Small graft size and hepatocellular carcinoma outcomes in living donor liver transplantation: a retrospective multicentric cohort study.

INTRODUCTION: This study examined associations between the graft-to-recipient weight ratio (GRWR) for adult-to-adult living donor liver transplantation (LDLT) and HCC outcomes. MATERIALS AND METHODS: Data from patients in the Korean Organ Transplantation Registry who underwent LDLT for HCC from 2014-2021 were retrospectively reviewed. Patients were categorized using the cutoff GRWR for HCC recurrence determined by an adjusted cubic spline (GRWR<0.7% vs. GRWR≥0.7%). Recurrence-free survival (RFS) and HCC recurrence were analyzed in the entire and a 1:5 propensity-matched cohort. RESULTS: The eligible cohort consisted of 2005 LDLT recipients (GRWR<0.7 [n=59] vs. GRWR≥0.7 [n=1946]). In the entire cohort, 5-year RFS was significantly lower in the GRWR<0.7 than in the GRWR≥0.7 group (66.7% vs. 76.7%, P =0.019), although HCC recurrence was not different between groups (77.1% vs. 80.7%, P =0.234). This trend was similar in the matched cohort ( P =0.014 for RFS and P =0.096 for HCC recurrence). In multivariable analyses, GRWR<0.7 was an independent risk factor for RFS (adjusted HR [aHR] 1.89, P =0.012), but the result was marginal for HCC recurrence (aHR 1.61, P =0.066). In the pretransplant tumor burden subgroup analysis, GRWR<0.7 was a significant risk factor for both RFS and HCC recurrence only for tumors exceeding the Milan criteria (aHR 3.10, P <0.001 for RFS; aHR 2.92, P =0.003 for HCC recurrence) or with MoRAL scores in the fourth quartile (aHR 3.33, P <0.001 for RFS; aHR 2.61, P =0.019 for HCC recurrence). CONCLUSIONS: A GRWR<0.7 potentially leads to lower RFS and higher HCC recurrence after LDLT when the pretransplant tumor burden is high.

Antiplatelet agent for the prevention of late hepatic vascular complications in living donor liver transplant dominant population.

BACKGROUND: Evidence for the long-term use of antiplatelet drugs to prevent hepatic vascular complications (HVC) is scarce in liver transplantation (LT). METHODS: From national claim data, LT recipients (about 80 % of living donor LT [LDLT]) without graft loss, HVC, or cardiovascular events within 1 year, were classified into those who took antiplatelets for ≥1 year (n = 1744) and for <1 year (n = 1975). Outcomes were compared after the 1-postoperative year index time point. RESULTS: During a mean follow up of 4.5 years, the risk of graft loss was similar between the groups (aHR 1.16, P = 0.23). However, ≥1-year antiplatelet therapy was associated with a higher risk of graft loss after 3 years (aHR 2.19, P < 0.01). HVC (aHR 0.94, P = 0.87) and major adverse cardiac events (aHR 1.20, P = 0.46) did not correlate with antiplatelet therapy for both groups. In contrast, ≥1-year antiplatelet therapy showed a significantly higher risk of severe bleeding compared to <1-year antiplatelet therapy (aHR 2.24, P < 0.01). This trend was similar in the LDLT subgroup. In our cohort, antiplatelet therapy for ≥1 year did not improve graft survival or HVC; however, it increased the risk of severe bleeding. CONCLUSION: We recommend against antiplatelet therapy for more than 1 year in clinically stable LT recipients.

Creatinine-cystatin C ratio and death with a functioning graft in kidney transplant recipients.

