[Sirolimus associated pneumonitis in a hematopoietic stem cell transplant patient]

Sirolimus (SR) is a lipophilic macrocytic lactone with immunosuppressive properties (mTOR inhibitor) commonly used in solid organ transplantation and recently introduced in the prophylaxis and treatment of graft-versus-host disease. Its numerous side effects include: hyperlipidemia, arthralgias, noncardiac peripheral edema, thrombotic microangiopathy and interstitial pneumonitis. SR-associated pneumonitis is a rare but potentially serious complication due to its increasing utilization in transplant patients.

We report the case of a patient undergoing hematopoietic stem cell transplantation with severe respiratory distress and SR therapy.

Microbiological tests were all negative and other complications related to transplantation were discarded. The chest computed tomography of high-resolution showed pneumonitis. The SR therapy was interrupted and treatment was started with steroids with resolution of symptoms.

SR associated pneumonitis is a potentially fatal side effect. In patients treated with SR and respiratory failure, we must suspect this complication because early recognition along with drug discontinuation and steroid treatment is essential to reverse this complication.