Sarah Blelock

Comparative analysis of synovial fluid and plasma proteomes in juvenile arthritis--proteomic patterns of joint inflammation in early stage disease.

Abstract Synovial fluid is a potential source of novel biomarkers for many arthritic disorders involving joint inflammation, including juvenile idiopathic arthritis. We first compared the distinctive protein ‘fingerprints’ of local inflammation in synovial fluid with systemic profiles within matched plasma samples. The synovial fluid proteome at the time of joint inflammation was then evaluated across clinical subgroups to identify early disease associated proteins. We measured the synovial fluid and plasma proteomes using the two-dimensional fluorescence difference gel electrophoresis approach. Image analysis software was used to highlight the expression levels of joint and subgroup associated proteins across the study cohort (n =32). A defined subset of 30 proteins had statistically significant differences (p <0.05) between sample types such that synovial fluid could be differentiated from plasma. Furthermore distinctive synovial proteome expression patterns segregate patient subgroups. Protein expression patterns localized in the chronically inflamed joint therefore have the potential to identify patients more likely to suffer disease which will spread from a single joint to multiple joints. The proteins identified could act as criteria to prevent disease extension by more aggressive therapeutic intervention directed at an earlier stage than is currently possible.

Early untreated juvenile idiopathic arthritis: predictors of outcome

Methods We are undertaking a five-year prospective study of children with newly diagnosed and untreated JIA. At least one knee was involved requiring intra-articular steroid injection. Detailed clinical, imaging, and laboratory parameters were measured at T0 and 3/12 for 2 years. At outset we obtained synovial biopsies. We report the outcome on those children for whom data is available for one year.