Assessment of calciprotein particle formation by AUC of the absorbance change: effect of FYB-931, a novel bisphosphonate compound.

OBJECTIVE: Ectopic calcification such as vascular calcification, involves the formation of calciprotein particle (CPP), that is, colloidal particle of calcium phosphate bound to serum protein. In this study, a novel parameter for CPP formation was introduced, thereby the effect of FYB-931, a bisphosphonate compound was evaluated. METHODS: CPP formation in rat serum was assessed by the area under the curve (AUC) of the change in absorbance over time, and the commonly used T50, as indices. In vivo, the rats were treated with vitamin D3 to induce vascular calcification and then intravenously administered FYB-931 or etidronate thrice weekly for 2 weeks. KEY FINDINGS: In vitro, FYB-931 was the most potent inhibitor of CPP formation and it also inhibited the maximum response of CPP formation at higher concentrations. The AUC of the change in absorbance provided obvious dose-dependency, while T50 did not. FYB-931 dose-dependently prevented aortic calcification in vivo as well as CPP formation ex vivo more potently than etidronate. AUC showed a stronger correlation with the degree of aortic calcification than T50. CONCLUSIONS: The AUC in CPP formation can be an alternative parameter that reflects calcification. Based on the findings, FYB-931 has potential as an anti-calcifying agent.

National haemodialysis guidelines: an assessment of compliance from 2001-2003.

AIM: The Caring for Australians with Renal Impairment (CARI) clinical practice guidelines were established in 2000 to provide recommended ranges for parameters associated with anaemia management in patients with chronic kidney disease. This study used data from the Renal Anaemia Management (RAM) database to determine the level of compliance with the CARI Guidelines in Australia since their implementation. METHODS: De-identified data from haemodialysis patients at 15 dialysis centres were obtained from the RAM database provided by Janssen-Cilag Pty Ltd, Australia. Validated data were extracted over 6 months (April-September) in 2001 (n = 2586 patients) and 2003 (n = 3190 patients). The percentage of patients with biochemical and haematological parameters that were within the ranges recommended in the CARI Guidelines was compared from 2001-2003. RESULTS: There was a significant increase in the number of patients with values within the recommended ranges for serum ferritin, phosphate, calcium phosphate product and urea reduction ratio from 2001-2003. There was no change in the proportion of patients with values within the recommended ranges for haemoglobin, transferrin saturation, calcium or parathyroid hormone. There was considerable variation in compliance with recommended ranges between and within individual dialysis centres. Compliance to the target haemoglobin level (> or =110 g/L) ranged from 42-78% of patients at different centres in 2003. CONCLUSION: Although the number of patients with values within those recommended in the CARI guidelines has increased for some parameters, many patients in Australia have clinical parameters outside the ranges recommended in the CARI Guidelines.