Elsevier

Respiratory Medicine

Volume 102, Issue 12, December 2008, Pages 1753-1761
Respiratory Medicine

HRCT and histopathological evaluation of fibrosis and tissue destruction in IPF associated with pulmonary emphysema

https://doi.org/10.1016/j.rmed.2008.07.010Get rights and content
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Summary

Idiopathic pulmonary fibrosis has been associated with emphysema in cigarette smokers as a new clinical entity: combined pulmonary fibrosis and emphysema (CPFE).

In order to compare histomorphometrical, roentgenological and immunohistochemical aspects of usual interstitial pneumonia (UIP) with and without associated pulmonary emphysema, 17 patients with biopsy-proven UIP were evaluated. Morphometrical evaluation of lung parenchyma destruction was used to divide patients in two subgroups: emphysema/UIP (n = 9) and UIP alone (n = 8); four patients with biopsy-proven emphysema without fibrosis were also evaluated.

At HRTC scan, emphysematous lesions were prevalent in the upper fields of both emphysema/UIP and emphysema groups and the distribution of fibrotic lesions was similar in emphysema/UIP compared to UIP alone. The semiquantitative histopathological fibrotic score was also similar in emphysema/UIP and UIP alone. In addition, the expression of tumor necrosis factor (TNF)-α, matrix metalloproteinase (MMP)-2, MMP-9, MMP-7 and membrane type 1-metalloproteinase (MT1-MMP) by fibroblasts of myofibroblastic foci was similar in emphysema/UIP and UIP alone patients. In contrast, fibroblasts in areas of parenchymal destruction of emphysema/UIP expressed MMP-2, MMP-9, MMP-7 and MT1-MMP at variable but significantly higher levels when compared to emphysema subjects, in the presence of similar levels of TIMP-1, TIMP-2 and TNF-α.

Fibrotic and emphysematous lesions in emphysema/UIP patients appear to follow the roentgenological and histopathological patterns expected for either UIP or emphysema. Interstitial fibroblast activation is more pronounced in the areas of lung destruction in emphysema/UIP compared to those with emphysema alone, as for exaggerated tissue remodeling.

Keywords

Usual interstitial pneumonia
Emphysema
Combined pulmonary fibrosis and emphysema
Matrix metalloproteinase

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