PO:24:066 | Antibody profile in myositis and early risk of interstitial lung disease: clinical and laboratory correlations in patients with suspected rheumatologic disease

Lindsay Brooke Boling¹, Gaia Deleonardi², Alarico Ariani³, Tania Silvestri², Ana Gabriela Grondona², Marica Trevisani³, Rita Mulè³, Enrica Vandelli³, Gentiana Vukatana³, Elisa Rossi³, Olga Addimanda³, Francesca Bergossi³, Angela Buffa³, Giovanni B. Canestrari³, Francesco Cianci³, Daniela Chiarini³, Laura Gigante³, Nicolò Girolimetto³, Daniele Lini³, Luca Magnani³, Mirco Magnani³, Erika Meleddu³, Francesca Pignataro³, Sofia Testoni³, Massimo Reta³ | ¹Scuola di Allergologia ed Immunologia Clinica-Università di Bologna; ²LUM Laboratorio Unico Metropolitano - Immunologia Clinica, Ospedale Maggiore, Bologna; ³UO Medicina Interna ad indirizzo reumatologico SC interaziendale - IRCCS AOU, AUSL Bologna, Italy

Background. Interstitial lung disease (ILD) is a frequent comorbidity not only in idiopathic inflammatory myopathies (IIM) but also in other rheumatologic disorders such as Sjögren’s syndrome, systemic sclerosis, and rheumatoid arthritis. Since ILD can represent a potentially life-threatening complication of these conditions, several recent studies have investigated possible risk factors useful for early diagnosis. The aim of this study was to assess the correlation between positivity for an antibody associated with IIM, together with clinical and laboratory data, and the risk of ILD at the time of diagnosis of a rheumatologic disease.

Materials and Methods. In this single-center, cross-sectional study, patients were enrolled according to the following inclusion criteria: a) suspected rheumatologic disease with myositic involvement; b) evaluation between January 2022 and May 2025 at a tertiary care center; c) diagnostic work-up including a line immunoassay for myositis autoantibodies (Euroimmun blot) with at least one positive result; d) chest CT scan performed. Data were collected on age, sex, clinical manifestations, creatine kinase (CPK) levels, and antibody positivity (from 1+ to 3+). A multivariate logistic regression model was applied to analyze the relationship between these variables and the presence of ILD at the time of diagnosis.

Results. A total of sixty-three patients were included (45 females, 18 males). Sixteen had ILD (documented by chest CT) at the time of rheumatologic disease diagnosis (polymyositis, dermatomyositis, Sjögren’s syndrome, undifferentiated connective tissue disease, antisynthetase syndrome, or systemic sclerosis). After adjusting for clinical and laboratory variables, the strongest risk factor for ILD at diagnosis was a strong positivity for anti-Ro52 antibodies (≥2–3+). Older age at diagnosis and CPK levels <300 U/L were also identified as independent risk factors associated with ILD at disease onset (FIG 1). Raynaud’s phenomenon and sex were not found to be significant risk factors.

Conclusions. A clear positivity for anti-Ro52 antibodies, normal CPK levels, and older age appear to be risk factors for the presence of ILD at the time of diagnosis—not only in inflammatory myopathies but also in other rheumatologic diseases. The presence of these features should prompt clinicians to pay particular attention to the possible occurrence of interstitial lung disease.