Prevalence of CTD-ILDs

Pulmonary fibrosis is a critical threat across a broad range of connective tissue disease-associated interstitial lung diseases (CTD-ILDs)1–5



ILDs make up a diverse group of more than 200 heterogeneous lung disorders, mostly classified as rare or only infrequently seen in clinical practice8–10

While some ILDs are idiopathic, others manifest as a result of environmental exposure to antigens or as a pulmonary complication of an underlying CTD11

In CTD-ILDs, pulmonary fibrosis is characterised by the often chronic and irreversible scarring of lung tissue,12,13 and is a key driver of irreversible lung damage and early mortality in CTDs.1–5,14

What is the prevalence of ILD in CTDs?

Prevalence estimates for different CTDs and CTD-ILDs vary between different studies. Prevalence figures shown below are based on a range of different estimates from different studies15–40

Prevalence of RA, SSc, primary Sjögren’s syndrome and PM/DM/CADM as CTDs and CTDs-ILDs per 100,000


Prevalence of CTDs and CTD-ILDs per 100,000.
Prevalence figures sourced as midpoint values from ranges for CTD and CTD-ILD prevalence as follows: RA prevalence 500–1000 per 100,000;15–17 RA-ILD prevalence 10%–30% of RA.18-22 SSc prevalence 7.2–44.3 per 100,000;23 SSc-ILD prevalence 42% of SSc.24 primary Sjögren’s syndrome prevalence 90–2700 per 100,000;25,26 primary Sjögren’s syndrome-ILD prevalence 8%–20% of primary Sjögren’s syndrome.27-30 PM/DM prevalence 5–22 per 100,000;31,32 PM/DM/CADM-ILD prevalence 20%–78% of PM/DM/CADM.33-40

Varying prevalence of ILD in diverse CTDs has led to different approaches to screening

CTD-ILDs are an important subgroup of ILDs10
CTD-ILDs a large / important subgroup of ILDs


* Not an estimated clinical diagnosis
† For example: asbestosis, silicosis.
Adapted from: Cottin V, et al. Eur Respir Rev. 2018;27:180076.


ILD occurs in 42%–50% of all SSc patients24,41


Find out more about the prevalence of SSc-ILD


ILD develops in up to 30% of patients with RA18-22


Find out more about the prevalence of RA-ILD


ILD develops in 8%–20% of patients with primary Sjögren’s syndrome27-30


Find out more about the prevalence of primary Sjögren’s syndrome-ILD



ILD often develops early in the course of a CTD, and may even be the first manifestation of a previously undiagnosed or unrecognized CTD.1,2,5,6 ILD in CTDs may be subclinical in nature (presenting without symptoms),7 be chronically progressive, or even present in a life-threatening manner.42

Acute exacerbation of ILD, characterized by rapid respiratory deterioration with severe hypoxemia, can occur in patients with CTD-ILDs at any point during the course of disease.43–47 Based on patients with IPF, acute exacerbation of ILD is most likely triggered by an acute event, such as infection.48 Post-exacerbation hospital mortality in patients with CTD-ILDs is reported to range from 50%–100%.43

What could fibrotic ILD mean for your patients with CTDs?

CTD, connective tissue disease; CTD-ILD, connective tissue disease-associated interstitial lung disease; IIP, idiopathic interstitial pneumonia; ILD, interstitial lung disease; HP, hypersensitivity pneumonitis; IPAF, interstitial pneumonitis with autoimmune features; IPF, idiopathic pulmonary fibrosis; LAM, lymphangioleiomyomatosis; LCH, Langerhans cell histiocytosis; NSIP, non-specific interstitial pneumonia; RA, rheumatoid arthritis; RA-ILD, rheumatoid arthritis-associated interstitial lung disease; SSc, systemic sclerosis; SSc-ILD, systemic sclerosis-associated interstitial lung disease.

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