Assessment of clinical utility of the whole parathyroid hormone assay ( 184 PTH ) in patients with end-stage renal disease on maintenance dialysis

KDIGO group does not recommend the use in everyday practice the determination of serum PTH by the third generation assay (1-84 PTH). No optimum values of serum 1-84 PTH have been established in dialysis patients. We assessed if the proposed interpretation of 1-84 PTH results allows, in a different way than intact PTH (iPTH) assay, to evaluate the mineral and bone disorders (MBD) in this group of patients. Eighty-nine dialysis patients underwent single measurements of iPTH and 1-84 PTH. According to the KDIGO guidelines, iPTH levels were classified as low, optimum and high. The 1-84 PTH results were arbitrarily divided using the same principle, and the patients were compared according to an adequate PTH value range. Seventyeight out of 89 subjects (87.6%) were classified within the same range of iPTH and 1-84 PTH levels (all 17 with low iPTH). In 11 patients there was a value range shift to a lower group (from high to optimum in 6 and from optimum to low in 5 patients). They did not differ from the remaining subjects as to their clinical conditions nor biochemical results. Interpretation of 1-84 PTH values in the same way as iPTH (low, optimum and high) does not provide any significant contribution in assessment of MBD in the dialysis patients, particularly those with a low iPTH. It did not allow any other interpretation of MBD in patients, who, with absent clinical manifestations, were found to have high iPTH levels.