Positive identification in situ of mRNA expression of IL-6, and IL-12, and the chemotactic cytokine RANTES in patients with chronic sinusitis and polypoid disease. Clinical relevance and relation to allergy

[Immunology of chronic rhinosinusitis with nasal polyps as a basis for treatment with biologicals]

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous and multifactorial inflammation of the nasal and paranasal mucosa. Until now, no internationally standardized classification could be developed. In most cases, CRS is phenotypically classified according to chronic rhinosinusitis with (CRScNP) and without nasal polyps (CRSsNP). However, recent studies could show that there are numerous endotypes within these phenotypes based on different inflammatory mechanisms. This review describes the important immunological mechanisms of CRScNP and highlights modern treatment options with biologicals directly addressing particular immunological processes.

METHODS

Current knowledge on immunological and molecular processes of CRS, particularly CRScNP, was extracted from Medline, PubMed, national and international study- and guideline-registers, and the Cochrane library by a systematic review of the literature.

RESULTS

Based on current literature, various immunological mechanisms for CRS and CRScNP could be identified. Relevant studies for the treatment of eosinophilic conditions such as asthma or CRScNP are presented and, if available, results of these studies are discussed.

CONCLUSION

The growing insight into the underlying immunological mechanisms of CRScNP could pave the way for new personalized treatment options such as biologicals in the future.

Does procalcitonin have a role in the pathogenesis of nasal polyp?

PURPOSE

The aim of this study is to investigate serum and tissue procalcitonin (PCT) levels in patients with nasal polyps.

METHODS

The study was designed to be prospectively controlled and included 26 patients chronic rhinosinusitis with nasal polyp (CRSwNP) endoscopically diagnosed and as a control group 25 chronic rhinosinusitis without nasal polyp (CRSsNP). NP specimens, nasal mucosal tissue and venous blood samples of both groups were collected and PCT levels determined by Elisa method. The results were compared statistically.

RESULTS

Serum PCT values were 1319.5 pg/mL in the NP group and 818.8 pg/mL in the control group. The difference between the groups was statistically significant (p = 0.0001). In the NP group, the average PCT value of the polyp tissue was 1521.5 pg/gr, while the mean PCT value of the control group in the nasal mucosa was 414.6 pg/gr. There was a statistically significant difference between the groups (p = 0.0001). The tissue cut-off value of PCT 750 was significant [area under curve 0.940 (0.863-1.00)]. Serum PCT 950 cut-off value was significant [area under curve 0.860 (0.748-0.972)] activity (CI: 95%).

CONCLUSIONS

This is the first study of its kind to objectively examine PCT in the polyp and serum of CRSwNP patients. PCT may serve as a diagnostic biomarker in nasal polyps.

Subtyping of polyposis nasi: phenotypes, endotypes and comorbidities

BACKGROUND

Chronic rhinosinusitis (CRS) is a heterogeneous, multifactorial inflammatory disease of the nasal and paranasal mucosa. It has not been possible to date to develop an internationally standardized, uniform classification for this disorder. A phenotype classification according to CRS with (CRSwNP) and without polyposis (CRSsNP) is usually made. However, a large number of studies have shown that there are also different endotypes of CRS within these phenotypes, with different pathophysiologies of chronic inflammation of the nasal mucosa. This review describes the central immunological processes in nasal polyps, as well as the impact of related diseases on the inflammatory profile of nasal polyps.

MATERIALS AND METHODS

The current knowledge on the immunological and molecular processes of CRS, in particular CRSwNP and its classification into specific endotypes, was put together by means of a structured literature search in Medline, PubMed, the national and international guideline registers, and the Cochrane Library.

RESULTS

Based on the current literature, the different immunological processes in CRS and nasal polyps were elaborated and a graphical representation in the form of an immunological network developed. In addition, different inflammatory profiles can be found in CRSwNP depending on related diseases, such as bronchial asthma, cystic fibrosis (CF), or NASID-Exacerbated Respiratory Disease (N‑ERD).

CONCLUSION

The identification of different endotypes of CRSwNP may help to improve diagnostics and develop novel individual treatment approaches in CRSwNP.

