Sirolimus serum level and efficacy.
Serum trough levels of sirolimus were assessed after 1 month of treatment, allowing adaptation of sirolimus doses to reach a serum level ranging between 10 and 15 ng/mL. Among the 18 patients who had transient worsening at 1 month compared with baseline and with available serum level of sirolimus, 9 were below 10 ng/mL and the other 9 were at 10 ng/mL or higher. The serum levels varied between 4.3 and 15.2 ng/mL. In the 69 patients who presented an improvement at 1 month compared with baseline and with available serum level (