IL-6, IL-8, and IL-10 Are Associated with Hyperferritinemia in Rapidly Progressive Interstitial Lung Disease with Polymyositis/Dermatomyositis

OBJECTIVE Hyperferritinemia is frequently accompanied by rapidly progressive (RP) interstitial lung disease (ILD) with polymyositis (PM)/dermatomyositis (DM). To clarify the mechanism of RP-ILD with hyperferritinemia, we investigated the associations between serum ferritin levels and various cytokines in patients with PM/DM. METHODS This retrospective study included 38 patients admitted to our hospital with PM/DM. Levels of serum ferritin and cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, IL-18, TNF-α, IFN-α, IFN-γ, and IP-10) were measured. Disease activity was evaluated using the tool proposed by the International Myositis Assessment and Clinical Studies Group. We analyzed the associations between disease activity and levels of serum ferritin and cytokines. RESULTS The levels of serum ferritin, IL-8, IL-10, IL-18, and TNF-α, were significantly correlated with disease activity. In a multivariate analysis, IL-6 (t = 3.6, P = 0.0010), IL-8 (t = 4.8, P < 0.0001), and IL-10 (t = 5.7, P < 0.0001) significantly contributed to serum ferritin levels. The levels of serum ferritin, IL-6, IL-8, and IL-10, were higher in the RP-ILD subset than in the non-ILD subset or the chronic ILD subset. CONCLUSION IL-6, IL-8, and IL-10 are significant contributors to hyperferritinemia in PM/DM. The regulation of these cytokines might offer a possible treatment strategy for RP-ILD with PM/DM.