Development of a serum-antibody test specific for a bacterium associated with rheumatoid arthritis patients

Abstract

Rheumatoid arthritis (RA) is an incurable inflammatory autoimmune disease of synovial joints that affects nearly 1% of the global population and an estimated 1.36 million Americans. The disease has significant economic impacts—resulting in annual healthcare expenses totaling $19 billion annually. Pathogenesis is driven by a complex interplay between genetic and environmental factors. Recent literature suggests the presence of microbial communities in synovial joints of both RA patients and normal healthy donors (NHDs). Further analysis revealed that the Raoultella genus of bacteria was present in the synovium of RA patients, but not NHDs. This is suggestive of a possible involvement of the synovial microbiome in the pathogenesis of RA. In this project, pure culture of Raoultella ornitholytica and R. planticola were established and used to generate bacterial whole cell lysates. Each lysate was screened against 10 RA patient and 5 normal healthy donor human serum samples. Checkerboard titrations were performed to optimize the assay and the indirect ELISA protocol established in this study will be used in future lab projects.