关键词:
tacrolimus
pharmacokinetics
pharmacogenetics
immunogenetics
acute rejection
kidney function
摘要:
Tacrolimus (TAC) is the mainstay of current immunosuppressive therapy following kidney transplantation. However, TAC pharmacokinetics (PK) are highly variable and excessive high and low whole blood trough TAC concentrations (TAC C0) have been associated with toxicity and acute rejection, respectively. Therefore, therapeutic drug monitoring (TDM), targeting TAC C0 between 5-15 ng/mL or a slightly varied range, has been adopted in most transplant centres to maximise immunosuppression and minimise toxicity. Nonetheless, a TAC C0-rejection relationship has not been adequately shown under TDM. In addition, TAC pharmacogenetic (PGx) and innate immunogenetic studies reported conflicting findings (except for CYP3A5*3) regarding their impact on dose-adjusted TAC C0 (TAC C0/D), acute rejection and kidney function. Therefore, this thesis hypothesised that: 1) TAC dispositional genes would affect TAC C0/D inter-individual variability, biopsy-proven acute rejection (BPAR) and estimated glomerular filtration rate (eGFR); 2) there would be a temporal relationship between TAC C0 and BPAR; and 3) innate immunogenetics would predict BPAR incidence. Chapters 2 and 3 investigated if CYP3A4/5, POR, ABCB1 and NR1I2 genetics affect TAC C0/D inter-individual variability, BPAR and eGFR in a retrospective cohort of 165 Australian kidney transplant recipients in the first 3 months post-transplantation. CYP3A5 expressors (*1/*1 + *1/*3) (P = 5.5×10-16) and ABCB1 61G allele carriers (P = 0.001) had lower log-transformed TAC C0/D (56% and 26% lower geometric mean TAC C0/D, respectively) and accounted for approximately 30% and 4%, respectively, of log 10-transformed TAC C0/D variability in the first 3 months post-transplantation. However, CYP3A4, POR and NR1I2 genotypes did not significantly affect TAC C0/D. In addition, none of these TAC PK genes significantly affected BPAR incidence in the first 14 days, or eGFR in the first 3 months, post-transplantation. Notably, an incidental finding was tha