Phenotypes of post covid interstitial lung disease, clinical, radiological, and pathological correlations

Introduction: The clinical-radiologic-pathologic features of post-COVID interstitial lung disease (ILD) remain to be explored. Method(s): In a prospective multicenter Italian study (PCOILS), subsequent patients seen at 4-18 months after the acute infection underwent transbronchial lung cryobiopsy and BAL if they showed a significant ILD (progressive and/or symptomatic and/or with pulmonary function impairment). Result(s): 19 patients enrolled;characteristics are summarized in Fig.2. We identified 3 post-COVID phenotypes: 1) prominent vascular changes;2) post-COVID fibrosis;3) persistent COVID. Fig. 1. Phenotype 1 was detected only in 2 cases with similar characteristics as showed in Fig. 1 Phenotype 2 was detected in 7 patients all with HRCT NSIP/OP features. Histology showed fibrotic or mixed NSIP, fibrotic OP, fibrotic DAD and bronchiolar damage. Phenotype 3 was detected only in the case reported in Fig.1.The remaining 9 patients were reclassified as known ILDs and treated according to current guidelines. Conclusion(s): We identified 3 phenotypes of postcovid damage with heterogeneous pictures and leading to differenttreatment choices.

The role of chest ct in understanding interstitial lung disease (ILD): Systemic sclerosis (SSC). versus COVID-19

Background: COVID-19 pandemic is a global emergency which may overlap on the clinical and radiological scenario of ILD in SSc. In clinical practice, the striking similarities observed at computed tomography (CT) between the diseases make it difficult to distinguish a COVID-19 superinfection from a progression of SSc-ILD. Objectives: The aim of our study was to identify the main CT features that may help distinguishing SSc-ILD from COVID-19 pneumonia. Methods: 22 international readers were included and divided in the radiologist group (RAD) and non-radiologist group (nRAD). The RAD group included nonchest RAD and chest-RAD. A total of 99 patients, 52 with COVID-19 and 47 with SSc-ILD, were included in the study. Results: Fibrosis inside focal ground glass opacities (GGO) in the upper lobes;fibrosis in the lower lobe GGO;reticulations in lower lobes (especially if bilateral and symmetrical or associated with signs of fibrosis) were the CT parameters most frequently associated with SSc-ILD. The CT parameters most frequently associated with COVID-19 pneumonia were: consolidation (CONS) in the lower lobes, CONS with peripheral (both central/peripheral or patchy distributions), anterior and posterior CONS and rounded-shaped GGOs in the lower lobes. After multivariate analysis, the presence of CONS in the lower lobes (p <0.0001) and signs of fibrosis in GGO in the lower lobes (p <0.0001) remained independently associated with COVID-19 pneumonia or SSc-ILD, respectively. These two variables were combined in a predictive score which resulted positively associated with the COVID-19 diagnosis, with 96.1% sensitivity and 83.3% specificity: 3 different risk class for COVID-19 pneumonia may be identified: high risk for COVID-19 pneumonia (5-9 points);probable overlap COVID-19 pneumonia in SSc-ILD (4 points);low risk for COVID-19 pneumonia (0-3 points). Conclusion: The CT differential diagnosis between COVID-19 Pneumonia and SSc-ILD is possible and may be fostered in practice by the use of a radiological score. In the case where an overlap of both diseases is suspected, the presence of consolidation in the lower lobes may suggest a COVID-19 pneumonia while the presence of fibrosis inside GGO may indicate a SSc-ILD.

A multidisciplinary multicenter study evaluating risk factors, prevalence and characteristics of post-COVID-19 interstitial lung syndrome pcoils

Backgrounds: Available data indicate that a large minority of patients with COVID-19 develop ARDS, and pulmonary fibrosis is a recognized sequela of ARDS. However, the long-term pulmonary consequences of COVID-19 remain speculative. The aim of this study is to evaluate risk factors, prevalence and characteristics of POST-COVID-19 interstitial lung changes, with the unique opportunity to evaluate radiologic and pathologic correlations using HRCT and transbronchial lung cryobiopsy specimens.Methods: Here we present the preliminary data on HRCT features of POST-COVID-19 ILD. Data were collected at the time of the first interim analysis (28/11/2020) of the PCOILS trial: a prospective, multicenter national study involving 12 Italian centers (Fig 1). We collected data of consecutively hospitalized patients at baseline and then at 6 (+/-1) months after hospital discharge. HRCT changes at 6 months involving more than 5% of the total lung volume were considered significant. Patients with significant HRCT changes will undergo BAL and/or cryobiopsy and a subsequent follow-up with HRCT and lung function evaluation at 12(+/-1) and 18 (+/-1) months.Results: At the time of the present interim analysis, 524 patients from 9 centers were enrolled (enrollment is still ongoing and will end on January 31st, 2021). Median age was 67 years (range 18-87), 330 were males (62.9%). HRCT changes were detected in 333 participants (63.5%), and in 219 (41.7%) were considered significant. 118 cases (22.5%) showed fibrotic changes including the following HRCT patterns: 7 (1.3%) probable UIP, 45 (8.5%) NSIP (with or without OP), 38 (7.2%) indeterminate, 28 (5.3%) fibrotic consolidations. Among the remaining 101 (19.2%) non fibrotic cases the radiologists described: 11 (2%) NSIP-OP, 15 (2.8%) indeterminate, 67 (12.7%) pure ground glass, 8 (1.5%) consolidations all suspected for lung cancer. Conclusions: This preliminary analysis confirms that after COVID-19 infection a large minority of patients develops interstitial lung changes mostly with NSIP-OP, indeterminate features or ground glass. The hypothesis that post-COVID-19 interstitial changes and interstitial lung diseases may share common risk factors, pathogenetic mechanisms and disease behaviour warrants further evaluations. .