Case 7
A 19-year-old female with CF (F508del and W1282X) status post liver transplant in October 2018 for CFLD. She was initially managed with corticosteroids and tacrolimus and then transitioned to tacrolimus monotherapy with a goal trough of 6-8 ng/mL. Since transplant, all transplant related labs have been remained within acceptable ranges. She has not had any episodes of rejection. Her baseline ppFEV1 in 2019 was 73%. She was initiated on full dose elx/tez/iva at the end of January 2020. Baseline LFTs and bilirubin were WNL and the tacrolimus trough was 7.9 ng/mL. LFTs were repeated 1 week after starting therapy and were WNL. The repeat tacrolimus concertation was 8.8 ng/mL and as it was drawn one hour late which prompted a tacrolimus dosage reduction. No other therapies other than elx/tez/iva were started which could have impacted tacrolimus trough concentrations and she was noted to have no changes in diet or notable illnesses. Additionally, she also had an acute increase in total bilirubin to 1.5 mg/dL which was primarily unconjugated bilirubin of 1.4mg/dL. Repeat labs 1 week later remained WNL including a tacrolimus level of 7.7 ng/mL. Her total bilirubin continued to be elevated with a level of 1.1 mg/dL which remained primarily unconjugated bilirubin of 1 mg/dL. Labs were repeated 1 month after starting elx/tez/iva and all were stable and WNL except for a total bilirubin of 1.3 mg/dL which again was primarily unconjugated. After two months of elx/tez/iva, her labs remained stable and monitoring was spaced to every three months. No other adverse events have been reported. Her ppFEV1 increased to 100% after two weeks of therapy.