Joint counts to assess rheumatoid arthritis for clinical research and usual clinical care: advantages and limitations.
ABSTRACT A joint examination is prerequisite to a diagnosis of rheumatoid arthritis (RA), and quantitative counts of swollen and tender joints are the most specific of the 7 RA Core Data Set measures for patient assessment. Therefore, joint counts are weighted of greater importance than the other 5 Core Data Set measures in American College of Rheumatology response criteria and all RA indices in which it is included. Nonetheless, several limitations to the joint count have been recognized: (1) poor reproducibility with a requirement to be performed by the same observer at each visit; (2) likelihood to improve with placebo treatment as much or more than the other 5 RA Core Data Set measures; (3) similar or lower relative efficiencies than global and patient measures to document differences between active and control treatments in clinical trials; (4) improvement over 5 years while joint damage and functional disability may progress; (5) lower sensitivity in detecting inflammatory activity than ultrasound and magnetic resonance imaging. Most visits to a rheumatologist do not include a formal quantitative joint count. Quantitative patient self-report data are as sensitive to change and as informative about prognosis and outcomes as joint counts. It may be suggested that a careful qualitative (nonquantitative) joint examination, supplemented by quantitative self-report questionnaire scores to interpret physical examination findings, may be adequate to monitor patients and document changes in status in busy clinical settings.
Article: Saposin C coupled lipid nanovesicles specifically target arthritic mouse joints for optical imaging of disease severity.[show abstract] [hide abstract]
ABSTRACT: Rheumatoid arthritis is a chronic inflammatory disease affecting approximately 1% of the population and is characterized by cartilage and bone destruction ultimately leading to loss of joint function. Early detection and intervention of disease provides the best hope for successful treatment and preservation of joint mobility and function. Reliable and non-invasive techniques that accurately measure arthritic disease onset and progression are lacking. We recently developed a novel agent, SapC-DOPS, which is composed of the membrane-associated lysosomal protein saposin C (SapC) incorporated into 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) lipid nanovesicles. SapC-DOPS has a high fusogenic affinity for phosphatidylserine-enriched microdomains on surfaces of target cell membranes. Incorporation of a far-red fluorophore, CellVue Maroon (CVM), into the nanovesicles allows for in vivo non-invasive visualization of the agent in targeted tissue. Given that phosphatidylserine is present only on the inner leaflet of healthy plasma membranes but is "flipped" to the outer leaflet upon cell damage, we hypothesized that SapC-DOPS would target tissue damage associated with inflammatory arthritis due to local surface-exposure of phosphatidylserine. Optical imaging with SapC-DOPS-CVM in two distinct models of arthritis, serum-transfer arthritis (e.g., K/BxN) and collagen-induced arthritis (CIA) revealed robust SapC-DOPS-CVM specific localization to arthritic paws and joints in live animals. Importantly, intensity of localized fluorescent signal correlated with macroscopic arthritic disease severity and increased with disease progression. Flow cytometry of cells extracted from arthritic joints demonstrated that SapC-DOPS-CVM localized to an average of 7-8% of total joint cells and primarily to CD11b+Gr-1+ cells. Results from the current studies strongly support the application of SapC-DOPS-CVM for advanced clinical and research applications including: detecting early arthritis onset, assessing disease progression real-time in live subjects, and providing novel information regarding cell types that may mediate arthritis progression within joints.PLoS ONE 01/2012; 7(3):e33966. · 4.09 Impact Factor