SIROLIMUS ASSOCIATED INTERSTITIAL PNEUMONITIS IN A RENAL TRANSPLANT PATIENT: IS ITAHYPERSENSITIVITY RESPONSE?

Abstract

Sirolimus is a maintenance immunosuppressive agent after renal transplantation. Interstitial pneumonitis due to sirolimus which had no identified infectious etiology has been recently reported. We describe a case of recurrent sirolimus associated interstitial pneumonitis after renal transplantation, on the basis of its mechanism of action. The diagnosis of sirolimus-associated pulmonary toxicity was made after an exhaustive work-up to exclude infectious causes and other pulmonary disease. Sirolimus discontinuation resulted in clinical and radiologic improvement of interstital pneumonitis within 2 weeks. The precise etiology underlying sirolimus-induced pneumonitis remains unknown. However, observations in animals and humans indicate that this agent may cause lung injury in selected cases via differential regulation of the Th1/Th2 lymphocyte balance. We thought that bronchoalveolar lavage cell counts may provide some information about the mechanism of sirolimus-induced pneumonitis.