Decreased osteoblastogenesis from synovial fluid progenitors as a marker of systemic inflammatory process in juvenile idiopathic arthritis

Methods Peripheral blood (PB) samples were obtained from children with oligoarticular JIA (oJIA, n=18), polyarticular JIA (pJIA, n=20), and healthy controls (n=18). SF samples were collected from children with oJIA (n=20) and pJIA (n=7). Osteoblastogenesis was induced with 50 μg/ml ascorbic acid and 5 mmol b-glycerophosphate, in SF cells and BM cells obtained from a healthy donor, and assessed by alkaline phosphatase (AP) histochemistry. Gene expression of Runx-genes, osteoprotegerin (OPG) and receptor activator of nuclear factorB ligand (RANKL) was analyzed by qPCR.