Denosumab associated with bone density increase and clinical improvement in a long-term hemodialysis patient. Case report and review of the literature

Summary: Denosumab is a human monoclonal antibody representing a novel therapy of osteoporosis. Contrary to always other antiosteoporotic drugs, it is not contraindicated in advanced chronic kidney disease, as its pharmacokinetic does not differ from patients with normal kidney function. However, published case reports in chronic kidney disease (CKD) patients stopped the therapy after single dose because of hypocalcemia. We present a case of successful treatment of osteoporosis in a young hemodialysis patient with repeated denosumab doses.Key words: Denosumab; Bone density; Hemodialysis; Hypocalcemia; Parathormone Introduction Denosumab is a full length human monoclonal antibody binding to the receptor activator of nuclear factor kappa-B ligand (RANKL), mimicking the action of osteoprotegerin (OPG, natural decoy receptor of RANKL) and representing a novel therapy of osteoporosis, approved by FDA in 2010 (1). By its action on RANKL, denosumab reduces the sig-nal that is essential for osteoclasts formation, maturation, function and survival. RANKL inhibition has no effect on osteoblasts. Denosumab is not cleared by the kidneys. In chronic kidney disease (CKD) dose adjustment of denosumab is not required but calcium and vitamin D supplementation is strongly recommended (2). So far, only few case reports or very limited case series describing the experience with denosumab in CKD have been published. They all stopped the therapy after single dose because of hypocalcemia (3, 4, 5, 6, 7, 8) (Table 1).We present a case of successful treatment of osteoporosis in a young hemodialysis patient with repeated denosumab doses.