Inflammatory genes in nasal polyposis

Histopathological Features of Chronic Rhinosinusitis with Nasal Allergic Polyps

Chronic rhinosinusitis with nasal polyps of allergic etiology is one of the most common pathology in the ENT sphere that affect a significant percentage of population. The paper aims to establish the involvement of the allergic component in the genesis of nasal polyposis. The study included 150 nasal polyps from patients hospitalized and operated in the ENT Department of Craiova's Clinical Emergency County Hospital. The biological material was fixed in 10% buffered formalin, processed by classical paraffin embedding technique followed by hematoxylin-eosin staining and it was interpreted in the Pathology Department of the same hospital. We evaluated a number of histopathological parameters that were given severity scores. The most common changes at epithelial level were: basal layer hyperplasia observed in 87 cases (58%), goblet cell hyperplasia in 121 cases (80.66%), basal membrane thickening with values between 10-42μm corresponding to a number of 118 cases (78.66%). The most important stromal changes were edema in 88% and infiltration with eosinophils 100%, indicating the allergic nature of this disease.

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.

TNF-α and IL-1 β Cytokine Gene Polymorphism in Patients with Nasal Polyposis

Objective

Nasal Polyp (NP) is a benign mass of the paranasal sinuses that protrudes into the nasal cavity. The exact underlying pathogenesis is not known. In this study we aimed to determine the genetic susceptibility of NP formation in relation to TNF-α-308 and IL-1β-511 promoter region gene polymorphisms.

Methods

A total of 71 patients with NP with asthma (n=21) or without asthma (n=50) were taken as the study group, and 91 healthy volunteers were taken as the control group. Blood was gathered into EDTA-containing tubes, and patient DNA was extracted. The polymorphisms of the IL-β and TNF-α cytokine genes were analyzed using real time polymerase chain reaction.

Results

The GG genotype in the TNF-α-308 region and the CC genotype in the IL-1β-511 region were found to be risk factors for NP formation (OR: 9.2, p=0.007 and OR: 33.3, p=0.001, respectively). Regarding allelic frequencies, the G allele at the TNF-α-308 promoter region was a risk factor for NP formation (OR: 6.06, p<0.001).

Conclusion

TNF-α GG genotype in the -308 promoter region and the IL-1β CC genotype in the -511 region are genetic risk factors for NP formation.

Vγ1⁺ γδT Cells Are Correlated With Increasing Expression of Eosinophil Cationic Protein and Metalloproteinase-7 in Chronic Rhinosinusitis With Nasal Polyps Inducing the Formation of Edema

PURPOSE

We have found that expression of γδT cells is increased in pathological mucosa of chronic rhinosinusitis with nasal polyps (CRSwNP) compared with normal nasal mucosa. This increase is correlated with the infiltration of eosinophils in CRSwNP. Here, we investigated the expression of γδT cells, inflammation and tissue remodeling factors as well as their probable relationships in different types of chronic rhinosinusitis (CRS) in China.

METHODS

A total of 76 surgical tissue samples that included 43 CRSwNP samples (15 eosinophilic and 28 non-eosinophilic), 17 CRS samples without nasal polyps (CRSsNP), and 16 controls were obtained. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the mRNA expression levels of Vγ1⁺ γδT cells, Vγ4⁺ γδT cells, eosinophil cationic protein (ECP), interleukin (IL)-8, transforming growth factor (TGF)-β2, metalloproteinase (MMP)-7, tissue inhibitor of metalloproteinase (TIMP)-4 and hypoxia-inducible factor (HIF)-1α. Enzyme linked immunosorbent assay (ELISA) was used to measure the protein level of ECP and MMP-7 in CRSwNP. The eosinophils were counted and the level of edema was analyzed with HE staining.

RESULTS

The mRNA expression levels of the Vγ1 subset, ECP and MMP-7 were significantly increased in CRSwNP with histological characteristics of eosinophilic infiltration and edema. The expression of the Vγ1 gene in CRSwNP correlated positively with the expression of both ECP and MMP-7. No significant decreases in the mRNA expression levels of TGF-β2, TIMP-4 or HIF-1α were observed in the CRSwNP samples. The expression levels of Vγ1 gene, ECP and MMP-7 were significantly increased in eosinophilic CRSwNP compared to non-eosinophilic CRSwNP.

