Longitudinal Comparison of Calprotectin and C-Reactive Protein in Rheumatoid Arthritis: Real-World Evidence Across...

Area of Science:

• Rheumatology
• Clinical Immunology
• Biomarker Research

Background:

• Serum calprotectin is a potential biomarker for inflammation in rheumatoid arthritis (RA).
• Limited real-world data exists on longitudinal calprotectin comparisons across different targeted RA therapies.
• Understanding biomarker dynamics is crucial for optimizing RA management.

Purpose of the Study:

• To evaluate serum calprotectin and C-reactive protein (CRP) dynamics in RA patients.
• To assess the remission-predictive ability of calprotectin and CRP under adalimumab, upadacitinib, and tocilizumab treatments.
• To compare the performance of calprotectin versus CRP in predicting remission across different RA therapy subgroups.

Main Methods:

• Retrospective cohort study of RA patients initiating adalimumab, upadacitinib, or tocilizumab.
• Serum calprotectin and CRP measured at baseline, 3 months, and 6 months.
• Disease activity assessed by DAS28 and CDAI; ROC analysis for remission prediction.

Main Results:

• Significant reductions in serum calprotectin, CRP, and DAS28 observed over time (p < 0.001).
• Overall, CRP outperformed calprotectin in predicting remission (AUC 0.739 vs. 0.636).
• Calprotectin significantly outperformed CRP in adalimumab/upadacitinib groups (AUC 0.929 vs. 0.857), while performance was similar in the tocilizumab group.

Conclusions:

• Serum calprotectin levels significantly decrease post-treatment initiation in RA.
• Calprotectin demonstrates superior remission prediction compared to CRP under TNFα and JAK inhibition.
• Calprotectin serves as a valuable, treatment-sensitive biomarker, potentially complementing CRP in RA monitoring, especially when CRP reliability is affected.