Abstract
Calcitriol, 1, 25(OH)2D3 (1, 25D3) modulates several neutrophil and monocyte functions in vitro, including phorbol myristate acetate (PMA)-induced superoxide production (SOP), HLA-DR (DR) expression, and phagocytic activity. We therefore investigated SOP and phagocytic activity using peripheral blood neutrophils and DR expression using peripheral blood CD14+ monocytes from 12 patients on periodic hemodialysis (HD), before and after oral treatment with 1, 25D3 (5μg twice a week). Both SOP by neutrophils and DR expression by monocytes were significantly higher in HD patients than in the normal control group (p<0.001 and p<0.05, respectively). Phagocytic activity by neutrophils in the HD patients was slightly reduced but not significantly different from that in the normal control group.
1, 25D3 therapy resulted in a marked increase in plasma 1, 25D3 level (>200pg/ml) within 4 hours after treatment. After 3 days of treatment, DR expression by monocytes was significantly reduced (p<0.01). Treatment slightly enhanced PMA-induced SOP, but the effect was not significant. Phagocytic activity by peripheral blood neutrophils was not significantly affected by treatment. These findings suggest that 1, 25D3 has a role in the regulation of monocytic function in HD patients.
