Effects of RANK-Ligand Antibody (Denosumab) Treatment on Bone Turnover Markers in a Girl With Juvenile Paget's Disease

Context: Juvenile Paget's disease (JPD) is an extremely rare, yet painful and debilitating bone diseasewith onset occurring during early childhood. JPD can be caused by loss of function of osteoprotegerin, resulting in subsequent stimulation of osteoclasts via the receptor activator of nuclear factor-κB (RANK) pathway. Increased bone turnover and lack of bone modeling lead to severe deformities, frequent fractures, short stature, and loss of hearing. Setting: The treatment for JPD is challenging and has previously been based on administration of either calcitoninor bisphosphonates. However, with the development of denosumab, a receptor activator of nuclear factor-κB-ligand ( RANKL) antibody, a treatment targeting the pathophysiology of JPD may be available. We report the effects of denosumabtreatment on an 8-year-old girl with a severe form of JPD. Patient: Before starting the denosumabtreatment regimen, the patient had been treated for 3.5 years with iv pamidronate. Intervention and Outcome: The admin...