{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T21:48:27Z","timestamp":1785620907078,"version":"3.56.0"},"reference-count":60,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,8,13]],"date-time":"2025-08-13T00:00:00Z","timestamp":1755043200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>Giant cell arteritis (GCA) is an immune-mediated vasculitis predominantly affecting individuals aged 50 years and older, with clinical manifestations often overlapping with polymyalgia rheumatica (PMR). Despite advances in imaging and the advent of novel steroid-sparing agents, such as tocilizumab, challenges persist in accurately diagnosing and monitoring disease activity. Traditional inflammatory markers like C-reactive protein and erythrocyte sedimentation rate are frequently limited by their inability to fully capture disease dynamics, especially in patients receiving IL-6 inhibitors. In this context, calprotectin (CLP), a heterodimeric complex derived from S100A8\/S100A9 proteins, has emerged as a promising biomarker due to its integral role in mediating inflammatory responses and its relative independence from IL-6 pathways. This review synthesizes current evidence on the biological functions of CLP in GCA pathogenesis, its potential utility in distinguishing between different clinical forms of the GCA-PMR spectrum, and its role in assessing disease activity and guiding therapeutic decisions. Furthermore, emerging CLP-targeted therapies in other inflammatory conditions may offer novel treatment avenues for GCA. Future research should focus on validating CLP as a predictive marker for relapse and refining its integration into clinical monitoring protocols to enhance patient outcomes.<\/jats:p>","DOI":"10.3389\/fimmu.2025.1608402","type":"journal-article","created":{"date-parts":[[2025,8,13]],"date-time":"2025-08-13T04:15:58Z","timestamp":1755058558000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":3,"title":["The role of calprotectin in giant cell arteritis - from pathophysiology to possible clinical 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