Aluminium is measured to check for aluminium toxicity in patients who are undergoing dialysis.It is used for routine aluminium screening in patients with renal failure who are unable to naturally excrete aluminium from the body, but it’s most common use is in monitoring of patients with metallic prosthetic implant wear e.g hip replacements.
Under normal physiologic conditions, the usual daily dietary intake of aluminium (5-10 mg) is completely eliminated. Excretion is accomplished by filtration of aluminium from the blood by the glomeruli of the kidney. Patients in renal failure (RF) lose the ability to clear aluminium and are candidates for aluminium toxicity.If it is not removed by renal filtration, aluminium accumulates in the blood, where it binds to proteins such as albumin and is rapidly distributed through the body. Aluminium overload leads to accumulation of aluminium at two sites: brain and bone. Brain deposition has been implicated as a cause of dialysis dementia. In bone, aluminium replaces calcium at the mineralization front, disrupting normal osteoid formation.
Deposition of aluminium in bone also interrupts normal calcium exchange. The calcium in bone becomes unavailable for resorption back into blood under the physiologic control of parathyroid hormone (PTH) and results in secondary hyperparathyroidism.While PTH is typically quite elevated in RF, two different processes may occur:
- High turnover bone disease associated with high PTH (>150 pg/mL) and relatively low aluminium (60 ng/mL).
- Low turnover bone disease indicates aluminium intoxication.
Normal values are: 0 – 15 µg/L
Serum: Blood sample collected in white-top Z-10 tube provided by dialysis centre.