Circulating Cancer Stem Cells Expressing EpCAM/CD90 in Hepatocellular Carcinoma: A Pilot Study for Predicting Tumor Recurrence after Living Donor Liver Transplantation

Background/aims@#Circulating tumor cells (CTCs) with cancer stemness have been demonstrated to be a direct cause of tumor recurrence, and only few studies have reported the role of CTCs in liver transplantation (LT) for hepatocellular carcinoma (HCC). @*Methods@#Epithelial cell adhesion molecule+ (EpCAM+), cluster of differentiation 90+ (CD90+) and EpCAM+/CD90+ CTCs were sorted via fluorescence-activated cell sorting, and transcripts level of EpCAM, K19 and CD90 in the peripheral blood were analyzed via real-time polymerase chain reaction preoperatively and on postoperative days 1 and 7 in 25 patients who underwent living donor liver transplantation (LDLT) for HCC. EpCAM protein was assessed in HCC tissue using immunohistochemical staining. The median follow-up duration was 40 months. @*Results@#HCC after LDLT recurred in four out of 25 patients. Detection of EpCAM+ or CD90+ CTCs correlated well with their messenger RNA levels (p100 mAU/mL and postoperative day 1 EpCAM+/CD90+ CTCs were independent risk factors for HCC recurrence (hazard ratio, 14.64; 95% confidence interval, 1.08 to 198.20; p=0.043 and hazard ratio, 26.88; 95% confidence interval, 1.86 to 387.51; p=0.016, respectively). @*Conclusions@#EpCAM+/CD90+ CTCs can be used preoperatively and 1 day after LDLT as key biological markers in LT candidate selection and post-LDLT management.

Impact of everolimus on survival after liver transplantation for hepatocellular carcinoma

Background/Aims@#This study aimed to investigate whether everolimus (EVR) affects long-term survival after liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). @*Methods@#The data from 303 consecutive patients with HCC who had undergone LT from January 2012 to July 2018 were retrospectively reviewed. The patients were divided into two groups: 1) patients treated with EVR in combination with calcineurin inhibitors (CNIs) (EVR group; n=114) and 2) patients treated with CNI-based therapy without EVR (non-EVR group; n=189). Time to recurrence (TTR) and overall survival (OS) after propensity score (PS) matching were compared between the groups, and prognostic factors for TTR and OS were evaluated. @*Results@#The EVR group exhibited more aggressive tumor biology than the non-EVR group, such as a higher number of tumors (P=0.003), a higher prevalence of microscopic vascular invasion (P=0.017) and exceeding Milan criteria (P=0.029). Compared with the PS-matched non-EVR group, the PS-matched EVR group had significantly better TTR (P<0.001) and OS (P<0.001). In multivariable analysis, EVR was identified as an independent prognostic factor for TTR (hazard ratio [HR], 0.248; P=0.001) and OS (HR, 0.145; P<0.001). @*Conclusions@#Combined with CNIs, EVR has the potential to prolong long-term survival in patients undergoing LT for HCC. These findings warrant further investigation in a well-designed prospective study.

Curative liver transplantation after lung resection for advanced hepatocellular carcinoma with lung metastasis and inferior vena cava tumor thrombosis: a case report

Hepatocellular carcinoma (HCC) with distant metastasis is an absolute contraindication for liver transplantation (LT). However, it is still unclear whether LT is feasible or acceptable in such patients, albeit after being treated with a multidisciplinary approach and after any metastatic lesion is ruled out. We report one such successful treatment with living donor LT (LDLT) after completely controlling far-advanced HCC with inferior vena cava tumor thrombosis and multiple lung metastases. The patient has been doing well without HCC recurrence for eight years since LDLT. The current patient could be an anecdotal case, but provides a case for expanding LDLT indications in the context of advanced HCC and suchlike.

Curative liver transplantation after lung resection for advanced hepatocellular carcinoma with lung metastasis and inferior vena cava tumor thrombosis: a case report

Hepatocellular carcinoma (HCC) with distant metastasis is an absolute contraindication for liver transplantation (LT). However, it is still unclear whether LT is feasible or acceptable in such patients, albeit after being treated with a multidisciplinary approach and after any metastatic lesion is ruled out. We report one such successful treatment with living donor LT (LDLT) after completely controlling far-advanced HCC with inferior vena cava tumor thrombosis and multiple lung metastases. The patient has been doing well without HCC recurrence for eight years since LDLT. The current patient could be an anecdotal case, but provides a case for expanding LDLT indications in the context of advanced HCC and suchlike.

