Immunosuppressive treatment advancements have considerably improved acute rejection rates and short-term allograft survival in kidney transplant recipients. However, the accomplishment had not resulted in the same long-term advantages. 

Immunosuppression must be optimized to enhance the clinical outcome of transplant patients. It is vital to remember that each patient is unique, and immunosuppressive therapy should not be one-size-fits-all. Elderly transplant recipients are less likely to experience acute rejection but more likely to die from infectious or cardiovascular reasons than younger patients. Reduced immunosuppression may increase the risk of rejection in patients with post-transplant malignancies and BK polyomavirus-associated nephropathy. Therapeutic drug monitoring (TDM) is a common method for adjusting the dose of numerous immunosuppressive medications. Pharmacogenetics may be used to supplement TDM in optimizing medication exposure. 

Tacrolimus and CYP3A5 are the most promising drug-genotype combinations being studied. Several studies have demonstrated that CYP3A5 expressers require a greater tacrolimus dosage and take longer to attain target blood tacrolimus levels than non-expressers. However, before pharmacogenetics may be routinely employed, further clinical trials are required to establish the therapeutic advantages of genotype-guided dosages, such as reduced rejection and drug-related toxicities. In recent years, the development of many biomarkers may have aided in achieving real customized therapy in transplant patients.

Reference: onlinelibrary.wiley.com/doi/10.1111/nep.14035