5th June 2025

A 72-year-old female has a routine follow-up with her GP.

A 72-year-old female has a routine follow-up with her GP. You note swollen joints on both hands as well as ulnar deviation, and the patient tells you of her struggles with pain and stiffness in her hands, especially when she wakes up. On examination, there is a swan neck deformity of one of the fingers. You suspect rheumatoid arthritis. 

What investigation is the most specific for rheumatoid arthritis diagnosis? 

Select the SINGLE most appropriate option from the list below. Select ONE option only.