Prevalence and impact of SARS-CoV-2 infection in interstitial lung disease patients: an exploratory experience in two tertiary centers in South Italy

Viral infections are potential triggers of initiation and progression/acute exacerbation of interstitial lung diseases (ILDs). The impact of SARS-CoV-2 infection/COVID-19 on their natural history is a field of interest worth exploring. We aimed to monitor the prevalence and disease status of ILD patients in relation to SARS-CoV-2 infection. Clinical data of ILD patients referring to two South Italy tertiary centers from January 2022 to December 2023 were prospectively collected and updated on the last visit. Two-hundred-eighty-three patients (males 54.7%; mean age: 69.6 yrs; never smokers 33.9%), including 94 (33.2%) cases affected by idiopathic pulmonary fibrosis, were enrolled. The study population included 106 (37.4%) newly diagnosed ILDs. Overall, prevalence of SARS-CoV-2 infection was 51.9%. In 32 cases (21.7%), infection occurred before anti- COVID-19 vaccination. Hospitalization due to pneumonia was required in 21 cases (7.4%). Infection occurred asymptomatic/pauci-symptomatic in the remaining 126 patients. Vaccination coverage was extensive (96.8%), with a median of 3 doses. With reference to ILD status, disease progression/acute exacerbation occurred in 20 cases (13.6%), which led to exitus in 7 (35%). Disease evolution mainly occurred in ILD patients who developed COVID-19 pneumonia (61%). SARS-CoV-2 infection allowed the diagnosis of a subclinical ILD in 7 patients (6.6%). Our data dampen the alarmism on concerns about the possible consequences of SARS-CoV-2 on the ILD patient without lowering our guard. Careful surveillance of SARS-CoV-2 infection is expected to result in an increase in new ILD cases in the post-pandemic.