Comparison levels of RANKL, OPG, bone alkaline phosphatase, and Cathepsin K between patients with rheumatoid arthritis and patients with osteoporosis.

Objectıve: We aimed to investigate osteoprotegerin (OPG), receptor activator of nuclear factor ? B ligand (RANKL), bone alkaline phosphatase (BAP), cathepsin-K levels in patients with rheumatoid arthritis and patients with osteoporosis and the relationship between them and bone mineral density (BMD).Materıals and methods: Our study consist of total of 147 cases including postmenopausal (n = 30), postmenopausal women with osteoporosis (n = 30; The spine and/or femoral neck T score under -2.5 measured by DEXA device), premenopoz (n = 27), postmenopause with RA (n = 30) and premenopoz with RA (n = 30). Serum RANKL, OPG, cathepsin K and BAP were measured by ELISA method.Results: There was not a statistically significant difference between RANKL, OPG, RANKL/OPG levels of patients with Postmenopause osteoporosis and women with postmenopause. There was a statistically significant high serum RANK level and RANKL/OPG ratio of patients with rheumatoid arthritis than women with Postmenopause and women with premenopoz While there was no statistically significant difference between serum OPG level of them. There was no statistically significant difference between cathepsin K levels in postmenopause patients with RA and premenopause patients with RA. Was found no statistically significant difference between cathepsin K levels of postmenopause patients with osteoporosis and postmenopause patients without osteoporosis. In our study, was found a statistically significant negative correlation between BMD and OPG levels, but there was no significant correlation with the level of RANKL.Conclusıons: These results support that RANKL / RANK / OPG system played a role in the pathogenesis of osteoporosis and rheumatoid arthritis, and OPG may be important determinant of bone density, more numerous and extensive studies are needed.Keywords: Osteoporosis, Rheumatoid arthritis, RANKL, OPG, Cathepsin K