Clinical and pathologic differences in interstitial lung disease based on antisynthetase antibody type

Area of Science:

• Rheumatology
• Pulmonology
• Immunology

Background:

• Interstitial lung disease (ILD) is a frequent extramuscular manifestation of idiopathic inflammatory myopathies (IIMs), including dermatomyositis and polymyositis.
• Patients with antisynthetase antibodies (ASA) often present with features of antisynthetase syndrome, encompassing IIM and ILD.
• The clinical expression of antisynthetase syndrome may vary depending on specific ASAs.

Purpose of the Study:

• To investigate if the phenotype of myositis-associated ILD (MA-ILD) differs based on the presence and subtype of ASAs.
• To explore potential variations in MA-ILD presentation linked to specific ASA subtypes.

Main Methods:

• A cross-sectional and longitudinal analysis was performed on patients with ILD and clinically diagnosed autoimmune myositis.
• Data was collected from consecutive patients at the Johns Hopkins Myositis Center.

Main Results:

• Of 77 subjects, 36 were ASA-negative, 28 were anti-Jo1 positive, and 13 were non-Jo1 ASA positive (including anti-PL-12, anti-PL-7, anti-EJ, and anti-OJ).
• Non-Jo1 ASA positive participants were more likely to be African-American than Caucasian compared to anti-Jo1 positive and ASA-negative groups (p < 0.01).
• ASA-negative participants exhibited better mean forced vital capacity (FVC%) and total computed tomography (CT) scores over time than anti-Jo1 positive participants, after controlling for confounders.

Conclusions:

• Antisynthetase antibody status showed significant differences by race.
• Patients with anti-Jo1 antibodies demonstrated poorer lung function and CT scores over time compared to those without detectable ASAs.
• Further research in larger cohorts is necessary to confirm if antibody-specific differences in demographics and disease manifestations lead to significant clinical outcome disparities.