Periarticular Bone Alterations in Chronic Antigen-Induced Arthritis: Free and Liposome-Encapsulated Clodronate Prevent Loss of Bone Mass in the Secondary Spongiosa

Osteoprotegerin reduces the loss of periarticular bone mass in primary and secondary spongiosa but does not influence inflammation in rat antigen-induced arthritis

“…Remarkably OPG treatment had an additional increasing effect on bone mass in areas were bone formation is dominant. In contrast to low-dose clodronate therapy, which had only an effect on secondary spongiosa [23], OPG treatment did infl uence both primary and secondary spongiosa. No evidence was found that an increased amount of mineralized tissue or number of trabeculae in the primary spongiosa had any negative effects on trabecular bone formation in the secondary spongiosa.…”

“…Effects of bisphosphonate treatment have been previously reported in the rat AIA model. Contrary to the effect of OPG treatment on bone structure free and liposome encapsulated clodronate completely preserved the trabecular bone volume [23]. There is some evidence that bisphosphonates directly increase osteoblast activity and inhibit apoptosis [43].…”

“…AIA is also characterized by a marked decrease of periarticular trabecular bone volume in the primary and secondary spongiosa, associated with an increase of bone turnover in the secondary spongiosa [23,24].…”

Combination therapy with dexamethasone and osteoprotegerin protects against arthritis-induced bone alterations in antigen-induced arthritis of the rat

“…In various previous studies in rat AIA with parallel investigation of inflammatory disease activity, cartilage destruction and bone loss including healthy controls and investigation of the contralateral (non-arthritic) tibia head, spontaneous bone loss and cartilage destruction in healthy animals or at the knee joint not affected by arthritis were not observed [25][26][27].…”

“…This study compared the influence of a combination therapy consisting of a glucocorticoid and OPG with the respective monotherapies on arthritis-induced bone alterations and inflammatory disease activity in antigeninduced arthritis (AIA) of the rat-an animal model sharing essential features with RA such as synovial hyperplasia, inflammatory infiltration, cartilage destruction and substantial periarticular and moderate axial bone loss [22,[25][26][27][28].…”