Work

Impact of interstitial lung disease on COVID-19 severity: A nationwide register study

Year: 2025

Type: article

Abstract: AIM: To investigate if ILD is associated with increased severity of COVID-19 and if this association differs by disease type or vaccination status. METHODS: Data from Swedish national registers within the SCIFI-PEARL study was used to examine the relationship between ILD and three levels of COVID-19 severity: non-hospitalized, hospitalized, and critical (ICU admission or death) from January 2020 to May 2022. We performed multinomial logistic regression, adjusted for confounding factors, and examined interactions with vaccination status. RESULTS: Altogether, 18,666 patients with ILD were included, comprising 8774 with fibrotic ILD and 9181 with sarcoidosis. Among ILD patients with COVID-19 (n = 3384), 18.9 % required hospitalization and 8.5 % had critical disease, compared to 3.8 % and 1.3 % respectively, among COVID-19 patients without ILD. ILD was associated with increased severity of COVID-19 compared to patients without ILD (Conditional Odds Ratio (COR) (95 % CI)): hospitalization 2.30 (2.09-2.54), critical disease 2.50 (2.17-2.88)). Corresponding CORs were 3.25 (2.81-3.75) and 3.46 (2.88-4.15) for fibrotic ILD, and 1.56 (1.34-1.81) and 1.57 (1.21-2.03) for sarcoidosis. Two or more vaccine doses protected against severe COVID-19 among patients with ILD and COVID-19, reducing hospitalizations (non-vaccinated: 21.8 %; vaccinated: 16.3 %), and an even stronger reduction in critical disease (non-vaccinated: 12.0 %; vaccinated: 3.6). However, even among fully vaccinated individuals, ILD remained significantly associated with increased severity of COVID-19. CONCLUSIONS: ILD is associated with increased COVID-19 severity in patients with infection, particularly in patients with fibrotic ILD. Vaccination most effectively prevents critical illness. Our study underscores the continued importance of vaccination programs and preventive strategies.

Source: Respiratory Medicine

DOI: 10.1016/j.rmed.2025.108372