Impact of everolimus on survival after liver transplantation for hepatocellular carcinoma

Background/Aims@#This study aimed to investigate whether everolimus (EVR) affects long-term survival after liver transplantation (LT) in patients with hepatocellular carcinoma (HCC). @*Methods@#The data from 303 consecutive patients with HCC who had undergone LT from January 2012 to July 2018 were retrospectively reviewed. The patients were divided into two groups: 1) patients treated with EVR in combination with calcineurin inhibitors (CNIs) (EVR group; n=114) and 2) patients treated with CNI-based therapy without EVR (non-EVR group; n=189). Time to recurrence (TTR) and overall survival (OS) after propensity score (PS) matching were compared between the groups, and prognostic factors for TTR and OS were evaluated. @*Results@#The EVR group exhibited more aggressive tumor biology than the non-EVR group, such as a higher number of tumors (P=0.003), a higher prevalence of microscopic vascular invasion (P=0.017) and exceeding Milan criteria (P=0.029). Compared with the PS-matched non-EVR group, the PS-matched EVR group had significantly better TTR (P<0.001) and OS (P<0.001). In multivariable analysis, EVR was identified as an independent prognostic factor for TTR (hazard ratio [HR], 0.248; P=0.001) and OS (HR, 0.145; P<0.001). @*Conclusions@#Combined with CNIs, EVR has the potential to prolong long-term survival in patients undergoing LT for HCC. These findings warrant further investigation in a well-designed prospective study.

Living Donor Liver Transplantation for Advanced Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis after Concurrent Chemoradiation Therapy

Locally advanced hepatocellular carcinoma (HCC) with portal vein thrombosis carries a 1-year survival rate <10%. Localized concurrent chemoradiotherapy (CCRT), followed by hepatic arterial infusion chemotherapy (HAIC), was recently introduced in this setting. Here, we report our early experience with living donor liver transplantation (LDLT) in such patients after successful down-staging of HCC through CCRT and HAIC. Between December 2011 and September 2012, eight patients with locally advanced HCC at initial diagnosis were given CCRT, followed by HAIC, and underwent LDLT at the Severance Hospital, Seoul, Korea. CCRT [45 Gy over 5 weeks with 5-fluorouracil (5-FU) as HAIC] was followed by HAIC (5-FU/cisplatin combination every 4 weeks for 3-12 months), adjusted for tumor response. Down-staging succeeded in all eight patients, leaving no viable tumor thrombi in major vessels, although three patients first underwent hepatic resections. Due to deteriorating liver function, transplantation was the sole therapeutic option and offered a chance for cure. The 1-year disease-free survival rate was 87.5%. There were three instances of post-transplantation tumor recurrence during follow-up monitoring (median, 17 months; range, 10-22 months), but no deaths occurred. Median survival time from initial diagnosis was 33 months. Four postoperative complications recorded in three patients (anastomotic strictures: portal vein, 2; bile duct, 2) were resolved through radiologic interventions. Using an intensive tumor down-staging protocol of CCRT followed by HAIC, LDLT may be a therapeutic option for selected patients with locally advanced HCC and portal vein tumor thrombosis.

Effect of donor-specific antibodies and panel reactive antibodies in living donor liver transplant recipients

PURPOSE: Preformed circulating donor-specific antibodies (DSAs) immunologically challenge vascular endothelium and the bile duct. However, the liver is an immune-tolerant organ and can avoid immunological challenges. This study was undertaken to analyze the effects of DSAs after adult living donor liver transplantation (LDLT). METHODS: We retrospectively reviewed 219 LDLT patients' records treated at our center. RESULTS: Of the 219 patients, 32 (14.6%) were DSA (+) and 187 (85.4%) were DSA (-). Class I DSAs were present in 18 patients, class II in seven patients, and both in seven patients. Seven patients (3.2%) showed DSA to HLA-A, four (1.8%) to HLA-B, seven (3.2%) to HLA-DR, and 14 (6.4%) to two or more HLAs. More DSAs were observed in female recipients than male recipients in the DSA (+) group. The DSA (+) group showed significantly higher levels of class I and II panel reactive antibody (PRA) than did the DSA (-) group. No significant intergroup differences were found between incidences of primary nonfunction, acute rejection, vascular complication, or biliary complication. There were no significant differences in graft survival rates between the two groups. However, the recipients with multiple DSAs tended to have more acute rejection episodes and events of biliary stricture and lower graft survival rates than did patients in the DSA (-) group. CONCLUSION: In LDLT, the presence of multiple DSAs and high PRA seemed to be associated with poor graft outcomes, although our results did not reach statistical significance. Large cohort studies are necessary to clarify the impact of DSA and PRA in LDLT.

Quality of Life among End-stage Renal Disease Treatments and Economic Evaluation of Renal Transplantation and Hemodialysis Treatments / 대한이식학회지

BACKGROUND: Although renal transplantation is known as the best treatment for patients with end-stage renal disease, there are few of literature to identify economic evaluation of renal replacement therapies in Korea. This study was conducted to determine the cost-effectiveness of renal replacement treatments, particularly renal transplantation and hemodialysis. METHODS: We used the quality adjusted life year (QALY) calculated from survey data, which was collected from 124 patients who underwent kidney transplantation and 90 patients who were receiving hemodialysis. Medical costs were collected from five hospitals in Korea. The ERA-EDTA registry data (European Renal Association-European Dialysis and Transplant Association) were used for transition probability. A Markov model was used for predicting the cost-utility of transplantation and hemodialysis over the 10-year period. RESULTS: Renal transplantation offers lower cost and better outcome compared to hemodialysis. QALY per year of transplantation patients is higher than that of hemodialysis patients (transplantation 0.9465 vs. hemodialysis 0.8297). Cost per QALY gained is 15,566,000 won in transplantation patients whereas 32,765,000 won per QALY gained in hemodialysis patients was required. CONCLUSIONS: Although cost of first year after transplantation was expensive, over 2 years, transplantation was more effective and less costly than hemodialysis. The results suggest that transplantation is more cost-effective than hemodialysis in Korea.

Changes of Kidney Injury Molecule-1 Expression and Renal Allograft Function in Protocol and for Cause Renal Allograft Biopsy / 대한이식학회지

BACKGROUND: Kidney injury molecule-1 (KIM-1) is known as a good ancillary marker of acute kidney injury (AKI) and its expression has also been observed in acute rejection and chronic graft dysfunction. We tested usefulness of KIM-1 as an indicator of acute and chronic renal graft injury by correlating KIM-1 expression with renal graft function and histology. METHODS: A total of 133 zero-time biopsies and 42 follow-up biopsies obtained within 1 year posttransplantation were selected. Renal tubular KIM-1 staining was graded semiquantitatively from 0 to 3 and the extent of staining was expressed as the ratio of KIM-1 positive/CD10 positive proximal tubules using Image J program. RESULTS: KIM-1 was positive in 39.8% of zero-time biopsies. KIM-1 positive cases were predominantly male and had received grafts from donors with older age, deceased donors, and poor renal function at the time of donation, compared with KIM-1 negative cases. KIM-1 expression showed correlation with delayed graft function and acute tubular necrosis. In comparison of KIM-1 expression between stable grafts (n=23) and grafts with dysfunction (n=19) at the time of repeated biopsy, the intensity/extent of KIM-1 staining and renal histology at zero-time did not differ significantly between the two groups. Histologically, KIM-1 expression was significantly increased with both acute and chronic changes of glomeruli, tubules and interstitium, peritubular capillaritis, and arteriolar hyalinosis. CONCLUSIONS: KIM-1 can be used as an ancillary marker of AKI and a nonspecific indicator of acute inflammation and tubulointerstitial fibrosis. However, KIM-1 expression at zero-time is not suitable for prediction of long-term graft dysfunction.

