Impact of Severe COVID-19 on Interstitial Lung Disease in Autoimmune Systemic Diseases

The objective of this study was to assess the impact of severe COVID-19 pneumonia on the course of interstitial lung disease (ILD) in autoimmune systemic diseases (ASD). We conducted a multicentre case series of 27 ASD patients (20 systemic sclerosis, 4 rheumatoid arthritis, 1 interstitial pneumonia with autoimmune features, 1 dermatomyositis, 1 eosinophilic granulomatosis with polyangiitis) hospitalised for severe COVID-19. Clinical data, pulmonary function tests and HRCT before and after infection were analysed. Four patients died during acute COVID-19. Among the 23 survivors, 10 developed new symptomatic ILD and 13 showed worsening of pre-existing ILD. Six exhibited significant HRCT progression, including NSIP-to-UIP transition; one developed lung adenocarcinoma. Despite treatment, five more patients died during follow-up from progressive ILD. Overall mortality approached one-third, with systemic sclerosis most affected. Severe COVID-19 may trigger or accelerate ASD-related ILD. The observed NSIP-to-UIP shift highlights a multistep process potentially driven by SARS-CoV-2, underscoring the need for close ILD monitoring in ASD patients.