Pathogenesis of Paget's Disease Based on Viral Etiology

It has been slightly over 100 years since Sir James Paget's classic descriptions of "osteitis deformans" first appeared. He had described the mid- to late stages of patients with the chronic, debilitating, rare, and polyostotic forms of the disease. It is now known that the milder forms of the disease are quite common particularly in those of Anglo-Saxon ancestry. He believed the condition to be a chronic inflammation of unknown etiology because of its asymmetrical skeletal distribution, chronicity, and the gross appearance of the bones. With regard to the possible etiology of Paget's disease of bone, nothing worthy of note had been discovered until 1974 when viral-like inclusions were reported within the osteoclasts of all Paget's disease patients. In the ensuing decade, a great deal more circumstantial evidence from electron microscopic and immunologic studies supports the view that Paget's disease represents a slow virus infection. This article deals with the possible to probable viral etiology of Paget's disease with respect to its pathogenesis and its potential for eventual eradication. For many years Paget's disease was considered a disease almost exclusively confined to adulthood. Evidence now suggests that "familial chronic hyperphosphatasemia" represents the childhood form of Paget's disease.