Clinical analysis and outcome of interstitial lung disease complicated with juvenile dermatomyositis and juvenile polymyositis.

OBJECTIVE

The aim of this study was to determine the clinical phenotype and outcome of interstitial lung disease (ILD) complicated with juvenile dermatomyositis (JDM) or juvenile polymyositis (JPM).

METHODS

This was a single-center retrospective study. From 1984 to 2015, we retrospectively reviewed 29 patients who were diagnosed with JDM/JPM, among whom eight cases were ILD and 21 were non-ILD. The clinical features and laboratory findings included chest computed tomography (CT) images that were compared between the patients with ILD and non-ILD.

RESULTS

Eight cases (27.6%) were complicated with ILD. The mean age was 6.3 years, and 75% of the patients were women. We found that high fever, arthralgia, muscle weakness, and high serum Krebs von den Lungen-6 (KL-6) level were significantly associated with the presence of ILD (p < 0.05). Two patients were positive for the anti-Jo-1 antibody, and two other patients were positive for the anti-MDA5 antibody. Three cases were identified as rapidly progressive (RP)-ILD. The chest CT images of the ILD patients appeared to show ground glass opacity (GGO) with a lower lobe predominance, reticulation, and traction bronchiectasis consolidation. Three patients with RP-ILD showed random subpleural GGO with/without consolidation patterns. Further, three patients with RP-ILD died of respiratory failure (p < 0.01).

CONCLUSIONS

ILD is one of the most serious complications of JDM/JPM. In the early phase of ILD, high levels of serum KL-6 can be detected, regardless of the respiratory symptoms. Additionally, RP-ILD can be predicted based on the presence of anti-MDA5 antibodies and the chest CT findings, including random subpleural GGO with/without consolidation patterns.