Case 6:
A 21-year-old male with CF (F508del/F508del/Y301C) status post liver
transplant in 2009 for CFLD. He was initially managed with
corticosteroids and tacrolimus and then transitioned to tacrolimus
monotherapy with a goal trough of 3-5 ng/mL. Since transplant, all
transplant related labs have been remained within acceptable ranges. He
has not had any episodes of rejection. His baseline best ppFEV1 during
2019 was 77%. In December 2019, he started full dose elx/tez/iva.
Baseline LFTs, bilirubin, and a tacrolimus trough were obtained prior to
the start of therapy and were WNL. LFTs were repeated one week and two
weeks after starting therapy and remained WNL. His tacrolimus
concentration after one week was 3.3 ng/mL (goal: 3-4 ng/mL) and was not
repeated after two weeks due to stability. Labs were then spaced to
three months after the start of therapy and again remained stable WNL
including a tacrolimus of 3.6 ng/mL. During therapy, he experienced a
change in stool patterns including constipation and loose stools;
however, this was difficult to differentiate from baseline stool issues.
He also noted sometimes feeling more fatigued than previous in the
evenings. Overall, since starting therapy his baseline cough diminished
and respiratory symptoms improved though without marked change to
ppFEV1 which remained at 78%.