Increased Il-6 May Predict Severity of Clinically Amyopathic Dermatomyositis

Objectives Clinically amyopathic dermatomyositis (CADM) is considered as the subtype of dermatomyositis with amyopathy or hypomyopathy. Rapidly progressive interstitial lung disease (RP-ILD) is treatment-resistant and life-threatening in patients with CADM. Since useful markers for early diagnosis are necessary for early treatment in CADM patients with RP-IPD, this study aimed to investigate the differences of clinical and laboratory characteristics between alive patients (group A) and patients who died (group D). Methods Eleven patients with CADM complicating with RP-ILD were enrolled. Clinical manifestations and laboratory data before treatment were compared between group A and group D. Results Among them, six were alive and five died after treatment for RP-ILD. Serum IL-6 levels in group D were significantly higher than those in group A (median 19.7 vs 7.15 pg/ml; P=0.008). The stepwise regression analysis showed that IL-6 was the only prognostic factor significantly (p=0.035). Kaplan-Meier estimates showed that patient survivals were better in patients with IL-6 < 9pg/ml than those with > 9pg/ml (p=0.039). Other laboratory data were not different statistically between two groups. Conclusions Serum IL-6 may predict the prognosis of patients with CADM having Akita University