The Use of High-dose Rh Immunoglobulin for the Prevention of D Sensitization in RhD-incompatible Liver Transplantation

Approximately 80-85% of D-negative (D-) persons produce anti-D antibodies after exposure to D-positive (D+) red blood cells (RBCs). Previously, anti-D was the most commonly detected Rh antibody, but its incidence has greatly decreased due to the prophylactic use of Rh immunoglobulin (RhIG). Anti-D antibody formation may occur following RhD-incompatible organ transplantation when D- recipients are exposed to D+ RBCs that originate from a donor organ. As a large volume of donor blood may be contained within the transplanted organ, the use of a large amount of RhIG is required in RhD-incompatible liver transplantation. Here, we describe the use of a large amount of RhIG to treat a patient following RhD-incompatible liver transplantation. This patient was a 71-yr-old woman with hepatitis C virus-related liver cirrhosis, who had an A/D- blood type. The donor was her grandson, whose blood type was O/D+. The recipient's preoperative anti-D antibody test was negative. One unit of O/D- irradiated leukoreduced RBCs and three units of A/D- fresh frozen plasma were transfused during liver transplantation. An equal amount (12,000 IU) of RhIG was infused intravenously, immediately after liver transplantation and a second time on post-operation day 1. The anti-D titer was 1:64 on the first post-operation day, and had increased to 1:128 by the following day. By 1 month after the surgery, the titer had decreased to 1:4. In this case of liver transplantation, RhIG was actively used to prevent RhD sensitization and the subsequent occurrence of adverse events associated with RhD-incompatible liver transplantation.

Research for Modification of Emergency Status in Deceased Donor Liver Allocation: Survival Analysis of Waiting Patients for Liver Transplantation / 대한이식학회지

Despite a remarkable increase of deceased donors, organ shortage is the main hurdle of organ transplantation in Korea. Therefore, liver transplantation priority is a major issue of liver allocation. We confront a situation that needs to change in order to achieve more adequate and objective allocation of the system. We considered the MELD system as an alternative to the CTP score and Status system. For application of the MELD system, comparison between two systems is required; and a national-based retrospective review of liver transplantation candidates (waiting list) was conducted as a multi-center collaborative study. Eleven transplant centers participated in this national study. From 2009 to 2012, 2,702 waiting lists were enrolled. After mean 349+/-412 days follow-up, 967 patients (35.8%) of liver transplantation, 750 patients (27.8%) of drop-out/mortality, and 719 patients (26.6%) on waiting were identified. In analysis of patient mortality during waiting time, status system showed significant difference of waiting mortality by status at registration. However, differences of waiting mortality by MELD system were more prominent and discriminate. In comparisons by MELD score in exclusive Status 2A waiting patients, there was a significant difference of waiting mortality by MELD score. This means that the MELD system is a good predictor of short-term survival after listing compared with status system with CTP score. Korean national-based retrospective study showed the superiority of the MELD system in prediction of short-term mortality and usefulness as a determinant for allocation priority.

The Effects of Symptom Distress, Social Support, and Work Change on Liver Transplant Recipients / 대한이식학회지

BACKGROUND: The purpose of this study was to evaluate the factors influencing quality of life (QOL) in liver transplant recipients. METHODS: The subjects of this study were 103 liver recipients who received their follow-up more than 3 months after liver transplantation at one general hospital in Seoul. A questionnaire survey was perfomed from September 1, 2012 to September 30, 2012. QOL and factors were evaluated using SF-36, Transplant Symptom Distress Scale and Multidimensional Scale of Perceived Social Support. RESULTS: Symptom distress, work change after transplant, duration after transplant were significant factors influencing QOL (Cum R2=0.39, F=19.34, P<0.001). Symptom distress was the most important factors related QOL. There were significant differences in QOL according to general characteristics such as education (t=2.16, P=0.033), work change after transplant (t=3.67, P=0.000), duration after transplant (t=2.25, P=0.027), and economic status (t=3.08, P=0.027). CONCLUSIONS: In conclusion, symptom distress had an influence on the QOL of liver transplant recipients. Thus, it is necessary to develop interventions for symptom distress to improve the QOL of liver transplant recipients.

A Case of Rapidly Progressive Primary Sclerosing Cholangitis Requiring Liver Transplantation / 대한이식학회지

Primary sclerosing cholangitis (PSC) is a slowly progressive cholestatic liver disease. In cases of PSC, liver transplantation is the only effective treatment that can delay the disease's natural course. We report a case of rapidly progressive PSC requiring liver transplantation. A 52-year-old woman visited our hospital with abdominal pain. There was no evidence of PSC, as there was no elevation in cholestatic liver enzymes at her first visit. Although her total bilirubin was in a normal range at the initial visit, liver dysfunction progressed rapidly. Despite endoscopic procedures and ursodeoxycholic acid intake, total bilirubin levels rose to 18.9 mg/dL, and liver transplantation was performed 17 months after her first visit. PSC was pathologically confirmed after liver transplantation.