CONCLUSIONS

Our results suggest the associations between Vγ1⁺ γδT cells, ECP and MMP-7 in CRSwNP, indicating that Vγ1⁺ γδT cells can induce the eosinophilic inflammation, which has a further effect on the formation of edema.

Allergic Aspergillus Rhinosinusitis

Allergic fungal rhinosinusitis (AFRS) is a unique variety of chronic polypoid rhinosinusitis usually in atopic individuals, characterized by presence of eosinophilic mucin and fungal hyphae in paranasal sinuses without invasion into surrounding mucosa. It has emerged as an important disease involving a large population across the world with geographic variation in incidence and epidemiology. The disease is surrounded by controversies regarding its definition and etiopathogenesis. A working group on "Fungal Sinusitis" under the International Society for Human and Animal Mycology (ISHAM) addressed some of those issues, but many questions remain unanswered. The descriptions of "eosinophilic fungal rhinosinusitis" (EFRS), "eosinophilic mucin rhinosinusitis" (EMRS) and mucosal invasion by hyphae in few patients have increased the problem to delineate the disease. Various hypotheses exist for etiopathogenesis of AFRS with considerable overlap, though recent extensive studies have made certain in depth understanding. The diagnosis of AFRS is a multi-disciplinary approach including the imaging, histopathology, mycology and immunological investigations. Though there is no uniform management protocol for AFRS, surgical clearing of the sinuses with steroid therapy are commonly practiced. The role of antifungal agents, leukotriene antagonists and immunomodulators is still questionable. The present review covers the controversies, recent advances in pathogenesis, diagnosis, and management of AFRS.

Toll-like receptor 4-mediated expression of interleukin-32 via the c-Jun N-terminal kinase/protein kinase B/cyclic adenosine monophosphate response element binding protein pathway in chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is prolonged inflammation of the sinonasal mucosa. Interleukin-32 (IL-32) is involved in the pathogenesis of chronic lung inflammatory diseases. The aim of study is to compare the expression level of IL-32 in normal nasal mucosa and CRSwNP and to investigate the mechanism underlying IL-32 expression in CRSwNP.

METHODS

IL-32 expression in nasal tissues, normal nasal mucosa-derived fibroblasts (NorDFs) and nasal polyp-derived fibroblasts (NPDFs), ex vivo explants of nasal tissues was measured by reverse-transcription polymerase chain reaction (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). NorDFs and NPDFs were exposed to lipopolysaccharide (LPS) and the expression level of IL-32 was measured. LPS from Rhodobactersphaeroides (RS) and small interference RNA against Toll-like receptor 4 (siTLR4) were used to inhibit signaling by TLR4. Activation of mitogen-activated protein kinase (MAPKs) (extracellular related kinase [ERK], p38, and c-Jun N-terminal kinase [JNK]), protein kinase B (AKT), and cyclic adenosine monophosphate response element binding protein (CREB) was examined using western blot analysis.

RESULTS

Expression of IL-32 was increased in CRSwNP compared to normal nasal mucosa. LPS induced expression of IL-32 in a time-dependent manner. The induction of IL-32 expression in NPDFS was more effective than in NorDFs. Treatment with RS and siTLR4 inhibited the messenger RNA (mRNA) expression of TLR4, myeloid differentiation primary response 88 (MyD88), and IL-32 in LPS-stimulated NPDFs. IL-32 expression was specifically activated by JNK, AKT, and CREB in LPS-stimulated NPDFs and CRSwNP ex vivo explants.

CONCLUSION

The sensitivity for IL-32 expression by LPS was increased in CRSwNP compared to normal nasal mucosa. LPS effectively induced IL-32 expression in NPDFs than in NorDFs through the TLR4-JNK-AKT-CREB signaling pathway. Therefore, IL-32 seems to be involved in the pathogenesis of CRSwNP.

