The Relationship among the inflammation, osteoblast activity and adipogenesis in patients with Ankylosing Spondylitis

초록

Background: Many authors tried to elucidate the relationship among the inflammation, osteoblast activity or new bone formation, and adipogenesis in patients with ankylosing spondylitis (AS). But the results were disappointing. Objectives: We investigated the relationship among the inflammation, osteoblast activity or new bone formation, and adipogenesis in patients with AS by novel cell culture technique of osteoblast in peripheral blood and other methods. Methods: Male sixteen individuals with AS were enrolled. They met modified New York criteria and were candidates for infliximab therapy. Sex and age matched nineteen controls were also recruited. Peripheral blood mononuclear cells were collected and cultured in growth medium. Once cell multi-layering has been observed (about 7 days), cells were transferred to differentiation medium and cultured for 3 weeks. Cells were then fixed and stained with alizarin S stain to detect any calcified nodules. The optical density (OD) of alizarin S was measured for quantitative analysis. We evaluated the numbers, the differences and relationship of 1) the numbers of circulating osteoblast precursors in peripheral blood, 2) the OD of alizarin S red staining of circulating osteoblast precursors, 3) P1NP (total procollagen type 1 N-terminal propeptide), c-terminal telopeptide (CTX), osteocalcin, triglyceride, low density lipoprotein cholesterol(LDL), apolipoprotein A-1, apolipoprotein B, lipoportein (a) with enzyme linked immunosorbent assay (ELISA), 4) erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) before and after 14 week infliximab therapy, 5) bone densitometry (BMD) before infliximab therapy in patients with AS. Results: The number of osteoblast precursor cells and optic density of alizarin S were decreased after infliximab therapy (p = 0.028 for optic density of alizarin S). The serum level of P1NP was decreased after infliximab therapy (p = 0.002)