Highlights d Early immune response in COVID-19 patients is highly dynamic d Most pro-inflammatory genes, except IL1, were induced after respiratory function nadir d Reduced T cell activation in mild cases may contribute to prolonged RNAemia

Background: Chest radiography (CXR) is performed more widely and readily than CT for the management of coronavirus disease , but there remains little data on its clinical utility. This study aims to assess the diagnostic performance of CXR, with emphasis on its predictive value, for severe COVID-19 disease.Methods: A retrospective cohort study was conducted, 358 chest radiographs were performed on 109 COVID-19 patients (median age 44.4 years, 58 males and 30 with comorbidities) admitted between 22 January 2020 and 15 March 2020. Each CXR was reviewed and scored by three radiologists in consensus using a 72-point COVID-19 Radiographic Score (CRS). Disease severity was determined by the need for supplemental oxygen and mechanical ventilation.Results: Patients who needed supplemental oxygen (n=19, 17.4%) were significantly older (P<0.001) and significantly more of them had co-morbidities (P=0.011). They also had higher C-reactive protein (CRP) (P<0.001), higher lactate dehydrogenase (LDH) (P<0.001), lower lymphocyte count (P<0.001) and lower hemoglobin (Hb) (P=0.001). Their initial (CRS initial ) and maximal CRS (CRS max ) were higher (P<0.001).Adjusting for age and baseline hemoglobin, the AUROC of CRS max (0.983) was as high as CRP max (0.987) and higher than the AUROC for lymphocyte count min (0.897), and LDH max (0.900). The AUROC for CRS initial was slightly lower (0.930). CRS initial ≥5 had a sensitivity of 63% and specificity of 92% in predicting the need for oxygen, and 73% sensitivity and 88% specificity in predicting the need for mechanical ventilation.CRS between the 6 th and 10 th day from the onset of symptoms (CRS D6-10 ) ≥5 had a sensitivity of 89% and specificity of 95% in predicting the need for oxygen, and 100% sensitivity and 86% specificity in predicting the need for mechanical ventilation.Conclusions: Adjusting for key confounders of age and baseline Hb, CRS max performed comparable to or better than laboratory markers in the diagnosis of severe disease. CXR performed between the 6 th and 10 th days from symptom onset was a better predictor of severe disease than CXR performed earlier at presentation. A benign clinical course was seen in CXR that were normal or had very mild abnormalities.

Objectives High-risk CXR features in COVID-19 are not clearly defined. We aimed to identify CXR features that correlate with severe COVID-19. Methods All confirmed COVID-19 patients admitted within the study period were screened. Those with suboptimal baseline CXR were excluded. CXRs were reviewed by three independent radiologists and opacities recorded according to zones and laterality. The primary endpoint was defined as hypoxia requiring supplemental oxygen, and CXR features were assessed for association with this endpoint to identify high-risk features. These features were then used to define criteria for a high-risk CXR, and clinical features and outcomes of patients with and without baseline high-risk CXR were compared using logistic regression analysis. Results 109 patients were included. In the initial analysis of 40 patients (36.7%) with abnormal baseline CXR, presence of bilateral opacities, multifocal opacities, or any upper or middle zone opacity were associated with supplemental oxygen requirement. Of the entire cohort, 29 patients (26.6%) had a baseline CXR with at least one of these features. Having a high-risk baseline CXR was significantly associated with requiring supplemental oxygen in univariate (odds ratio 14.0, 95% confidence interval 3.90–55.60) and multivariate (adjusted odds ratio 8.38, 95% CI 2.43–28.97, P = 0.001) analyses. Conclusion We identified several high-risk CXR features that are significantly associated with severe illness. The association of upper or middle zone opacities with severe illness has not been previously emphasized. Recognition of these specific high-risk CXR features is important to prioritize limited healthcare resources for sicker patients.

Introduction: Non-cystic fibrosis bronchiectasis (NCFB) is a highly heterogenous disease. We describe the clinical characteristics of NCFB patients and evaluate the performance of Bronchiectasis Severity Index (BSI) in predicting mortality. Methods: Patients attending the bronchiectasis clinic between August 2015 and April 2020 with radiologically proven bronchiectasis on computed tomography were recruited. Clinical characteristics, spirometry, radiology, microbiology and clinical course over a median period of 2.4 years is presented. Results: A total of 168 patients were enrolled in this prospective cohort study. They were predominantly women (67.8%), Chinese (87.5%) and never-smokers (76.9%). Median age of diagnosis was 64 years (interquartile range 56–71) and the most common aetiology was “idiopathic” bronchiectasis (44.6%). Thirty-nine percent had normal spirometries. Compared to female patients, there were more smokers among the male patients (53.8% versus 8.5%, P<0.001) and a significantly larger proportion with post-tuberculous bronchiectasis (37.0% vs 15.8%, P=0.002). Fifty-five percent of our cohort had a history of haemoptysis. Lower body mass index, presence of chronic obstructive pulmonary disease, ever-smoker status, modified Reiff score, radiological severity and history of exacerbations were risk factors for mortality. Survival was significantly shorter in patients with severe bronchiectasis (BSI>9) compared to those with mild or moderate disease (BSI<9). The hazard ratio for severe disease (BSI>9) compared to mild disease (BSI 0–4) was 14.8 (confidence interval 1.929–114.235, P=0.01). Conclusion: The NCFB cohort in Singapore has unique characteristics with sex differences. Over half the patients had a history of haemoptysis. The BSI score is a useful predictor of mortality in our population. Keywords: Bronchiectasis, exacerbations, gender, haemoptysis, mortality, Reiff score, sex

INTRODUCTION Chest radiographs (CXRs) are widely used for the screening and management of COVID-19. This article describes the radiographic features of COVID-19 based on an initial national cohort of patients. METHODS This is a retrospective review of swab-positive patients with COVID-19 who were admitted to four different hospitals in Singapore between 22 January and 9 March 2020. Initial and follow-up CXRs were reviewed by three experienced radiologists to identify the predominant pattern and distribution of lung parenchymal abnormalities. RESULTS In total, 347 CXRs of 96 patients were reviewed. Initial CXRs were abnormal in 41 (42.7%) out of 96 patients. The mean time from onset of symptoms to CXR abnormality was 5.3 ± 4.7 days. The predominant pattern of lung abnormality was ground-glass opacity on initial CXRs (51.2%) and consolidation on follow-up CXRs (51.0%). Multifocal bilateral abnormalities in mixed central and peripheral distribution were observed in 63.4% and 59.2% of abnormal initial and follow-up CXRs, respectively. The lower zones were involved in 90.2% of initial CXRs and 93.9% of follow-up CXRs. CONCLUSION In a cohort of swab-positive patients, including those identified from contact tracing, we found a lower incidence of CXR abnormalities than was previously reported. The most common pattern was ground-glass opacity or consolidation, but mixed central and peripheral involvement was more common than peripheral involvement alone.