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Background: Childhood asthma is generally believed to be a disorder with a good prognosis. However, some asthmatics develop irreversible airway obstruction, probably as a result of airway remodelling.Methods: After 21-33 years, 228 adults (aged 13-44 years at baseline) with a history of asthma were re-examined to assess risk factors for the development of irreversible airway obstruction (IAO, forced expiratory volume in 1 second (FEV(1)) <80% predicted and reversibility <9% predicted) and a reduced postbronchodilator transfer coefficient (carbon monoxide transfer factor/alveolar volume, <80% predicted), both characteristics of COPD.Results: At follow up, 41% did not have airway obstruction (NAO), 43% had reversible airway obstruction (RAO), and 16% had IAO; 23% had a reduced transfer coefficient. Patients with RAO had asthma-like characteristics (wheezing, asthma attacks, bronchial hyperresponsiveness (BHR)) while patients with IAO had COPD-like symptoms (cough, phlegm, dyspnoea) at follow up. The development of IAO is determined by a lower FEV(1), less reversibility of airway obstruction and, surprisingly, less severe BHR at initial screening. Eighty percent of the patients with asthma who used anti-inflammatory medication still had airway obstruction, but IAO developed less frequently. Smoking was associated with a reduced transfer coefficient but not with the development of IAO. Female sex was associated with a reduced transfer coefficient, whereas corticosteroid use was not.Conclusions: Although IAO and a low transfer coefficient are both characteristics of COPD, they represent distinct entities in adult asthmatics in terms of symptomatology, aetiology, and probably in therapeutic approaches and disease prevention. [ABSTRACT FROM AUTHOR]

In April 2020 COVID-19 lockdown measures were instigated leading to a dramatic drop in non-COVID respiratory virus infections (RVI). This provided a unique situation to assess the impact of RVI on annual FEV1 decline, episodes of temporary drop in lung function suggestive of infection (TDLF) and CLAD in lung transplant recipients (LTR). All lung function tests (LFT) of LTR transplanted between 2009-April 2020 were used from post-transplant baseline onward. LFT were censored after COVID-19 infection. Weekly RVI counts from the virology department defined RVI pressure over time. TDLF was defined as sudden, reversible FEV1 drop compared to previous 4 values (any TDLF ≥10% and ≥200ml, severe TDLF ≥20% and ≥500ml). Annual FEV1 decline was estimated using linear mixed effects models with separate estimates for 2009/20 and 2020/21. Effect modification by TDLF frequency of individual LTR (two subgroups, split at median) and RVI pressure was tested. Rates of CLAD and TDLF were analyzed over time. 479 LTR (12,775 LFT) were included. Annual FEV1 change in 2009/20 was -114ml [95%CI -133; -94], while in 2020/21 this was significantly less: 5ml [-38; 48] (p<0.001). RVI pressure significantly affected FEV1 level (an increase in weekly RVI-count of 10 leading to a 7ml [-10; -5] lower FEV1 (p<0.001). FEV1 decline in 2009/20 was faster in frequent TDLF LTR vs. infrequent (-150ml [-181; -120] vs. -90ml [-115; -65] p=0.003 Fig A). 2020/21 showed significant decreases in number of any TDLF (OR 0.53 [0.33; 0.85], p=0.008) and severe TDLF (OR 0.34 [0.16; 0.71] p=0.005) and numerically lower CLAD (OR 0.53 [0.27; 1.02] p=0.060). Effect modification by RVI pressure (Figures B-D) indicated an association between the events and RVI. During the lockdown year 2020/21 the broad decline in RVI coincided with substantially less FEV1 decline, TDLFs and possibly CLAD. All these outcomes were moderated by RVI pressure suggesting an important role for RVI in lung function decline in LTR. [ABSTRACT FROM AUTHOR]