Urinary proteomics can define distinct diagnostic inflammatory arthritis subgroups.

Current diagnostic tests applied to inflammatory arthritis lack the necessary specificity to appropriately categorise patients. There is a need for novel approaches to classify patients with these conditions. Herein we explored whether urinary proteomic biomarkers specific for different forms of arthritis (rheumatoid arthritis (RA), psoriatic arthritis (PsA), osteoarthritis (OA)) or chronic inflammatory conditions (inflammatory bowel disease (IBD)) can be identified. Fifty subjects per group with RA, PsA, OA or IBD and 50 healthy controls were included in the study. Two-thirds of these populations were randomly selected to serve as a training set, while the remaining one-third was reserved for validation. Sequential comparison of one group to the other four enabled identification of multiple urinary peptides significantly associated with discrete pathological conditions. Classifiers for the five groups were developed and subsequently tested blind in the validation test set. Upon unblinding, the classifiers demonstrated excellent performance, with an area under the curve between 0.90 and 0.97 per group. Identification of the peptide markers pointed to dysregulation of collagen synthesis and inflammation, but also novel inflammatory markers. We conclude that urinary peptide signatures can reliably differentiate between chronic arthropathies and inflammatory conditions with discrete pathogenesis.

Trial of Atorvastatin in Rheumatoid Arthritis (TARA): double-blind, randomised placebo-controlled trial.

BACKGROUND: Rheumatoid arthritis is characterised by inflammatory synovitis, articular destruction, and accelerated atherogenesis. HMG-CoA (3-hydroxy-3-methylglutarylcoenzyme A) reductase inhibitors (statins) mediate clinically significant vascular risk reduction in patients without inflammatory disease and might have immunomodulatory function. We postulated that statins might reduce inflammatory factors in rheumatoid arthritis and modify surrogates for vascular risk. METHODS: 116 patients with rheumatoid arthritis were randomised in a double-blind placebo-controlled trial to receive 40 mg atorvastatin or placebo as an adjunct to existing disease-modifying antirheumatic drug therapy. Patients were followed up over 6 months and disease activity variables and circulating vascular risk factors were measured. Coprimary outcomes were change in disease activity score (DAS28) and proportion meeting EULAR (European League Against Rheumatism) response criteria. Analysis was by intention to treat. FINDINGS: At 6 months, DAS28 improved significantly on atorvastatin (-0.5, 95% CI -0.75 to -0.25) compared with placebo (0.03, -0.23 to 0.28; difference between groups -0.52, 95% CI -0.87 to -0.17, p=0.004). DAS28 EULAR response was achieved in 18 of 58 (31%) patients allocated atorvastatin compared with six of 58 (10%) allocated placebo (odds ratio 3.9, 95% CI 1.42-10.72, p=0.006). C-reactive protein and erythrocyte sedimentation rate declined by 50% and 28%, respectively, relative to placebo (p<0.0001, p=0.005, respectively). Swollen joint count also fell (-2.69 vs -0.53; mean difference -2.16, 95% CI -3.67 to -0.64, p=0.0058). Adverse events occurred with similar frequency in patients allocated atorvastatin and placebo. INTERPRETATION: These data show that statins can mediate modest but clinically apparent anti-inflammatory effects with modification of vascular risk factors in the context of high-grade autoimmune inflammation.