Mucous Cytokine Levels in Chronic Rhinosinusitis-Associated Olfactory Loss

IMPORTANCE

Olfactory loss is a frequent symptom of patients with chronic rhinosinusitis (CRS), but our understanding of how inflammatory cytokines affect olfaction is limited.

OBJECTIVES

To examine whether inflammatory cytokines are present in the olfactory cleft and whether they correlate with objective olfaction.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study, patients with CRS underwent quantitative olfactory testing using the Sniffin Sticks test to calculate a composite threshold discrimination identification (TDI) score from October 21, 2013, to November 12, 2015. Nasal mucus was collected using a sponge placed in the olfactory cleft for 5 minutes, and Cytometric Bead Array was used to measure secreted immunomodulatory products. Correlations between TDI score and secreted mediators were then calculated. Data analysis was performed from October 15, 2015, to December 17, 2015.

MAIN OUTCOMES AND MEASURES

Composite TDI scores and mean secreted mediator levels in mucus from the olfactory cleft.

RESULTS

Thirty-four patients were enrolled (mean [SD] age, 57.3 [15.7] years; female, 21 [61.8%]; white, 26 [76.5]). The TDI scores were lower in patients with CRS with nasal polyps (CRSwNP) than in patients with CRS without nasal polyps (CRSsNP) (difference, 8.7; 95% CI, 2.5-15.0; P = .007). Interleukin (IL) 5 levels were inversely correlated with TDI scores in patients with CRSwNP and those with CRSsNP (mean [SE] β estimate, -46.56 [15.11]; P = .005), whereas IL-6, IL-7, and vascular endothelial growth factor A were positively correlated with TDI scores only in the CRSwNP cohort. Subscale olfactory TDI scores followed similar correlations to composite TDI scores.

CONCLUSIONS AND RELEVANCE

In this study, inflammatory cytokines were found in mucus collected from the olfactory cleft. Levels of IL-5, in addition to other cytokines, were associated with objective olfactory function. Further inquiry is needed to establish the source of mucous cytokines and establish whether they play a causal role in olfactory loss.

C-C Chemokine Ligand 2 Gene Expression in Nasal Polyp Fibroblasts: Possible Implication in the Pathogenesis of Nasal Polyposis

Objectives:

Recruitment of macrophages is essential to the pathogenesis of nasal polyps (NP), since this disease is inflammation-related. In this study, the effects of tumor necrosis factor α (TNF-α) on the expression of C-C chemokine ligand 2 (CCL2) in fibroblasts derived from nasal polyps (NPFs) were investigated. The roles of cyclooxygenase (COX) 2 and prostaglandins in the mediation of TNF-α–stimulated CCL2 gene expression were also investigated.

Methods:

Northern blot analysis was used to study the expression of CCL2 and c-Fos in cultured NPFs. An electrophoretic mobility shift assay was used to explore the interactions between activator protein 1 (AP-1) and DNA. Immunohistochemistry was used to explore the in vivo expressions of COX-2, CCL2, and CD68 in NPs.

Results:

The Northern blot analysis showed that TNF-α stimulated the expression of CCL2 and COX-2 genes, and the synthesis of CCL2 messenger RNA was COX-2-dependent. A transient elevation of c-Fos and c-Jun messenger RNAs was induced by TNF-α, whereas COX-2 inhibitors NS-398 and meloxicam abolished the up-regulation of c-Fos. The electrophoretic mobility shift assay revealed that TNF-α triggered AP-1 and DNA binding and again, NS-398 and meloxicam inhibited this reaction via reducing c-Fos synthesis. Curcumin (AP-1 inhibitor) markedly suppressed the TNF-α–induced CCL2 expression. The immunohistochemical staining of NP surgical specimens also revealed an intimate alignment between CCL2-positive fibroblasts and CD-68-positive macrophages.

Conclusions:

These data suggest that NPFs may contribute to NP development by synthesizing CCL2 to promote macrophage recruitment. Furthermore, COX-2 facilitates CCL2 transcription in NPFs via a c-Fos and AP-1 signaling pathway.

Gene Expression Analysis in Sinonasal Polyposis before and after Oral Corticosteroids: A Preliminary Investigation

OBJECTIVE: To characterize gene expression in sinonasal polyps and to gain insight into change in expression after oral corticosteroid treatment.

