxin A on nasal epithelial cells

Eosinophilic chronic rhinosinusitis (ECRS) largely consists of allergic fungal sinusitis, non-allergic fungal rhinosinusitis, aspirin-exacerbated ECRS, and superantigen-induced ECRS. The pathophysiology of ECRS is not completely understood, in particular, the role of mycotoxins remains unknown. The aim of this study was to evaluate the effects of one of the most widespread mycotoxin, ochratoxin A (OTA), on the release of pro-inflammatory cytokines such as interleukin-(IL)-6 and the CXC-chemokine IL-8 from nasal epithelial cell cultures (NEC) of subjects with and without ECRS. NEC (ECRS group: n = 16; controls: n = 7) were stimulated with OTA for 24 h. Protein concentrations of IL-6 and IL-8 levels were measured in NEC supernatants by ELISA prior and 24 h after addition of OTA. Baseline levels in the supernatants of NEC were 183.3 pg/ml for IL-6 and 384.6 pg/ml for IL-8. Stimulation with OTA induced a significant increase of IL-6 (p < 0.001) and IL-8 (p < 0.001) in both NEC of controls and ECRS, respectively. There were no significant differences between controls and ECRS. This is the first study evaluating the effects of a mycotoxin on epithelial airway cells. Our data show that the ubiquitous mycotoxin OTA has a strong pro-inflammatory effect on NEC resulting in the release of IL-6 and IL-8. Mycotoxins may promote inflammation in nasal mucosa.

Serial cytokine levels during wound healing in rabbit maxillary sinus mucosa

CONCLUSION

Collagen deposition was increased in regenerative rabbit maxillary mucosa, and the elevated collagen deposition during wound healing was associated with increased interleukin (IL)-6 and IL-8, and decreased IL-10.

OBJECTIVES

To observe the natural progression of wound healing in rabbit maxillary sinus mucosa and to detect the expression of relevant cytokines.

METHODS

A rabbit wound-healing model was established in the maxillary sinus. At different times after injury, the sizes of maxillary ostia were recorded, and histological changes in the sinus mucosa were examined by means of hematoxylin and eosin (H&E) and Masson trichrome staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect the concentrations of IL-6, IL-8, IL-10, and collagen types I and III.

RESULTS

A large amount of immature spindled collagen deposition was observed in the basal lamina and lamina propria of regenerative mucosa. IL-6 was increased significantly in regenerative mucosa after injury, especially at 14 days post wounding when compared with normal mucosa. IL-8 was also increased significantly in regenerative mucosa; however, IL-10 was decreased significantly when compared with normal mucosa. IL-6 and IL-8 showed a significant correlation with the expression level of collagen type I.

Evidence for altered activity of the IL-6 pathway in chronic rhinosinusitis with nasal polyps

BACKGROUND

IL-6 activates T(H)17 cells and regulates the response of B lymphocytes and regulatory T cells. The IL-6 receptor and the membrane protein, glycoprotein 130 (gp130), form an active signaling complex that signals through signal transducer and activator of transcription 3 (STAT3) and other signaling molecules. Both the IL-6 receptor (IL-6R) and gp130 can be found in soluble forms that regulate the pathway.

OBJECTIVE

We measured IL-6 signaling components and IL-17 in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls to assess the IL-6 pathway in CRS.

METHODS

IL-6, soluble IL-6R, soluble gp130 (sgp130), and IL-17 were measured in sinus tissue extracts and in nasal lavage fluid by either cytokine bead array or ELISA. phosphoSTAT3 (p-STAT3) was determined by Western blot and by immunohistochemistry.

RESULTS

IL-6 protein was significantly (P < .001) increased in CRSwNP compared with CRSsNP and controls. Soluble IL-6R was also increased in nasal polyp compared with control tissue (P < .01). Despite elevated IL-6 and sIL-6R, IL-17A, E, and F were undetectable in the sinus tissue from most of the patients with CRS and controls. p-STAT3 levels were reduced in the polyp tissue, possibly indicating reduced activity of IL-6 in the tissue. sgp130 was elevated in CRSwNP compared with CRSsNP and controls.

