HRCT features of interstitial lung disease in dermatomyositis with anti-CADM-140 antibody.

BACKGROUND: Anti-CADM-140 antibody (anti-CADM-140), also referred to as anti-melanoma differentiation-associated gene 5 (MDA5) antibody, is a myositis-specific antibody identified in the sera of patients with clinically amyopathic dermatomyositis (C-ADM) and is associated with a worse prognosis in dermatomyositis-associated interstitial lung disease (DM-ILD). We sought to determine high-resolution computed tomography (HRCT) features of DM-ILD with anti-CADM-140.

METHODS: Twenty-five patients newly diagnosed with DM-ILD at Kyoto University Hospital between 2005 and 2009 were retrospectively reviewed. Serum anti-CADM-140 was measured in all patients at their first visit. Chest HRCT images taken prior to treatment were classified based on the dominant findings and their distribution, and compared between patients with and without the antibody.

RESULTS: Of 25 DM-ILD patients, 12 were positive and 13 were negative for anti-CADM-140. HRCT patterns differed significantly between anti-CADM-140-positive and negative patients (P = 0.002). Lower consolidation or ground-glass attenuation (GGA) pattern (50.0%) and random GGA pattern (33.3%) were the predominant patterns in anti-CADM-140-positive cases, while lower reticulation pattern (69.2%) was frequently seen in anti-CADM-140-negative cases. Anti-CADM-140-positive cases were also significantly characterized by the absence of intralobular reticular opacities (0% in anti-CADM-140 (+) vs. 84.6% in anti-CADM-140 (-), P < 0.0001).

CONCLUSIONS: Anti-CADM-140-positive DM-ILD was characterized by lower consolidation or GGA pattern, random GGA pattern, and the absence of intralobular reticular opacities.