STUDY DESIGN AND METHODS: Nasal polyps were obtained before and after oral corticosteroid treatment and gene expression was analyzed with a focused gene array technique.

RESULTS: Pretreated sinonasal polyps demonstrated high gene expression for chemokine and leukotriene receptor genes (CCR2, CCR5, CX3CL1, and LTB4R) in all patients. After treatment, the global effects of corticosteroids were evident on gene expression.

CONCLUSIONS: Gene array techniques hold promise as a research method in sinonasal polyposis. The potential benefits, as well as the potential challenges, in using these research methods will be discussed.

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.

Significance of susceptible gene expression profiles in nasal polyposis

Nasal polyposis (NP) is a common chronic inflammatory disease of the rhinosinus mucosa and a complex disease with strong genetic and environmental components. During the past 10 to 20 yr, many studies have been performed to determine differential gene expression profiles between NP and normal nasal tissues, in order to identify susceptible genes that are associated with NP-related traits. Despite achievement in the identification of candidate genes and their associated pathogenic pathways, the large challenges remain as the genetic and molecular alterations required for its development and progression are still unclear. Therefore, the development of novel, powerful tools for gene discovery, and a closer integration of genetics and medical biology would provide valuable insight into the pathogenesis of NP.

Histological evaluation of maxillary sinus mucosa after functional endoscopic sinus surgery

BACKGROUND

This study was performed to evaluate the histological changes of the maxillary sinus mucosa of patients with chronic rhinosinusitis (CRS) after functional endoscopic sinus surgery (FESS).

METHODS

In a cohort study, biopsy specimens were collected from the maxillary sinus of patients submitted for FESS. One year after surgery, patients were clinically reassessed. Patients showing recurrence of disease (group 1) required a revision surgery, through which a second biopsy specimen was collected. Patients showing a favorable clinical response (group 2) were submitted to an outpatient maxillary biopsy through the previous opened middle meatus antrostomy. Biopsy material from four cadavers was used as control. The histological and electron microscope findings were analyzed.

RESULTS

At the initial surgery, patients presented many histopathological alterations, such as an inflammatory process infiltrating the submucosa, atypical respiratory epithelium with an important increase in goblet cells, metaplasia, or mixed epithelium. Group 1 patients persisted with the same alterations 1 year later, but ciliary dysmorphy was more accentuated. Group 2 patients presented a predominantly pseudostratified epithelium, but some areas contained an increased number of goblet cells and a reduction in the number of ciliated cells.

CONCLUSION

Recovery of the maxillary sinus mucosa of patients with CRS, observed by electron and light microscopy, was incomplete 1 year after endoscopic surgery, even in nonsymptomatic patients; nevertheless, these alterations were more important in symptomatic patients than in asymptomatic patients.

Inflammatory pathway gene expression in chronic rhinosinusitis

BACKGROUND

The main objective in this preliminary experiment was to compare gene expression in the sinus mucosa of patients with chronic hyperplastic rhinosinusitis (CRS) against normal subjects, using gene microarray technology. The specific aim was to examine alterations in inflammatory mediator expression in patients with CRS. We performed a prospective experimental study.

METHODS

Total RNA samples were obtained from the sinus mucosa biopsies of 14 patients with chronic hyperplastic sinusitis and 4 normal controls, using the Affymetrix recommended protocol. The data for 22,000 genes on the GeneChip U133A were generated from 18 hybridizations. Affymetrix GeneChip 5.0 was used as the image acquisition software for the U133A chips. Data normalization, log transformation, statistical analysis, and pattern study were performed with GeneSpring software. Comparison between patients with CRS and normal controls were performed using the Welch t-test, with log transformed data.

RESULTS

There were a total of 1283 genes scored as differentially expressed between groups. The value of p, the probability of a false positive, was set to <0.05. Hierarchical clustering was applied to study coexpression patterns of the 1283 significant genes. The inflammatory pathway was overlaid with the differential expressed gene list. Four genes involved in the inflammatory pathway, interleukin (IL)-6, IL-12A, IL-13, and tumor necrosis factor (TNF) alpha (2) were consistently overexpressed in patients with hyperplastic CRS.

