The dermatologists' role in managing psoriatic arthritis: results of a Swiss Delphi exercise intended to improve collaboration with rheumatologists.

BACKGROUND: Psoriatic arthritis (PsA) substantially impacts the management of psoriatic disease. OBJECTIVE: This study aimed to generate an interdisciplinary national consensus on recommendations of how PsA should be managed. METHODS: Based on a systematic literature search, an interdisciplinary expert group identified important domains and went through 3 rounds of a Delphi exercise, followed by a nominal group discussion to generate specific recommendations. RESULTS: A strong consensus was reached on numerous central messages regarding the impact of PsA, screening procedures, organization of the interaction between dermatologists and rheumatologists, and treatment goals. CONCLUSION: These recommendations can serve as a template for similar initiatives in other countries. At the same time, they highlight the need to take into account the impact of the respective national health care system.

Diagnosis of rheumatoid arthritis: multivariate analysis of biomarkers.

OBJECTIVE: To test if a combination of biomarkers can increase the classification power of autoantibodies to cyclic citrullinated peptides (anti-CCP) in the diagnosis of rheumatoid arthritis (RA) depending on the diagnostic situation. METHODS: Biomarkers were subject to three inclusion/exclusion criteria (discrimination between RA patients and healthy blood donors, ability to identify anti-CCP-negative RA patients, specificity in a panel with major non-rheumatological diseases) before univariate ranking and multivariate analysis was carried out using a modelling panel (n = 906). To enable the evaluation of the classification power in different diagnostic settings the disease controls (n = 542) were weighted according to the admission rates in rheumatology clinics modelling a clinic panel or according to the relative prevalences of musculoskeletal disorders in the general population seen by general practitioners modelling a GP panel. RESULT: Out of 131 biomarkers considered originally, we evaluated 32 biomarkers in this study, of which only seven passed the three inclusion/exclusion criteria and were combined by multivariate analysis using four different mathematical models. In the modelled clinic panel, anti-CCP was the lead marker with a sensitivity of 75.8% and a specificity of 94.0%. Due to the lack in specificity of the markers other than anti-CCP in this diagnostic setting, any gain in sensitivity by any marker combination is off-set by a corresponding loss in specificity. In the modelled GP panel, the best marker combination of anti-CCP and interleukin (IL)-6 resulted in a sensitivity gain of 7.6% (85.9% vs. 78.3%) at a minor loss in specificity of 1.6% (90.3% vs. 91.9%) compared with anti-CCP as the best single marker. CONCLUSION: Depending on the composition of the sample panel, anti-CCP alone or anti-CCP in combination with IL-6 has the highest classification power for the diagnosis of established RA.

Intravenous human recombinant tumor necrosis factor receptor p55-Fc IgG1 fusion protein Ro 45-2081 (lenercept): a double blind, placebo controlled dose-finding study in rheumatoid arthritis.

OBJECTIVE: To determine the optimal dose regimen for intravenous Ro 45-2081 (lenercept) in patients with rheumatoid arthritis (RA) by evaluating efficacy, safety, tolerability, and pharmacokinetic and pharmacodynamic characteristics. METHODS: Adult patients with longstanding RA who were taking stable doses of nonsteroidal antiinflammatory drug and/or low dose corticosteroids but who had stopped their previous disease-modifying antirheumatic drug were randomly assigned to receive 3 intravenous infusions, one every 4 weeks, of placebo or Ro 45-2081 in a double blind, placebo controlled, parallel group multicenter trial. Patients received one of the following: (1) placebo, (2) low dose Ro 45-2081 (0.05 mg/kg, maximum 5 mg), (3) middle dose (mid-dose) Ro 45-2081 (0.2 mg/kg, maximum 20 mg), or (4) high dose Ro 45-2081 (0.5 mg/kg, maximum 50 mg). Efficacy measures included change from baseline in number of swollen joints and tender joints, scores on physician and patient assessments of disease activity, and patient assessment of pain, as well as acute phase reactants. RESULTS: Patients treated with Ro 45-2081 exhibited improvement after one day of the first intravenous infusion. This treatment benefit maximized by 2 weeks but diminished thereafter. After the second and third infusion, improvement was of shorter duration as non-neutralizing anti-Ro 45-2081 antibodies developed and accelerated clearance of Ro 45-2081. There were no antibodies after the first infusion. This made efficacy transient in the mid-dose group and modest in the low and high dose groups at 12 weeks of treatment, resulting in no statistical differences at most time points or doses of Ro 45-2081. The majority of adverse experiences were mild or moderate, and were not related or only remotely related to study drug. No clinically relevant changes in mean laboratory values were reported. The third dose pharmacokinetic measurements showed that the average Ro 45-2081 clearance rate more than doubled compared with the first dosing interval, thus reducing the average Ro 45-2081 AUC by 36%. CONCLUSION: Intravenous Ro 45-2081 every 4 weeks proved to be well tolerated and transiently effective in the mid-dose group and modestly effective in the low and high dose groups in patients with longstanding RA. The interactions between Ro 45-2081, its non-neutralizing anti-Ro 45-2081 antibody, and the clinical benefit remain complex, but affected efficacy over the 12 weeks of treatment as Ro 45-2081 concentrations fell.

Use of mass spectrometry to identify protein biomarkers of disease severity in the synovial fluid and serum of patients with rheumatoid arthritis.

OBJECTIVE: To identify a panel of candidate protein biomarkers of rheumatoid arthritis (RA) that can predict which patients will develop erosive, disabling disease. METHODS: A 2-step proteomic approach was used for biomarker discovery and verification. In the first step, 2-dimensional liquid chromatography-coupled tandem mass spectrometry was used to generate protein profiles of synovial fluid (SF) from patients with either erosive RA (n = 5) or nonerosive RA (n = 5). In the second step, the selected candidate markers were verified using quantitative multiple reaction monitoring mass spectrometry in sera of patients with erosive RA (n = 15) or nonerosive RA (n = 15) and of healthy controls (n = 15). RESULTS: Through differential profiling of proteins in the <40-kd portion of the SF proteome, we selected 33 prospective candidate biomarkers from a total of 418 identified proteins. Among the proteins that were elevated in the SF of patients with erosive RA were C-reactive protein (CRP) and 6 members of the S100 protein family of calcium-binding proteins. Significantly, levels of CRP, S100A8 (calgranulin A), S100A9 (calgranulin B), and S100A12 (calgranulin C) proteins were also elevated in the serum of patients with erosive disease compared with patients with nonerosive RA or healthy individuals. CONCLUSION: Several potential protein marker candidates have been identified for prognosis of the erosive form of RA. This study demonstrates the facility of using protein mass spectrometry in SF and serum for global discovery and verification of clinically relevant sets of disease biomarkers.