The KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD represents a selective update of the prior CKD-MBD Guideline published in 2009. This update, along with the 2009 publication, is intended to assist the practitioner caring for adults and children with chronic kidney disease (CKD), those on chronic dialysis therapy, or individuals with a kidney transplant. This review highlights key aspects of the 2017 CKD-MBD Guideline Update, with an emphasis on the rationale for the changes made to the original guideline document. Topic areas encompassing updated recommendations include diagnosis of bone abnormalities in CKD-mineral and bone disorder (MBD), treatment of CKD-MBD by targeting phosphate lowering and calcium maintenance, treatment of abnormalities in parathyroid hormone in CKD-MBD, treatment of bone abnormalities by antiresorptives and other osteoporosis therapies, and evaluation and treatment of kidney transplant bone disease.

The resistance of parathyroid cells to 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in uremic hyperparathyroidism is thought to be caused, in part, by a 1,25(OH)2D3 receptor (VDR) deficiency in the parathyroids. However, results of biochemical studies addressing VDR numbers in the parathyroids are controversial. Several studies have found VDR content to be decreased in the parathyroids of uremic patients and animals, while others have found no such decrease in the parathyroids of uremic animals. To clarify the role of VDR, we investigated VDR distribution in surgically-excised parathyroids obtained from chronic dialysis patients by immunohistochemistry. We classified the parathyroids as exhibiting nodular or diffuse hyperplasia. Our studies demonstrated a lower density of VDR in the parathyroids showing nodular hyperplasia than in those showing diffuse hyperplasia. Even in the parathyroids showing diffuse hyperplasia, nodule-forming areas were present; these areas were virtually negative for VDR staining. A significant negative correlation was found between VDR density and the weight of the parathyroids. These findings indicate that the conflicting results of biochemical studies may be caused by the heterogeneous distribution of VDR; the decreased VDR density in parathyroids may contribute to the progression of secondary hyperparathyroidism and to the proliferation of parathyroid cells that is seen in uremia. Images.

The Kidney Disease: Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease–Mineral and Bone Disorder (CKD–MBD) is a selective update of the prior CKD–MBD guideline published in 2009. The guideline update and the original publication are intended to assist practitioners caring for adults with CKD and those receiving long-term dialysis. Development of the guideline update followed an explicit process of evidence review and appraisal. The approach adopted by the Work Group and the evidence review team was based on systematic reviews of relevant trials, appraisal of the quality of the evidence, and rating of the strength of recommendations according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Searches of the English-language literature were conducted through September 2015 and were supplemented with targeted searches through February 2017. Final modification of the guidelines was informed by a public review process involving numerous stakeholders, including patients, subject matter experts, and industry and national organizations. The update process resulted in the revision of 15 recommendations. This synopsis focuses primarily on recommendations for diagnosis of and testing for CKD–MBD and treatment of CKD–MBD that emphasizes decreasing phosphate levels, maintaining calcium levels, and addressing elevated parathyroid hormone levels in adults with CKD stage G3a to G5 and those receiving dialysis. Key elements include basing treatment on trends in laboratory values rather than a single abnormal result and being cautious to avoid hypercalcemia when treating secondary hyperparathyroidism.