CONCLUSION

p-STAT3 levels are decreased in CRSwNP despite increased levels of IL-6 and sIL-6R and are associated with the absence of an IL-17 response. This may be a response to elevated levels of sgp130, a known inhibitor of IL-6 signaling. These results indicate that IL-6 and its signaling pathway may be altered in CRSwNP.

Expression of GATA3, T-bet, IL-4, and IFN-gamma mRNA in the effusion of OME patients

OBJECTIVE

The role of allergy in the pathophysiology of otitis media with effusion (OME) remains unclear. We evaluated the role of allergy and the Th1/Th2 balance in OME patients.

METHOD

Middle ear fluid was collected from 46 OME patients who had a ventilating tube inserted, and expression of GATA3, T-bet, IL-4, and IFN-gamma mRNA was assessed by RT-PCR. Expression of transcription factors and cytokines was compared in patients with and without allergy.

RESULTS

The levels of GATA3 and T-bet mRNA in effusion fluid correlated positively with the levels of IL-4 and IFN-gamma mRNA, respectively. However, the allergy and non-allergy groups showed no significant differences in expression of any of these transcription factors and cytokines. The T-bet:GATA3 ratio was higher in the non-allergy than in the allergy group, but the difference was not statistically significant.

CONCLUSION

Although we observed a significant positive correlation between GATA3 and IL-4 mRNA levels, we cannot conclude that OME with allergy is related to a Th-2 driven immune response.

[The cytokines at maxillary sinuses washings as inflammatory process expression]

INTRODUCTION

In a pathogenetic chain of chronic sinusitis there is a set of cellular and humoral factors that are accepted as characteristic of a chronic inflammatory process. These include mast cells, granulocytes (basophilic and acidophilic), macrophages, lymphocytes, leucotriens (leukotrieny), and some pro-inflammatory cytokines. In the majority of cases these are effector factors that finalise pathogenetic immunological response. By determining concentration of pro-anti-inflammatory and immunoregulatory cytokines present in the place where the disease process is in progress we can distinguish the type of inflammatory condition and thus select the type and duration of treatment.

MATERIAL AND METHODS

The subject of the study was a group of 75 patients aged 18-60 with clinically confirmed chronic sinusitis; the diagnosis was made on the basis of history, physical examination as well as otolaryngological and imaging (CT scans) examination. Measurement of cytokines' activity was based on establishing concentration of cytokines in 1 ml (millilitre) of liquid recovered from puncture of maxillary sinus and subjected to centrifugation (lavage of maxillary sinuses) using ELISA (an immuno-enzymatic method) and kits produced by R&D company (Minneapolis, USA.) The following levels were examined: IL-1beta, IL-1ra, IL-4, IL-6, IL-10.

RESULTS

Depending on the type of inflammatory process (allergic or bacterial), a difference in the level of IL-1beta/IL-1ra and IL-4 i IL-10 concentration was discovered in patients examined. The static analysis focused on how progression of the disease influenced the results obtained.

CONCLUSIONS

Determining the amount of cytokines in maxillary washings allows differentiating chronic sinusitis.

Telomerase in nasal polyps

BACKGROUND

The aim of this study was to determine the presence and location of telomerase activities and the possible influence of elevated human telomerase reverse transcriptase (hTERT) mRNA levels on the outcome after surgical treatment in nasal polyposis.

METHODS

Telomerase activity in nasal polyps of 21 patients was quantified by measuring the hTERT mRNA contents with one-step real-time polymerase chain reaction. Inferior turbinates of 12 patients served as controls. Immunohistochemistry with specific antibodies was performed against hTERT. The number of hTERT marked cells was determined in 15 randomly selected fields. All patients were followed up after surgery for 60 months.

