RESUMO
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is characterised by constant threat of acute exacerbation of IPF (AE-IPF). It would be significant to identify risk factors of AE-IPF. We sought to determine the prognostic value of lung transplantation candidacy testing for AE-IPF and describe explant pathology of recipients with and without AE-IPF before lung transplantation. METHODS: Retrospective cohort study of 89 IPF patients listed for lung transplantation. Data included pulmonary function testing, echocardiography, right heart catheterisation, imaging, oesophageal pH/manometry and blood tests. Explanted tissue was evaluated by pulmonary pathologists and correlated to computed tomography (CT) findings. RESULTS: Out of 89 patients with IPF, 52 were transplanted during stable IPF and 37 had AE-IPF before transplantation (n=28) or death (n=9). There were no substantial differences in candidacy testing with and without AE-IPF. AE-IPF had higher rate of decline of forced vital capacity (FVC) (21±22% versus 4.8±14%, p=0.00019). FVC decline of >15% had a hazard ratio of 7.2 for developing AE-IPF compared to FVC decline of <5% (p=0.004). AE-IPF had more secondary diverse histopathology (82% versus 29%, p<0.0001) beyond diffuse alveolar damage. There was no correlation between ground-glass opacities (GGO) on chest CT at any point to development of AE-IPF (p=0.077), but GGO during AE-IPF predicted secondary pathological process beyond diffuse alveolar damage. CONCLUSIONS: Lung transplantation candidacy testing including reflux studies did not predict AE-IPF besides FVC absolute decline. CT did not predict clinical or pathological AE-IPF. Secondary diverse lung pathology beyond diffuse alveolar damage was present in most AE-IPF, but not in stable IPF.
RESUMO
BACKGROUND: Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) has an expected median survival of 3 months. Lung transplantation is a potentially lifesaving therapy for AE-IPF. However, the current knowledge of transplantation outcomes during AE-IPF is limited to a few small retrospective studies, reporting only 1-year post-transplantation survival. METHODS: Study population included patients with IPF consecutively listed for lung transplantation at a single institution between the years 2012 and 2016. We collected lung allocation score (LAS), hospitalization, and survival data. The primary outcome was survival among patients transplanted during stable IPF vs during AE-IPF. RESULTS: Of 89 patients with IPF listed for lung transplantation, 52 were transplanted during stable IPF and 37 were hospitalized due to AE-IPF. Of these 37 patients, nine died before transplantation, and 28 were transplanted during AE-IPF. Fifty percent of patients transplanted during AE-IPF died in a mean follow-up of 1.6 ± 1.2 years compared with 12% of patients transplanted during stable IPF who died in a mean follow-up of 2.6 ± 1.2 years. The Kaplan-Meier survival curves post-transplantation after 1 and 3 years for patients who were transplanted during stable IPF were 94% and 90% vs 71% and 60% in patients who were transplanted during AE-IPF (P = .0001). LAS above 80 conferred a 3-year hazard ratio for mortality of 5.7 vs LAS lower than 80 (95% CI, 2.33-14.0; P < .0005). CONCLUSIONS: Patients with IPF transplanted during AE-IPF had significantly worse short-term and long-term survival compared with patients transplanted during stable IPF. Patients with AE-IPF and very high LAS may not experience the survival advantage expected from lung transplantation.