Profusion of Fibroblast Foci in Patients with Idiopathic Pulmonary Fibrosis Does Not Predict Outcome

Rationale: The prognostic significance of fibroblast foci in surgical lung biopsies from patients with idiopathic pulmonary fibrosis (IPF) is unclear.

Objectives: We assessed the relationship between profusion of fibroblast foci and survival in 43 patients with IPF seen at a tertiary referral medical center from 1996 to 2002.

Methods: Fibroblast foci in surgical lung biopsies were counted using a systematic morphometric point-counting technique. Patients with either clinical or pathologic evidence of accelerated disease were excluded from analysis. The association of fibroblast counts with survival was assessed using proportional hazards regression.

Results: The mean age (+/-SD) of the study population was 64+/-9 years; 26 (60%) patients were male. The mean (%+/-SD) profusion of fibroblastic foci was 0.6+/-0.7, expressed as a percentage of total points counted. Fibroblast foci counts did not differ markedly between upper, middle, and lower lobes. Median survival from the time of biopsy was 2.4 years; there were 25 (58%) deaths in the follow up period. There was no significant relationship between profusion of fibroblast foci and survival in the overall group (p=0.250).

Conclusions: Higher prevalence of fibroblast foci assessed using a simple point-counting technique applied to surgical lung biopsies is not associated with survival in patients with clinically stable IPF.