Lupus IgG Induces Synovial Inflammation but Inhibits Bone Erosions in SLE Arthritis

Bone erosion is an important feature of inflammatory arthritis. It remains unknown why lupus arthritis lacks bone erosion and destruction. Our recent published paper presents the interesting discovery that joint deposited lupus IgG triggers synovitis but suppresses osteoclastogenesis which is responsible for bone destruction. In this paper, data show that joint deposited lupus IgG induces synovitis through FcgRI on monocytes/macrophages and blocks RANKL-induced osteoclastogenesis through competing for FcgRI binding with RANKL. This study promotes understanding the pathogenesis of lupus arthritis and provides a novel therapeutic target of FcgRI to inhibit bone destruction in inflammatory arthritis.