Do oral aluminium phosphate binders cause accumulation of aluminium to toxic levels?

HD patients only treated with Reverse Osmosis(RO) treated dialysis water with either current or past exposure to Alucaps were given standardised DFO tests. Post-DFO serum Al level > 3.0 μmol/L was defined to indicate toxic loads based on previous bone biopsy studies.39 patients (34 anuric) were studied. Mean dose of Alucap was 3.5 capsules/d over 23.0 months. Pre-DFO Al levels were > 1.0 μmol/L in only 2 patients and none were > 3.0 μmol/L. No patients had a post DFO Al levels > 3.0 μmol/L. There were no correlations between the serum Al concentrations (pre-, post- or the incremental rise after DFO administration) and the total amount of Al ingested.No patients had unexplained EPO resistance or biochemical evidence of adynamic bone.Although this is a small study, oral aluminium exposure was considerable. Yet no patients undergoing HD with RO treated water had evidence of Al toxicity despite doses equivalent to 3.5 capsules of Alucap for 2 years. The relationship between the DFO-Al results and the total amount of Al ingested was weak (R2 = 0.07) and not statistically significant. In an era of financial prudence, and in view of the recognised risk of excess calcium loading in dialysis patients, perhaps we should re-evaluate the risk of using Al-based phosphate binders in HD patients who remain uric.The importance of preventing hyperphosphataemia is well established and its management is outlined in the bone and mineral metabolism section of the K-DIGO [1]. The evolution of phosphate binder therapy in patients with chronic renal disease has followed an interesting pattern over the past 35 years. Historically, aluminium salts were used to treat hyperphosphataemia, but safety concerns about accumulation and toxic effects including osteomalacia and encephalopathy meant there was a switch to calcium based binders (carbonate or acetate) [2].However, the accumulation of aluminium was found in dialysis patients at a time when haemodialysis was conducted against water that mig