Death with a functioning graft is important cause of graft loss after kidney transplantation. However, little is known about factors predicting death with a functioning graft among kidney transplant recipients. In this study, we evaluated the association between post-transplant creatinine-cystatin C ratio and death with a functioning graft in 1592 kidney transplant recipients. We divided the patients into tertiles based on sex-specific creatinine-cystatin C ratio. Among the 1592 recipients, 39.5% were female, and 86.1% underwent living-donor kidney transplantation. The cut-off value for the lowest creatinine-cystatin C ratio tertile was 0.86 in males and 0.73 in females. The lowest tertile had a significantly lower 5-year patient survival rate and was independently associated with death with a functioning graft (adjusted hazard ratio 2.574, 95% confidence interval 1.339-4.950, P < 0.001). Infection was the most common cause of death in the lowest tertile group, accounting for 62% of deaths. A low creatinine-cystatin C ratio was significantly associated with an increased risk of death with a functioning graft after kidney transplantation.

Cumulative exposure to tacrolimus during early period after liver transplantation does not affect the recurrence of hepatocellular carcinoma.

The clinical effects of tacrolimus (TAC) exposure on hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) remain unclear. In this retrospective single centric study, 512 patients who underwent LT for HCC were divided into four groups according to cumulative exposure to tacrolimus (CET) during 3 months after LT: conventional (n = 218), aggressive minimization (n = 32), minimization (n = 161), and high exposure (n = 101). Impact of CET on HCC recurrence and death were analyzed. Compared with the conventional group, the other three CET groups showed a similar risk of HCC recurrence. The aggressive minimization group showed a higher risk [hazard ratio (HR) 5.64, P < 0.001] and the high exposure group showed a marginal risk (HR 1.67, P = 0.081) of overall death compared to the conventional group. CET during 3 months was not associated with HCC recurrence in the matched cohort and various subgroups. TAC minimization is not effective to prevent HCC recurrence but could result in higher mortality in LT recipients.

The Effect of Model for End-Stage Liver Disease 3.0 on Disparities between Patients with and without Hepatocellular Carcinoma in Korea.

PURPOSE: The model for end-stage liver disease (MELD) 3.0 has recently been suggested for determining liver allocation. We aimed to apply MELD 3.0 to a Korean population and to discover differences between patients with and without hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This study is a retrospective study of 2203 patients diagnosed with liver cirrhosis at Severance Hospital between 2016-2022. Harrell's concordance index was used to validate the ability of MELD scores to predict 90-day survival. RESULTS: During a mean follow-up of 12.9 months, 90-day survival was 61.9% in all patients, 50.4% in the HCC patients, and 74.8% in the non-HCC patients. Within the HCC patients, the concordance index for patients on the waitlist was 0.653 using MELD, which increased to 0.753 using MELD 3.0. Among waitlisted patients, the 90-day survival of HCC patients was worse than that of non-HCC patients with MELD scores of 31-37 only (69.7% vs. 30.0%, p=0.001). Applying MELD 3.0, the 90-day survival of HCC patients was worse than that of non-HCC patients across a wider range of MELD 3.0 scores, compared to MELD, with MELD 3.0 scores of 21-30 and 31-37 (82.0% vs. 72.5% and 72.3% vs. 24.3%, p=0.02 and p<0.001, respectively). CONCLUSION: MELD 3.0 predicted 90-day survival of the HCC patients more accurately than original MELD score; however, the disparity between HCC and non-HCC patients increased, particularly in patients with MELD scores of 21-30. Therefore, a novel exception score is needed or the current exception score system should be modified.

Outcomes and Risk Factors for Liver Transplantation Using graft-to-Recipient Weight Ratio Less than 0.8 Graft from Living Donors: Multicentric Cohort Study.

