title: Metabolic responses to change in disease activity during tumor necrosis factor inhibition in patients with rheumatoid arthritis.
abstract: Assessment of disease activity in patients with rheumatoid arthritis (RA) is of importance in the evaluation of treatment. The most important measure of disease activity is the Disease Activity Score counted in 28 joints (DAS28). In this study, we evaluated whether metabolic profiling could complement current measures of disease activity. Fifty-six patients, in two separate studies, were followed for two years after commencing anti-TNF therapy. DAS28 was assessed, and metabolic profiles were recorded at defined time points. Correlations between metabolic profile and DAS28 scores were analyzed using multivariate statistics. The metabolic responses to lowering DAS28 scores varied in different patients but could predict DAS28 scores at the individual and subgroup level models. The erythrocyte sedimentation rate (ESR) component in DAS28 was most correlated to the metabolite data, pointing to inflammation as the primary effect driving metabolic profile changes. Patients with RA had differing metabolic response to changes in DAS28 following anti-TNF therapy. This suggests that discovery of new metabolic biomarkers for disease activity will derive from studies at the individual and subgroup level. Increased inflammation, measured as ESR, was the main common effect seen in metabolic profiles from periods associated with high DAS28.
authors.affiliation: Computational Life Science Cluster (CLiC), Department of Chemistry, Umeå University, 90187 Umeå, Sweden.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Madsen
authors.forename: Solbritt
authors.initials: S
authors.lastname: Rantapää-Dahlqvist
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Lundstedt
authors.forename: Thomas
authors.initials: T
authors.lastname: Moritz
authors.forename: Johan
authors.initials: J
authors.lastname: Trygg
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D005260:Female; D006801:Humans; D000069285:Infliximab; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012720:Severity of Illness Index; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab