Tai Yeon Koo

Kidney donor risk index is a good prognostic tool for graft outcomes in deceased donor kidney transplantation with short, cold ischemic time

We performed a retrospective cohort study to determine the prognostic value of standard criteria donor/expanded criteria donor (SCD/ECD) designation, with regard to one‐yr GFR and graft survival rate, in a region with short, cold ischemic time (CIT), and how this designation compares with the kidney donor risk index (KDRI) and zero‐time kidney biopsies.

Outcomes of combination therapy for chronic antibody-mediated rejection in renal transplantation

Chronic antibody‐mediated rejection (CAMR) in renal transplant patients has poor allograft outcomes. However, treatment strategy has not been established yet. Herein, we present short‐term outcomes of combination therapy for CAMR.

Initial Report of the Korean Organ Transplant Registry: The First Report of National Kidney Transplantation Data

PURPOSE A national organ transplant registry is an indispensable organizational requirement for patient care, research, and planning. Even though the Korean Network for Organ Sharing (KONOS) has established a database for a waiting list, organ allocation, and incidence of organ transplantation since 2000, an integrated registry including post-transplantation data is needed for better understanding of organ transplantation. Recently, the Korean Society for Transplantation (KST) and the Korean Center for Disease Control (KCDC) designed a web-based organ transplant registry, named the Korean Organ Transplant Registry (KOTRY). As an initial project of KOTRY, we retrospectively analyzed kidney transplantations (KTs) performed in 2009 and 2010. METHODS A total of 2292 KTs (91.9%) from 46 hospitals (80.7%) were collected and analyzed. Ninety-five elements related to KT were selected and analyzed. RESULTS Proportions of male recipients and retransplantations were 58.4% and 7.1%, respectively. Even though glomerulonephritis was the most common cause of end-stage renal disease (ESRD) (28.4%), the number of diabetic nephropathy cases was increasing. The living donor (LD) to deceased donor (DD) ratio was 1.69:1. Because of a serious organ shortage in Korea, DD kidneys with a low initial estimated glomerular filtration rate (eGFR) of <45 mL/min/1.73 m(2) (21.2%) and expanded criteria donors (ECDs; 18.3%) are frequently used. Other noticeable findings are the increasing number of wife donors and ABO-incompatible (ABOi) transplants for O(+) recipients. CONCLUSIONS The epidemiological profile of transplantation is different from country to country. The number of organ transplantations in East Asian countries is rapidly growing, however, there are few epidemiological data about this region in the literature. With the establishment of KOTRY, it was possible to present the first nationwide epidemiological data of Korean KTs.

Impact of parathyroidectomy on allograft outcomes in kidney transplantation

We performed retrospective, multi‐center study of the impacts of parathyroidectomy (PTX) after or before kidney transplantation on allograft outcomes. A total of 63 patients who underwent PTX after kidney transplantation were identified. Deterioration in eGFR by more than 25% at 1 month after PTX occurred in 20% of the patients. The baseline eGFR was significantly lower in impairment group than nonimpairment group [adjusted odds ratio (OR) 0.87, 95% confidence interval (CI) 0.77–0.99, P = 0.033]. Low iPTH concentration after PTX was also a significant risk factor for the renal impairment (OR 0.96, CI 0.94–0.99, P = 0.009). A total of 37 patients who underwent PTX before transplantation were identified. Thirty‐six percent of the patients had persistent hyperparathyroidism by 1 year after transplantation. A high iPTH level before PTX was a significant risk factor for persistent post‐transplant hyperparathyroidism (adjusted OR 1.002, CI 1.000–1.005, P = 0.039). Finally, eGFR values during the first 5 years after transplantation were significantly lower in the patients who underwent PTX at less than 1 year after transplantation, than the pretransplant PTX patients (P = 0.032). As PTX after kidney transplantation has a risk of deterioration of allograft function, pretransplant PTX should be considered for patients with severe hyperparathyroidism, who could undergo post‐transplant PTX.

Pre-transplant Evaluation of Donor Urinary Biomarkers can Predict Reduced Graft Function After Deceased Donor Kidney Transplantation.

AbstractSeveral recipient biomarkers are reported to predict graft dysfunction, but these are not useful in decision making for the acceptance or allocation of deceased donor kidneys; thus, it is necessary to develop donor biomarkers predictive of graft dysfunction. To address this issue, we prospectively enrolled 94 deceased donors and their 109 recipients who underwent transplantation between 2010 and 2013 at 4 Korean transplantation centers. We investigated the predictive values of donor urinary neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and L-type fatty acid binding protein (L-FABP) for reduced graft function (RGF). We also developed a prediction model of RGF using these donor biomarkers. RGF was defined as delayed or slow graft function. Multiple logistic regression analysis was used to generate a prediction model, which was internally validated using a bootstrapping method. Multiple linear regression analysis was used to assess the association of biomarkers with 1-year graft function. Notably, donor urinary NGAL levels were associated with donor AKI (P = 0.014), and donor urinary NGAL and L-FABP were predictive for RGF, with area under the receiver-operating characteristic curves (AUROC) of 0.758 and 0.704 for NGAL and L-FABP, respectively. The best-fit model including donor urinary NGAL, L-FABP, and serum creatinine conveyed a better predictive value for RGF than donor serum creatinine alone (P = 0.02). In addition, we generated a scoring method to predict RGF based on donor urinary NGAL, L-FABP, and serum creatinine levels. Diagnostic performance of the RGF prediction score (AUROC 0.808) was significantly better than that of the DGF calculator (AUROC 0.627) and the kidney donor profile index (AUROC 0.606). Donor urinary L-FABP levels were also predictive of 1-year graft function (P = 0.005). Collectively, these findings suggest donor urinary NGAL and L-FABP to be useful biomarkers for RGF, and support the use of a new scoring system based on donor biomarkers to facilitate decision-making in acceptance and allocation of deceased donor kidneys and contribute to maximal organ utilization.

Current progress in ABO-incompatible kidney transplantation

ABO-incompatible kidney transplantation (ABOi KT) was introduced to expand the donor pool and minimize shortage of kidneys for transplantation. Because improved outcomes of ABOi KT were reported in Japan in the early 2000s, the number of ABOi KTs has been increasing worldwide. In addition, a better understanding of immune pathogenesis and subsequent aggressive immunosuppression has helped to make effective desensitization protocols. Current strategies of ABOi KT consist of pretransplant antibody removal using plasmapheresis or immunoadsorption to prevent hyperacute rejection and potent maintenance immunosuppression, such as tacrolimus and mycophenolate mofetil, to inhibit antibody-mediated rejection. Recent outcomes of ABOi KT are comparable with ABO-compatible KT. However, there are still many problems to be resolved. Very high anti-ABO antibody producers are difficult to desensitize. In addition, ABOi KT is associated with an increased risk of infection and possibly malignancy due to aggressive immunosuppression. Optimization of desensitization and patient-tailored immunosuppression protocols are needed to achieve better outcomes of ABOi KT. This review provides an overview of the history, immune mechanism, immunosuppressive protocol, outcomes, current obstacles, and future perspectives in ABOi KT.

Efficacy and safety of hepatitis A vaccination in kidney transplant recipients

In recent years, symptomatic hepatitis A virus (HAV) infection has been reported with increasing frequency in Korea. Therefore, HAV vaccination should be considered in kidney transplant recipients (KTRs). The study investigated the efficacy and safety of HAV vaccination in KTRs under modern triple immunosuppressive agents.

Impact of Combined Acute Rejection on BK Virus-Associated Nephropathy in Kidney Transplantation

BK virus-associated nephropathy (BKVAN) is one of the major causes of allograft dysfunction in kidney transplant (KT) patients. We compared BKVAN combined with acute rejection (BKVAN/AR) with BKVAN alone in KT patients. We retrospectively analyzed biopsy-proven BKVAN in KT patients from 2000 to 2011 at Seoul National University Hospital. Among 414 biopsies from 951 patients, biopsy-proven BKVAN was found in 14 patients. Nine patients had BKVAN alone, while 5 patients had both BKVAN and acute cellular rejection. BKVAN in the BKVAN alone group was detected later than in BKVAN/AR group (21.77 vs 6.39 months after transplantation, P=0.03). Serum creatinine at diagnosis was similar (2.09 vs 2.00 mg/dL). Histological grade was more advanced in the BKVAN/AR group (P=0.034). Serum load of BKV, dose of immunosuppressants, and tacrolimus level showed a higher tendency in the BKVAN alone group; however it was not statistically significant. After anti-rejection therapy, immunosuppression was reduced in the BKVAN/AR group. Renal functional deterioration over 1 yr after BKVAN diagnosis was similar between the two groups (P=0.665). These findings suggest that the prognosis of BKVAN/AR after anti-rejection therapy followed by anti-BKV therapy might be similar to that of BKVAN alone after anti-BKV therapy.

Outcomes of dialysis and the transplantation options for patients with diabetic end-stage renal disease in Korea

The best therapeutic option for diabetic end‐stage renal disease (DMESRD) has not been established among living donor kidney transplantation (LDKT), deceased donor kidney transplantation (DDKT), simultaneous pancreas and kidney transplantation (SPK), and dialysis.

VDJ Gene Usage of B Cell Receptors in Peripheral Blood of ABO-incompatible Kidney Transplantation Patients

INTRODUCTION B cell subtypes and immunoglobulin variable (V), diversity (D), joining (J) gene segment usage of B cell receptors in ABO-incompatible (ABOi) kidney transplantation (KT) in comparison to ABO-compatible KT have not been studied. The aims of this study were to analyze the VDJ gene segment usages of B cell receptors in peripheral blood of ABOi KT recipients. METHODS Eighteen ABOi KT patients with accommodation (ABOiA), 10 ABO-compatible stable KT patients (ABOcS), and 10 ABOi KT patients with biopsy-proven acute antibody-mediated rejection (ABOiR) at day 10 after transplantation were selected. Complete transcriptomes of their peripheral blood samples were sequenced and analyzed through RNA sequencing. RESULTS By family, immunoglobulin heavy chain variable 3 (IGHV3), immunoglobulin light kappa chain variable 1 (IGKV1), immunoglobulin light lambda chain variable 2 (IGLV2), and immunoglobulin light lambda chain joining 3 (IGLJ3) gene segments were most frequently used in all groups, and their usage was not statistically different among the three groups except for IGHV3 and IGKV1. IGKV1 was more frequently used in the ABOiA group than in the ABOcS group. According to individual gene segments, IGHV3-7, IGHV3-15, IGHV4-59, IGKV3-11, IGLV1-44, IGLV2-14, IGLV4-69, and IGLV7-46 were more frequently used in the ABOcS group than other groups, and IGKV3-7 was more frequently used in the ABOiR group than other groups. IGLV5-52 and IGLV7-43 were more frequently used in the ABOiA group than in ABOcS group. CONCLUSIONS Our findings suggest that RNA sequencing transcriptomic analyses of peripheral blood can provide information on the VDJ gene usage of B cell receptors and the mechanisms of accommodation and immune reaction in ABOi KT.