Objectives: We retrospectively investigated clinical prognostic factors for interstitial pneumonia (IP) in anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab)-positive dermatomyositis (DM) patients.
Methods: Subjects comprised 18 patients with anti-MDA5 Ab-positive DM-IP (9 survivors; 9 deaths).
Results: Initial serum albumin levels, ferritin levels, and ground-glass opacity (GGO) scores in the right middle lobes were significantly higher in the death group than in the survivor group (p = .033, .013, and .005, respectively). Initial alveolar-arterial oxygen gradient (P[A-a]O2) was also higher in the death group than in the survivor group (p = .064). Initial serum ferritin, P[A-a]O2, and right middle lobe GGO score were found to significantly relate to death. Survival rates after 24 weeks were significantly lower among patients with an initial ferritin level of ≥450 ng/mL (25%), P[A-a]O2 of ≥30 mmHg (31%), and a right middle lobe GGO score of ≥2 (11%) than each of the others (p = .006, .020, and .002, respectively).
Conclusions: An initial serum ferritin level of ≥450 ng/mL, P[A-a]O2 of ≥30 mmHg, and right middle lobe GGO score of ≥2 (GGO ≥5% of the lobe) were identified as poor prognostic factors for anti-MDA5 Ab-positive DM-IP patients.
Keywords: Dermatomyositis; interstitial pneumonia; prognosis.