Interleukin-18 Levels in Still's Disease Diagnosis

This research article investigates the diagnostic potential of serum levels of interleukin-18 (IL-18) in distinguishing Still's disease from other systemic autoinflammatory diseases (SAIDs). The study involved a cohort of patients with active SAIDs, including both monogenic and genetically undiagnosed forms, across various European countries. Serum levels of IL-18, IL-1β, their inhibitors, and IFN-γ were measured using immunoassays. The results indicated that serum levels of total and free IL-18 were significantly elevated in patients with Still's disease compared to other SAIDs and non-inflammatory controls. Receiver operating characteristic curve analysis demonstrated that total IL-18 was the most sensitive and specific marker for diagnosing Still's disease, with an area under the curve of 0.91. Additionally, a correlation was found between IL-18 levels and ferritin. The findings suggest that IL-18 could serve as a valuable biomarker for the diagnosis and monitoring of therapeutic response in Still's disease patients.