Association between anti-PL7 antibodies and increased fibrotic component in patients with antisynthetase syndrome and interstitial lung disease: a cross-sectional study

To evaluate whether anti-PL7 and anti-PL12 autoantibodies are associated with a greater extent of the fibrotic component of ILD in ASSD patients.

Patients with ILD-ASSD who were positive for one of the following autoantibodies: anti-Jo1, anti-PL7, anti-PL12, and anti-EJ were included. Clinical manifestations, CPK levels, pulmonary function tests, and HCRT assessments were prospectively collected according to the Goh index. The fibrotic, inflammatory, and overall extension of the Goh index and DL_CO were assessed by multiple linear analyses and compared between ASSD antibody subgroups.

Sixty-six patients were included; 17 were positive for anti-Jo1 (26%), 17 for anti-PL7 (26%), 20 for anti-PL12 (30%), and 9 (14%) for anti-EJ. Patients with anti-PL7 and anti-PL12 had a more extensive fibrotic component than anti-Jo1. Anti-PL7 patients had a 7.9% increase in the fibrotic extension (cβ = 7.9; 95% CI 1.863, 13.918), and the strength of the association was not modified after controlling for sex, age, and time of disease evolution (aβ = 7.9; 95% CI 0.677, 15.076) and also was associated with an increase in ILD severity after adjusting for the same variables, denoted by a lower DL_CO (aβ =  − 4.47; 95% CI − 8.919 to − 0.015).

Anti-PL7-positive ASSD patients had more extensive fibrosis and severe ILD than the anti-Jo1 subgroup. This information is clinically useful and has significant implications for managing these patients, suggesting the need for early consideration of concurrent immunosuppressive and antifibrotic therapy.