Impact of Pharmacogenomic Testing in Pediatric Heart and Kidney Transplant

Pediatric solid organ transplantation is a complex process including a tightly orchestrated medication regimen, essential for prevention of infection, rejection, graft failure, and mortality. Pharmacogenomic (PGx) testing tailors medication therapy to the individual patient, focusing on safety, efficacy, and avoidance of adverse effects. Implementation of PGx panel results into clinical practice for pediatric transplant patients has not been evaluated.

Pediatric patients evaluated for heart, kidney, or combined heart-kidney transplant at a tertiary children's hospital from October 2021 to October 2023 received PGx panel testing.

Report the prevalence of actionable PGx variants for key genes impacting pharmacotherapy in pre- and post-heart and kidney transplant populations.

A total of 73 patients were included, predominately white (84.9%) and male (64.4%), with a mean age of 8.8 ± 6.4 years. Indications for PGx testing included evaluation for heart transplant (38.4%), kidney transplant (38.4%), combined heart-kidney transplant (4.1%), or to inform posttransplant care (19.2%). All patients had at least one actionable phenotype identified. 37 of 73 patients (50.7%) had at least one actionable phenotype for the transplant-specific genes captured including CYP3A5, SLCO1B1, G6PD, TPMT, prothrombin (Factor 2), and Factor V Leiden. 16 of 73 patients (21.9%) had actionable CYP3A5 phenotypes. 15 of 73 (20.5%) had actionable SLCO1B1 phenotypes. 9 of 73 patients (12.3%) had actionable TPMT phenotypes. 5 of 73 (6.8%) had Prothrombin or Factor V Leiden variants.

Routine pretransplant PGx testing provided information that was actionable and could be utilized to optimize posttransplant medications for all patients.