Aluminum bone content in dialysis osteodystrophy with secondary hyperparathyroidism

To assess whether parathyroid hormone (PTH) has any effect on bone aluminium (A1) accumulation, we evaluated the relationship between bone quantitative histomorphometry and bone A1 content in 25 dialysis patients with clinical features of secondary hyperparathyroidism. By means of bone biopsy, patients were classified as showing predominant hyperparathyroidism in 17 cases and mixed lesions in 8. The A1 burden was low, judging from the dialysate A1 and the oral A1 assumption. Bone A1 content and serum A1 levels were higher than normal in both groups, particularly so in the patients with predominant hyperparathyroidism. Significant positive correlations were found between bone indexes of hyperparathyroidism and bone A1 content. Moreover, bone and serum A1 concentrations were directly related. Aluminium staining appeared faintly positive only in a minority of bone samples, and was mainly localized at the neutral bone surfaces. We conclude that in dialysis osteodystrophies with features of secondary hyperparathyroidism and in a clinical setting characterized by low-grade A1 burden, PTH may favour A1 accumulation into the bone.