Early IL‐1 Inhibition in Still's Disease: A Window of Opportunity for Improving Outcomes

Objective Still's disease is a complex, multisystemic disorder requiring prompt diagnosis and treatment. This study provides a general assessment of a Still's disease cohort aiming to evaluate the efficacy of early intervention with interleukin‐1 inhibitors (IL‐1i) in achieving clinical inactive disease (CID) and reducing glucocorticoid use in patients with Still's disease. Methods We retrospectively analyzed 42 adult patients diagnosed with Still's disease after 2010 and treated with IL‐1i. Patients were categorized as early treated (IL‐1i started before six months from symptom onset) or late treated (IL‐1i started after 6 months). CID achievement, glucocorticoid use, flares, and imaging findings were assessed. The chi‐square test was employed as a statistical test, and P < 0.05 was considered significant. GraphPad Prism 8 was used for statistical analysis. Results The median time from symptom onset to IL‐1i introduction was six months (interquartile range: 2‐19). Overall, 55% of patients achieved CID at six months. Early treated patients showed a trend toward higher proportion of CID achievement compared to that of late‐treated patients (67% vs 38%; P = 0.17). A meta‐analysis including our cohort and two other observational studies showed that early treatment was associated with an odds ratio of 6.73 (95% confidence interval: 2.31–19.64) in comparison to late treatment. All our patients initially received glucocorticoids, with 48% of those achieving CID able to discontinue glucocorticoids within six months. Ten major flares were observed, with 62% occurring after IL‐1i suspension or spacing. At baseline, F‐fluorodeoxyglucose positron emission tomography (PET)–computed tomography (CT) or magnetic resonance (MR) scans revealed hypermetabolic areas primarily in the bone marrow, spleen, and lymph nodes. After IL‐1i introduction, these hypermetabolic regions generally showed a reduction in activity. Conclusions Early introduction of IL‐1i in patients with Still's disease may lead to higher rates of CID achievement and glucocorticoid discontinuation. PET‐CT/MR imaging may be valuable in assessing disease activity and guiding treatment decisions. These findings support the concept of a “window of opportunity” in Still's disease management, emphasizing the importance of prompt diagnosis and treatment initiation.