Background: Sirolimus is a potent immunosuppressive drug that has been shown to decrease the incidence of rejection post renal transplantation. Dyslipidemia is a well recognized side effect of sirolimus therapy, which may have an impact on patient survival and post-transplant cardiac morbidity and mortality. It is unknown whether sirolimus-induced dyslipidemia is aggravated by concomitant use of tacrolimus which may also affect lipid profile. To compare sirolimus induced dyslipidemia in tacrolimus based vs. tacrolimus free regimens in renal transplant recipients.
Material/Methods: Patients who received sirolimus post kidney transplantation for at least nine sequential months were included in our retrospective study. Forty-eight renal transplant recipients were divided into 2 groups based on the immunosuppressive regimen; Group 1 received prednisone, sirolimus and mycophenolate mofetil, while Group 2 received prednisone, sirolimus, mycophanolate mofetil and tacrolimus. Lipid profile was assessed pre-transplantation and at one, three, six and nine months post sirolimus therapy.
Results: Both groups showed significant but comparable elevation in total cholesterol, LDL-C and triglycerides with sirolimus therapy. The elevation was evident starting from the first month of sirolimus administration and remained to the ninth month at the end of the follow up period. At first month, mean triglycerides was 2.68 and 2.6 mmol/L (P>0.1) and mean total cholesterol was 6.3 and 5.7 mmol/L in group 1 and 2 (P>0.1); respectively. By the ninth month, triglycerides level was 2.6 and 3.9 mmol/L (P>0.1) while mean total cholesterol level was 6.2 and 6.1 mmol/L (P>0.1) in group 1 and 2 respectively. Lipid-lowering agents and total steroids dose were similar in both groups.
Conclusions: Hypercholesterolemia and hypertriglyceridemia secondary to sirolimus therapy is independent from concomitant tacrolimus use. Lipid-profile should be monitored in all renal transplant recipients receiving sirolimus as early as first month regardless of the immunosuppressive regimen used.

Keywords: Sirolimus, drug-induced dyslipidemia, renal transplant, Tacrolimus