Bone disease after renal transplantation

Bone disease after renal transplantation requires preventive therapies to reduce high fracture rates as well as to assuage other conditions associated with the disturbance of calcium-phosphate metabolism. The bone disease that develops with renal insufficiency is aggravated after renal transplantation by a number of factors, including immunosuppressive therapy, especially a high-dose steroid regimen, hypophosphataemia and persistent hyperparathyroidism. The administration of vitamin D and calcium is effective in preventing post-transplant bone density loss. This also applies to therapies with bisphosphonates, which are indicated in patients with a high fracture risk. However, the use of vitamin D and calcium is limited by hypercalcaemic episodes and hyperparathyroidism in many cases. The development of adynamic bone is a risk factor associated with bisphosphonate therapy, especially when parathyroidectomy cannot be avoided. Treatment of hypophosphataemia by oral phosphate administration aggravates hyperphosphaturia and may support the development of nephrocalcinosis, with a possible negative effect on transplant function. Hyperparathyroidism after transplantation frequently improves over time, and parathyroid hormone levels return to normal in a number of cases. However, this process may take months or even years. For early, effective treatment of hyperparathyroidism during the period of the most severe bone damage after transplantation and to take advantage of existing therapeutic options for the preventive treatment of bone disease, cinacalcet is available, apart from parathyroidectomy. Preliminary data from renal transplant recipients show that cinacalcet can lower parathyroid hormone levels, reduce the frequency of hypercalcaemic episodes and improve hyperphosphataemia. The potency of this substance should be evaluated in larger studies to lay the foundation for its widespread use among renal transplant recipients, in de novo therapies after transplantation, or for the continuation of treatment initiated during haemodialysis. However, the use of cinacalcet for the treatment of hyperparathyroidism after transplantation has not been approved.