Influence of aluminium overload on the course of post-transplant parathyroid function

Aluminium intoxication exerts profound effects on secondary hyperparathyroidism in chronic renal failure and could influence the evolution of post-transplant parathyroid function. We have evaluated 44 patients after successful renal transplantation, sequentially from day 0 up to day 90 from the beginning of graft function, determining serum and urinary aluminium, PTH (intact molecule) and several other parameters of mineral metabolism. Patients were grouped according to their basal serum aluminium: Group LA (n = 25) had serum aluminium less than 40 micrograms/l (mean 21 +/- 10 micrograms/l), and Group HA (n = 19) had serum aluminium greater than 40 micrograms/l (mean 100 +/- 43 micrograms/l). This latter group also had greater urinary aluminium excretion during the study period. Evolution of renal function was similar in both groups. Group LA had increased pre-transplant iPTH (353 +/- 416 pg/ml vs 175 +/- 94, P = 0.05). Seven days after regaining renal function both groups showed a marked decrease in iPTH and then a continued decline up to day 90 with mean serum values of the hormone showing no further differences between groups. The incidence of hypercalcaemia was similar in both groups but no patients in Group HA developed hypercalcaemia at post-transplant day 7 while 12% in Group LA did so. Urinary phosphate excretion and the incidence of post-transplant hypophosphataemia were similar in both groups. These findings suggest: (a) patients with more aluminium intoxication have lower values of pre-transplant iPTH and they correct parathyroid function in a different way than non-intoxicated patients in early post-transplant days; (b) they have lower and later incidence of hypercalcaemia.