Erosive progression by high-resolution peripheral quantitative computed tomography and conventional radiography in rheumatoid arthritis
Josephine Therkildsen, Rasmus Klose‐Jensen, Mathias Hänel, Bente Langdahl, Jesper Thygesen, Jesper Skovhus Thomsen, Sarah L. Manske, Kresten Krarup Keller, Ellen‐Margrethe Hauge
Abstract
OBJECTIVES: To investigate the diagnostic accuracy of high-resolution peripheral quantitative computed tomography (HR-pQCT) to assess erosive progression during 1 year compared with conventional radiography (CR) in rheumatoid arthritis (RA). METHODS: This prospective study included 359 patients with RA (disease duration ≥5 years) between March 2018 and October 2020. HR-pQCT and CR were obtained at inclusion and after 1 year. Erosive assessment was performed at two metacarpophalangeal joints of the dominant hand using HR-pQCT, and progression was defined as an increase in erosion number ≥1 or an increase in erosive volume > least significant change. CR of hands, wrists and feet was evaluated using Sharp/van der Heijde scores and erosive progression was defined as a 1.1-point increase in erosion score according to the smallest detectable change. RESULTS: In paired analyses (n = 310), erosive progression was identified in 30 patients using CR and in 40 patients using HR-pQCT. In the 40 patients with erosive progression on HR-pQCT, progression was not identified by CR in 33 patients. Adding HR-pQCT to CR doubled the proportion of patients identified with progression from 30 (10%) to 63 (20%) patients. Using CR as the reference, the sensitivity of HR-pQCT for identifying erosive progression was 23.3% (95% CI: 9.9, 42.3%) and the specificity was 88.2% (95% CI: 83.8, 91.7%). CONCLUSION: A substantial proportion of patients with erosive progression are overlooked using CR only to monitor erosive progression. Adding high-resolution peripheral CT to CR doubles the proportion of patients who may benefit from individualized therapy targeting erosive progression in RA.