CONCLUSION

There is overexpression of four major genes of the inflammatory pathway (IL-6, IL-12A, IL-13, and TNF-alpha (2)) in patients with CRS compared with the normal population. Defining gene expression profiles may help elucidate new key factors in the pathogenesis of CRS and perhaps aid in the development of new therapeutic modalities.

Mucin gene expression in rhinitis syndromes

Rhinitis and rhinosinusitis are often associated with airway diseases such as asthma, cystic fibrosis, and nasal polyposis. In these diseases, the alteration of both the quantity and quality of mucus results in an impaired mucociliary clearance, and this produces, in extreme cases, the airway obstruction. Mucins are the major component in mucus and are responsible for its viscoelastic properties. Mucin expression patterns have been shown to be altered in rhinitis-associated diseases. It has been proposed that this is one of the causes of hyperviscid mucus plugs in these pathologies. For this reason, the study of mucin expression and regulation in upper- and lower-airway diseases, such as asthma, cystic fibrosis, and nasal polyposis, may be crucial for the development of new therapies against mucus hypersecretion. In this review, we report major findings regarding mucin expression and regulation in rhinitis syndromes.

Endoscopic endonasal sinus surgery: a review of 18 years of practice and long-term follow-up

A study of 1,915 patients operated on with a total of 4,285 endoscopic endonasal ethmoidal procedures during a period of 18 years is presented. The study comprises five groups of patients with (1) acute recurrent and chronic sinusitis--long-standing symptoms >3 months--(n = 733), (2) nasal/paranasal polyposis (n = 710), (3) sinogenic headache (n = 325), (4) mucoceles (n = 59) and (5) other nasal/paranasal disorders (n = 88). This group includes acute sinus infection with complications (n = 38), acute trauma/injury (n = 22), Grave's disease with exophthalmus (n = 12) and olfactory dysfunction (n = 16). The need for a thorough examination leading to a final diagnosis is emphasized. Endoscopy and CT/MRI are standard tools in the diagnostic and postoperative process. Close cooperation and educational teaching of the patient are necessary to obtain highest compliance. Long-standing medical treatment of inflammatory diseases is important to the long-term outcome and is of utmost importance to surgical success. Surgery is recommended to be performed under general anesthesia (total intravenous anesthesia or laryngeal mask anesthesia) with additional local, topical anesthetics, and can be easily performed on a day-case out-patient basis. The surgery is based upon the Messerklinger technique (MT). Peroperative complications are reduced by a skilled and meticulous surgical conduct and an adequate medication preoperatively. During this period of time, necessary controls within the first postoperative month were reduced from 3-4 to only one. Long-term follow-up secures a long-standing optimal result. Endoscopic surgery for more rare conditions, such as orbital decompression, CSF leaks and meningoceles, is recommended to be performed in specialized centers with adequate trained staff and necessary equipment. The possibilities of the picture archiving communication system, giving a number of different projections and angles and video-guided imaging peroperatively, facilitates safe surgical performances in areas usually associated with great risks and hazards. The long-term results are very good during the above circumstances. Reoperations are few and the patient satisfaction is very high.

Interleukin 5, IL6, IL12, IFN-gamma, RANTES and Fractalkine in human nasal polyps, turbinate mucosa and serum

Polyps are considered to develop as an end result of an inflammatory process. Cytokines and chemokines in the respiratory mucosa may be a key to polyp pathophysiology. The main objective was to identify IL-5, IL-6, IL-12, RANTES, IFN-gamma and Fractalkine in humans on the protein level in nasal polyps and mucosa from the inferior turbinate (IT). Furthermore, the cytokines and chemokines RANTES and Fractalkine were analyzed in plasma. Tissue homogenates and plasma from 13 patients were analyzed by the ELISA technique. All the patients had longstanding nasal/paranasal polyposis. Fractalkine was detected in polyps and IT in two different patients. IL-5 was expressed in polyps and IT. IL-6 was expressed in all patients with a higher level in polyps than IT. IL-12 was present in plasma, polyps and IT, though at an increased level in polyps. RANTES was present at a higher level in plasma than in polyps and IT. IFN-gamma was detectable in polyps and IT. Fractalkine is detected in nasal polyps, which is a new observation. The overall results indicate a mixed T(H)1/T(H)2 cytokine profile in nasal polyps. RANTES and IL-12 are strongly present in plasma, suggesting an ongoing inflammatory "drive". IL-6 and IL-12 are up-regulated in polyps versus the IT. Up-regulation of IL-6 may be explained by increased fibroblast activity dependant on an ongoing local inflammation possibly initiated by an infection. IL-5, RANTES and IFN-gamma are equally represented in polyps and IT, indicating equilibrium between the nasal polyps and surrounding tissue, and that an up-regulation of cytokines in the polyp indicates a potential for polyp growth.