OBJECTIVE: To compare graft survival after LDLT in patients receiving GRWR<0.8 versus GRWR≥0.8 grafts and identify risk factors for graft loss using GRWR<0.8 grafts. SUMMARY BACKGROUND DATA: Favorable outcomes after living donor liver transplantation (LDLT) using graft-to-recipient weight ratio (GRWR)<0.8 grafts were recently reported; however, these results have not been validated using multicenter data. METHODS: This multicentric cohort study included 3450 LDLT patients. Graft survival was compared between 1:3 propensity score-matched groups and evaluated using various Cox models in the entire population. Risk factors for graft loss with GRWR<0.8 versus GRWR≥0.8 grafts were explored within various subgroups using interaction analyses, and outcomes were stratified according to the number of risk factors. RESULTS: In total, 368 patients (10.7%) received GRWR<0.8 grafts (GRWR<0.8 group), whereas 3082 (89.3%) received GRWR≥0.8 grafts (GRWR≥0.8 group). The 5-y graft survival rate was significantly lower with GRWR<0.8 grafts than with GRWR≥0.8 grafts (85.2% vs. 90.1%, P=0.013). Adjusted hazard ratio (HR) for graft loss using GRWR<0.8 grafts in the entire population was 1.66 (95% confidence interval [CI] 1.17-2.35, P=0.004). Risk factors exhibiting significant interactions with GRWR<0.8 for graft survival were age ≥60 y, MELD score ≥15, and male donor. When ≥2 risk factors were present, GRWR<0.8 grafts showed higher risk of graft loss compared to GRWR≥0.8 graft in LDLT (HR 2.98, 95% CI 1.79-4.88, P<0.001). CONCLUSIONS: GRWR<0.8 graft showed inferior graft survival than controls (85.2% vs. 90.1%), especially when ≥2 risk factors for graft loss (among age ≥60 y, MELD score ≥15, or male donor) were present.

Survival benefit of living-donor liver transplantation in patients with a model for end-stage liver disease over 30 in a region with severe organ shortage: a retrospective cohort study.

BACKGROUND: The benefits of living-donor liver transplantation (LDLT) in patients with a high Model for End-stage Liver Disease (MELD) score (who have high waitlist mortality) are unclear. Regional availability of deceased-donor organs must be considered when evaluating LDLT benefits. The authors aimed to compare the survival benefit of intended-LDLT to awaiting deceased-donor liver transplantation (DDLT) in patients with a MELD score greater than or equal to 30 in a region with severe organ shortage. MATERIALS AND METHODS: This retrospective review included 649 patients with a MELD score greater than or equal to 30 placed on the liver transplantation waitlist. They were divided into intended-LDLT ( n =205) or waiting-DDLT ( n =444) groups based on living-donor eligibility and compared for patient survival from the time of waitlisting. Post-transplantation outcomes of transplant recipients and living donors were analyzed. RESULTS: Intended-LDLT patients had higher 1-year survival than waiting-DDLT patients (53.7 vs. 28.8%, P <0.001). LDLT was independently associated with lower mortality [hazard ratio (HR), 0.62; 95% CI, 0.48-0.79; P <0.001]. During follow-up, 25 patients were de-listed, 120 underwent LDLT, 170 underwent DDLT, and 334 remained on the waitlist. Among patients undergoing transplantation, the risk of post-transplantation mortality was similar for LDLT and DDLT after adjusting for pretransplantation MELD score (HR, 1.86; 95% CI, 0.73-4.75; P =0.193), despite increased surgical complications after LDLT (33.1 vs. 19.4%, P =0.013). There was no mortality among living-donors, but 4.2% experienced complications of grade 3 or higher. CONCLUSIONS: Compared to awaiting DDLT, LDLT offers survival benefits for patients with a MELD score greater than or equal to 30, while maintaining acceptable donor outcomes. LDLT is a feasible treatment for patients with a MELD score greater than or equal to 30 in regions with severe organ shortages.

Entecavir versus tenofovir on the recurrence of hepatitis B-related HCC after liver transplantation: A multicenter observational study.

