The Natural Sequence in Which Subclinical Inflamed Joint Tissues Subside or Progress to Rheumatoid Arthritis:A Study of Serial MRIs in the TREAT EARLIER Trial

Objective: The natural trajectory of clinical arthritis progression at the tissue level remains elusive. We hypothesized that subclinical inflammation in different joint tissues (synovitis, tenosynovitis, osteitis) increases in a distinct temporal order in patients with clinically suspect arthralgia (CSA) who develop rheumatoid arthritis (RA) and subsides in a different sequence when CSA spontaneously resolves. Methods: We studied 185 serial magnetic resonance images (MRIs) from CSA patients with subclinical joint inflammation from the placebo arm of the TREAT EARLIER trial: 52 MRIs from 21 RA progressors (MRIs conducted at 1 year before, at 4 months before, and upon RA development), and 133 MRIs from 35 patients with spontaneous resolution of pain (MRIs conducted at baseline and at 4, 12, and 24 months). MRIs were scored for osteitis, synovitis, and tenosynovitis. We used cross-lagged models to evaluate 2 types of time patterns between pairs of inflamed tissues: a simultaneous pattern (coinciding changes) and a subsequent pattern (inflammatory changes in 1 tissue preceding changes in another tissue). Results:In patients who developed RA, synovitis, tenosynovitis, and osteitis increased simultaneously. Increasing osteitis occurred in the final 4 months before RA diagnosis, following incremental tenosynovitis and synovitis changes during the 1 year to 4 months before diagnosis (P &lt; 0.01). In anti–citrullinated protein antibody (ACPA)-positive and ACPA-negative patients who progressed to RA, osteitis increased just before RA development. In patients with pain resolution, simultaneous decreases in synovitis, tenosynovitis, and osteitis occurred, with tenosynovitis decreasing in the first 4 months after CSA onset preceding decreasing synovitis and osteitis during 4–12 months (P = 0.02 and P &lt; 0.01). Conclusion:We identified natural sequences of subclinical inflammation in different joint tissues, which deepens our understanding of clinical arthritis and RA development. During RA progression, increasing osteitis followed previous increases in tenosynovitis and synovitis. During pain resolution, tenosynovitis decreased first, followed by decreasing synovitis and osteitis.</p

Differing time-orders of inflammation decrease between ACPA subsets in RA patients suggest differences in underlying inflammatory pathways

Objectives: Advanced imaging modalities have shown that not only joints but also bones and tendon sheaths can be inflamed at diagnosis of RA. We aimed to better understand the time-order in which the inflamed tissues respond to DMARD treatment. Also, because ACPA status may reflect a different pathophysiology, differences in time-order of inflammation decrease were hypothesized between these disease types. Methods: A total of 216 consecutive patients presenting with RA (n = 176) or undifferentiated arthritis (n = 40), who all started with conventional synthetic DMARD treatment, were studied. 1.5T contrast-enhanced hand and foot MRIs were performed before treatment and after 4, 12 and 24 months. Cross-lagged models evaluated the influence of two time patterns: a simultaneous pattern ('change in one inflammatory feature associated with change in another feature') and a subsequent pattern ('change in one inflammatory feature preceded change in another feature'). ACPA stratification was performed. Results: The median symptom duration at presentation was 13 weeks. Forty-four percent of patients was ACPA-positive. All pairs of inflammatory features decreased simultaneously in all time intervals (0-4/4-12/12-24 months; P 4-12 months; P = 0.02 and 4-12 to >12-24 months; P = 0.03). Largely similar results were obtained in both ACPA subgroups. Additionally, in ACPA-positive but not ACPA-negative patients, synovitis decrease preceded osteitis decrease (4-12 to >12-24 moths; P = 0.002). Conclusion: This study increased the understanding of the response to treatment on the tissue level. In addition to simultaneous decrease of inflammation, synovitis decrease preceded tenosynovitis decrease. Differences in time-order of inflammation decrease between ACPA subgroups suggest differences in underlying inflammatory pathways

Hand function is already reduced before RA development and reflects subclinical tenosynovitis