RESULTS

Elevated hTERT mRNA expression and number of hTERT+ cells was detected in nasal polyps in comparison with inferior turbinates (p < 0.001). hTERT+ cells were detected in the basal layer of the epithelia, the endothelia, and in some seromucous glands. During follow-up, it was discovered that tissue samples of five patients with recurrent polyposis did not have higher amounts of hTERT when compared with patients without relapse.

CONCLUSION

Telomerase activity is elevated in nasal polyps. Elevated hTERT expression does not predict the recurrence of nasal polyposis after surgical treatment.

Inflammatory mechanisms and remodeling in chronic rhinosinusitis and nasal polyps

Chronic rhinosinusitis (CRS) is presently classified into two subgroups: CRS without and CRS with nasal polyps. A variety of inflammatory mediators, including cytokines and chemokines, as well as adhesion molecules and matrix metalloproteinases, are upregulated in both subgroups of CRS; remodeling is also observed in both. However, there are also characteristic differences. Whereas CRS without nasal polyps has more neutrophilic infiltration, in CRS with nasal polyps (especially when associated with allergy/asthma) eosinophil infiltration is strikingly increased. Although several features of remodeling (eg, squamous metaplasia, basement membrane thickening, collagen deposition, hyperplasia of mucous glands, and goblet cells) are features seen in both subgroups of CRS, epithelial shedding as observed in asthma is not seen in either subgroup. Furthermore, pseudocyst formation seen in CRS with nasal polyps is not seen in CRS without nasal polyps.

Relationship between matrix metalloproteinases MMP-2, MMP-9, tissue inhibitor of matrix metalloproteinases-1 and IL-5, IL-8 in nasal polyps

BACKGROUND

Nasal polyps (NP), a subgroup of chronic rhinosinusitis, are characterized by interleukin 5 (IL-5) mediated infiltration of eosinophils in sinus mucosa, leading to pseudostratified ciliated columnar epithelium, thickening of the epithelial basement membrane and tissue edema. Matrix metalloproteinases (MMP) constitute a large group of Zn2+ dependent endopeptidases with the ability to degrade extracellular matrix and are possibly responsible for the development of tissue edema in chronic sinusitis.

OBJECTIVE

The aim of this study was to determine the expression of MMP-2, MMP-9 and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) mRNA and to locate the distribution of MMP-2, MMP-9 and TIMP-1 by immunohistochemistry in ethmoid sinus mucosa in NP. Furthermore the correlation between IL-5 or IL-8 and MMP-2, MMP-9 or TIMP-1 is examined.

METHODS

Nasal polyps of 33 patients and 18 specimens of inferior turbinate mucosa were examined by real time RT-PCR for MMP-2, MMP-9, TIMP-1, IL-5 and IL-8 mRNA expression. Immunohistochemical labeling for MMP-2, MMP-9 and TIMP-1 was performed.

RESULTS

Differences between both locations were detectable for MMP-9 (P < 0.001) and IL-5 (P=0.003) but not for MMP-2 (P=0.278), TIMP-1 (P=0.515) and IL-8 (P=0.386). Correlation was detected only between TIMP-1 and IL-5 (r=0.422, P =0.014). Cytoplasmic staining of MMP-2 was present in the apical part of the ciliated cells, submucosal glands and in smooth muscle cells. Matrix metalloproteinase-9 was expressed in surface epithelium, in seromucous glands and in polymorphonuclear cells.

CONCLUSIONS

Expression of MMP-9 and IL-5 mRNA are associated with NP. The correlation between IL-5 and TIMP-1 indicates the role of TIMP-1 in maintaining the homeostasis in NP.

