The prognostic value of HRCT in myositis-associated interstitial lung disease

Polymyositis and dermatomyositis-associated interstitial lung disease (PM/DM-ILD) can have variable courses. We evaluated the prognostic value of high-resolution computed tomography (HRCT) in PM/DM-ILD.

The cases of 51 patients newly diagnosed with PM/DM-ILD were retrospectively reviewed. HRCT images at diagnosis were categorized into four radiological patterns based on the major findings and distributions of these abnormalities, and the disease extent on HRCT was scored. The impact of HRCT findings and other clinical parameters on day 90 and overall mortality were analyzed.

Of the 51 patients (11 with polymyositis and 40 with dermatomyositis), the lower consolidation/ground-glass attenuation (GGA) pattern was observed in 21 patients (41%), lower reticulation was observed in 23 patients (45%), random GGA was observed in four patients (8%), and other patterns were observed in three patients (6%). Twenty-one patients (42%) were positive for anti-CADM-140. The lower consolidation/GGA pattern, clinically amyopathic dermatomyositis, fever (≥38.0 °C), ferritin levels >500 ng/mL, and the presence of anti-CADM-140 were significantly associated with 90-day mortality in univariate analysis. Multivariate analysis revealed that the lower consolidation/GGA pattern (odds ratio, 23.1; P = 0.02) and the presence of anti-CADM-140 (odds ratio, 14.1; P = 0.03) were independent predictors of 90-day mortality. This HRCT pattern was also associated with a higher 90-day morality rate among anti-CADM-140-positive patients. The lower consolidation/GGA pattern was also associated with overall mortality in univariate analysis, whereas only the presence of anti-CADM-140 was an independent determinant of overall mortality in multivariate analysis.

HRCT patterns at diagnosis can help predict the prognosis of patients with PM/DM-ILD as well as the presence of anti-CADM-140.