Fibroblastic Foci in Usual Interstitial Pneumonia: Idiopathic versus Collagen Vascular Disease

• Published in: American journal of respiratory and critical care medicine 2003-05, Vol.167 (10), p.1410-1415
• Main Authors: Flaherty, Kevin R, Colby, Thomas V, Travis, William D, Toews, Galen B, Mumford, Jeanette, Murray, Susan, Thannickal, Victor J, Kazerooni, Ella A, Gross, Barry H, Lynch, Joseph P., III, Martinez, Fernando J
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Biological and medical sciences; Biopsy, Needle; Bronchoalveolar Lavage Fluid - cytology; Chronic obstructive pulmonary disease, asthma; 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; Medical sciences; Pneumology; 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
• ISSN: 1073-449X; 1535-4970
• DOI: 10.1164/rccm.200204-373OC

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.