Rhinosinusitis: establishing definitions for clinical research and patient care

Background

There is a need for more research on all forms of rhinosinusitis. Progress in this area has been hampered by a lack of consensus definitions and the limited number of published clinical trials.

Objectives

To develop consensus definitions for rhinosinusitis and outline strategies useful in clinical trials.

Methods

Five national societies, The American Academy of Allergy, Asthma and Immunology; The American Academy of Otolaryngic Allergy; The American Academy of Otolaryngology Head and Neck Surgery; The American College of Allergy, Asthma and Immunology; and the American Rhinologic Society formed an expert panel from multiple disciplines. Over two days, the panel developed definitions for rhinosinusitis and outlined strategies for design of clinical trials.

Results

Committee members agreed to adopt the term “rhinosinusitis” and reached consensus on definitions and strategies for clinical research on acute presumed bacterial rhinosinusitis, chronic rhinosinusitis without polyposis, chronic rhinosinusitis with polyposis, and classic allergic fungal rhinosinusitis. Symptom and objective criteria, measures for monitoring research progress, and use of symptom scoring tools, quality-of-life instruments, radiologic studies, and rhinoscopic assessment were outlined for each condition.

Conclusion

The recommendations from this conference should improve accuracy of clinical diagnosis and serve as a starting point for design of rhinosinusitis clinical trials.

Rhinosinusitis: Establishing definitions for clinical research and patient care

Background

There is a need for more research on all forms of rhinosinusitis. Progress in this area has been hampered by a lack of consensus definitions and the limited number of published clinical trials.

Objectives

To develop consensus definitions for rhinosinusitis and outline strategies useful in clinical trials.

Study design

Five national societies, The American Academy of Allergy, Asthma and Immunology; The American Academy of Otolaryngic Allergy; The American Academy of Otolaryngology Head and Neck Surgery; The American College of Allergy, Asthma and Immunology; and the American Rhinologic Society formed an expert panel from multiple disciplines. Over two days, the panel developed definitions for rhinosinusitis and outlined strategies for design of clinical trials.

Results

Committee members agreed to adopt the term “rhinosinusitis” and reached consensus on definitions and strategies for clinical research on acute presumed bacterial rhinosinusitis, chronic rhinosinusitis without polyposis, chronic rhinosinusitis with polyposis, and classic allergic fungal rhinosinusitis. Symptom and objective criteria, measures for monitoring research progress, and use of symptom scoring tools, quality-of-life instruments, radiologic studies, and rhinoscopic assessment were outlined for each condition.

Conclusions

The recommendations from this conference should improve accuracy of clinical diagnosis and serve as a starting point for design of rhinosinusitis clinical trials.

Establishment of osteoblast culture from human ethmoidal sinus

OBJECTIVE

Chronic sinusitis is characterized by persistent chronic inflammation of the sinus system and local expression and release of various cytokines, such as IL-1 beta, IL-4, IL-6, IL-8, TGF-beta and TNF-alpha are deeply involved in the pathogenesis of the disease. We hypothesized that not only the sinus mucosa-containing cells, such as epithelial cells and fibroblasts, but also osteoblasts, of which sinus bone structure consists, may contribute to this inflammatory network. This study evaluates the development and establishment of an osteoblasts culture system derived from human ethmoidal sinus as an initial step toward verifying this hypothesis.