Intercellular adhesion molecule-1 expression in activated eosinophils is associated with mucosal remodeling in nasal polyps

Nasal polyposis (NP) is characterized by chronic mucosal inflammation with infiltrating eosinophils. Eosinophil-mediated tissue remodeling may be involved in NP pathogenesis; therefore, improved understanding of tissue remodeling may result the identification of novel pathways and therapeutic strategies. The present study aimed to investigate the pathological changes occurring during tissue remodeling in NP, in order to assess the role of intercellular adhesion molecule-1 (ICAM-1) in localized tissue remodeling and the potential association between ICAM-1 expression and markers of eosinophil activation. A total of 28 eligible patients and 10 healthy controls participated in the current study. Nasal mucosal tissues of these subjects were retrospectively evaluated for mucosal remodeling using histopathological staining. ICAM-1 and eosinophil cationic protein (ECP) expression levels were determined by immunohistochemical analysis. Compared with the healthy controls, all the specimens from NP patients presented substantial epithelial damage, skewed cellular distribution with a reduced density of goblet cells, an increased density of subepithelial gland and increased subepithelial collagen deposition. In addition, the NP specimens exhibited significantly higher eosinophil infiltration and ICAM-1 expression compared with the controls. Positive correlations were observed between ICAM-1 and ECP expression levels (P=0.010), as well as between extracellular collagen deposition and ICAM-1 (P=0.010) and ECP (P=0.012) expression levels in the NP specimens, but not in the control specimens. Morphological evidence demonstrated eosinophil-mediated tissue remodeling in NP tissues. ICAM-1 expression in activated eosinophils was associated with NP remodeling, indicating the possibility that ICAM-1 may regulate NP remodeling.

Autophagy is deficient in nasal polyps: implications for the pathogenesis of the disease

BACKGROUND

Nasal polyposis is characterized by persistent inflammation but the pathogenesis is complex and still debatable. Autophagy has been associated with many human health problems including chronic inflammatory airway diseases. Whether autophagy plays a role in nasal polyps and could be a therapeutic target is completely unknown.

METHODS

We studied light chain 3 (LC3) protein expression, a common indication of autophagy, in fresh tissue specimens of 5 nasal polyps and 6 normal nasal mucosa by Western blot analysis. The results were also confirmed by immunohistochemistry (IHC) using additional 25 paraffin-embedded nasal tissue sections. Finally the autophagic activity was validated in nasal polyp-derived fibroblasts by evaluating the number of green fluorescent protein (GFP)-labeled LC3 puncta.

RESULTS

The expression of LC3 was dramatically decreased in all 5 nasal polyp tissues. In contrast, protein kinase B-mechanistic target of rapamycin (Akt-mTOR) signaling, an established negative regulator of autophagy, was significantly activated in these tissues. Immunohistochemical results further demonstrated a negative correlation between autophagy and nasal polyps (p < 0.05). GFP-LC3 puncta formation, an alternative indicator of autophagy, was also diminished in nasal polyp-derived fibroblasts (p < 0.01).

CONCLUSION

Autophagy is deficient presumably due to suppression by high Akt-mTOR activity in nasal polyps, which may provide a molecular basis for future mechanistic study of the disease.

Expression of RANTES, eotaxin-2, ICAM-1, LFA-1 and CCR-3 in chronic rhinosinusitis patients with nasal polyposis

PURPOSE

To compare gene expression of the chemokines RANTES and eotaxin-2, its receptor, CCR-3, adhesion molecule ICAM-1 and its receptor LFA-1 in eosinophilic polyps and in control normal nasal mucosa.

METHODS

Gene expression was quantified by Real Time PCR in polyps (n=35) and in healthy nasal mucosa (n=15).

RESULTS

Eosinophilic polyps showed a higher expression of eotaxin-2 and RANTES, but not of CCR-3, ICAM-1 or LFA-1 compared to control nasal mucosa.