Considerable controversy exists regarding the superiority of tenofovir disoproxil fumarate (TDF) over entecavir (ETV) for reducing the risk of HCC. This study aimed to compare outcomes of ETV versus TDF after liver transplantation (LT) in patients with HBV-related HCC. We performed a multicenter observational study using data from the Korean Organ Transplantation Registry. A total of 845 patients who underwent LT for HBV-related HCC were divided into 2 groups according to oral nucleos(t)ide analogue used for HBV prophylaxis post-LT: ETV group (n = 393) and TDF group (n = 452). HCC recurrence and overall death were compared in naïve and propensity score (PS)-weighted populations, and the likelihood of these outcomes according to the use of ETV or TDF were analyzed with various Cox models. At 1, 3, and 5 years, the ETV and TDF groups had similar HCC recurrence-free survival (90.7%, 85.6%, and 84.1% vs. 90.9%, 84.6%, and 84.2%, respectively, p = 0.98) and overall survival (98.4%, 94.7%, and 93.5% vs. 99.3%, 95.8%, and 94.9%, respectively, p = 0.48). The propensity score-weighted population showed similar results. In Cox models involving covariates adjustment, propensity score-weighting, competing risk regression, and time-dependent covariates adjustment, both groups showed a similar risk of HCC recurrence and overall death. In subgroup analyses stratified according to HCC burden (Milan criteria, Up-to-7 criteria, French alpha-fetoprotein risk score), pretransplantation locoregional therapy, and salvage LT, neither ETV nor TDF was superior. In conclusion, ETV and TDF showed mutual noninferiority for HCC outcomes when used for HBV prophylaxis after LT.

Effect of statins on the recurrence of hepatocellular carcinoma after liver transplantation: An illusion revealed by exposure density sampling.

BACKGROUND: Statins have been reported to reduce overall death and hepatocellular carcinoma (HCC) recurrence in liver transplantation (LT) recipients. However, previous retrospective studies have significant flaws in immortal time bias. METHODS: Using data from 658 patients who received LT for HCC, we matched 140 statin users with statin nonusers in a 1:2 ratio at the time of the first statin administration after LT using the exposure density sampling (EDS). The propensity score, calculated using baseline variables (including explant pathology), was used for EDS to equilibrate both groups. HCC recurrence and overall death were compared after adjusting for information at the time of sampling. RESULTS: Among statin users, the median time to statin start was 219 (IQR 98-570) days, and intensity of statins was mainly moderate (87.1%). Statin users and nonusers sampled using EDS showed well-balanced baseline characteristics, including detailed tumour pathology, and similar HCC recurrence with cumulative incidences of 11.3% and 11.8% at 5 years, respectively (p = .861). In multivariate Cox models (HR 1.04, p = .918) and subgroup analyses, statins did not affect HCC recurrence. Conversely, statin users showed a significantly lower risk of overall death than nonusers (HR 0.28, p < .001). There was no difference in the type and intensity of statin usage between statin users who experienced HCC recurrence and those who did not. CONCLUSION: Upon controlling immortal time bias by EDS, statins did not affect HCC recurrence but reduced mortality after LT. Statin usage is encouraged for survival benefits but not for preventing HCC recurrence in LT recipients.

Quantitative Prediction of Posttransplant Hepatocellular Carcinoma Prognosis Using ADV Score: Validation with Korea-Nationwide Transplantation Registry Database.

OBJECTIVE: The aim of this study is to validate the prognostic impact of ADV score (α-fetoprotein [AFP]-des-γ-carboxyprothrombin [DCP]-tumor volume [TV] score) for predicting prognosis of hepatocellular carcinoma (HCC) following liver transplantation (LT). BACKGROUND: ADV score has been reported as a prognostic surrogate biomarker of HCC following LT and hepatectomy. METHODS: The study patients were 1599 LT recipients selected from the Korean Organ Transplantation Registry database. RESULTS: Deceased-donor and living-donor LTs were performed in 143 and 1456 cases, respectively. Weak correlation was present among AFP, DCP, and TV. The viable HCC group showed ADV score-dependent disease-free survival (DFS) and overall patient survival (OS) rates from 1log to 10log (p<0.001). Prognosis of complete pathological response group was comparable to that of ADV score <1log (p≥0.099). ADV score cutoff of 5log (ADV-5log) for DFS and OS was obtained through receiver operating characteristic curve analysis with area under the curve ≥0.705. Both ADV-5log and Milan criteria were independent risk factors for DFS and OS, and their prognostic impacts were comparable to each other. Combination of these two factors resulted in further prognostic stratification, showing hazard ratios for DFS and OS as 2.98 and 2.26 respectively for one risk factor and 7.92 and 8.19 respectively for two risk factors (p<0.001). ABO-incompatible recipients with ADV score ≥8log or two risk factors showed higher recurrence rates. CONCLUSIONS: This validation study revealed that ADV score is a reliable surrogate biomarker for posttransplant HCC prognosis, which can be used for selecting LT candidates and guiding risk-based posttransplant follow-up surveillance.

