Lymphedema: an unusual complication of sirolimus therapy.

INTRODUCTION: Lymphedema is an increasingly observed complication of sirolimus (SIR) therapy. In this report, we describe four renal recipients with SIR-induced lymphedema of varying severity. CASES REPORTS: Patient 1, a 38-year-old man developed lymphedema of the left upper limb after being exposed to SIR for 30 months (mean daily Rapamune dose, 3 mg; trough level, 10-18 ng/mL). Venography and duplex ultrasound were normal. Lymphangiography was showed delayed lymphatic drainage. SIR was replaced with Prograf with significant improvement in the lymphedema over the next 6 months. Patient 2, a 26-year-old woman, developed lymphedema of the left lower limb at 24 months after starting SIR (mean daily dose, 3 mg; trough level, 10-15 ng/mL). Lymphangiography showed delayed drainage of lymphatics in the left lower limb. The patient was shifted to Prograf and there was some improvement over the next 4 months. Patient 3, a 28-year-old man, developed lymphedema of the left upper limb at 24 months after the start of SIR (mean daily dose, 2 mg, trough level, 6-15 ng/mL). Lymphangiography showed evidence of lymphatic obstruction. SIR was changed to cyclosporine with only mild improvement in lymphedema over the next 6 months. Patient 4, a 46-year-old man, developed lymphedema of the right upper limb at 7 months after starting SIR (mean daily dose, 6 mg; trough level, 10-16 ng/mL). Lymphangiography showed complete blockage of the lymphatic channels. SIR was changed to cyclosporine and there was mild improvement in lymphedema over the next 8 to 10 months.
CONCLUSION: The exact mechanism of SIR-induced lymphedema is unknown. The absence of other demonstrable etiologies and spontaneous improvement after discontinuation of SIR suggest that this drug was the responsible factor in these four patients. It occurred 7 to 30 months after transplantation. This is the fourth such report in the literature to the best of our knowledge.