Combined pulmonary fibrosis and emphysema alters physiology but has similar mortality to pulmonary fibrosis without emphysema

Our plain-English summary of Combined pulmonary fibrosis and emphysema alters physiology but has similar mortality to pulmonary fibrosis without emphysema, by M.D. Jankowich, S. Rounds (Lung, 2010).

The study

• Authors: M.D. Jankowich, S. Rounds
• Journal: Lung
• Published: 2010;188(5):365-73
• Cited by: 75 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Studies have described individuals with combined pulmonary fibrosis and emphysema (CPFE), with preserved lung volumes, significant reductions in gas exchange, and high prevalence of pulmonary hypertension. While physiologic changes in CPFE are well documented, there is little mortality data in the CPFE population compared to appropriate controls. A study was performed to determine the features and outcomes of a group of individuals with imaging and/or pathologic evidence of CPFE to determine if individuals with combined pulmonary fibrosis and emphysema have different features and survival than individuals with pulmonary fibrosis alone. We conducted a retrospective study at a Veterans Affairs Medical Center. Included in the study were individuals hospitalized over a 5-year period who were given a clinical diagnosis of pulmonary fibrosis. Individuals with confirmed imaging or pathologic evidence of pulmonary fibrosis were divided into a study group with concomitant emphysema (CPFE group, n = 20) and a control group without emphysema (isolated pulmonary fibrosis (PF) group, n = 24). The CPFE group, all current or former cigarette smokers, had significantly larger lung volumes, more expiratory airflow obstruction, and worse gas exchange than the isolated pulmonary fibrosis group. Mortality did not differ between the groups. Combined pulmonary fibrosis and emphysema results in unique physiologic features but no difference in survival compared with a group with pulmonary fibrosis alone.

In plain English

This retrospective study reviewed veterans hospitalized at the Providence VA Medical Center from 1 April 2003 to 1 April 2008 with diagnoses related to pulmonary fibrosis. Of 79 identified, 44 had CT or pathology support: 20 also had emphysema (combined pulmonary fibrosis and emphysema, CPFE) and 24 did not. All 20 CPFE patients had smoked cigarettes, versus 19 of 24 others. Asbestos exposure by history was recorded in 8 of 20 CPFE patients and 5 of 24 others, not significantly different. The CPFE group had larger lung volumes, more airflow obstruction, and lower diffusing capacity (29% versus 50% of predicted). By the study's end, 13 of 20 CPFE patients (65%) and 17 of 24 others (71%) had died, not significantly different. Pulmonary hypertension was found in 8 of 19 CPFE patients assessed and 5 of 16 others, not significantly different; the authors said this limited study could not show whether it was more or less common with CPFE. The authors concluded their study did not support worse survival with CPFE. Stated limitations included the retrospective design and incomplete testing.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective, single-center clinical study comparing patients with combined pulmonary fibrosis and emphysema (CPFE) to patients with isolated pulmonary fibrosis
• Who was studied: Veterans hospitalized at the Providence VA Medical Center (USA) from 1 April 2003 to 1 April 2008 with an ICD-9 discharge diagnosis related to pulmonary fibrosis. Of 79 identified, 35 were excluded for lacking CT or pathologic support, leaving 44 (20 CPFE, 24 isolated pulmonary fibrosis). All were male.
• Exposure: Presence of emphysema or bullous disease on a CT or pathology report, alongside pulmonary fibrosis. Cigarette smoking and asbestos exposure by history were recorded as baseline characteristics.
• Main results:
  • Mortality by the end of the study period was 13/20 (65%) in the CPFE group and 17/24 (71%) in the isolated pulmonary fibrosis group, not statistically significant
  • Past cigarette use was 20/20 (100%) in the CPFE group and 19/24 (79%) in the isolated pulmonary fibrosis group (p 0.053, not significant)
  • Asbestos exposure by history was 8/20 (40%) in the CPFE group and 5/24 (21%) in the isolated pulmonary fibrosis group, not significant
  • Pleural plaque was reported on CT in 4/20 CPFE subjects and 3/24 isolated pulmonary fibrosis subjects. One more isolated pulmonary fibrosis subject had a small pleural plaque at autopsy.
  • CPFE subjects (n = 18 tested) had significantly higher forced vital capacity (77 ± 14 vs 62 ± 16 % predicted, p 0.006), a lower FEV1/FVC ratio (0.67 vs 0.78, p 0.006), higher total lung capacity (76 vs 66 % predicted, p 0.032) and lower diffusing capacity than isolated pulmonary fibrosis subjects (n = 19 tested)
  • Diffusing capacity was 29 ± 11 % predicted in the CPFE group versus 50 ± 22 % predicted in the isolated pulmonary fibrosis group (p 0.003)
  • Pulmonary hypertension in total (by echocardiogram or catheterization) was 8/19 in the CPFE group versus 5/16 in the isolated pulmonary fibrosis group, not significant. The authors stated they could not conclude whether it is more or less common in CPFE.
  • One CPFE lung specimen showed centriacinar emphysema and usual interstitial pneumonia without asbestos bodies
• The authors' conclusion: The authors concluded that CPFE has distinct features of a clinical syndrome occurring in people exposed to cigarette smoke, and that their study does not support worse survival in CPFE than in pulmonary fibrosis alone
• Limitations the authors state:
  • Retrospective design relying on tests ordered for clinical reasons. Not all subjects had pulmonary function tests or echocardiograms.
  • Few right heart catheterizations were done, so the authors could not conclude whether pulmonary hypertension is more or less common in CPFE
  • Helium dilution may underestimate lung volumes in emphysema, which could reduce apparent differences between the groups
  • Pathology results were incompletely available
  • No quantitative radiographic scoring of the extent of emphysema and fibrosis

Topics

Medical terms in this study, explained in our Lexicon: Pulmonary Fibrosis, Emphysema, Pulmonary Hypertension, Obstructive Lung Disease.

Related studies

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• Neutrophil elastase promotes myofibroblast differentiation in lung fibrosis — A.D. Gregory, C.R. Kliment, et al. (2015)
• Oxidative stress alters syndecan-1 distribution in lungs with pulmonary fibrosis — C.R. Kliment, J.M. Englert, et al. (2009)
• Emphysema findings associated with heavy asbestos-exposure in high resolution computed tomography of finnish construction workers — O. Huuskonen, L. Kivisaari, et al. (2004)
• Emphysema in silica- and asbestos-exposed workers seeking compensation. A CT scan study — R. Bégin, R. Filion, et al. (1995)
• Frequency of HLA antigen in asbestos workers with and without pulmonary fibrosis — C.C. Evans, H.C. Lewinsöhn, et al. (1977)

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