METHODS

Ethmoidal sinus bone was obtained from patients at the time of sinus surgery for chronic sinusitis and outgrowth cell sheets were obtained according to the explant-outgrowth cell culture technique. In order to examine the specific characteristics of osteoblasts in the obtained cells, four major features of osteoblasts (collagen type I, osteocalcin synthesis, alkaline phosphatase activity and extracellular matrix mineralization ability) were investigated at the third passage of the culture and productions of TGF-beta 1, which modulate osteoblast proliferation and maturation in an autocrine fashion, in the cultured medium was also investigated in time of culture up to 20 days.

RESULTS

The cells obtained in our study clearly show collagen type I synthesis, osteocalcin synthesis, alkaline phosphatase activity and production of visible extracellular matrix mineralization. Production of TGF-beta 1 in the medium did not significantly different in time of culture up to 20 days.

CONCLUSION

Our results, the first of their kind, indicate that osteoblast-like cells can be cultured from adult human ethmoidal sinus bones. It suggested that proliferation and maturation of the osteoblast were continuously modulated in an autocrine fashion by producing TGF-beta 1.

Nuclear factor-kappa B activation in the nasal polyp epithelium: relationship to local cytokine gene expression

OBJECTIVES

A panel of cytokines has been found to be important for eosinophil accumulation and activation in nasal polyps. The aims of this study were to ascertain whether the activation of nuclear factor-kappa B (NF-kappaB) occurred in the polyp epithelium, and to examine the relationship between the degree of activation and local cytokine gene expression.

STUDY DESIGN/METHODS

Nasal polyp specimens were obtained from 26 untreated patients. The proportion of nuclear translocation of the NF-kappaB p50 subunit in the polyp epithelium was quantitatively analyzed by a combination of fluorescent immunohistochemistry and a laser scanning confocal microscope image system. The levels of GM-CSF, IL-5, IL-8, IL-16, and eotaxin mRNA expression in the same speci-mens were measured using reverse transcription-polymerase chain reaction.

RESULTS

Both cytoplasmic and nuclear localization of the p50 subunit was observed mainly in the epithelial layer in all specimens. The percentages of epithelial cells with nuclear translocation ranged from 4.5% to 40.5% (median, 18%). Significant correlations were observed between the degree of epithelial NF-kappaB activation and the levels of IL-8, IL-16, and eotaxin mRNA expression (r = 0.468, 0.47, and 0.739, respectively).

CONCLUSION

The activation of NF-kappaB in the nasal polyp epithelium is responsible for the recruitment of inflammatory cells, particularly eosinophils, through the initiation of the transcriptional pathway of the related cytokines. The increased NF-kappaB activity in the polyp epithelium may reflect hypersensitivity to unknown stimuli.

Quantitative analysis of eotaxin and RANTES messenger RNA in nasal polyps: association of tissue and nasal eosinophils

OBJECTIVES/HYPOTHESIS

Nasal polyps develop in the ethmoidal and middle turbinate area, often in relation to inflammatory conditions. Their exact etiology and pathogenesis are still under debate. Histologically, the polyps are infiltrated by a number of inflammatory cells, with eosinophil predominating in most specimens. This finding suggests that the nasal polyp is an inflammatory growth that is controlled by the local environment. The chemokines eotaxin and RANTES (regulated on activation normal T cell expressed and secreted) have been postulated to be involved in the recruitment and activation of eosinophils to certain inflamed tissues. The purpose of this study was to investigate eotaxin and RANTES mRNA expression in nasal polyps and its effect on tissue and nasal eosinophils.

METHODS

Nasal polyps (917 allergic and 30 nonallergic cases) were obtained from endoscopic sinus surgery, and 15 normal inferior turbinates also were taken. Immunohistochemical staining for eosinophils and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) tests for eotaxin and RANTES mRNA expression were performed, and the concentration of nasal eosinophil cationic protein (ECP) was measured.

RESULTS

The amounts of eotaxin mRNA in the allergic nasal polyps were 11.4 times higher and the levels in the nonallergic polyps were 6.4 times higher than in the normal inferior turbinate. However, the RANTES mRNA expression did not show any differences among the three groups. Tissue eosinophilia and nasal ECP levels were significantly correlated with eotaxin mRNA level but not with RANTES mRNA expression.

