Prognostic value of myositis-specific antibodies in patients with idiopathic interstitial pneumonia

Abstract Background Patients with idiopathic interstitial pneumonias (IIP) often exhibit positivity for myositis-specific antibodies (MSA). However, the significance of MSA remains unclear. In this study, we investigated the association of MSA with the prognosis and risk of acute exacerbation in patients with IIP. Methods We retrospectively reviewed the medical records of patients with IIP and examined the impact of each MSA subtype on survival and acute exacerbation. Results Of 240 patients with IIP, 48 (20%) exhibited positivity for MSA. The MSA subtypes included: PL-7 (antithreonyl; n = 16, 6.7%); signal recognition particle (n = 13, 5.4%); PL-12 (antialanyl; n = 9, 3.8%); Mi-2 (n = 8, 3.3%); OJ (anti-isoleucyl; n = 7, 2.9%). During the 382 days (382 ± 281 days) of observation, 32 (13%) patients expired and 27 (11%) experienced an acute exacerbation. Cox proportional hazards regression analysis demonstrated that age at initial visit (hazard ratio [HR]: 1.072; 95% confidence interval [CI]: 1.017–1.131; P = 0.01), PL-7 (HR: 4.785; 95% CI: 1.528–14.925; P = 0.007), and PL-12 (HR: 3.922; 95% CI: 1.198–12.82; P = 0.024) were independent predictors of survival time. PL-7 (HR: 3.268; 95% CI: 1.064–10; P = 0.039) and PL-12 (HR: 5.747; 95% CI: 1.894–7.544; P = 0.002) were independent predictors of time from first visit to acute exacerbation. Conclusion The detection of MSA in patients with interstitial lung disease may be useful in predicting prognosis and providing a rationale for intensive treatment.