Absence of airway inflammation in a large proportion of adolescents with asthma

Abstract

Background and objective: Neutrophilic inflammation has been implicated in non-eosinophilic asthma (NEA) in adults, but little is known about NEA in children/adolescents. We assessed clinical and inflammatory characteristics of NEA in adolescent asthma. Methods: Airway inflammation, sputum endotoxin, airway hyper-reactivity, atopy and lung function were assessed in 77 adolescents with asthma and 68 without asthma (12-17 years). Asthma was identified on the basis of wheeze and asthma history. Results: The proportion of NEA (sputum eosinophils <2.5%) was 54%. In this group, atopy, sputum neutrophil, eosinophil, eosinophil cationic protein (ECP), endotoxin, neutrophil elastase and IL-8 levels were not different from those without asthma. In contrast, eosinophilic asthma (EA) was associated with atopy and sputum ECP and IL-8. The majority of NEA had no evidence of inflammation; only 14% had neutrophilia (≥61% neutrophils), compared with 11% of EA, and 15% of those without asthma. Small differences in FEV1 (NS) were found between EA and NEA, but symptom prevalence and severity was not different (63% of EA and 52% of NEA were classified moderate to severe). Conclusion: NEA is common in adolescent asthma and has similar clinical characteristics as EA. Neutrophils do not appear to play a role in NEA in adolescents, and underlying mechanisms may not involve airway inflammation.

Respiratory health in professional cleaners: Symptoms, lung function, and risk factors

“…Atopy was assessed using skin prick tests as previously described 19 using the following aeroallergen solutions: positive control (histamine), negative control (diluent), cat, dog, grass mix, Alternaria , Cladosporium , Penicillium , and house dust mite (Hollister‐Stier Laboratories, Spokane, WA, USA). All tests were read at 15 minutes.…”

Маркери нейрогенного запалення в дітей iз синдромом вертебробазилярної артеріальної системи і рекурентними бронхітами

“…тканевых структур бронхов, нарушая ме-ханизмы мукозального иммунитета и обусловливая частую заболеваемость острыми бронхитами. Повы-шенный уровень субстанции Р напрямую определял тяжесть и длительность клинической симптомати-ки, патофизиологически вызывая длительный спазм гладких мышц с развитием одышки, отека и гиперсе-креции слизи, обтурирующих дыхательные пути [6].…”

Year in review 2016: Chronic obstructive pulmonary disease and asthma

“…Brooks et al . showed that eosinophilic inflammation, defined by >2.5% sputum eosinophils, is absent in 52% of asthma patients, whereas they have comparable increases in symptoms and airflow obstruction . Interestingly, the majority of these non‐eosinophilic asthmatic patients were not found to display any other signs of inflammation such as an increase in neutrophil levels or other inflammatory markers in blood or sputum compared with healthy controls.…”