Improvement of symptoms in clinically suspect arthralgia and resolution of subclinical joint inflammation: a longitudinal study in patients that did not progress to clinical arthritis.
INTRODUCTION
Arthralgia and MRI-detected subclinical inflammation can precede the development of clinically evident rheumatoid arthritis (RA). However, part of the patients presenting with clinically suspect arthralgia (CSA) do not progress to RA. In these 'non-progressors', we aimed to study the frequencies of spontaneous improvement of arthralgia and its relation with the course of subclinical inflammation.


METHODS
Between April 2012 and April 2015, 241 patients were considered at risk for RA based on the clinical presentation and included in the CSA cohort. One hundred fifty-two patients with complete data on clinical follow-up did not develop clinical arthritis, of which 98 underwent serial 1.5T MRI scans (wrist, MCP2-5, and MTP1-5 joints) at baseline and after 2 years. MRI scans were scored for synovitis, tenosynovitis, and bone marrow oedema (summed: MRI inflammation score). MRI scores were compared to scores of symptom-free persons.


RESULTS
After a 2-year follow-up, 33% of the 'non-progressors' had complete resolution of symptoms; 67% had no symptom resolution and were diagnosed as persistent CSA (44%), osteoarthritis (10%), and tendinomuscular complaints (13%). With symptom-free controls as a reference, patients without resolution did not have increased MRI scores at any time point. However, patients achieving resolution of symptoms had increased MRI inflammation scores at baseline (4.0 vs. 2.6, p = 0.037), but not after 2 years (3.0 vs. 2.6; p = 0.57), and during follow-up, their MRI inflammation score decreased significantly (p = 0.036).


CONCLUSIONS
A subgroup of CSA patients that did not progress to RA had spontaneous improvement of symptoms and resolution of subclinical joint inflammation. This time relationship suggests that symptoms and inflammation were causally related in these patients. Further research is needed to identify the mechanisms underlying the resolution of inflammation.
['Ten Brinck|Robin M|RM|0000-0002-6128-6888', 'Boeters|Debbie M|DM|', 'van Steenbergen|Hanna W|HW|', 'van der Helm-van Mil|Annette H M|AHM|']
D000328:Adult D018771:Arthralgia D001172:Arthritis, Rheumatoid D018450:Disease Progression D005260:Female D006801:Humans D008137:Longitudinal Studies D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged
Rheumatoid arthritis Clinical research Imaging Outcome measures