SP642DENOSUMAB IN NINE CHRONIC KIDNEY DISEASE STAGE 5D PATIENTS WITH LOW BONE MINERAL DENSITY. A SINGLE CENTER PILOT STUDY

Abstract

Introduction and Aims: To evaluate the effect of Denosumab (DMAb) in bonemineral density (BMD) of HD patients with osteopenia or osteoporosis. Also, to test how DMAb affects biochemical indices of bone metabolism in the same group of patients. Methods: Nine (9) CKD stage 5D patients (five men;mean age 67) with osteopenia or osteoporosis received two doses of 60mg DMAb sc at days 0 and 180. The patients were followed until day 360. BMD at the total hip region was measured twice in every patient (at entry and at day 360) by Dual Energy X-ray Absorbsiometry (DEXA). Inclusion criteria were intact PTH (iPTH)>200 pg/ml, serum calcium (Ca)>8,4mg/dl and serum phosphorus (P)>3,5mg/dl. Also, no intake of vitamin D analogs or calcium supplements. PTH, Ca and P were measured weekly for the first 14 days after each dose and then monthly. BMD change was correlated with demographic and biochemical data. Results: All results were expressed as mean (± standard error) or median (interquartile range) value. One patient was lost at follow up. BMDincreased in seven of the remaining eight patients. Mean BMD at entry was 0,717gr/cm2 (± 0,043) and after the treatment period it raised to 0,762gr/cm2 (± 0,045). Mean BMD increase was 0,044gr/cm2 (± 0,015) (t-test, p=0,026). The percentage change was +6,47% (± 2,36). A great increase in iPTH levels was observed after the first dose of DMAb accompanied with a high decrease in serum Ca and a proportionate decrease in serum P.Maximum iPTH levels andminimum Ca levels were observed at day 14 (1085pg/ml and 7,6mg/dl respectively). There was a need for addition of vitamin D analogs and calcium supplements in patients' regimen after the first dose. PTH and Ca levels returned to initial values by day 120. Study protocol had to change before the second dose of DMAb (all patients were administered vitamin D analogs and calcium supplements in low doses). Modest changes in iPTH and Ca levels were observed after the second dose. The magnitude of increase in BMD was significantly correlated with maximum iPTH increase after the first dose (pearson, p=0,049). Conclusions: Administration of DMAb in HD patients with osteopenia or osteoporosis resulted in significant increase of BMD. Decline in serum Ca and increase in iPTH levels were observed. Vitamin D analogs and calcium supplements addition before second DMAb dose seemed to preserve Ca and iPTH levels.