Risk factors for late-onset Pneumocystis jirovecii pneumonia in liver transplant recipients.

OBJECTIVES: The risk factors for late-onset Pneumocystis jirovecii pneumonia (PCP) after liver transplantation (LT) have not been well studied. We aimed to analyze the clinical features preceding PCP in LT recipients that would guide individualized prophylaxis. METHODS: Among 742 patients who underwent LT and routine PCP prophylaxis from January 2009 through December 2019 at Severance Hospital, 27 patients developed PCP. We conducted a retrospective case-control study matching each patient with four controls and analyzed the risk factors for late-onset PCP. RESULTS: After 6 months, post-transplant PCP cases increased steadily with an overall incidence of 6.36 cases per 1000 patient-year. The PCP-related mortality was 37.0%. In the multivariate analyses, age at LT ≥65 years (odds ratio [OR], 13.305; 95% confidence interval [CI], 2.507-70.618; P = 0.002), cytomegalovirus infection (OR, 5.390; 95% CI, 1.602-18.132; P = 0.006), steroid pulse therapy (OR, 6.564; 95% CI, 1.984-21.719; P = 0.002), hepatocellular carcinoma recurrence (OR, 18.180; 95% CI, 3.420-96.636; P = 0.001), and lymphocytopenia (OR, 3.758; 95% CI, 1.176-12.013; P = 0.026) were independently associated with PCP. CONCLUSION: Late-onset PCP after routine prophylaxis after LT remains a lethal infection and is associated with age ≥65 years at LT, cytomegalovirus infection, steroid pulse therapy, hepatocellular carcinoma recurrence, and lymphocytopenia. Targeted prophylaxis considering these risk factors could improve the prevention of this potentially lethal complication.

Robotic ureter reconstruction using the native ureter to treat long-segment ureteral stricture of the transplant kidney utilizing Indocyanine green: The first Korean experience.

PURPOSE: Ureteral strictures are a common complication after kidney transplantation. Open reconstruction is preferred for long-segment ureteral strictures that cannot be resolved endoscopically; however, it is known to have the potential to fail. We report 2 successful cases of robotic reconstruction surgery of a transplant ureter using the native ureter with the aid of intraoperative Indocyanine green (ICG). MATERIALS AND METHODS: Patients were placed in semi-lateral position. Using Da Vinci Xi, the transplant ureter was dissected, and the stricture site was identified. End-to-side anastomosis of the native ureter to the transplant ureter was performed. ICG was utilized to identify the course of the transplant ureter and confirm the vascularity of the native ureter. RESULTS: Case 1: A 55-year-old female underwent renal transplantation at another hospital. She had recurrent febrile urinary tract infections (UTIs) and a ureteral stricture requiring percutaneous nephrostomy (PCN). The PCN and ureteral stent were removed successfully after surgery. The patient had only 1 febrile UTI episode after surgery. Case 2: A 56-year-old female underwent renal transplantation at another hospital. She had acute pyelonephritis 1-month post-transplantation, and a long-segment ureteral stricture was identified. She developed a UTI with anastomosis site leakage in the early postoperative period, which resolved with conservative treatment. The PCN and ureteral stent were removed 6 weeks after surgery. CONCLUSIONS: Robotic surgery for managing long-segment ureteral stricture after kidney transplantation is safe and feasible. The use of ICG during surgery to identify the ureter course and its viability can improve the success.

Quantitative ultrasound for non-invasive evaluation of subclinical rejection in renal transplantation.

