Impact of specific organic exposure on the prognosis in Idiopathic Pulmonary Fibrosis

Abstract

Background: Evidence for an important heterogeneity in the clinical behaviour of Idiopathic Pulmonary Fibrosis (IPF) is emerging, depending on specific genetic, radiologic and clinical aspects. Despite the observation that IPF incidence is increased in patients exposed to specific organic inhalants (birds and moulds), their impact on prognosis is unknown. Aims and objectives: To compare the prognosis of IPF patients exposed to specific organic inhalants with IPF patients without such exposure and with CHP patients. Methods: we analysed exposure and survival data in IPF and CHP patients recorded in our ILD database. We investigated the impact of specific organic exposure (moulds and birds) and diagnosis on survival using a Cox proportional hazard model. Results: 293 patients were included. From the 244 patients diagnosed with IPF, 73 were exposed. 49 patients were diagnosed with CHP. Median survival (MS) of IPF patients exposed to specific organic exposure was 84 months, which was significantly different from both not-exposed IPF patients (MS = 43 months, p = 0.002) and CHP patients (MS = 157 months, p = 0.037). Conclusion: Exposure to specific organic inhalants was associated with a better survival in IPF patients. This observation strengthens the emerging evidence of an important clinical heterogeneity in IPF.