Predictors of Low and High Exhaled Nitric Oxide Values in Asthma: A Real-World Study.

BACKGROUND: In asthma, exhaled nitric oxide (FENO) is a clinically established biomarker of airway T2 inflammation and an indicator for anti-inflammatory therapy. OBJECTIVES: The aim of the study was to identify, in an observational real-world cross-sectional study, the main characteristics of patients with asthma as classified by their FENO level. METHOD: We stratified 398 patients with stable mild-to-severe asthma according to FENO level as low (≤25 ppb) versus elevated (>25 ppb), subdividing the latter into two subgroups: moderately elevated (26-50 ppb) versus very high FENO (>50 ppb). Clinical, functional, and blood parameters were extrapolated from patients' chart data and compared with the FENO stratification. Predictors of low and elevated FENO asthma were detected by logistic regression model. RESULTS: Low BMI, higher blood eosinophilia, allergen poly-sensitization, the severest airflow obstruction (FEV1/FVC), and anti-leukotriene use are predictors of elevated FENO values in asthma, as well as persistent rhinitis and chronic rhinosinusitis with or without nasal polyps. Beyond these, younger age, more than 2 asthma exacerbations/year, higher airflow reversibility (post-bronchodilator ∆FEV1), and oral corticosteroid dependence are predictors of very high FENO values. In contrast, obesity, obstructive sleep apnoea syndrome, gastroesophageal reflux disease, arterial hypertension, and myocardial infarction are predictors of low FENO asthma. In our population, FENO correlated with blood eosinophils, airflow obstruction, and reversibility and negatively correlated with age and BMI. CONCLUSIONS: Stratifying patients by FENO level can identify specific asthma phenotypes with distinct clinical features and predictors useful in clinical practice to tailor treatment and improve asthmatic patients' outcomes.

Characterization of T2-Low and T2-High Asthma Phenotypes in Real-Life.

Asthma is a heterogeneous and complex condition characterized by chronic airway inflammation, which may be clinically stratified into three main phenotypes: type 2 (T2) low, T2-high allergic, and T2-high non-allergic asthma. This real-world study investigated whether phenotyping patients with asthma using non-invasive parameters could be feasible to characterize the T2-low and T2-high asthma phenotypes in clinical practice. This cross-sectional observational study involved asthmatic outpatients (n = 503) referring to the Severe Asthma Centre of the San Luigi Gonzaga University Hospital. Participants were stratified according to the patterns of T2 inflammation and atopic sensitization. Among outpatients, 98 (19.5%) patients had T2-low asthma, 127 (25.2%) T2-high non-allergic, and 278 (55.3%) had T2-high allergic phenotype. In comparison to T2-low, allergic patients were younger (OR 0.945, p < 0.001) and thinner (OR 0.913, p < 0.001), had lower smoke exposure (OR 0.975, p < 0.001) and RV/TLC% (OR 0.950, p < 0.001), higher prevalence of asthma severity grade 5 (OR 2.236, p < 0.05), more frequent rhinitis (OR 3.491, p < 0.001) and chronic rhinosinusitis with (OR 2.650, p < 0.001) or without (OR 1.919, p < 0.05) nasal polyps, but less common arterial hypertension (OR 0.331, p < 0.001). T2-high non-allergic patients had intermediate characteristics. Non-invasive phenotyping of asthmatic patients is possible in clinical practice. Identifying characteristics in the three main asthma phenotypes could pave the way for further investigations on useful biomarkers for precision medicine.

Oral health in asthmatic patients: a review : Asthma and its therapy may impact on oral health.

Different drugs used to treat asthma, such as beta 2 agonists and inhaled steroids, may promote a higher risk of caries, dental erosion, periodontal disease and oral candidiasis. This article reviews the evidences of mechanisms involved in oral diseases in patients affected by asthma. The main mechanism involved is the reduction of salivary flow. Other mechanisms include: acid pH in oral cavity induced by inhaled drugs (particularly dry powder inhaled), lifestyle (bad oral hygiene and higher consumption of sweet and acidic drinks), gastroesophageal reflux, and the impairment of local immunity. In conclusion asthma is involved in the genesis of oral pathologies both directly and indirectly due to the effect of the drugs used to treat them. Other cofactors such as poor oral hygiene increase the risk of developing oral diseases in these patients. Preventive oral measures, therefore, should be part of a global care for patients suffering from asthma.