OBJECTIVES: This study aimed to investigate the predictive efficacy of shear-wave elastography, superb microvascular imaging (SMI), and CEUS for allograft rejection in kidney transplants without graft dysfunction. METHODS: From January 2021 to November 2021, 72 consecutive patients who underwent both allograft biopsy and ultrasound were evaluated. Blood test results were obtained within a week of the ultrasound examinations, which were performed before the protocol biopsy. Resistive index (RI), tissue viscoelasticity, vascular index, and quantitative CEUS parameters were measured. Patients were divided based on biopsy results into the rejection and non-rejection groups. RESULTS: Among the 72 patients, 21 patients had pathological characteristics of acute rejection. RI of allograft was significantly higher in the rejection group (p = 0.007), compared to the non-rejection group. There were no significant between-group differences in vascular indices of SMI, mean elasticity, and mean viscosity. Meanwhile, among the parameters obtained by the time-intensity curve on CEUS, the cortical and medullary ratios of average contrast signal intensity, peak enhancement, wash-in area AUC, wash-in perfusion index, wash-out AUC, and wash-in and wash-out AUC were significantly different between the two groups (p < 0.05). In the receiver operating characteristic curve analysis for predicting allograft rejection, the AUC was 0.853 for the combination of six CEUS parameters, RI, and blood urea nitrogen. CONCLUSIONS: Among non-invasive quantitative ultrasound measurements, CEUS parameters are the most useful for diagnosing subclinical allograft rejection. Furthermore, the combination of CEUS parameters, RI, and blood urea nitrogen may be helpful for the early detection of renal allograft rejection. KEY POINTS: • Among non-invasive quantitative ultrasound measurements, CEUS parameters are the most useful for the diagnosis of subclinical allograft rejection. • On CEUS, the C/M ratios of MeanLin, PE, WiAUC, WiPI, WoAUC, and WiWoAUC are significantly lower in the rejection group; the combination of these showed reliable predictive performance for rejection. • The combination of CEUS parameters, RI, and BUN has a high predictive capability for subclinical allograft rejection.

Antiplatelet Drugs on the Recurrence of Hepatocellular Carcinoma after Liver Transplantation.

Previous studies reported suppressive effects of antiplatelet agents on hepatocellular carcinoma (HCC); however, this has never been assessed in patients who underwent liver transplantation (LT). This retrospective observational study used data from LT recipients with pre-transplant HCC in a single tertiary hospital. The study population was divided into two groups according to the use of antiplatelet agents for >90 days within the study period (377 antiplatelet groups versus 91 non-antiplatelet groups). Matched groups containing 79 patients in each group were also compared regarding HCC-recurrence and HCC-related mortality, which were analyzed by treating non-HCC death as a competing risk. In Kaplan−Meier analyses of the matched cohort, the 5-year cumulative incidences of HCC recurrence and HCC-specific death were similar between the antiplatelet (p = 0.876) and non-antiplatelet groups (p = 0.701). All-cause and non-HCC deaths were also similar between the two groups (p = 0.867 and p = 0.413, respectively). In multivariable analyses of the entire cohort, antiplatelet use was not associated with HCC recurrence (hazard ratio [HR] 1.37, p = 0.300) or HCC-specific death (HR 1.54, p = 0.310). Therefore, unlike the usual setting with liver disease, antiplatelet therapy did not affect HCC recurrence or HCC-specific mortality when used after LT.

Antithymocyte globulin versus basiliximab induction for kidney transplantation in elderly patients: matched analysis within the Korean multicentric registry.

