Reduction of immunosuppressant therapy requirement in heart transplantation by calcitriol.

Calcitriol has been shown to have immunomodulatory effects. We examined whether heart transplant recipients, randomly assigned to receive calcitriol to reduce bone loss, required less immunosuppressive therapy or demonstrated different rejection and survival outcomes. Patients receiving low-dose calcitriol required substantially lower cumulative doses of cyclosporin (29% [95% confidence interval; 8%-50%] and 28% [7%-50%] for 1 and 2 years, respectively) for organ rejection without any detectable change in episodes of rejection, infection, or deaths. This major reduction of oral cyclosporine requirement, in addition to the skeletal benefits of calcitriol in those receiving immunosuppressive therapy, indicates a potential role for co-therapy with calcitriol or its analogues in the management of patients with solid-organ transplantation.