Comparative effects of alfacalcidol and parathyroidectomy with vitamin D in hyperparathyroid renal bone disease

Parathyroidectomy is now rarely undertaken for hyperparathyroid bone disease in chronic uraemia unless treatment with 1 alpha-hydroxylated vitamin D3 derivatives is unsuccessful. However, no comparisons have been reported of the use of parathyroidectomy with 1 alpha-hydroxylated vitamin D3 derivatives in patients with bone disease of comparative severity. We studied 14 uraemic patients on maintenance haemodialysis treatment before and after treatment with 1 alpha-hydroxyvitamin D3 (alfacalcidol) and compared the findings with those from 12 patients studied before and after parathyroidectomy followed by treatment with vitamin D. The initial severity of the bone disease in the two groups was similar as judged by biochemical, radiographic and histological findings. Both groups demonstrated significant falls in plasma alkaline phosphatase (p less than 0.005) and healing of radiographic erosions after treatment. The histological changes in bone, however, were more marked in patients after parathyroidectomy. Significant reductions were observed in the active osteoblastic surface (p less than 0.005), the total resorption surface (p less than 0.05), the active resorption surface (p less than 0.02) and the index of marrow fibrosis (p less than 0.001), but these indices did not change significantly in the alfacalcidol-treated patients. We concluded that the responses to alfacalcidol in bone are less complete than those obtained with parathyroidectomy despite similar biochemical and radiographic responses.