Inflammatory endotypes of chronic rhinosinusitis based on cluster analysis of biomarkers.

BACKGROUND: Current phenotyping of chronic rhinosinusitis (CRS) into chronic rhinosinusitis with nasal polyps (CRSwNP) and chronic rhinosinusitis without nasal polyps (CRSsNP) might not adequately reflect the pathophysiologic diversity within patients with CRS. OBJECTIVE: We sought to identify inflammatory endotypes of CRS. Therefore we aimed to cluster patients with CRS based solely on immune markers in a phenotype-free approach. Secondarily, we aimed to match clusters to phenotypes. METHODS: In this multicenter case-control study patients with CRS and control subjects underwent surgery, and tissue was analyzed for IL-5, IFN-γ, IL-17A, TNF-α, IL-22, IL-1ß, IL-6, IL-8, eosinophilic cationic protein, myeloperoxidase, TGF-ß1, IgE, Staphylococcus aureus enterotoxin-specific IgE, and albumin. We used partition-based clustering. RESULTS: Clustering of 173 cases resulted in 10 clusters, of which 4 clusters with low or undetectable IL-5, eosinophilic cationic protein, IgE, and albumin concentrations, and 6 clusters with high concentrations of those markers. The group of IL-5-negative clusters, 3 clusters clinically resembled a predominant chronic rhinosinusitis without nasal polyps (CRSsNP) phenotype without increased asthma prevalence, and 1 cluster had a TH17 profile and had mixed CRSsNP/CRSwNP. The IL-5-positive clusters were divided into a group with moderate IL-5 concentrations, a mixed CRSsNP/CRSwNP and increased asthma phenotype, and a group with high IL-5 levels, an almost exclusive nasal polyp phenotype with strongly increased asthma prevalence. In the latter group, 2 clusters demonstrated the highest concentrations of IgE and asthma prevalence, with all samples expressing Staphylococcus aureus enterotoxin-specific IgE. CONCLUSION: Distinct CRS clusters with diverse inflammatory mechanisms largely correlated with phenotypes and further differentiated them and provided a more accurate description of the inflammatory mechanisms involved than phenotype information only.

Dissemination and implementation of the ARIA guidelines for allergic rhinitis in general practice.

BACKGROUND: Allergic rhinitis (AR) is a prevalent problem in general practice. The first evidence-based guidelines for AR, the ARIA guidelines, were published and have been updated repeatedly since 2001 in order to improve the care of AR patients. Very limited information, however, is available on the impact of these guidelines on everyday clinical practice. The aim of this study was to evaluate the dissemination and implementation of the ARIA guidelines in general practice. METHODS: Three hundred and fifty Flemish general practitioners (GPs) were recruited to complete a questionnaire covering their demographic and professional characteristics, awareness, perception and implementation of the ARIA guidelines. To assess compliance with the ARIA treatment recommendations, 4 fictitious case scenarios of AR were presented, in which the respondents were asked to select the treatment of choice. RESULTS: Of the 350 GPs included, only 31% were aware of the ARIA guidelines and 10% stated that they implement them. For the diagnosis of AR, 71% of the GPs ask specific IgE tests or perform skin prick tests, whereas only 29% perform an anterior rhinoscopy. ARIA users are more likely to screen for concomitant asthma. In the clinical-case section, there was a large variability in proposed therapeutic strategies. Adherence to the evidence-based ARIA treatment guidelines was low, but recent graduation was a significant predictor of compliance with these recommendations. CONCLUSIONS: The ARIA guidelines remain relatively unknown among Flemish GPs and even those who are aware of them still tend to treat AR independently of the guideline recommendations.