Pediatric transplant bone disease

This chapter reviews the organ-specific epidemiology of pediatric solid-organ transplantation, the skeletal impacts of the underlying disease and subsequent transplant complications. 90% of peak bone mass is established by 18 years of age. This rapid accumulation of bone mass correlates with the rate of growth and requires the coordinated actions of growth hormone, insulin-like growth factor-I, and sex steroids. Individuals with higher peak bone mass in early adulthood have a protective advantage against fracture when the inexorable decline in bone mass associated with older age or menopause occurs. Pediatric transplant recipients have multiple risk factors for impaired bone development, including pre-existing metabolic bone disease, poor growth, delayed development, malnutrition, decreased weight-bearing activity, chronic inflammation, and immunosuppressive therapies. The impact of these threats to bone health may be immediate, resulting in fragility fractures. The chapter discusses the classification of bone health in children and adolescents and the advantages and disadvantages of available technologies for the assessment of bone in children and adolescents. It reviews selected studies that describe the difficulties in assessing and interpreting bone measures in pediatric transplantation and discusses potential therapies. Currently, the prevention of bone disease is best accomplished by providing adequate, but not excessive, calcium and vitamin D stores, and by encouraging physical activity prior to and after transplantation along with using the minimum effective glucocorticoid dose.