Personalized Prediction of Kidney Function Decline and Network Analysis of the Risk Factors after Kidney Transplantation Using Nationwide Cohort Data.

We developed a machine-learning-based model that could predict a decrease in one-year graft function after kidney transplantation, and investigated the risk factors of the decreased function. A total of 4317 cases were included from the Korean Organ Transplant Registry (2014−2019). An XGBoost model was trained to predict the recipient's one-year estimated glomerular filtration rate (eGFR) below 45 mL/min/1.73 m2 using 112 pre- and peri-transplantation variables. The network of model factors was drawn using inter-factor partial correlations and the statistical significance of each factor. The model with seven features achieved an area under the curve of 0.82, sensitivity of 0.73, and specificity of 0.79. The model prediction was associated with five-year graft and rejection-free survival. Post-transplantation hospitalization >25 days and eGFR ≥ 88.0 were the prominent risk and preventive factors, respectively. Donor age and post-transplantation eGFR < 59.8 were connected to multiple risk factors on the network. Therefore, careful donor−recipient matching in older donors, and avoiding pre-transplantation risk factors, would reduce the risk of graft dysfunction. The model might improve long-term graft outcomes by supporting early detection of graft dysfunction, and proactive risk factor control.

The tacrolimus metabolism affect post-transplant outcome mediating acute rejection and delayed graft function: analysis from Korean Organ Transplantation Registry data.

Tacrolimus is a key drug in kidney transplantation (KT) with a narrow therapeutic index. The association between the tacrolimus metabolism rate and KT outcomes have not been investigated in large-scale multi-center studies. The Korean Organ Transplantation Registry (KOTRY) datasets were used. A total of 3456 KT recipients were analyzed. The tacrolimus metabolism rate was defined as blood trough concentration of tacrolimus (C0 ) divided by the daily dose (D). The patients were grouped into fast, intermediate, or slow metabolizers by the C0 /D measured 6 months after transplantation. The slow metabolism group was associated with a 2.7 ml/min/1.73 m2 higher adjusted estimated glomerular filtration rate (eGFR) at 6 months [95% confidence interval (C.I.) 1.2-4.3, P = 0.001], less acute rejection (AR) within 6 months [Odds ratio (OR) 0.744, 95% C.I. 0.585-0.947, P = 0.016], and less interstitial fibrosis and tubular atrophy [OR 0.606, 95% C.I. 0.390-0.940, P = 0.025]. Fast tacrolimus metabolism affected the 6-month post-KT eGFR through mediation of AR [natural indirect effect (NIE) -0.434, 95% C.I. -0.856 to -0.012, P = 0.044) and delayed graft function (DGF; NIE -0.119, 95% C.I. -0.231 to -0.007, P = 0.038). Slow tacrolimus metabolism was associated with better post-KT eGFR. AR and DGF were found to be significant mediators.

ABO incompatible living donor kidney transplantation in Korea: highly uniform protocols and good medium-term outcome.

The organ shortage is as serious in Korea as in other parts of the world. As about one-third of the potential living donors are ABO incompatible (ABOi), transplantation across the blood group barrier can help overcome this shortage. One hundred and twenty-five ABOi kidney transplantations (KTs) were performed between 2007 and 2010 in Korea. We collected the perioperative and follow-up data for 118 of these patients until September 2011. The preconditioning and immunosuppressive protocols were almost identical across the different transplant centers, with rituximab but no splenectomy; pre-transplant plasmapheresis (PP) with target anti-A/B titer 8 or 16 on transplant day, on-demand, rather than routine, post-transplant PP, and tacrolimus-based immunosuppressants. The number of patients and participating centers showed a rapid increase over time, and in 2010, ABOi KT (n = 79) comprised 10% of all the living donor KTs in Korea. The mean follow-up period was 21 months (range, 1-56 months). Sixteen (14%) patients developed acute rejection, and three of these had antibody-mediated rejection (AMR). Two-yr patient and graft survival were 99.2% and 97.5%, respectively. No graft was lost due to AMR. ABOi KT is rapidly expanding in Korea with excellent medium-term outcome and will help mitigate the organ shortage.

Kidney transplantation after desensitization in sensitized patients: a Korean National Audit.

INTRODUCTION: The number of end-stage renal disease (ESRD) patients with preformed antibodies waiting for a kidney transplant has been increasing lately. We conducted a nationwide study on the outcomes of kidney transplantation after desensitization in Korea. METHODS: Six transplant centers have run desensitization programs. The patients who underwent living donor kidney transplantation after desensitization from 2002 to 2010 were retrospectively analyzed. RESULTS: A total of 86 cases were enrolled. Thirty-five of these were cases of re-transplantation (40.7 %). Indications of desensitization were positive complement-dependent cytotoxicity (CDC) cross-match responses (CDC(+), 36.0 %), positive flow-cytometric cross-match responses (FCX(+), 54.7 %), and positive donor-specific antibodies (DSA(+), 8.1 %). The desensitization protocols used pre-transplant plasmapheresis (95.3 %), intravenous immunoglobulin (62.8 %), and rituximab (67.4 %). Acute rejection occurred in 18 patients (20.9 %), graft failure occurred in 4 patients, and the 3-year graft survival rate was 93.8 %. The presence of DSA increased the acute rejection rate (P = 0.015) and decreased the 1-year post-transplant estimated glomerular filtration rate (P = 0.006). Although rejection-free survival rates did not differ significantly between the CDC(+) and FCX(+) groups, the 1-year estimated glomerular filtration rate was lower in the CDC(+) group (P = 0.010). Infectious and significant bleeding complications occurred in 15.5 % and 4.7 % of cases, respectively. CONCLUSION: Kidney transplantation after desensitization had good graft outcomes and tolerable complications in Korea, and therefore, this therapy can be recommended for sensitized ESRD patients.