elevated GGT post liver transplantion

my father 57 year old he did liver transplantation 4 years ago because of a mass on his liver which was completely chirrotic due to HCV, he is generally well  but in the last few months his enzymes minimally elevated  ALT 81, AST 50, GGT 99, he did biopsy since 2months which show minimal  perivascular fibrosis and at that time ALT 160,GGT 77 other CE/Lliver function are within normal ranges ,he is on treatment in form of FK dose 1.5 twice daily,CELICEPT 1000 twice daily ,thanks  

[Thomas D Schiano, MD]

he may have mild recurrence of the HCV.  Overall though he sounds like he's doing fairly well