Endotyping Chronic Rhinosinusitis with Nasal Polyps: Understanding Inflammation Beyond Phenotypes

Biologics versus functional endoscopic sinus surgery for the treatment of chronic rhinosinusitis with nasal polyps: a literature review

OBJECTIVE

To review the literature comparing functional endoscopic sinus surgery to dupilumab for the treatment of chronic rhinosinusitis with nasal polyps, in terms of symptom control, cost-effectiveness and complications.

METHOD

A literature review was conducted using PubMed, ScienceDirect and Cochrane databases. Data were extracted manually.

RESULTS

A total of six papers relevant to the main objective were found.

CONCLUSION

Chronic rhinosinusitis with nasal polyps has a significant impact on patients' quality of life. Both functional endoscopic sinus surgery and dupilumab achieve comparable disease control and result in good symptom relief. Dupilumab is far more expensive than functional endoscopic sinus surgery and is not considered cost-effective for the time being. This is expected to change after 10 years when the drug patent expires. More research is needed to compare the complications of both treatment modalities.

Immune endotyping and gene expression profile of patients with chronic rhinosinusitis with nasal polyps in the aspirin-exacerbated respiratory disease (AERD) and the non-AERD subgroups

BACKGROUND

Chronic Rhinosinusitis (CRS) is a paranasal sinus inflammatory disease and is divided into two subgroups defined as CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP displays a T helper (Th)2 biased phenotype, and based on sensitivity or tolerance to aspirin or non-steroidal anti-inflammatory drugs (NSAID), is further subdivided into Aspirin-exacerbated respiratory disease (AERD) and non-AERD groups. Considering the challenge of diagnosis and treatment in patients with CRSwNP, particularly the AERD subtype, and the significance of endotyping in these patients, we examined the immune profile and endotyping based on gene expression analysis in the AERD and the non-AERD groups of patients with CRSwNP.

MATERIAL AND METHOD

In this study, 21 patients were enrolled and were categorized into AERD (N = 10) and non-AERD (N = 11) groups based on their sensitivity to aspirin. After the special washing period, nasal polyps were biopsied in both groups, and the infiltration of eosinophils, neutrophils, plasma cells, and lymphocytes was compared between the AERD and the non-AERD groups. Also, gene expression levels of transcription factors including Tbet, GATA3, RoRγt, and FoxP3 and inflammatory cytokines including interleukin (IL)1β, IL1RAP (IL1 receptor accessory protein), IL2, IL4, IL5, IL10, IL13, IL17, TNFα, and IFNγ were investigated by quantitative Real-time PCR (qRT-PCR). Statistical analyses were performed using analytical tests including Kolmogorov-Smirnov, Mann-Whitney, and T-test. A P value less than 0.05 was considered statistically significant.

RESULTS

The mean ± SD age of the studied groups was 37 ± 8.7 years old (21-50) for the AERD, and 40.4 ± 7.7 years old (31-52) for the non-AERD. LMS/EPOS/SNOT scores and pulmonary function tests showed no difference between the two groups. Serum immunoglobulin E (IgE) levels were found to be higher in patients with AERD (p = 0.04), however, the peripheral blood counts of eosinophils were comparable in the two groups. In the histopathologic analysis, the AERD group showed higher percentages of eosinophils (p = 0.04), neutrophils (p = 0.04), and plasma cells (p = 0.04) than the non-AERD group. Additionally, the gene expression levels of GATA3 (p = 0.001), IL4 (p = 0.04), IL5 (p = 0.007), and IL17 (p = 0.03) were significantly higher in the AERD than the non-AERD groups.

CONCLUSION

Higher gene expression levels of GATA3, IL4, IL5, and IL17 were observed in the AERD group compared with the non-AERD group. These findings point to distinct patterns of inflammation in patients with AERD, with a predominance of Th2 inflammation.

Metabolic syndrome facilitates histopathological changes and the risk of postoperative recurrence in chronic rhinosinusitis with nasal polyps

BACKGROUND

The relationship between metabolic syndrome (MS) and chronic rhinosinusitis with nasal polyps (CRSwNP) remains unclear. This study aimed to examine the effects of MS on histopathological features and postoperative recurrence in patients with CRSwNP.

METHODS

We recruited 529 patients with CRSwNP who underwent functional endoscopic sinus surgery. They were divided into MS and non-MS groups and followed up for 2 years to evaluate postoperative recurrence. Clinical characteristics, histopathological features, the immunoactivity of signature cytokines, and the risk of postoperative recurrence were compared between the two groups.

RESULTS

In total, 490 patients with CRSwNP were included in the study, 145 of whom experienced postoperative recurrence. The recurrence rate, tissue eosinophil count and percentage, and expression levels of IL-5 and IL-17A were significantly higher in the MS group compared to the non-MS group. Furthermore, within the MS group, patients who experienced recurrence exhibited higher tissue eosinophil counts and IL-5 and IL-17A levels than those in the non-MS group. Notably, the eosinophil count and IL-5 and IL-17A levels were higher in tissues collected during revision surgery than in those collected during primary surgery, particularly in patients with MS. Binary logistic regression analysis and Kaplan-Meier survival curves consistently indicated that MS independently increased the risk of postoperative recurrence in patients with CRSwNP. Furthermore, the risk increased with the number of MS components presented.

CONCLUSION

MS promoted tissue eosinophil infiltration, and IL-5 and IL-17A expression, and increased the risk of postoperative recurrence in patients with CRSwNP. MS was identified as an independent risk factor for postoperative recurrence, and the risk increased with an increase in the number of MS components.