Assessing disease activity in polymyalgia rheumatica: Is the treat-to-target concept feasible?

Polymyalgia rheumatica (PMR) is a prevalent immune-mediated inflammatory rheumatic disease that typically affects individuals over the age of 50. Despite significant advances in the diagnosis and treatment of PMR, challenges remain in the objective assessment of disease activity, which hinders the development and implementation of the treat-to-target (T2T) strategy. Diagnosis is primarily based on clinical symptoms and laboratory markers of inflammation—most notably, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). However, the diagnostic value of these markers is reduced in patients receiving interleukin-6 inhibitors, emphasizing the need for alternative biomarkers. The Polymyalgia Rheumatica Activity Score (PMR-AS) and its modifications (CRP-PMR-AS, ESR-PMR-AS, and clin-PMR-AS) are among the most thoroughly studied tools for the quantitative assessment of disease activity. The potential of imaging modalities such as ultrasound and magnetic resonance imaging (MRI) is also being actively explored for visualizing structural changes and assessing inflammatory activity in PMR. These techniques have demonstrated high sensitivity and specificity but require further standardization and validation of their clinical relevance. The development of a comprehensive monitoring strategy based on validated indices and objective biomarkers may serve as a foundation for the creation of national clinical guidelines and facilitate the successful implementation of the T2T approach in routine rheumatologic practice.