PT  - JOURNAL ARTICLE
AU  - Hironao Hozumi
AU  - Tomoyuki Fujisawa
AU  - Noriyuki Enomoto
AU  - Ran Nakashima
AU  - Yasunori Enomoto
AU  - Yuzo Suzuki
AU  - Masato Kono
AU  - Masato Karayama
AU  - Kazuki Furuhashi
AU  - Akihiro Murakami
AU  - Naoki Inui
AU  - Yutaro Nakamura
AU  - Tsuneyo Mimori
AU  - Takafumi Suda
TI  - Clinical Utility of YKL-40 in Polymyositis/dermatomyositis-associated Interstitial Lung Disease
AID  - 10.3899/jrheum.170373
DP  - 2017 Jul 15
TA  - The Journal of Rheumatology
PG  - jrheum.170373
4099  - http://www.jrheum.org/content/early/2017/07/11/jrheum.170373.short
4100  - http://www.jrheum.org/content/early/2017/07/11/jrheum.170373.full
AB  - Objective Interstitial lung disease (ILD) is involved in polymyositis/dermatomyositis (PM/DM), a disease associated with poor prognoses. Chitinase-3-like-1 protein (YKL-40) has pleiotropic biological activities involved in inflammation, cell proliferation, and tissue remodeling; however, the clinical application of YKL-40 remains limited. We investigated the clinical significance of YKL-40 in PM/DM−ILD. Methods Sixty-nine consecutive patients with PM/DM–ILD and 34 healthy controls were analyzed. We measured baseline and followup serum YKL-40 using an ELISA, evaluated the association of YKL-40 with clinical variables and survival, and examined YKL-40 expression in lung specimens from patients with PM/DM–ILD using immunohistochemistry. Results Serum YKL-40 levels were significantly greater in patients with PM/DM–ILD compared with healthy controls (p < 0.0001). Serum YKL-40 was correlated with arterial oxygen pressure (r = –0.40, p < 0.001) and percent-predicted DLCO (r = –0.41, p = 0.01) in patients with PM/DM–ILD. Multivariate Cox hazard analysis demonstrated that higher serum YKL-40 and lower percent-predicted forced vital capacity were independently associated with a poor prognosis. Immunohistochemistry analysis demonstrated that YKL-40 expression was enhanced in aggregated intraalveolar macrophages and hyperproliferative alveolar epithelial cells in patients with PM/DM–ILD. Conclusion YKL-40 is a promising biomarker for evaluating PM/DM−ILD activity/severity and predicting disease prognosis. Insights into YKL-40 might help elucidate the pathogenesis of PM/DM−ILD.