Distribution of aluminium between plasma and erythrocytes

It is common use to monitor body burdens of toxic trace metals by measuring concentrations in whole blood. To monitor aluminium (Al) body burden in renal patients on haemodialysis, which is a high-risk group for Al poisoning, the concentrations of Al in plasma (AlP) or serum (AlS) are determined rather than Al in whole blood (AlB). To evaluate this custom, which exists in clinical laboratories, an investigation was made into the distribution of Al between the plasma and the blood-cell compartment and on the extent of binding of Al to the blood cells both in rats and in dialysed patients. The results show that Al is distributed between plasma and blood cells with only very small quantitative differences, that binding of Al to blood cells is very weak and that AlP and AlB have similar prognostic value for toxicity.