CONCLUSION

Eosinophilic polyps present greater expression of eotaxin-2 and RANTES, but not of CCR-3, ICAM-1 or LFA-1 compared to control nasal mucosa.

Variations in expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in nasal mucosa of aspirin-sensitive versus aspirin-tolerant patients with nasal polyposis

BACKGROUND

Matrix metalloproteinases (MMPs) are key enzymes responsible for extracellular matrix degradation contributing to the progressive histological changes seen in lower airway disease, including asthma. MMP-9 and TIMP-1 have also shown some role in the pathogenesis of chronic rhinosinusitis (CRS) and nasal polyposis (NP).

OBJECTIVE

We aim to determine variability in expression of MMP-9 and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), in sinus tissue from distinct patient populations presenting with nasal polyposis.

METHODS

The expression of MMP-9 and TIMP-1 was investigated in nasal polyp tissue from 6 aspirin-sensitive (AS) and 6 aspirin-tolerant (AT) patients undergoing endoscopic sinus surgery for chronic rhinosinusitis with nasal polyposis (CRSwNP). Sinus mucosa from 6 patients with chronic rhinosinusitis without nasal polyposis (CRSsNP) was used as control. The MMP-9 and TIMP-1 expression was measured using immunofluorescence technique and graded using manual and computerized methods.

RESULTS

Expression of TIMP-1 was significantly reduced in the AS group when compared with both the AT and CRSsNP (control) groups (P < .001). The MMP-9/TIMP-1 ratio was significantly increased in the AS group when compared with other patient groups (P < .001). The MMP- 9 expression was similar between study and control groups.

CONCLUSION

These results support the importance of MMP-9 and TIMP-1 expression in nasal polyp formation. The decreased expression of TIMP-1 in AS patients may promote the effects of MMP-9 expression and thus contribute to tissue remodeling and inflammatory changes. This finding may lead to further understanding of disease severity and resistance to treatment in this group of patients, as well as the pathogenesis of nasal polyps.

Expression of galectin-9 by IFN-γ stimulated human nasal polyp fibroblasts through MAPK, PI3K, and JAK/STAT signaling pathways

Galectin-9 exhibited potent and selective eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo. Nasal polyposis is a chronic inflammatory disease of the upper airway characterized by the marked presence of inflammatory cells, particularly eosinophils. Thus, galectin-9 may be implicated in the pathogenesis of nasal polyposis. The study was designed to investigate whether interferon-gamma (IFN-γ) can induce the augmentation of galectin-9 expression and induce the expression of galectin-9 in nasal polyps. We examined the correlation between galectin-9 expression and eosinophil infiltration in nasal polyps. In addition, we identified the signaling pathways involved in the elevation of galectin-9 expression in response to IFN-γ. Our data demonstrate that the involvement of mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3 phosphate kinase (PI3K), and Janus kinase/signal transducer and activator of transcription (JAK/STAT) may play important roles in the selective recruitment of eosinophils in nasal polyp tissues through the production of galectin-9. These findings suggest that galectin-9 expression is associated with eosinophil infiltration in polyps of patients with nasal polyposis.

Does maxillary arch remodeling exist in nasal polyposis?

BACKGROUND

The potential transformation in the maxillary complex morphology is mostly complete during childhood. Recent studies suggest a nasal tissue remodeling both in the overlying mucosa and in the underlying sinus bone in nasal polyposis (NP). Our evaluation of computed tomography (CT) revealed that the maxillary arch is more flat and shallow in patients with chronic rhinosinusitis with NP. The purpose of this study was to determine the possible effects of NP to the maxillary arch morphology in adulthood and to investigate a possible remodeling of the maxillary bone during the course of NP.

METHODS

A prospective study was performed on 25 patients. Grading of the polyps, acoustic rhinometry and rhinomanometry assessments, and CT scans were documented initially, 1 year after diagnosis, and 2 years postoperatively. Twenty-five subjects' CT scans randomly selected from our CT database formed the comparison group. The plane angle between the maxillary alveolar processes (MAP) and the palatine process of the maxillary bone (MPP), and the depth of the maxillary arch of both groups were compared.

