RANKL/RANK/OPG molecular complex--control factors in bone remodeling in psoriatic arthritis

To investigate the blood levels of bone remodeling factors (RANKL, OPG and Bone-ALP) in psoriatic arthritis patients.Included in this study were 27 patients with psoriatic arthritis (CASPAR classification criteria) and 20 healthy subjects. The RANKL , OPG and Bone-ALP levels have been quantified by ELISA method.Peripheral blood concentrations were higher in psoriatic arthritis than in the healthy subjects, and a strong negative correlation between RANKL and OPG and between RANKL and Bone-ALP was also found.The increase in OPG and Bone-ALP serum level is strongly related to the increase in RANKL serum level in patients with psoriatic arthritis. The increase in OPG and Bone-ALP serum level induces the production of bone matrix parallel to the bone destruction mediated by RANKL. The follow up of the patients with psoriatic arthritis by early RANKL, OPG and Bone-ALP serum level determinations, and of bone metabolism markers (with specific role in bone remodeling), allows an accurate evaluation of disease activity and, in the future, could be a criterion for the initiation of specific, targeted treatment.