Quantitative assessment of interstitial lung disease in Sjögren's syndrome.

Background: Interstitial lung disease (ILD) is a frequent manifestation of Sjögren's syndrome (SS), an autoimmune disease of salivary and lacrimal glands, and affects approximately 20% of patients. No clinical or serological features appear to be useful to predict its presence, severity or progression, and chest high-resolution computed tomography (CT) remains the gold standard for diagnosis. Semiquantitative CT (SQCT) based on visual assessment (Goh and Taouli scoring) can estimate ILD extent, although it is burdened by relevant intra- and interobserver variability. Quantitative chest CT (QCT) is a promising alternative modality to assess ILD severity.
Aim: To determine whether QCT assessment can identify extensive or limited lung disease in patients with SS and ILD.
Methods: This multi-center, cross-sectional and retrospective study enrolled patients with SS and a chest CT scan. SQCT assessment was carried out in a blinded and centralized manner to calculate both Goh and Taouli scores. An operator-independent analysis of all CT scans with the open-source software platform Horos was used to evaluate the QCT indices. Patients were classified according to the extent of ILD and differences in QCT index distribution were investigated with non-parametric tests.
Results: From a total of 102 consecutive patients with SS, the prevalence of ILD was 35.3% (36/102). There was a statistically significant difference in QCT index distribution between the SS with ILD and SS without ILD groups (p<0.001). Moreover, SS-ILD patients with ILD >20% (by Goh score) had a QCT index statistically different from those with limited ILD extent (p<0.001). Finally, QCT indices showed a moderate-to-good correlation with the Goh and Taouli scores (from 0.44 to 0.65; p<0.001).
Conclusions: QCT indices can identify patients with SS and ILD and discriminate those with lesser or greater lung disease.
Competing Interests: Prof. Carlo Vanchieri is part of F. Hoffmann-La Roche Ltd. Scientific Board. He has received consulting fees and/or speaker fees from Astrazeneca, Boehringer Ingelheim, Chiesi, F. Hoffmann-La Roche Ltd and Menarini. Prof. Stefano Palmucci has reveived personal fees and honoraria for lectures from Boehringer Ingelheim, Delphi International srl and F. Hoffmann-La Roche Ltd. He has been included in the scientific board for Boehringer Ingelheim. This does not alter our adherence to PLOS ONE policies on sharing data and materials. None of the other authors have any potential conflicts of interest to disclose in relation to this work.