Impact of donor-recipient height and age mismatches on long-term graft survival in pediatric kidney transplants: a retrospective study.

BACKGROUND

Pediatric kidney transplant recipients face a lack of size-matched donors. Optimal donor-recipient differences in age, height, and weight remain unclear. This study evaluated associations between these anthropometric differences and estimated glomerular filtration rate (eGFR) over time.

METHODS

We retrospectively analyzed 45 pediatric living donor kidney transplant recipients (2014-2019) at Ege University Medical Faculty Children's Hospital. Donor-recipient age, height, weight, and body mass index (BMI) differences were recorded. eGFR was measured at 1, 3, and 5 years posttransplant. Data on human leukocyte antigen mismatch, rejection, infection, dialysis duration, and primary disease were collected. Univariate and multivariable analyses (linear mixed-effects and logistic regression) assessed factors associated with graft function.

RESULTS

Univariate analysis showed donor-recipient height difference correlated positively with 1-year (ρ=0.363, P=0.045) and 5-year eGFR (ρ=0.50, P=0.009). Age difference correlated negatively with eGFR, peaking at 5 years (ρ=-0.41, P=0.011); weight difference was nonsignificant. Multivariable modeling showed age difference marginally associated with lower eGFR over time (β=-1.03, P=0.052), while a higher donor-to-recipient BMI ratio predicted higher eGFR (β=+43.11, P=0.024). Logistic regression linked height difference to higher odds of 5-year eGFR <60 mL/min/1.73 m2, whereas a larger body surface area ratio reduced these odds.

CONCLUSIONS

Donor-recipient age difference and body size-related measures showed trends toward association with long-term eGFR in pediatric living donor kidney transplant recipients. However, findings were inconsistent across models. These results are hypothesis-generating and should be interpreted cautiously, warranting larger pediatric studies of donor-recipient age and size matching in long-term graft function.