Effect of Caring for Potential Brain Death Organ Donors during the Organ Donation Process upon Physician Attitudes / 대한이식학회지

BACKGROUND: The purpose of this study was to identify the attitude of physicians stemming from their experiences of caring for potential brain death donors during the organ donation process. METHODS: Grounded theory methodology was used for this study. In depth interviews were conducted with six physicians who had experience of management of potential brain death donors. Data collection was done from January to October 2011. Theoretical sampling was used until the data reached saturation. RESULTS: As a result of the analysis, dilemma of organ donation solicitation was identified as the core category. Twelve subcategories were identified and they were integrated to the core category. Obtaining organ donation counseling skills was identified as the consequence. CONCLUSIONS: The results of the study will provide a frame for understanding the attitudes stemming from their experience of caring for potential brain death donor and helping the development of effective intervention strategies for increasing organ donation.

Clinical Characteristics and Risk Factors for Renal Cell Carcinoma after Kidney Transplantation / 대한이식학회지

BACKGROUND: The occurrence of malignancy following kidney transplantation has been estimated three to five times the incidence compared to that of the general population. It is estimated that particularly in renal cell carcinoma (RCC), the relative risk increases. The aim of this study was to analyze the characteristics, risk factors, and prognosis of RCC following kidney transplantation. METHODS: Total number of 3,272 kidney recipients who underwent transplantation from April 1979 to December 2012 and patients who had RCC following kidney transplantation were retrospectively reviewed and analyzed. RESULTS: We found that among 232 cases of posttransplant malignancies, 25 recipients were diagnosed with RCC. We have observed in our study that it took an average of 175.2+/-71.0 months to develop RCC after their first kidney transplantation. However, with longer follow up period, interval incidence of RCC increased. Fourteen patients (56%) were diagnosed with RCC 15 years after transplantation. We also found that with reference to the risk factor analysis for posttransplant RCC, the long-term follow-up period was the only independent risk factor. In our study, 21 patients with RCC were treated with radical nephrectomy. Of them, 16 patients survived, and four RCC-related deaths occurred. Furthermore, the patient survival rate of RCC recipients was lower than that of the nonmalignancy group despite the graft survival rate were not different. CONCLUSIONS: We conclude that the incidence of RCC increased in a time-dependent manner following kidney transplantation. Therefore, we strongly recommend the procedure of regular-interval screening for the patients who are on compulsive long-term immunosuppression.

Erratum to: A Case of Rapidly Progressive Primary Sclerosing Cholangitis Requiring Liver Transplantation / 대한이식학회지

A printing error was identified in the figure 3.

Pediatric Liver Transplantation Outcomes in Korea

Pediatric liver transplantation is the standard of care for treatment of liver failure in children. The aim of this study was to identify the characteristics of pediatric liver transplantation in centers located in Korea and determine factors that influence outcomes. This retrospective study was performed using data from between 1988 and 2010 and included all recipients 18 yr old and younger who underwent pediatric liver transplantation in Korea during that period. Our data sources were hospital medical records and the outcome measure was overall patient survival. Univariate and multivariate statistical analyses were undertaken using the Cox proportional hazards model. Five hundred and thirty-four pediatric liver transplantations were performed in 502 children. Median age and average pediatric end-stage liver disease (PELD) score were 20 months and 18 point, respectively. Biliary atresia (57.7%, 308/534) was the most common cause of liver disease. Eighty-two (15.3%) were deceased donor liver transplantations and 454 (84.7%) were living donor liver transplantations. Retransplantation was performed in 32 cases (6%). Overall, 1-, 5-, and 10-yr patient survival rates were 87.8%, 82.2%, and 78.1%, respectively. In multivariate analysis, independent significant predictors of poor patient survival were chronic rejection and retransplantation. This study presents the epidemiologic data for nearly all pediatric liver transplantation in Korea and shows that the independent prognostic factors in patient survival are chronic rejection and retransplantation.

