Effect of intravenous 1-alpha-hydroxy cholecalciferol on serum parathyroid hormone [PTH] level and T-cell subsets in hemodialysis patients with severe secondary hyperparathyroidism

Chronic renal failure and dialysis are commonly associated with increased liability to infection and abnormal immune reactions. However, the exact definition and pathogenetic mechanisms of such immune dysregulation have remained elusive. The present work has been undertaken to examine the effect of lowering serum parathyroid hormone [PTH] level with 1-alpha hydroxy cholecalciferol [alfacalcidol] injections on the disturbance of T cell subpopulations in chronic renal failure patients having severe hyperparathyroidism. Twenty-two chronic renal failure patients maintained on regular hemodialysis therapy completed the 3-month period of the study. All had a starting serum PTH level> 1000 pg/ml. Patients with diabetes mellitus, liver disease, chronic infections, hypercalcemia or marked hyperphosphatemia were excluded. During the study period, alfacalcidol [One-Alpha] 2-4 mcg were injected intravenously at the end of each dialysis session 3 times per week. Routine biochemistry and blood count as well as serum PTH were examined monthly. At the start- and end-points of the study, total lymphocytic count and T cell subpopulations were analyzed utilizing monoclonal antibodies against the surface markers CD3, CD4 and CD8 by double-color flow-cytometry technique. The changes in serum PTH and T cell subsets as well as the other routine biochemical parameters were compared at the start- and end points of the study, and the linear association of their degree of change was tested. Serum PTH dropped sign [p