title: Heterogeneous remodeling of lung vessels in idiopathic pulmonary fibrosis.
abstract: Recently, several reports suggest differences in the vascularization of the various histopathologic patterns of parenchymal remodeling seen in usual interstitial pneumonia (UIP). In this study, we sought to validate the importance of vascular remodeling in patients with idiopathic pulmonary fibrosis (IPF) and to examine the relationship between vascular remodeling and parenchymal remodeling or pulmonary function. Open lung biopsies were performed in 57 patients with IPF, and vascular changes in alternating areas of parenchymal remodeling (UIP histologic patterns) were studied. Quantitative analysis of the internal area, internal perimeter, wall thickness, and surrounding cellularity of medium or large pulmonary arteries, as well as their distribution according to air/parenchymal ratios, was performed. Semiquantitative analysis also was used to determine the grade of vascular occlusion. An inverse association was found between vascularization and UIP parenchymal remodeling (p < 0.05); that is, the decreased internal luminal area and perimeter as well as the increased wall thickness run in parallel with progression from alveolar collapse toward severe mural-organizing fibrosis with honeycombing. Vascular regression (diminished internal area and perimeter of vessels) was also associated with higher FEV(1), FVC, and RV values (r = 0.48, p< 0.05), reflecting a tight relationship between vascular remodeling and pulmonary function. A progressive regression of vascularization, reflected by different degrees of luminal occlusion after vascular remodeling, coincided with parenchymal remodeling (alveolar collapse, mural-organizing fibrosis, and honeycombing). This vascular regression may be responsible for the impaired wound healing and progressive fibroproliferation found in patients with IPF. Further studies are needed to determine whether this relationship is causal or consequential.
authors.affiliation: Department of Pathology, University of São Paulo Medical School, Av. Dr. Arnaldo 455, 01246-903 São Paulo, Brazil.
authors.forename: Edwin Roger
authors.initials: ER
authors.lastname: Parra
authors.forename: Yonara Rivelle
authors.initials: YR
authors.lastname: David
authors.forename: Lígia Rodrigues Silvério
authors.initials: LR
authors.lastname: da Costa
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ab'Saber
authors.forename: Rogerio
authors.initials: R
authors.lastname: Sousa
authors.forename: Ronaldo Adib
authors.initials: RA
authors.lastname: Kairalla
authors.forename: Carlos Roberto Ribeiro
authors.initials: CR
authors.lastname: de Carvalho
authors.forename: Mario Terra
authors.initials: MT
authors.lastname: Filho
authors.forename: Vera Luiza
authors.initials: VL
authors.lastname: Capelozzi
mesh_terms: D006801:Humans; D011650:Pulmonary Alveoli / Q000473:pathology; D011658:Pulmonary Fibrosis / Q000473:pathology* / Q000503:physiopathology; D012129:Respiratory Function Tests; D018709:Statistics, Nonparametric