Severity of End-stage Liver Disease in Liver Transplant Candidate; Comparison of KONOS Status with MELD Score / 대한이식학회지

BACKGROUND: We have allocated liver according to the Korean Network Organ Sharing (KONOS) status. However, it was necessary to change the system to a more adequate and objective system. We analyzed the correlation between KONOS status and MELD score under the current status of organ allocation. METHODS: We reviewed medical records of 70 liver recipients as KONOS status 2A and 2B between September 2005 and December 2010. We analyzed their KONOS status, MELD score, clinical characteristics, waiting time, Child-Turcotte-Pugh (CTP) score and clinical symptoms accorded to KONOS status 2A. RESULTS: Mean MELD and CTP score of the 2A group was significantly higher than the 2B group (P<0.001). In the 2B group, the blood types of all recipients were identical to those of the donors. However, 2A group included 7 cases (23.3%) of non-identical blood types. The MELD score of all recipients were correlated with CTP score (R=0.798, P<0.001). However, there was an overlapping area between the 2B group and the 2A group that was registered by the condition of intractable ascites. Those who had hepatorenal syndrome and hepatic encephalopathy showed high MELD score over 20. However, 36.4% of the patients who had only intractable ascites showed a MELD score of less than 20. CONCLUSIONS: CTP score was highly correlated with MELD score. However, KONOS status showed some overlapping area of the MELD score between 2A and 2B groups. We should make an effort to improve KONOS allocation system to meet the Korean situation.

Evaluation of Independent Risk Factors Affecting Renal Allograft Survival by Transplant Era / 대한이식학회지

BACKGROUND: Using long-term (more than 30 years) data from a single center, this retrospective study evaluated changes of independent risk factors affecting renal allograft survival by transplant era. METHODS: Of 3,000 cases of kidney transplantation, 2,708 (90.3%), including their follow-up observations, were reviewed. Transplant era was classified according to immunosuppressive regimens as either early group (transplant serial No. 1~1,500) or recent group (transplant serial No. 1,501~3,000). RESULTS: There was a significant difference observed in pre-transplant clinical manifestations between the early and recent groups. The number of elderly recipients and donors, number of deceased donors, and cases related to pre-transplant diabetes, pre-emptive transplantation, and retransplantation were differed relative to transplant era. The short- and long-term graft survival rate of the recent group improved significantly, and the effect of human leukocyte antigen mismatching and living donor type disappeared in the recent group. Moreover, pre-emptive transplantation and retransplantation were effective only in the recent group. However, non-immunological factors such as elderly recipients and donors, and immunologic factors such as episodes of acute rejection and types of immunosuppressive regimen were persistent independent risk factors affecting graft survival rate. CONCLUSIONS: According to the retrospective survival analysis of a large number of recipients in a single center, risk factors for kidney transplant patients differed by transplant era. However, the independent risk factors associated with elderly recipients and donors (non-immunologic), and episodes of acute rejection, and types of immunosuppressive regimen (immunologic) persisted regardless of transplant era.

Waiting Time for Deceased Donor Kidney Allocation in Korea: A Single Center Experience / 대한이식학회지

BACKGROUND: The kidney recovery rate associated with deceased donors has increased after the establishment of the Korean Network for Organ Sharing (KONOS). And the KONOS organ allocation system gives priority to candidates affiliated with a Hospital based Organ Procurement Organization (HOPO) and/or donor recovery hospital. Regardless of whether or not this organ allocation system is fair, it can make an important impact on the waiting time for an organ transplant. METHODS: A total of 157 deceased donor kidney transplantations were performed at Severance Hospital between January 2006 and April 2011. The recipients of these transplantations were retrospectively divided into five groups according to their allocation types; general allocation group (GA, n=54), HOPO priority group (HP, n=65), zero antigen mismatching group (ZM, n=23), marginal donor allocation group (MD, n=7), and the combined organ transplant allocation group (CT, n=8). The five groups were assessed in terms of their waiting time for organ allocation, cold ischemia time, and post-transplant graft outcome. RESULTS: Mean waiting time for organ allocation of the HP group (69.5+/-27.4 months) was significantly shorter than for the GA group (90.0+/-34.0 months)(P<0.05). However, the degree of HLA mismatching was not different between each group. The cold ischemia time for the HP group (301.5+/-133.9 min) was significantly shorter than all other groups, except for the ZM group. There were no differences between groups in terms of acute rejection episodes, delayed graft function events or graft survival rates. CONCLUSIONS: Our retrospective analysis of the kidney allocation pattern showed that there were disparities in distribution by priority of allocation. We should make a consensus within the Korean transplant society in order to further develop the allocation system to decease donor kidney transplantation time.