Background: Distinct clinical presentations of interstitial lung disease (ILD) with the myositis-specific antibodies, including anti-synthetase antibodies, are well-recognized. However, the association between ILD and the myositis-associated antibodies, including anti-Ro52, is less established. Our objectives were to compare presenting phenotypes of patients with anti-Ro52 alone versus in combination with myositis-specific autoantibodies and to identify predictors of disease progression or death.
Methods: We performed a retrospective cohort study of 73 adults with ILD and a positive anti-Ro52 antibody. We report clinical features, treatment, and outcomes.
Results: The majority of patients with ILD and anti-Ro52 had no established connective tissue disease (78%), and one-third had no rheumatologic symptoms. Thirteen patients (17.8%) required ICU admission for respiratory failure, with 84.6% all-cause mortality. Of the 73 subjects, 85.7% had a negative SS-A, and 49.3% met criteria for idiopathic pneumonia with autoimmune features (IPAF). The 50 patients with anti-Ro52 alone were indistinguishable from patients with anti-Ro52 plus a myositis-specific autoantibody. ICU admission was associated with poor outcomes (HR 12.97, 95% CI 5.07-34.0, p < 0.0001), whereas rheumatologic symptoms or ANA > = 1:320 were associated with better outcomes (HR 0.4, 95% CI 0.16-0.97, p = 0.04, and HR 0.29, 95% CI 0.09-0.81, p = 0.03, respectively).
Conclusions: Presentations of ILD with the anti-Ro52 antibody are heterogeneous, and outcomes are similar when compared to anti-Ro52 plus myositis-specific antibodies. Testing for anti-Ro52 may help to phenotype unclassifiable ILD patients, particularly as part of the serologic criteria for IPAF. Further research is needed to investigate treatment of ILD in the setting of anti-Ro52 positivity.
Keywords: Antibodies; Connective tissue disease; Interstitial lung disease; Interstitial pneumonia with autoimmune features; Myositis.