A Multicenter Study of Post-COVID-19 Interstitial Lung Syndrome

26noIntroduction: 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 pulmo- nary consequences of COVID-19 remain speculative. Objects: The aim of this study is to evaluate risk factors, preva- lence 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 fea- tures of POST-COVID-19 ILD. Data were collected at the time of the first interim analysis (28/11/2020) of the PCOILS trial: a pro- spective, 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 subse- quent 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 par- ticipants (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 consoli- dations. 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 intersti- tial lung changes mostly with NSIPOP, indeterminate features or ground glass. The hypothesis that post-COVID-19 interstitial changes and interstitial lung diseases may share common risk fac- tors, pathogenetic mechanisms and disease behaviour warrants further evaluations.noneopenValentina Luzzi, Tiberio Oggionni, Emanuela Barisione, Elena Bargagli, Martina Bonifazi, Stefano Gasparini, Marco Confalonieri, Raffaele Scala, Catherine Klersy, Federica Meloni, Adele Torricella, Federico Lavorini, Elisabetta Rosi, Leonardo Gori, Sonia Bambina, Martina Marinato, Giulia Biadene, Diletta Cozzi, Edoardo Cavigli, Vittorio Miele, Sara Piciucchi, Nicola Sverzellati, Silvia Puglisi, Venerino Poletti, Claudia Ravaglia, Sara TomassettiLuzzi, Valentina; Oggionni, Tiberio; Barisione, Emanuela; Bargagli, Elena; Bonifazi, Martina; Gasparini, Stefano; Confalonieri, Marco; Scala, Raffaele; Klersy, Catherine; Meloni, Federica; Torricella, Adele; Lavorini, Federico; Rosi, Elisabetta; Gori, Leonardo; Bambina, Sonia; Marinato, Martina; Biadene, Giulia; Cozzi, Diletta; Cavigli, Edoardo; Miele, Vittorio; Piciucchi, Sara; Sverzellati, Nicola; Puglisi, Silvia; Poletti, Venerino; Ravaglia, Claudia; Tomassetti, Sar