Longevity Matching for Living Donor Renal Transplantation

INTRODUCTION

This study identifies the effect of individual donor and recipient characteristics on graft survival in living-donor kidney transplantation (LDKT) using a recently described novel measure, kidney life years (KLYs).

MATERIALS AND METHODS

The Organ Procurement and Transplantation Network/United Network for Organ Sharing database was used to identify first-time kidney-only LDKT recipients between 1987 and 2020 who did not experience death with a functioning graft (DWFG) and were not missing relevant information (n = 87,290). Patient characteristics were evaluated using Cox and multiple regression analyses, with the dependent variable being KLYs. An equation for expected KLYs based on patient characteristics was created using regression coefficients. The equation was validated using bootstrapped Pearson correlations and then applied to the DWFG group for comparison.

RESULTS

Based on statistical significance from Cox and multiple linear regression analyses, 9 of the original 18 variables were selected for inclusion in the equation. Variables with notable impact included HLA match points (0.021 KLYs; 95% CI: [0.019,0.024]; P ≤ .001), Donor Age (-0.030 KLYs; 95% CI: [-0.035,-0.025]; P ≤ .001), and Donor African American Ethnicity (-2.356 KLYs; 95% CI: [-2.552,-2.159]; P ≤ .001). Equation validation was supported, given a negative correlation (r = -0.071; P ≤ .001) between expected KLY change and observed graft failure. Expected KLY change was found to be greater in those who eventually DWFG when compared with all other LDKTs (t = -5.735, P ≤ .001).

CONCLUSIONS

Increasing HLA match points may be more beneficial for graft longevity than minimizing donor age in comparisons using realistic between-donor differences. Additionally, greater average expected KLYs in those who ultimately DWFG may illustrate an opportunity for improved donor-recipient matching.

Benefit of Kidney Transplantation for Post Lung Transplantation Renal Failure

INTRODUCTION

Nephrotoxicity is a significant side effect of thoracic transplantation. Many lung transplant patients will require subsequent renal transplantation (KAL). Recently, simultaneous lung/kidney transplants (SLuK) have become an attractive option for patients with end-stage renal disease at the time of lung transplantation. This article explores SLuK outcomes compared to conventional KAL, as well as outcomes among KAL patients against those were KAL listed but never transplanted.

MATERIALS AND METHODS

The United Network for Organ Sharing/the Organ Procurement and Transportation Network database was used to identify SLuK patients (n = 74), KAL transplants (n = 456), and patients who were listed for KAL but were never transplanted (n = 626). Significance was determined by chi², Wilcoxon rank sum test, or independent t-tests. Death-censored graft survival for subgroups was estimated using Kaplan-Meier with log-rank for significance. Analyses were completed using SPSS Statistics 28.

RESULTS

The SLuK cohort was older (P = 0.04), more likely diabetic (P < 0.001), and had shorter life expectancies (P < 0.001) than KAL patients. Of those SLuK transplants within 5 y, 84% of patients were alive 1 y post transplant and 82% were alive 3 y post-transplant (compared to 74.6% and 60.3% of overall SLuK). Patients who did undergo KAL were younger and had a lower body mass index (both P < 0.001) compared to those who did not. Those who received a kidney had increased survival times compared to WL patients (P < 0.001).

CONCLUSIONS

Conventional KAL transplants are still favorable for average lung recipients. However, recent improvements have made SLuK an option for patients with renal dysfunction. Those patients who were able to receive KAL transplants were better surgical candidates than those who remained on the waitlist.