Efficacy of conversion to sirolimus in posttransplantation Kaposi's sarcoma

The increased incidence of Kaposi's sarcoma (KS) in organ transplantation has been related to the KS herpes virus and the permissive effect of immunosuppressive therapy. We postulated that conversion to SRL in renal recipients with KS favored regression of KS lesions without increasing the risk of graft rejection. Methods. In this estudy we performed a retrospective chart review of 7 caucasian renal transplant recipients affected by KS to determine demographic data, etiology of ESRD, immunologic risk factors, immunosuppressive treatment, KS disease follow-up, and renal function before and after SRL conversion. Results. All seven patients were under calcineurin inhibitor treatment at the onset of KS which was limited to the skin, without regression despite attempts to minimize immunosuppression. After conversion to SRL, six patients showed progressive regression of KS lesions, with only hyperpigmented atrophic cutaneous lesions remaining after a mean time of 8.1 months (2-18 months). The seventh patient has completed 9 months follow-up with a near complete regression of KS lesions. One patient returned to hemodialysis after 13 months following irreversible acute renal failure not directly related to SRL conversion; in the other six, renal function was stable. The mean serum creatinine was 1.87 +/- 0.64 versus 1.74 +/- 0.68 mg/dL, pre-conversion versus the end of follow up, respectively. Mean SRL blood level was 9.2 +/- 2.0 ng/mL. Conclusion. After SRL conversion, patients with KS showed progressive regression without an increased risk of acute rejection. SRL offers a promising approach to the management of posttransplantation KS and probably other malignancies in organ transplant recipients.