RESULTS

The results pointed out that the maxillary arch was shallower and the bilateral angles between MAP and MPP were significantly greater than those of the comparison group in all evaluation periods. This difference was less at the end of the postoperative follow-up period.

CONCLUSION

Although it is a common belief that maxillofacial formation expires in childhood, this may not be the case under some special conditions such as NP in adulthood. NP might cause maxillary arch remodeling in adults.

Endoscopic diode laser polypectomy and high-dose intranasal steroids in recurrent nasal polyposis

BACKGROUND

The aim of this clinical investigation was to determine the outcomes of an outpatient videoendoscopic diode laser polypectomy (DLPE) and subsequent topical high-dose corticosteroid application in chronic rhinosinusitis with recurrent nasal polyposis (NP).

METHODS

After ineffective revision sinus surgery and prolonged mometasone furoate application, 19 consecutive mild and moderate NP patients suffering from nasal obstruction (NO) and olfactory dysfunction (OD) were prospectively entered into the study to undergo DLPE under topical anesthesia. Beginning 1 week postoperatively, 250 microg of beclomethasone dipropionate aerosol spray (BDPAS) was self-administered into each nostril twice a day. Treatment efficacy was assessed after 1, 6, and 12 weeks and at quarterly long-term follow-ups based on objective parameters (videoendoscopic photodocumentation and rhinomanometry) and subjective evaluation of NO, OD, and satisfaction (visual analog scales [VASs]).

RESULTS

VASs indicated very low values for intraoperative pain and discomfort and high postoperative satisfaction. After 6 weeks, subjective and objective data revealed a significant improvement of NO and OD (p < 0.0005). Topical BDPAS application was well tolerated. At a median follow-up of 32 months (range, 1-4 years), 21% of the patients developed NP disappearance, 53% had a stable disease, and 26% had a progressive disease.

CONCLUSION

In therapy-refractory NP, endonasal DLPE represents a minimally invasive, symptom-oriented, safe and easily reapplicable outpatient treatment option that provides effective improvement of NO and OD. Compared with the pre-DLPE period, the proposed long-term quarterly follow-up combined with high-dose topical BDPAS application might reduce or delay the need for major surgery and appears to be suitable for disease control.

The glutathione-S-transferase gene polymorphisms (Gstt1, Gstm1, and Gstp1) in patients with non-allergic nasal polyposis

There is an ongoing dilemma about the pathogenesis of nasal polyp (NP). The etiology of NP is multifactorial. Reactive oxygen species and oxidative stress are also suggested to be among the possible factors in NP development. Glutathione-S-transferase (GST) is one of the important detoxifying enzymes. It is not known whether GST plays any role in NP development. We aimed to investigate the relationship between GST subgroup (GSTT1, GSTM1, and GSTP1) polymorphisms, and NP development. Seventy-five patients with NP with or without asthma (NP with asthma: 22, NP without asthma: 53) were used as a study group. As much as 167 healthy individuals were involved as the control group. NP diagnosis was made by nasal endoscopy and paranasal sinus computed tomography (CT). NP was defined as the presence of endoscopically visible bilateral polyps originated from the middle meatus to the nasal cavity and affecting more than one paranasal sinus confirmed by CT. Blood was collected in EDTA-containing tubes and DNA was extracted from the leukocytes. The genotyping of polymorphisms of GSTT1, GSTM1, and GSTP1 were done using real time polymerase chain reaction. Chi-square (chi(2)) and Fisher's (F) exact tests were used for statistical evaluation. A 2-fold increased risk of NP could be found in individuals with the GSTT1 null genotype (OR = 2.03, 95% CI = 1.03-4.011). The distribution of GSTM1 null genotypes was not significantly different between the NP patients and controls and there was also no significance between the GSTP1 genotypes and NP. In conclusion, GST gene polymorphisms may be important in pathogenesis of NP. Additional studies which include larger study groups in different geographic localizations may be more useful to evaluate association with GST polymorphism and NP.

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.