Posttransplant bone disease: A case illustrating dramatic improvements in bone density with vitamin D replacement therapy

Although bisphosponates are proposed as first-line treatment for posttransp lant bone disease they are not optimal in all situations. A kidney transpla nt recipient developed hypercalcemia from mobilization of extraskeletal cal cium. He had low serum parathyroid hormone and vitamin D; high calcium excr etion; and normal calcium intake. Bone biopsy revealed severe osteomalacia. Bisphosphonates, used in the early treatment of acute hypercalcemia, were not indicated to treat osteomalacia. However, over several months serum cal cium declined sufficiently to allow treatment of the bone disease with oral calcitriol, Dual-energy radiographic absorptiometry over the next 2 years documented dramatic improvements in bone density (percent of young-normal c ontrols) : from 63 to 85%, at the lumbar spine; from 38 to 67%, at the femo ral neck. This response to treatment could not have been achieved with an a ntiresorptive strategy. Optimal management of posttransplant bone disease r equires a diagnostic approach, which considers all plausible contributing f actors.