Cellular Metabolic Heterogeneity and Therapeutic Targeting in Rheumatoid Arthritis

Metabolic abnormalities in rheumatoid arthritis (RA) differ across cell populations and anatomical compartments. Glycolytic synovial fibroblasts coexist with blood T-cell populations showing impaired glycolytic induction or mitochondrial function, while macrophage metabolism can sustain inflammation or tissue protection. These differences complicate systemic metabolic inhibition. This narrative review integrates human RA studies, experimental arthritis and mechanistic work in other systems to identify dependencies that support defined pathogenic functions. We examine metabolite transport, nutrient adaptation and nutrient and energy sensing, distinguishing causal perturbation from descriptive signatures and preclinical hypotheses from clinical efficacy signals. Systemic cardiometabolic disease and nutritional interventions provide a clinical context for interpreting local metabolic findings. Small trials of repurposed drugs suggest possible benefit during treatment, but do not establish durable metabolic correction. We propose that a claim of reprogramming requires persistent functional change after drug removal, exclusion of residual exposure and selective cell loss, and preservation of immune regulation and host defence. These criteria could guide more selective metabolic interventions and their evaluation in patient tissue.