Sirolimus induced granulomatous interstitial pneumonitis

Objectives: Report a case of sirolimus induced granulomatous pneumonitis. Background: Sirolimus is used in clinical transplantation as an immunosuppressive agent. Pulmonary toxicity does occur, but only a few cases of sirolimus associated granulomatous interstitial pneumonitis have been reported. Methods: Case report and literature review. Results: This 53-year-old woman with ESRD from polycystic kidney disease status post deceased donor kidney transplantation presented with fever, progressive dyspnea, and hypoxia for two weeks. She had been switched to sirolimus two months before admission. A CT scan of the chest revealed bilateral ill-defined patchy ground glass opacities. Extensive investigations were negative for infection. Video-assisted thoracoscopic biopsy showed granulomatous interstitial pneumonitis. Her symptoms and infiltrates resolved after sirolimus discontinuation and corticosteroid treatment. Conclusions: Drugs induced pneumonitis should always be considered in transplant patients after infectious or other etiologies have been excluded. Sirolimus can cause granulomatous infiltrates in the lung possibly secondary to T-cell mediated hypersensitivity.