Background: Sirolimus is a powerful immunosuppressive drug which is being used increasingly after liver transplantation because of its renal sparing and anti-tumour effects. It has been associated with uncommon, but potentially fatal, interstitial pneumonitis.
Aim: To determine the frequency and outcome of sirolimus-associated pneumonitis following liver transplantation.
Methods: Retrospective study in an adult liver transplant centre.
Results: We identified five patients with siromimus-associated pneumonitis, three of whom were transplanted at our centre. Between 1999 and 2008 a total of 522 liver transplants were performed, in our unit, and 45 patients were switched from calcineurin inhibitors to sirolimus. Three of these 45 patients subsequently developed pneumonitis (6.7%). The most common presenting symptoms were cough and dyspnea. The duration of use of sirolimus before diagnosis of pneumonitis varied between 4 and 16 months. Trough serum sirolimus levels were elevated in 3/5 patients with pneumonitis. Sirolimus was withdrawn in all five patients with complete resolution of symptoms and radiological findings.
Conclusions: Pneumonitis is a relatively common side effect of sirolimus in liver transplant patients and can occur despite normal therapeutic blood levels. It is reversible on stopping the medication. Early recognition is important to prevent unnecessary investigations and prolonged morbidity.