Evaluation of Apelin, and Tartrate-Resistant Acid Phosphatase-5b in Ankylosing Spondylitis Male Patients With and Without Osteoporosis


Osteoporosis is a common complication of ankylosing spondylitis (AS), and it is related to the high levels of biochemical markers such as tartrate-resistant acid phosphates (TRACP)-5b and other proinflammatory cytokines. In early AS, osteoporosis may appear due to the action proinflammatory cytokines, however spinal osteoporosis commonly observed in those patients with severe AS of long duration but it can occur as a result of ankylosis and lack of movement. Apelin is a new adipokine that has a negative impact on bone formation and can act as an anti-anabolic agent. The aim of this study is to evaluate serum (apelin and TRACP-5b) levels in ankylosing spondylitis (AS) male patients with and without osteoporosis and look for the relation between osteoporosis and the studied parameters. About fifty-eight male AS patients were included in this study. Serum (apelin and tartrate-resistant acid phosphates (TRACP)-5b) were measured using commercial enzyme-linked immunosorbent assay (ELISA) kits. Bone mineral density (BMD)(Z-score)of Lumbar spine was determined using dual-energy X-ray absorptiometry (DXA).This study shows that AS male patients with osteoporosis had significantly high serum TRACP-5b level (P-value <0.001) while no significant differences of serum apelin level (P-value=0.06) between AS male patients with and without osteoporosis. A significant correlation has been found between BMD (Z-score) and serum TRACP-5b level while no correlation has been found between BMD (Z-score) and serum apelin level. The results of this study suggest that serum TRACP-5b is could be used in detection of AS disease with osteoporosis, while serum Apelin level is would not be effected.