Reticulation Is a Risk Factor of Progressive Subpleural Nonfibrotic Interstitial Lung Abnormalities.

Rationale: Interstitial lung abnormalities (ILAs) are being increasingly identified in clinical practice. In particular, for subpleural nonfibrotic ILAs, the risk of progression over time and the risk factors for progressive behavior are still largely unknown. Objectives: To determine the age band prevalence of ILAs and the risk of radiological progression of subpleural nonfibrotic ILAs over time in a large health checkup population and to identify how reticulation contributes to the risk of radiological progression. Methods: On the basis of the ILAs definition by the Fleischner Society, low-dose chest computed tomography images from the community-dwelling population who have undergone health checkups were evaluated for ILAs. Multivariable logistic regression was used to assess the risk of radiological progression. Measurements and Main Results: Among 155,539 individuals, 3,300 (2.1%) were confirmed to have ILAs: the vast majority (81.7%) were defined as subpleural nonfibrotic ILAs. The prevalence of ILAs increased linearly with age (P for trend < 0.0001). Of 454 individuals with subpleural nonfibrotic ILAs, 198 (43.6%) had radiological progression over 4 years. The presence of reticulation on initial imaging was an independent predictor of radiological progression (odds ratio, 1.9; 95% confidence interval, 1.2-3.0; P = 0.0040). No difference in radiological progression was identified between subpleural nonfibrotic ILAs with extensive reticulation and subpleural fibrotic ILAs (73.0% vs. 68.8%; P = 0.7626). Conclusions: The prevalence of ILAs increases linearly with age. Nearly half of subpleural nonfibrotic ILAs progress radiologically over 4 years. The presence of reticulation is a risk factor for radiological progression. Subpleural nonfibrotic ILAs with extensive reticulation are likely to be a feature of subpleural fibrotic ILAs.

Comparison of clinical characteristics between coronavirus disease 2019 pneumonia and community-acquired pneumonia.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) has high morbidity and mortality, and spreads rapidly in the community to result in a large number of infection cases. This study aimed to compare clinical features in adult patients with coronavirus disease 2019 (COVID-19) pneumonia to those in adult patients with community-acquired pneumonia (CAP). METHODS: Clinical presentations, laboratory findings, imaging features, complications, treatment and outcomes were compared between patients with COVID-19 pneumonia and patients with CAP. The study group of patients with COVID-19 pneumonia consisted of 120 patients. One hundred and thirty-four patients with CAP were enrolled for comparison. RESULTS: Patients with COVID-19 pneumonia had lower levels of abnormal laboratory parameters (white blood cell count, lymphocyte count, procalcitonin level, erythrocyte sedimentation rate and C-reactive protein level) and more extensive radiographic involvement. More severe respiratory compromise resulted in a higher rate of intensive care unit admission, acute respiratory distress syndrome (ARDS) and mechanical ventilation (36% vs 15%, 34% vs 15% and 32% vs 12%, respectively; all p < .05). The 30 day mortality was more than twice as high in patients with COVID-19 pneumonia (12% versus 5%; p = .063), despite not reaching a statistically significant difference. CONCLUSIONS: Lower levels of abnormal laboratory parameters, more extensive radiographic involvement, more severe respiratory compromise, and higher rates of ICU admission, ARDS and mechanical ventilation are key characteristics that distinguish patients with COVID-19-associated pneumonia from patients with CAP.