Background
Rheumatoid arthritis (RA) is a systemic inflammatory disease affecting cartilage and bone. Recently, much attention on the role of neutrophils in the pathology of RA has been paid. However, the capability of RA neutrophils from periphery and bone marrow (BM) to produce cytokines like IL-17 and IFN-γ has not been well understood. Our aim is to analyze neutrophil distribution in BM, blood and synovium and to elucidate IL-17, IL-4 and IFN-γ production and surface expression of RANKL on peripheral and synovial neutrophils during the progression of zymosan-induced arthritis (ZIA).