Toxicological aspects of aluminum poisoning in clinical nephrology

Several dialysis-related diseases can be ascribed to an increased body burden of aluminum (Al). Determination of this metal in clinical samples is of great assistance in the diagnosis, treatment and prevention of Al intoxication. As there are many pitfalls in the estimation of Al in biological fluids, the performance of these assays should be restricted to laboratories specializing in the human toxicology of metals, which are experienced in flameless atomic absorption spectrophotometry and which participate in an external quality assessment scheme. One laboratory can serve ten dialysis centers. Serum, plasma or blood are equivalent samples for the biological monitoring of Al. The assay should be performed once in a three month period, but when oral Al-containing medication is changed, toxic symptoms are suspected, or levels exceeding 100 micrograms/l are observed, Al should be determined much more frequently, e.g., once weekly. A high incidence of symptoms associated with Al poisoning is seen in patients with serum concentrations (AlS) greater than 100 micrograms/l, and it is therefore recommended to keep AlS well below this level. Scalp hair appears to be of no use for the assessment of the body burden of Al in the individual patient. For "environmental monitoring", regular analysis of the dialysis fluid is necessary. The concentration of Al in this fluid should not exceed 5 micrograms/l; higher levels lead to a positive Al balance during dialysis and may eventually result in poisoning.