CONCLUSION

Nasal polyp eosinophilic infiltration and activation correlate mainly with increased eotaxin gene expression rather than with RANTES expression.

Apoptosis and phagocytosis of tissue-dwelling eosinophils in sinonasal polyps

OBJECTIVE

Sinonasal polyps contain numerous tissue-dwelling eosinophils, but the mechanisms causing their accumulation, functional activities, and resolution are largely unknown.

STUDY DESIGN

Nasal polyp tissue from 14 patients was evaluated for cellular expression of CD95, CD68, and annexin-V, for the degree of apoptosis, and for phagocytosis of eosinophils.

MATERIAL AND METHODS

Histological sections were immunostained as single stains for CD95, CD68, and annexin-V, and as an immunostaining for CD68 combined with a modified Vital New Red staining. The latter staining is specific for eosinophils. Other sections were stained by terminal d-UTP nick end labeling (TUNEL) assay and routinely stained for H&E. Evaluation of the amount of stained cells was performed by counting the average number in 10 randomly chosen high-power fields. The TUNEL positivity was in all cases confirmed with apoptotic morphology.

RESULTS

The inflammatory infiltrate consisted of numerous eosinophils but also a considerable amount of lymphocytes, mast cells, and macrophage-like CD68+ cells. CD95 was frequently expressed on eosinophils, on numerous other inflammatory cells, and also on morphologically apoptotic cells. annexin-V-positive eosinophils were not as frequent as CD95+ cells, but numerous annexin-V-positive eosinophils were found. CD68+ cells approximately equalled the number of eosinophils. The number of cells phagocytosing eosinophils varied between polyps. Apoptosis of eosinophils (as evaluated by TUNEL combined with apoptotic morphology) was a common finding in six of the polyps.

CONCLUSIONS

Previous in vitro and ex vivo findings of CD95 on eosinophils are now supported by demonstration of CD95 on eosinophils in this in vivo study. This investigation revealed a switch of the membrane-bound phosphatidylserine of apoptotic cells, which is a novel observation. The study has demonstrated apoptosis of tissue-dwelling eosinophils, and that CD68+ macrophage-like cells phagocytose eosinophils within the sinonasal polyps.

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

This study aimed to investigate expression of various cytokine mRNAs, including IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma in maxillary sinus mucosa of patients with chronic sinusitis. Maxillary sinus mucosae of six patients with chronic sinusitis and turbinate mucosae of six healthy subjects were obtained. We performed RT-PCR and Southern blot to examine gene expression of the cytokines IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma in maxillary sinus mucosa and compared the results with cytokine gene expressions in normal turbinate mucosa. IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma mRNAs were expressed more frequently in maxillary sinus mucosa from patients with chronic sinusitis than in normal turbinate mucosa. All the maxillary sinus mucosa specimens revealed relatively higher mean density ratio for each cytokine investigated than did normal turbinate mucosa. IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma mRNAs were expressed simultaneously in maxillary sinus mucosa of chronic sinusitis. These cytokines may be responsible for recruitment of inflammatory cells and for mucosal thickening in chronic sinusitis, and thus chronicity of the disease.

Abnormal expression of the cystic fibrosis transmembrane regulator in chronic sinusitis in cystic fibrosis and non-cystic fibrosis patients

Cystic fibrosis (CF) patients commonly suffer from chronic sinusitis. Mutations of a single gene, the cystic fibrosis transmembrane conductance regulator (CFTR) gene, have been associated with CF. Functional CFTR protein is localized to the apical cell membrane, while dysfunctional CFTR is commonly found in the cytoplasm. We undertook a preliminary immunocytochemical study of CFTR subcellular localization in CF and non-CF pediatric and adult patients using a newly developed murine monoclonal antibody, TAM. Immunostaining was evaluated for subcellular localization (cytoplasmic versus membranous) and for epithelial layer (basal versus luminal). Analysis of the predominant CFTR distribution patterns demonstrated significant differences in adult versus pediatric groups independent of whether the latter were CF or non-CF (p<.0001 and p<.008, respectively), and no significant difference between the 2 pediatric groups (p = .70). This suggests that the pathophysiology of pediatric sinusitis differs from that of adult sinusitis at the level of secretion production.