Abstract
Renal transplantation is the treatment of choice for patients with end-stage renal disease. While transplantation improves the quality of life and reduces the mortality risk for most patients when compared with maintenance dialysis, it introduces significant morbidity associated with induction and maintenance immune suppression. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, is frequently used as a second-line maintenance immunosuppressive agent in solid organ transplant recipients. Sirolimus may, however, have adverse vascular effects and has previously been shown to induce endothelial cell dysfunction and impaired nitric oxide production in vitro. Sirolimus-eluting coronary artery stents have been associated with rare reports of severe coronary artery vasospasm; however, systemic sirolimus therapy has not previously been associated with vasospastic complications.