Effect of CYP3A5*1 expression on tacrolimus required dose for transplant pediatrics: A systematic review and...

Area of Science:

• Pharmacogenomics
• Transplantation Medicine
• Pediatric Nephrology

Background:

• Tacrolimus is a crucial immunosuppressant post-transplantation.
• Individual responses to tacrolimus vary significantly.
• CYP3A5*1 genotype influences tacrolimus metabolism and required dosage.

Purpose of the Study:

• To determine the optimal tacrolimus dose in pediatric patients based on CYP3A5*1 genotype.
• To perform a meta-analysis comparing tacrolimus dosing and concentrations between CYP3A5*1 expressers and non-expressers.
• To evaluate the potential of genetic profiling for rapid, individualized tacrolimus dose prediction.

Main Methods:

• Systematic literature search of PubMed, Scopus, Web of Science, ProQuest, Cochrane Library, and ClinicalTrials.gov.
• Meta-analysis of data from 11 studies involving 596 pediatric transplant recipients.
• Extraction and analysis of tacrolimus dose, blood concentration, and concentration-to-dose ratio at 14 time points post-transplantation.

Main Results:

• Significant differences in tacrolimus dose, blood concentration, and C/D ratio were observed between CYP3A5*1 expressers and non-expressers.
• A higher tacrolimus dose (approximately 0.06 mg/kg/day) may be required for expressers to achieve similar blood levels as non-expressers.
• Therapeutic drug monitoring (TDM) for tacrolimus dose adjustment currently takes approximately one month for stabilization, increasing risks.

Conclusions:

• CYP3A5*1 genotype significantly impacts tacrolimus pharmacokinetics in pediatric transplant recipients.
• Pre-treatment genetic profiling can facilitate rapid and accurate prediction of individual tacrolimus dosage requirements.
• Genotype-guided dosing strategies can potentially minimize the time to achieve therapeutic tacrolimus levels, reducing risks of rejection or toxicity.