Abstract
Background: Idiopathic pulmonary fibrosis (IPF) is usually characterized by the insidious onset of dyspnea or cough, but there is a subgroup of patients who display a rapid progression to an end-stage disease. These two phenotypes, slow progressors (SP) and rapid progressors (RP) have not yet been fully characterized.
Aim: To characterize SP and RP and identify baseline factors predicting each progression.
Methods: A retrospective study with 81 IPF patients was performed. They were classified as SP and RP. Patients with acute exacerbations were excluded. Baseline differences in progression covariates or factors were assessed through U Mann-Whitney, Chi square or Fisher exact test. Median survival was estimated using Kaplan-Meier survival curves.
Results: Patients were classified as SP in 55 (67.9%) and as RP in 10 (12.3%). Median survival time was 41 months in SP and 9 months in RP (Log Rank test p<0.001). The comparison between two groups showed lower median values of FVC (60 versus 73) and TLC (57.8 versus 72) and a higher percentage of non-smokers in RP group at time of diagnosis.
Conclusion: The analysis of this group of IPF patients confirms two clearly separated phenotypes, SP and RP, that must be discriminated, since they seem to have different presentations and a remarkably different evolution. These results could mean distinct physiopathological pathways, which could implicate different therapeutic approaches.
- © 2011 ERS
