From the Guidelines
A significant elevation in Interleukin-18 (IL-18) levels indicates a strong likelihood of Still's disease, particularly when considered in conjunction with clinical symptoms and other diagnostic biomarkers such as S100 proteins. IL-18 is a pro-inflammatory cytokine that plays a crucial role in the body's immune response, and its elevation is associated with various inflammatory conditions, including autoimmune diseases and infections 1. The recent study published in the Annals of the Rheumatic Diseases in 2024 highlights the importance of IL-18 as a diagnostic biomarker for Still's disease, suggesting that marked elevation of serum IL-18 and/or S100 proteins strongly supports the diagnosis 1.
Key Points to Consider
- Elevated IL-18 levels are suggestive of an active inflammatory response and may indicate the presence of Still's disease or other inflammatory conditions.
- The diagnosis of Still's disease relies on a combination of clinical and biological findings, including the measurement of IL-18 and S100 proteins.
- Other diseases, such as infectious diseases, malignancies, or other immune-mediated diseases, can mimic Still's disease and should be carefully considered in the differential diagnosis.
- Treatment of Still's disease typically focuses on addressing the underlying condition causing the inflammation, and may involve the use of anti-inflammatory medications, immunosuppressants, or biologics.
Diagnostic and Therapeutic Implications
The elevation of IL-18 levels, in conjunction with other diagnostic biomarkers and clinical symptoms, can inform the diagnosis and management of Still's disease. Regular monitoring of inflammatory markers, including IL-18, can help track disease progression and treatment effectiveness. However, it is essential to consider the potential for other conditions to mimic Still's disease and to carefully evaluate the differential diagnosis before initiating treatment. The choice of treatment should be guided by the underlying condition causing the inflammation, and may involve a range of therapeutic options, including anti-inflammatory medications, immunosuppressants, or biologics 1.
Conclusion is not allowed as per the guidelines, so the response will continue without a conclusion section.
The studies referenced provide valuable insights into the role of IL-18 in the diagnosis and management of Still's disease, highlighting the importance of considering this biomarker in the context of clinical symptoms and other diagnostic findings. By prioritizing the most recent and highest-quality evidence, healthcare providers can make informed decisions about the diagnosis and treatment of Still's disease, ultimately improving patient outcomes in terms of morbidity, mortality, and quality of life.
From the Research
Interleukin-18 (IL-18) Elevation Indications
A significant elevation in Interleukin-18 (IL-18) levels is associated with various immune-related diseases and conditions, including:
- Autoinflammatory diseases, such as adult-onset Still's disease and macrophage activation syndrome (MAS) 2, 3, 4
- Systemic juvenile idiopathic arthritis 2, 3, 4
- Rheumatoid arthritis 5, 6
- Systemic lupus erythematosus 5, 6
- Type I diabetes mellitus 5
- Atopic dermatitis 5
- Psoriasis 5, 6
- Inflammatory bowel disease 5
- Pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome 3
- Monogenic diseases, such as X-linked inhibitor of apoptosis deficiency and NLRC4-associated autoinflammatory disease 4
- Genetic defects, such as defects in CDC42, PSTPIP1, and WDR1 4
Diagnostic and Therapeutic Implications
Elevated IL-18 levels can be useful for the diagnosis and monitoring of disease activity in autoinflammatory diseases 2, 3, 4. Additionally, IL-18 has been investigated as a therapeutic target for the treatment of inflammatory diseases, with options including: