Effect of Interstitial Lung Disease Subtypes on COVID-19 Mortality

Interstitial lung disease, CT scan
How does the COVID-19 mortality rate vary among patients with different subtypes of interstitial lung disease?

Mortality related to SARS-CoV-2 may potentially be higher among patients with varying subtypes of interstitial lung diseases (ILDs), according to study findings published recently in the Annals of the American Thoracic Society Journal.

A previous study suggested the risk of death related to SARS-CoV-2 was 4 times more likely in patients with ILDs, noted researchers for the current study. Because of the wide variety of ILD disorders, these investigators sought to assess whether a higher COVID-19 mortality rate was associated with all ILDs or just with certain ILD subtypes.

To accomplish this, they conducted a retrospective multicenter cohort study of 133,526 adult patients (≥18 years of age) all with SARS-CoV-2 along with 1 of the following 5 ILD subtypes: idiopathic pulmonary fibrosis (IPF; 74,783); rheumatoid arthritis (RA-ILD; 1306); systemic sclerosis (SSc-ILD; 5639); Sjogren syndrome with lung involvement (47,327); hypersensitivity pneumonitis (HP; 4471). Patient data were gathered from the TriNetX Analytics Network. Patients in the control cohorts tested positive for SARS-CoV-2 but did not have a comorbid ILD, and were matched with other patients in the study with respect to age, sex, BMI, hypertension, ischemic heart disease, history of nicotine dependence, diabetes mellitus (DM), and cerebrovascular disease. The primary outcome was death at 90 days following SARS-CoV-2 onset.

The investigators found risk of death from COVID-19 was increased for IPF, RA-ILD, SSc-ILD, and HP; however, mortality risk was decreased among patients with Sjogren’s syndrome. Among the 4 subtypes of ILD with increased risk, this study did not identify the precise factors causing the increase. Similarly, any contributing factors in patients with Sjogren’s syndrome leading to a reduced mortality rate were not identified in this study. The increase in mortality in IPF vs the other ILDs was not significant.

“Our major finding is that all ILDs increase mortality from SARS-CoV-2, with the exception of Sjogren’s syndrome, which had a lower mortality compared to controls,” study authors concluded.

Study limitations include inaccuracies in coding in the data network; the likelihood of unaccounted for confounding variables; and the lack of details for severity, treatments, drugs, and primary cause of death. Additionally, some of the cohorts were underpowered.


Zhao J, Metra B, George G, et al. Mortality among patients with SARS-CoV-2 and different interstitial lung disease subtypes: A multicenter cohort study. Ann Am Thorac Soc. Published online May 2, 2022. doi:10.1513/AnnalsATS.202202-137RL

This article originally appeared on Pulmonology Advisor