Background Clinically suspect arthralgia (CSA) is characterised by arthralgia of small joints and considered a risk stage for development of rheumatoid arthritis (RA). However, it remains unknown if the function of the hands is already affected and what mechanisms underlie impaired hand-function in CSA. Methods We studied various measures of hand function in two CSA populations. CSA patients in the TREAT EARLIER-trial (n=236) were evaluated at baseline for: grip strength on a dynamometer (GS), patient-reported difficulties in the grip domain of the Health Assessment Questionnaire (HAQ) questionnaire and incomplete fist closure at physical examination. Findings were validated in an independent CSA cohort (n=600) where hand function was measured as: GS evaluated by squeezing the examiner's fingers, grip domain of the HAQ questionnaire and fist closure. Contrast-enhanced MRI of the hands measured synovitis, tenosynovitis and bone marrow oedema (summed as subclinical inflammation) in both cohorts. Results GS (on a dynamometer) was reduced in 75% compared with reference values in healthy controls, 60% reported grip difficulties and 13% had incomplete fist closure. Reduced GS was associated with subclinical inflammation (-0.38 kg/point inflammation, 95% CI -0.68 to -0.08). Studying separate MRI features, GS reduction was independently associated with tenosynovitis, decreasing with -2.63 kg (95% CI -2.26 to -0.33)/point tenosynovitis (range observed tenosynovitis scores: 0-20). Similar relations with tenosynovitis were seen for patient-reported grip difficulties (OR 1.12/point, 95% CI 1.07 to 1.42) and incomplete fist closure (OR 1.36/point, 95% CI 1.03 to 1.79). In the validation cohort, 36% had decreased examiner-assessed GS, 51% reported grip difficulties and 14% incomplete fist closure: all were associated with tenosynovitis. Decreased dynamometer-measured GS was most sensitive for detecting tenosynovitis (75%), while incomplete fist closure was most specific (88%-90%). Conclusion Hand function is already often affected before RA development. These limitations are related to subclinical inflammation and tenosynovitis in particular

Determining in which pre-arthritis stage HLA-shared epitope alleles and smoking exert their effect on the development of rheumatoid arthritis

Objectives The human leukocyte antigen-shared epitope (HLA-SE) alleles and smoking are the most prominent genetic and environmental risk factors for rheumatoid arthritis (RA). However, at which pre-arthritis stage (asymptomatic/symptomatic) they exert their effect is unknown. We aimed to determine whether HLA-SE and smoking are involved in the onset of autoantibody positivity, symptoms (clinically suspect arthralgia (CSA)) and/or progression to clinical arthritis. Methods We performed meta-analyses on results from the literature on associations of HLA-SE and smoking with anti-citrullinated protein antibodies (ACPAs) in the asymptomatic population. Next, we studied associations of HLA-SE and smoking with autoantibody positivity at CSA onset and with progression to clinical inflammatory arthritis (IA) during follow-up. Associations in ACPA-positive patients with CSA were validated in meta-analyses with other arthralgia cohorts. Analyses were repeated for rheumatoid factor (RF), anti-carbamylated protein antibodies (anti-CarP) and anti-acetylated protein antibodies (AAPA). Results Meta-analyses showed that HLA-SE is not associated with ACPA positivity in the asymptomatic population (OR 1.06 (95% CI:0.69 to 1.64)), whereas smoking was associated (OR 1.37 (95% CI: 1.15 to 1.63)). At CSA onset, both HLA-SE and smoking associated with ACPA positivity (OR 2.08 (95% CI: 1.24 to 3.49), OR 2.41 (95% CI: 1.31 to 4.43)). During follow-up, HLA-SE associated with IA development (HR 1.86 (95% CI: 1.23 to 2.82)), in contrast to smoking. This was confirmed in meta-analyses in ACPA-positive arthralgia (HR 1.52 (95% CI: 1.08 to 2.15)). HLA-SE and smoking were not associated with RF, anti-CarP or AAPA-positivity at CSA onset. Longitudinally, AAPA associated with IA development independent from ACPA and RF (HR 1.79 (95% CI: 1.02 to 3.16)), anti-CarP did not. Conclusions HLA-SE and smoking act at different stages: smoking confers risk for ACPA and symptom development, whereas HLA-SE mediates symptom and IA development. These data enhance the understanding of the timing of the key risk factors in the development of RA