Denosumab (Prolia) specifically prevents the development of which type of bone cell?

• A. Osteoblasts
• B. Chondrocytes
• C. Osteoclasts
• D. Osteocytes

Answer: (C)

Denosumab, marketed as Prolia, is a monoclonal antibody that specifically targets and inhibits the activity of osteoclasts, which are the cells responsible for bone resorption. By binding to RANKL (Receptor Activator of Nuclear Factor Kappa-B Ligand), Denosumab prevents RANKL from activating its receptor RANK on osteoclast precursor cells. This action effectively reduces the differentiation and activity of osteoclasts, leading to decreased bone resorption, increased bone density, and a lower risk of fractures in individuals with conditions such as osteoporosis.

Osteoblasts, chondrocytes, and osteocytes play different roles in bone physiology. Osteoblasts are responsible for bone formation, chondrocytes are involved in cartilage formation, and osteocytes are mature bone cells that maintain bone tissue. Denosumab's mechanism does not directly impact these cells, making its effect specific to osteoclasts and highlighting its therapeutic importance in managing bone density and health.