Aluminum
Aluminum is a ubiquitous trace element. The normal daily intake of aluminum is completely eliminated by glomerular filtration in the kidney. Patients with renal failure have an increased risk of developing aluminum toxicity primarily due to aluminum contaminated water used for dialysis and oral administration of aluminum-based phosphate binder gels. Sustained exposure to aluminum can cause severe encephalopathy, iron refractory microcytic anemia and osteomalacia.
National Kidney Foundation guidelines recommend annual serum aluminum testing of asymptomatic patients undergoing chronic dialysis who do not have other risk factors for aluminum toxicity, such as medications. These guidelines further recommend followup testing to access toxicity whenever the serum concentration is between 60 and 200 ng/mL. This involves performing a baseline aluminum measurement and a second measurement collected 2 days after a 5 mg/kg deferoxamine infusion. A 50 ng/mL incremental rise in serum aluminum after deferoxamine infusion is indicative of aluminum toxicity and the need for treatment.
Prosthetic devices produced by a few companies are composed of aluminum, vanadium, and titanium. Patients with these prostheses are likely to have serum aluminum levels increased above the reference range.
Serum aluminum concentration is measured by dynamic reaction cell-Inductively coupled plasma-mass spectrometry (DRC-ICP-MS).Serum reference value is 0-6 ng/mL in healthy individuals. The goal for dialysis patients is to keep serum aluminum concentrations below 60 ng/mL.
Blood must be collected in a metal free vacutainer tube. Environmental contamination of specimens with exogenous aluminum during specimen collection or processing may cause falsely elevated results.
References
McCarthy JT, Milliner DS, Kurtz SB, et al: Interpretation of serum aluminum values in dialysis patients. Am J Clin Pathol 1986;86:629-636.
Schifman RB and Luevano DR. Aluminum Toxicity. Arch Pathol Lab Med 2018;142:742-46.
