Three distinct disease course trajectories have been identified for people in the early stages of rheumatoid arthritis.
A UK observational study that followed 267 newly diagnosed, treatment naïve patients with seropositive rheumatoid arthritis found three different subpopulations of people based on their disease activity and remission rates up to 18 months.
The most common trajectory (71%) was for a group of patients who on average started with moderate levels of disease activity and showed sustained improvement (Lower Baseline Activity Responders). A second group comprising 22.4% of patients started with high baseline disease activity but showed sustained improvement over time (Higher Baseline Activity Responders). A third group, deemed Inadequate Responders (6.5%), started with high baseline disease activity that early on showed improvement, in association with initial medication, and then plateaued with 202 moderate to high levels of disease activity.
The different trajectory groups were not associated with standard clinical factors but the evidence of clear differences in outcomes as early as six months suggested they may instead be linked to distinct immunopathogenic subsets, according to Dr Brian Tom and colleagues in the RA-MAP Consortium at the University of Cambridge, UK.
The researchers followed newly diagnosed RA patients who were enrolled in the ‘Towards A CurE for RA’ (TACERA) cohort with clinical and biochemical measures taken at baseline and at three month intervals.
Overall 24.3% of patients attained 6-month remission by SDAI definition. Remission was associated with lower levels of disease activity and functional disability at baseline. Moderate consumption of alcohol was also associated with high rates of remission.
The researchers said it was notable there were no differences in prescribing patterns amongst the trajectory classes, but there were differences in effect sizes.
For example, in the Inadequate Responder group, lower disease activity was associated with being prescribed dual therapy of MTX and a second DMARD at baseline compared to monotherapy with or without glucocorticoid use. However this association was not seen in the Lower Baseline Activity Responder group. Better mental well-being at baseline was also associated with lower disease activity in the inadequate responder group.
“This provides evidence to support a stratified approach to management and treatment of patients falling into different trajectory groups,” the researchers said.
“Our data further highlight RA heterogeneity (i.e. trajectory classes) not explainable by clinical factors and indicate the possible use of biomarkers collected at baseline and early follow-up to help patient management and better targeting of existing and novel therapies,” they concluded.
The findings are published in medRxiv preprint.