Clinical implications of the immunomodulatory effects of macrolides on sinusitis

This article reviews the treatment of chronic sinusitis with macrolides. Chronic sinusitis is often the result of bacterial infections that lead to chronic inflammation with thickening of the sinus mucosa and hypersecretion of mucus. In addition to their anti-infective properties, some macrolides possess immunomodulatory effects. These macrolides have been used successfully to treat diffuse panbronchiolitis, a progressive inflammatory lung disease, and may be useful for treatment of asthma, chronic bronchitis, chronic sinusitis, cystic fibrosis, and bronchiectasis. The clinical benefits of macrolides in patients with chronic sinusitis include decreased nasal secretions and postnasal drip, with improvement in nasal obstruction. In vivo and in vitro studies show that some macrolides affect neutrophil chemotaxis and infiltration, inflammatory cytokine production, mucus production, and the transportability of airway secretions. These findings indicate that macrolides are promising agents for treating chronic inflammation of the airways.

Effect of clarithromycin on nuclear factor-kappa B and transforming growth factor-beta in chronic rhinosinusitis

OBJECTIVES

Long-term, low-dose macrolide therapy is effective in the treatment of chronic rhinosinusitis. It is believed that macrolide antibiotics produce this benefit through an anti-inflammatory effect. In this study, the effect of clarithromycin treatment on the expression of transforming growth factor (TGF)-beta and the key pro-inflammatory nuclear transcription factor, NF-kappa B, was examined in vitro and in vivo.

STUDY DESIGN AND METHODS

In vitro: nasal mucosa was obtained from 10 patients with chronic sinusitis and was cultured for 24 hours in the presence of clarithromycin or control. Cellular expression of TGF-beta and NF-kappa B was determined by immunohistochemistry. In vivo: 10 patients with chronic rhinosinusitis were treated for 3 months with clarithromycin. Nasal mucosal biopsies were taken pre- and posttreatment. Cellular expression of TGF-beta and NF-kappa B was again determined by immunohistochemistry.

RESULTS

Clarithromycin, when applied to nasal biopsies in vitro, reduced cellular expression of TGF-beta and NF-kappa B. Nasal biopsies taken before and after clarithromycin treatment showed no differences in cellular expression of NF-kappa B or TGF-beta.

CONCLUSION

Clarithromycin can reduce cellular expression of TGF-beta and NF-kappa B when applied in vitro, but its action during clinical therapy is less clear. Clarithromycin is capable of inhibiting pro-inflammatory cytokines in vitro, and reductions of TGF-beta and NF-kappa B may represent additional mechanisms by which macrolides reduce inflammation in chronic airway disease. Discrepancies between the actions of clarithromycin on nasal biopsies in vitro and after clinical therapy warrant further investigation.

Reduced nitric oxide in sinus epithelium of patients with radiologic maxillary sinusitis and sepsis

Radiologic maxillary sinusitis is an important risk factor for development of bronchopneumonia in mechanically ventilated patients. Nitric oxide produced within the paranasal sinuses is considered to provide an antibacterial environment and to modulate mucociliary clearance function. We hypothesized that a reduced formation of nitric oxide might contribute to the compromised local host defense in radiologic maxillary sinusitis and measured nitric oxide levels directly within maxillary sinuses of septic patients with radiologic maxillary sinusitis (n = 11), whose sinuses were fenestrated to eliminate a possible septic focus. Data were compared with those of patients without airway inflammation (n = 11, control subjects). Despite local inflammation and infection, we found considerably lower maxillary nitric oxide levels than in control subjects (31 +/- 10 versus 2554 +/- 385 parts per billion, mean +/- standard error of the mean, p < 0.001). Consistently, immunohistochemical and in situ hybridization investigations revealed strongly reduced expression of inducible nitric oxide synthase. By applying ultrastructural immunolocalization, we identified cilia and microvilli of the maxillary sinus epithelium as the major nitric oxide production site in control subjects. Our findings provide evidence of markedly reduced nitric oxide production in maxillary sinuses of patients with radiologic maxillary sinusitis and sepsis, implicating impaired local host defense and an increased risk for secondary infections.