Fibroblastic foci in usual interstitial pneumonia: idiopathic versus collagen vascular disease

Am J Respir Crit Care Med. 2003 May 15;167(10):1410-5. doi: 10.1164/rccm.200204-373OC. Epub 2003 Feb 20.


A histologic feature of usual interstitial pneumonia is the presence of fibroblastic foci. As some patients with usual interstitial pneumonia and an underlying collagen vascular disease have a better prognosis, we hypothesized that they would have fewer fibroblastic foci. Pathologists reviewed surgical lung biopsies from 108 patients with usual interstitial pneumonia (nine with collagen vascular disease) and assigned a score (absent 0, mild 1, moderate 2, and marked 3) for fibroblastic foci. Patients with idiopathic usual interstitial pneumonia had a higher median profusion of fibroblastic foci (1.75 vs. 1.0, p = 0.003). Baseline characteristics were similar, although patients with a collagen vascular disease were younger, had a shorter duration of symptoms, and had a higher percentage of predicted total lung capacity. Profusion of fibroblastic foci was the most discriminative feature for separating idiopathic from collagen vascular disease-associated usual interstitial pneumonia (odds ratio 8.31; 95% confidence interval, 1.98, 59.42; p = 0.002 for a one-unit increase in fibroblastic foci score). No deaths were noted in the collagen vascular disease-associated usual interstitial pneumonia group; 52 deaths occurred in the idiopathic usual interstitial pneumonia group (log rank; p = 0.005). We conclude that patients with collagen vascular disease-associated usual interstitial pneumonia have fewer fibroblastic foci and improved survival.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Analysis of Variance
  • Biopsy, Needle
  • Bronchoalveolar Lavage Fluid / cytology
  • Cohort Studies
  • Collagen Diseases / diagnostic imaging
  • Collagen Diseases / mortality*
  • Collagen Diseases / pathology*
  • Female
  • Fibroblasts / pathology*
  • Humans
  • Immunohistochemistry
  • Lung Diseases, Interstitial / diagnostic imaging
  • Lung Diseases, Interstitial / mortality*
  • Lung Diseases, Interstitial / pathology*
  • Male
  • Predictive Value of Tests
  • Probability
  • Prognosis
  • Proportional Hazards Models
  • Pulmonary Fibrosis / diagnostic imaging
  • Pulmonary Fibrosis / pathology
  • Respiratory Function Tests
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Survival Analysis
  • Tomography, X-Ray Computed