Kidney Disease: Improving Global Outcomes (KDIGO) CKD-MBD Work Group. KDIGO clinical practice guideline for the diagnosis, evaluation, prevention, and treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). Kidney Int. 2009;S1-S130. [PMID: 19644521 DOI: 10.1038/ki.2009.193]

Changes in bone mineral density following long-term simultaneous pancreas-kidney transplantation

The symptoms of chronic renal disease-related mineral and bone disease improve significantly in patients after successful simultaneous pancreas-kidney transplantation (SPKT); however, bone pathology is still present even after many post-transplant years. The aim of this study was to analyze the bone densitometry in different periods after SPKT. Three-point densitometry was performed with the dual-energy X-ray absorptiometry (DXA) technique. Serum levels of alkaline phosphatase (ALP), total serum calcium, phosphate and parathyroid hormone were analyzed as markers of mineral metabolism. The study population consisted of 48 patients (28 females, 20 males) with a mean age of 35 ± 6 years and mean 24 ± 6 years of prior diabetes. Mean period of maintenance dialysis was 36 ± 26 months. The median time from SPKT and DXA measurement was 0.53, 26.2 and 41.9 months, respectively. Based on the DXA technique, 35.4 % of patients were categorized as having osteoporosis at the lumbar spine and 39.6 % at the femoral neck. Patients with diagnosed osteoporosis had significantly higher levels of ALP (OR = 1.5; 95 % CI = 1.1-2.2; p < 0.05 at the lumbar spine; OR = 1.4; 95 % CI = 1.0-1.9; p < 0.05 at the femoral neck). In addition, subjects with lumbar osteoporosis were characterized by a significantly lower body mass index (BMI) (OR = 0.5; 95 % CI = 0.3-0.9; p < 0.05). In the long-term follow-up, BMD increased significantly at the lumbar spine (T-score -1.86 ± 1.07 to -1.08 ± 0.89) and femoral neck (T-score -2.12 ± 0.78 to -1.63 ± 0.65). A multivariate linear model identified a BMI increase as a significant factor associated with improvement in BMD. Results of our study led us to conclude that, according to three-point densitometry, BMD among patients with functioning kidney and pancreas grafts improved. Increased serum levels of ALP were significantly associated with a decrease in BMD, suggesting a higher risk of osteoporosis. BMI gain was predictive of BMD improvement.

New options for the management of hyperparathyroidism after renal transplantation

The persistence and severity of hyperparathyroidism (HPT) post-renal transplantation is relatively frequent and primarily associated with the timing and its magnitude in the pre-transplant period and with the presence of parathyroid adenomas. HPT after renal transplantation is clinically manifested with hypercalcemia, hypophosphatemia, bone pain, fractures, and in more serious cases with cardiovascular calcifications that affect the survival. The primary clinical objective for patients with secondary HPT after renal transplantation is to obtain a level of parathyroid hormone (PTH) adequate to the renal transplanted function and to normalize levels of calcium, phosphorus and vitamin D. In many cases during this period, the development of hypercalcemia and/or hypophosphatemia makes it necessary to take different therapeutic measures. The use of vitamin D or its analogues has been extrapolated from the management of pre-transplant HPT obtaining variable outcomes, although its use is limited by its capacity to produce hypercalcemia. Calcimimetics are drugs that have proven be effective in reducing PTH levels in patients with HPT on dialysis and has been effective in reducing up to 50% PTH levels in moderate to severe HPT in post-renal transplantation.When HPT persists after renal transplantation and does not respond to medical treatment, invasive management by percutaneous ethanol injection therapy of parathyroid glands or parathyroidectomy should be considered. The emergence of new methods for the management of HPT expands the availability of therapeutic tools for transplant patients.