Reply to Marruchella: Preserved Ratio Impaired Spirometry and Interstitial Lung Abnormalities in Smokers
Year: 2019
Type: letter
Abstract: I read with great interest the paper by Wan and coworkers evaluating the preserved ratio impaired spirometry (PRISm) functional pattern (FEV 1 /FVC > 0.7 and FEV 1 .80%) in their longitudinal study of a large cohort of current or ex-smokers (1).The prevalence of this heterogeneous condition is remarkable (12.4% and 12.5% at baseline and follow-up, respectively) and its association with increased mortality, comparable to that observed in Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2 subjects, deserves special consideration.Individuals with PRISm are characterized by a significantly lower TLC% predicted and percent emphysema, as measured on quantitative computed tomography scans, in comparison with GOLD 0 and GOLD 1-4 groups.In the study cohort, the PRISm status was not stable at 5-year follow-up; in particular, the authors report a transition to GOLD 0 in 22% of the subjects with PRISm and a transition to PRISm in about one-third of baseline GOLD 0 individuals.The latter group was characterized by a lesser amount of emphysema and air trapping on computed tomography scans, an increase in body mass index, and decreased TLC% predicted and percent emphysema at baseline.Moreover, this group exhibited the largest functional decline (either FEV 1 or FVC) in comparison with all other groups, suggesting a restrictive physiologic impairment.Interstitial lung abnormalities have been found in a substantial minority of a cohort of smokers enrolled in the COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease) study (1 out of 12) and were associated with a reduced TLC and a lesser amount of emphysema.Smokers with interstitial lung abnormalities were more likely to have an "unclassified" spirometric pattern, analogous to PRISm (2).Under this definition are grouped various morphological pictures that may represent static imaging findings or the early stage of a progressive fibrosing disease (3).The evidence of many similarities between smokers identified as carriers of interstitial lung abnormalities and those functionally classified as having PRISm makes me think that at least a small subset of baseline GOLD 0 subjects who transitioned to the PRISm group could have developed a smoke-related interstitial disorder.
Authors: Emily S. Wan, Edwin K. Silverman
Institutions: Brigham and Women's Hospital, VA Boston Healthcare System
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W2915134136