Eosinophil-mast cell pattern of intraepithelial infiltration as a marker of severity in CRSwNP

Dupilumab's impact on nasal citology: Real life experience after 1 year of treatment

BACKGROUND

Biologic agents are considered a new revolutionized therapy for severe and recurrent forms of CRSwNP which disease burden is not sufficiently controlled by conservative and/or surgical treatments. Recent Research has focused on evaluating their real-life efficacy in CRSwNP, as only limited reports on real-life data are available. However, in most studies, the response to treatment is evaluated in terms of improvement in Nasal Polyp Score (NPS) or in Sino-Nasal Outcome test (SNOT-22) scores. However, both criteria do not consider nasal immunophlogosis, which can be easily assessed by nasal cytology. The aim of our study was to evaluate changings in the nasal inflammatory infiltrate of CRSwNP patients treated with Dupilumab for 12 months.

METHODS

27 patients suffering from severe CRSwNP treated with Dupilumab were recruited. Nasal cytology findings, NPS, SNOT-22, ACT scores and blood eosinophil count at T0 (before treatment) and at T1 (after 1 year of treatment) were compared.

RESULTS

After 1 year of biological therapy with Dupilumab, NPS, SNOT-22 and, among the 17 asthmatic patients, ACT scores improved significantly. At T1, a statistically significant percentage of patients showed negative citology. Moreover, a significant reduction in the mast cell-eosinophilic pattern and an increase of neutrophils and bacteria was reported.

CONCLUSIONS

The response to treatment can be considered both in the case of negative nasal cytology and in the case of the appearance of neutrophils and bacteria. In this context, eosinophils, the specific target of biological therapies, play a crucial role in regulating tissue homeostasis and, consequently, the nasal immunophlogosis.

Mast Cells in Aspirin-Exacerbated Respiratory Disease

PURPOSE OF REVIEW

Aspirin-exacerbated respiratory disease (AERD) is a syndrome of high type 2 inflammation and is known to critically involve mast cell activation. The mast cell is an important cell in the baseline inflammatory processes in the upper and lower airway by maintaining and amplifying type 2 inflammation. But it also is prominent in the hypersensitivity reaction to COX-1 inhibition which defines this condition.

RECENT FINDINGS

Recent work highlights the mast cell as a focal point in AERD pathogenesis. Using AERD as a specific model of both high type 2 asthma and chronic sinusitis, the role of mast cell activity can be better understood in other aspects of airway inflammation. Further dissecting out the mechanism of COX-1-mediated mast cell activation in AERD will be an important next phase in our understanding of NSAID-induced hypersensitivity as well as AERD pathophysiology.

Expression Profiles of Matrix Metalloproteinases and Their Inhibitors in Nasal Polyps

Purpose

Nasal polyp (NP) is characterized by inflammation of the sinonasal mucosa with predominant inflammatory cell infiltration. Matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) are recognized to play an important role in leukocyte migration in airway inflammation. Herein, efforts were made to confirm the expression levels of MMPs/TIMPs and study the relationship between the infiltration of inflammatory cells and local expression levels of MMPs/TIMPs in NPs.

Patients and Methods

NP tissues were obtained from 42 Chinese patients with bilateral nasal polyps during the endoscopic sinus surgery. Inferior turbinate (IT) tissues from 19 patients with septal deviation were taken during the rhinoplasty surgery as controls. mRNA and protein levels of MMP1, MMP9, MMP10, MMP12, TIMP1 and TIMP3 were assessed by quantitative PCR and immunohistochemistry.

Results

Eosinophilia (72%, 23/32 samples), neutrophilia (41%, 13/32 samples), and increase in macrophages (38%, 12/32 samples) were found in NP tissues. mRNA expression of MMP1 (10.9-fold), MMP9 (4.1-fold), MMP10 (6.7-fold) and MMP12 (3.5-fold) were significantly up-regulated, while TIMP1 (1.5-fold) and TIMP3 (6.0-fold) were significantly down-regulated in NPs (n=42) as compared to the controls (n=19). The immunostaining levels of all 4 MMPs and two TIMPs were higher in NPs than those in controls. The co-localization of MMP1/MMP10/MMP12 and macrophages were identified in NPs. MMP9 was mainly expressed in neutrophils, while TIMP1 or TIMP3 were mostly found in eosinophils in NPs.

Conclusion

The results of our study indicate that tissue remodeling is significant in NPs, where MMPs/TIMPs play important roles in both tissue remodeling and inflammatory cells infiltration.