Sumikawa, Hiromitsu

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a distinctive interstitial pneumonia with upper lobe predominance that shows unique morphological features among idiopathic interstitial pneumonias (IIPs). Affected patients have a variety of clinical presentations with heterogeneous clinical courses. Cluster analysis is a valuable tool for identifying distinct clinical phenotypes under heterogeneous conditions. This study aimed to identify the phenotypes of patients with idiopathic PPFE. Using cluster analysis, novel PPFE phenotypes were identified among subjects from our multicenter cohort, and outcomes were stratified according to phenotypic clusters. Among the subjects with baseline data (N = 84), four clusters were identified. Cluster 1 included younger male subjects with coexisting non-UIP-like patterns. Cluster 2 included elderly female nonsmokers with low body mass index (BMI). Cluster 3 included elderly male smokers with a coexisting IP-like pattern. Cluster 4 included younger male smokers without lower lobe lesions. Patients in cluster 3 had significantly worse survival outcomes than those in clusters 1, 2, and 4 (p < 0.001, p = 0.0041, and p = 0.0155, respectively). Among idiopathic PPFE patients, cluster analysis using baseline characteristics identified four distinct clinical phenotypes that might predict survival outcomes.

ABSTRACTBackground and objectivePneumothorax is a co‐morbidity in patients with idiopathic pulmonary fibrosis (IPF). However, its incidence, risk factors and prognostic significance in IPF remain unclear. The aim of this study was to clarify the incidence and prognostic significance of pneumothorax in patients with IPF, and to further investigate the risk factors for its onset.MethodsEighty‐four consecutive patients with IPF based on the consensus guideline were included in this study. We retrospectively reviewed the medical records, pulmonary function tests and chest high‐resolution computed tomography images, and determined the incidence of pneumothorax. The prognostic significance of pneumothorax was evaluated using the Cox proportional hazards model analysis with time‐dependent covariates. We also assessed the cumulative incidence and the risk factors for pneumothorax.ResultsOf the 84 patients, 17 (20.2%) developed pneumothorax. The cumulative incidence of pneumothorax was 8.5%, 12.5% and 17.7% at 1, 2 and 3 years, respectively. Univariate analysis demonstrated that pneumothorax was significantly related to poor prognosis (hazards ratio, 2.99; P = 0.002). Multivariate analysis, adjusting for sex, age and forced vital capacity (% predicted), revealed that pneumothorax was an independent predictor of poor outcome in IPF (hazards ratio, 2.85; P = 0.006). Lower BMI and the presence of extensive reticular abnormalities were significantly associated with developing pneumothorax.ConclusionThese results confirm that patients with IPF often develop pneumothorax during their clinical course and that the onset of pneumothorax predicts a poor outcome.

AbstractBackground and objectiveDespite significant recent progress in the understanding of idiopathic pulmonary fibrosis (IPF), the early phase of the disease is still poorly understood. We studied patients with IPF without pulmonary function impairment in order to determine the clinical features, natural history and key findings for physiological progression.MethodsTwenty‐five patients without pulmonary function impairment were identified from among patients with previously diagnosed IPF who underwent surgical lung biopsies between January 1997 and December 2006 at our institutions. ‘Without pulmonary function impairment’ was defined as both forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLco) >80% predicted. Patients diagnosed with IPF through multidisciplinary discussion based on the new IPF guidelines were the subjects of this study.ResultsSixteen patients had a confirmed diagnosis of IPF. Eleven patients presented with chest X‐ray abnormality found during an annual health examination. Seven patients were asymptomatic. Eleven patients showed physiological disease progression (median time; 19.9 ± 12.3 months) defined by a decline of at least 10% in FVC or at least 15% in DLco. Univariate analysis revealed that both usual interstitial pneumonia pattern and extent of honeycombing on high‐resolution computed tomography (HRCT) were factors associated with disease progression (odds ratio 5.634, 95% confidence interval 1.364–23.278; odds ratio 2.371/5%, 95% confidence interval 1.042–5.395).ConclusionsIPF patients without pulmonary function impairment have a progressive but slow clinical course. The existence and extent of honeycombing on HRCT are predictive of disease progression.

Abstract Rationale Patients with a clinicopathological diagnosis of idiopathic pulmonary fibrosis (IPF) may have typical findings of usual interstitial pneumonia (UIP) on computed tomography (CT) or nonspecific or atypical findings, including those often seen in nonspecific interstitial pneumonia. Objectives The aims of this study were to revisit the high-resolution CT findings of IPF and to clarify the correlation between the CT findings and mortality. Methods The study included 98 patients with a histologic diagnosis of UIP and a clinical diagnosis of IPF. Two observers evaluated the CT findings independently and classified each case into one of the following three categories: (1) definite UIP, (2) consistent with UIP, or (3) suggestive of alternative diagnosis. The correlation between the CT categories and mortality was evaluated using the Kaplan-Meier method and the log-rank test, as well as Cox proportional hazards regression models. Measurements and Main Results Thirty-three of the 98 CT scans were classified as definite UIP, 36 as consistent with UIP, 29 as suggestive of an alternative diagnosis. The mean survival was 45.7, 57.9, and 76.9 months, respectively. There was no significant difference in survival among the three categories (all P &gt; 0.05). Traction bronchiectasis and fibrosis scores were significant predictors of outcome (hazard ratios: 1.30 and 1.10, respectively; 95% confidence intervals: 1.18–14.2 and 1.03–1.19, respectively). Conclusions In patients with IPF and UIP pattern on the biopsy, the pattern of abnormality on thin-section CT, whether characteristic of UIP or suggestive of alternative diagnosis, does not influence prognosis. Prognosis is influenced by traction bronchiectasis and fibrosis scores.