Short summary

Rheumatoid arthritis (RA) associated interstitial lung disease (RA-ILD) may be prevalent in 30% and clinically evident in 10% of RA patients. Feasible methods of detecting RA-ILD are warranted.

Objectives:

To determine the diagnostic accuracy of thoracic ultrasound for ILD in RA patients with respiratory symptoms by using chest high-resolution computed tomography as reference standard

Rationale

Background:

Pulmonary diseases are significant contributors to morbidity and mortality in patients with rheumatoid arthritis (RA). RA associated interstitial lung disease (RA-ILD) may be prevalent in 30% and clinically evident in 10% of RA patients. Feasible methods of detecting concomitant RA-ILD are warranted.

Objectives:

To determine the diagnostic accuracy of thoracic ultrasound (TUS) for ILD in RA patients with respiratory symptoms by using chest high-resolution computed tomography (HRCT) as the reference standard. Further, we aim to evaluate the diagnostic accuracy for the promising blood biomarkers surfactant protein-D (SP-D) and microfibrillar-associated protein 4 (MFAP4) in the detection of ILD in this group of patients.

Description of the cohort

Ethics and dissemination:

Patients eligible for inclusion, after signing the informed consent; adults (≥18 years) diagnosed with RA (according to the 2010 ACR-criteria for RA) and respiratory symptoms indicating RA-ILD, included from rheumatological department in the Region of Southern Denmark.

Data will be collected and stored in a REDCap database. The study is approved by the Committees on Health Research Ethics (S-20210154) and the Danish Data Protection Agency. Data will be published in peer reviewed journals.

Data and biological material

Relevant clinical data from the patient journal as well as anonymized TUS images will be stored in OPEN facilities. A blood biobank at Odense University Hospital is also established.

Collaborating researchers and departments

South Danish Center for Interstitial Lung Diseases (SCILS), Department of Respiratory Medicine, Odense University Hospital, Denmark, and Odense Respiratory Research Unit (ODIN), University of Southern Denmark, Odense, Denmark

• Jesper R. Davidsen

The department of Radiology, Odense University Hospital, Denmark

• Stefan M. W. Harders

The department of Rheumatology , Hospital of South West Jutland & Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Denmark, Denmark

• Philip R. Lage-Hansen

Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital & Section for Biostatistics and Evidence-Based Research, the Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark

• Robin Christensen

Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Denmark

• Heidi L. Munk
• Torkell Ellingsen