Case Presentation: The patient is a 58-year-old male with a past medical history of end-stage liver cirrhosis status post-liver transplantation in 1991 who was on tacrolimus (TAC) 1 mg twice a day. He was admitted for altered mental status, fever and respiratory distress. He was found to have bilateral pneumonia treated as community-acquired pneumonia. The patient was intubated due to acute hypoxic respiratory failure. In the meanwhile patient also has developed thrombocytopenia and acute kidney injury with leukocytosis and anemia. Liver enzymes were normal, peripheral blood smear did not show schistocyte to suggest acute hemolysis and thrombotic thrombocytopenic purpura (TTP) was ruled out. High-resolution CT of the chest without contrast revealed new extensive bilateral ground-glass and consolidative opacification compatible with multifocal pneumonia or severe ARDS with FiO2/PaO2 78. PCP was ruled out by bronchoscopy and the Fungitell Glucan Assay test was negative. Bronchoalveolar (BAL) cytology and culture were negative. All the blood cultures were negative. The patient developed oliguric acute tubular necrosis and metabolic acidosis compatible with TAC induced nephropathy, treated with 3 sessions of hemodialysis. Despite the aggressive treatment of ARDS with mechanical ventilatory support and antibiotherapies, his respiratory status couldn’t improve. On the day of twelve of admission, the TAC level was at the therapeutic level, TAC was discontinued due to possible TAC-induced interstitial pneumonitis and ARDS. The treatment with intravenous methylprednisolone initiated. Respiratory status dramatically improved within a few days, we were able to successfully extubate the patient. After the day of eighteen, we switched intravenous methylprednisolone to per-oral prednisone treatment and tapered gradually within 10 days. On the day of twenty of admission, we were able to discharge the patient with a complete resolution. These findings suggested that TAC-induced lung injury is mainly reversible.
Discussion: Tacrolimus (TAC) is an immunosuppressant medication usually given after organ transplants. It is also used as a disease-modifying ant rheumatic drug (DMARD). TAC is well known to cause hypertension, diabetes mellitus, seizure, confusion, kidney problems however, only a few cases of severe lung injury related to TAC administration have been reported in the current literature. We describe a case of interstitial pneumonitis and near-fatal acute respiratory distress syndrome (ARDS) case related to TAC toxicity.
Conclusions: In conclusion, here we reported the case of TAC-induced severe ARDS and interstitial pneumonia presented with near-fatal respiratory failure. Until now, there have been only a few reports of TAC- induced severe lung injury. Considering the catastrophic complication of respiratory failure and reversibility of nature, it is important to consider the dose reduction or cessation of TAC if severe ARDS and interstitial pneumonitis are detected during the administration of this agent.