Clinical factors, anticitrullinated peptide antibodies and MRI-detected subclinical inflammation in relation to progression from clinically suspect arthralgia to arthritis

Patients with clinically suspect arthralgia (CSA) have, according to their rheumatologists, an increased risk of rheumatoid arthritis (RA), but their actual outcome is unexplored. This longitudinal study investigated (1) progression from CSA to clinically detectable arthritis and (2) associations of clinical factors, serological factors (among which are anticitrullinated peptide antibodies (ACPAs)) and MRI-detected subclinical inflammation with arthritis development. 150 patients with CSA were followed for ≥6 months. At baseline, clinical and serological data were collected and unilateral 1.5 T-MRI of metacarpophalangeal (MCP), wrist and metatarsophalangeal (MTP) joints was made. MRI scoring was done according to the RA MRI scoring system. Subclinical MRI inflammation was defined based on MRI results of 193 symptom-free persons. During follow-up (median=75 weeks, IQR=41-106 weeks), 30 patients developed clinical arthritis; 87% did so