Sirolimus: a single center experience in combination with calcineurin inhibitors

A retrospective survey was performed to establish patient and graft outcome for all 41 patients at our centre receiving sirolimus (SRL) in combination with calcineurin inhibition (CNI) as primary therapy for the 6 years prior to March 2002. Patient mortality [12%; n = 5 (TTP, lymphoma, mucormycosis, and small bowel perforation] was significantly higher at 3 months compared with those not receiving SRL, but not thereafter. 12.8% had delayed graft function and 33% had one or more episodes of rejection in the first 6 months. Mean GFR at 12 months was significantly lower (47.3 mL/min) in the SRL group compared with those not receiving SRL (51.3 mL/min). Twenty-two patients had a 12-month protocol biopsy; CNI toxicity was present in 36%. SRL was associated with significant hyperlipidaemia (serum cholesterol, 5.2 +/- 1.4 at baseline vs 7.3 +/- 1.7 mmol/L at 3 months, P <.001; triglycerides, 2.3 +/- 1.4 at baseline vs 2.7 +/- 1.1 mmol/L at 3 months, P <.05). Mild thrombocytopenia occurred in 23% but was not associated with haemorrhagic events. LDH increased by 62%, remaining elevated out to 2 years post engraftment. Seven patients developed insulin requiring diabetes mellitus, similar to the rate observed in our general transplant population.Thus, in this early experience, SRL in combination with CNI was associated with significant mortality and morbidity including CNI toxicity, presumably a reflection of a heavy burden of immunosuppression. However, 1-year graft survival on SRL was similar to the mean Australia-wide graft survival regardless of immunosuppression. The future use of SRL may center around CNI sparing and avoidance type protocols.