INFLUENCE OF ALUMINUM OVERLOAD ON THE COURSE OF POSTTRANSPLANT PARATHYROID FUNCTION

Aluminium intoxication exerts profound effects on secondary hyperparat hyroidism in chronic renal failure and could influence the evolution o f posttransplant parathyroid function. We have evaluated 44 patients a fter successful renal transplantation, sequentially from day 0 up to d ay 90 from the beginning of graft function, determining serum and urin ary aluminium, PTH (intact molecule) and several other parameters of m ineral metabolism. Patients were grouped according to their basal seru m aluminium: Group LA (n=25) had serum aluminium less than 40 mu g/l ( mean 21+/-10 mu g/l), and Group HA (n=19) had serum aluminium greater than 40 mu g/l (mean 100+/-43 mu g/l). This latter group also had grea ter 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 afte r regaining renal function both groups showed a marked decrease in iPT H and then a continued decline up to day 90 with mean serum values of the hormone showing no further differences between groups, The inciden ce of hypercalcaemia was similar in both groups but no patients in Gro up HA developed hypercalcaemia at posttransplant day 7 while 12% in Gr oup LA did so. Urinary phosphate excretion and the incidence of posttr ansplant hypophosphataemia were similar in both groups. These findings suggest: (a) patients with more aluminium intoxication have lower val ues of pretransplant iPTH and they correct parathyroid function in a d ifferent way than non-intoxicated patients in early post-transplant da ys; (b) they have lower and later incidence of hypercalcaemia.