For immunosuppressive treatment regimens, relatively few associations existed between expression of cytokines and use of glucocorticoids and biologic treatments at either visit. time increases activation of B cells and monocytes without requirements for T- cell functions. Keywords:chemokines, cytokines, immunostimulation, rheumatoid arthritis, rheumatoid factor == Introduction == Rheumatoid arthritis (RA) exacts a costly toll on patients, with debilitating effects ranging from pain and disability to death, associated comorbidities, decreased quality of life, and increased financial costs. The autoimmune nature of RA has been clearly established, with involvement of both innate and adaptive immune systems. The resultant articular and systemic responses involve multiple lymphoid cell types with multiple effector functions. Accordingly, it is difficult to assign specific RA symptoms to specific cell types or to identify the most deleterious autoimmune mechanisms. The assessment of disease progression and therapeutic efficacy in patients with RA is dependent on a combination of 1) laboratory tests for acute-phase proteins, 2) clinical assessment of joint inflammation and damage and the extent and severity of pain and disability, and 3) patient selfassessment of pain and disability. Despite the effort expended on developing informative assessments, the present approaches do not appear to be sufficiently sensitive to detect the low levels of inflammation that are suspected of driving continued joint damage in patients classified as having low disease activity [1,2]. Biomarkers that can be objectively quantitated at relatively high-resolution levels and whose levels correlate with disease severity should provide an important adjunct to present clinical assessments. Previously we reported our development of an experimental platform that was designed to probe the multiple lymphoid cell types involved in innate and adaptive responses in patients with RA. A panel of immunostimulants was chosen to activate a wide range of lymphoid cell types in vitro, with FIGF activation quantitated by expression of a diverse set of cytokines and chemokines that can be used to identify cell types that respond to individual stimulants. We have used this approach to develop immune signatures of cytokine and chemokine expression that distinguish patients with RA who differ by 1) duration of disease [3], 2) risk of infection [4], 3) severity of RA-associated left ventricular diastolic dysfunction [5], 4) probability of adequate response to initial disease-modifying antirheumatic drug therapy [6], and 5) LGB-321 HCl severity of radiographic joint damage [7]. In the LGB-321 HCl present study we aimed to LGB-321 HCl evaluate changes in cytokine and chemokine expression after 5 years of follow-up in order to assess our immune signature platform for predicting future disease outcomes. We used our immune signature platform to assess the capacity of the immune system of patients with RA to express cytokines and chemokines before and after a 5-year interval during the course of the disease to compare levels of expression with disease characteristics. Factor analysis was used to reduce the complexity of data by identifying groups of associated cytokines and chemokines, to identify the responding lymphoid cell types, and to correlate changes in these cell types with different characteristics of the disease over the 5-year study period. == Materials and Methods == == Study Design and Participants == We conducted a cross-sectional analysis of baseline and 5-year follow-up data from a prospective study of patients with RA in a community, population-based, incidence cohort as previously described [5]. This study used resources of the Rochester Epidemiology Project, a medical records linkage system providing access to complete medical records for residents of Olmsted County, Minnesota, who receive medical attention [8]. We identified Olmsted County residents who were 18 years or older and who first fulfilled the American College of Rheumatology classification criteria for RA between January 1, 1980, and December 31, 2007. From this cohort, 324 of475 eligible patients with RA were recruited for the initial study visit (visit 1). After 5 years, 155 patients returned to participate in the.