BACKGROUND: Basiliximab (BSX) and antithymocyte globulins (ATGs), are two major immunosuppressive agents commonly used as induction therapy for kidney transplant (KT) recipients. The superiority of ATG over BSX has not been well established, especially in elderly KT recipients with low immunological risk. METHODS: A total of 847 elderly (≥60 years old), low-risk KT patients in the Korean Organ Transplantation Registry were propensity score-matched at a 1:2 ratio and compared according to ATG or BSX induction therapy. The primary outcome was patient and graft survival and biopsy-proven acute cellular rejection. The secondary outcome was graft function, BK virus nephropathy, infection, cancer, new-onset diabetes mellitus after transplantation (NODAT), and delayed graft function. RESULTS: In total, 165 patients in the ATG group were matched with 298 patients in the BSX group with average ages of 64.3 and 64.2 years, respectively. During a follow-up of 28.5 ± 10.4 months, the cumulative probabilities of death-censored graft failure at 3 years posttransplantation were 1.3% and 1.4% in ATG and BSX groups, respectively, without a significant difference (p = 0.72). The cumulative probability of NODAT at 3 years posttransplantation was significantly higher in the BSX group (35.6% vs. 21.6%, p = 0.02). The median tacrolimus trough level was significantly lower at 6 months after KT in the ATG group (5.7 ng/mL vs. 6.4 ng/mL, p = 0.001). There were no differences in the other evaluated outcomes. CONCLUSION: Compared with BSX, in elderly, low-risk KT patients, ATG reduced tacrolimus and steroid requirements without differences in all-cause mortality, rejection, or infection, resulting in a reduced NODAT incidence.

Non-Renal Risk Factors for Chronic Kidney Disease in Liver Recipients with Functionally Intact Kidneys at 1 Month.

Chronic kidney disease (CKD) is a critical complication of liver transplants, of which non-renal risk factors are not fully understood yet. This study aimed to reveal pre- and post-transplant risk factors for CKD (<60 mL/min/1.73 m2), examining liver recipients with functionally intact kidneys one month after grafting using nationwide cohort data. Baseline risk factors were analyzed with multivariable Cox regression analyses and post-transplant risk factors were investigated with the time-dependent Cox model and matched analyses of time-conditional propensity scores. Of the 2274 recipients with a one-month eGFR ≥ 60 mL/min/1.73 m2, 494 (22.3%) developed CKD during a mean follow-up of 36.6 ± 14.4 months. Age, female sex, lower body mass index, pre-transplant diabetes mellitus, and lower performance status emerged as baseline risk factors for CKD. Time-dependent Cox analyses revealed that recurrent hepatocellular carcinoma (HR = 1.93, 95% CI 1.06−3.53) and infection (HR = 1.44, 95% CI 1.12−1.60) were significant post-transplant risk factors for CKD. Patients who experienced one of those factors showed a significantly higher risk of subsequent CKD compared with the matched controls who lacked these features (p = 0.013 for recurrent hepatocellular carcinoma, and p = 0.003 for infection, respectively). This study clarifies pre- and post-transplant non-renal risk factors, which lead to renal impairment after LT independently from patients' renal functional reserve.

Safety of Tacrolimus Monotherapy within 12 Months after Liver Transplantation in the Era of Reduced Tacrolimus and Mycophenolate Mofetil: National Registry Study.

Tacrolimus monotherapy is accepted as a feasible option during early post-liver transplantation as per current international consensus guidelines. However, its effects in the recent era of reduced tacrolimus (TAC) and mycophenolate mofetil (MMF) remain unclear. Liver recipients who either received TAC monotherapy from the treatment onset or switched from TAC/MMF to TAC-mono within 12 months (TAC-mono group; n = 991) were chronologically matched to patients who continued to receive TAC/MMF (TAC/MMF group; n = 991) at the corresponding time points on time-conditional propensity scores. Outcomes within 12 months after matched time points were compared. Biopsy-proven rejection (TAC/MMF: 3.5% vs. TAC-mono: 2.6%; p = 0.381) and graft failure (0.2% vs. 0.7%; p = 0.082) were similar in both groups. However, the decline in eGFR was 3.1 mL/min/1.73 m2 (95% CI: 0.8-5.3) greater at six months (p = 0.008) and 2.4 mL/min/1.73 m2 (95% CI: -0.05-4.9) greater at 12 months (p = 0.048) after the matched time points in TAC-mono group than that in TAC/MMF group. TAC trough levels were also higher in the TAC-mono group throughout the study period. TAC-mono within 12 months after liver transplantation is immunologically safe. However, it can increase the required TAC dose and the decline in renal function than that in TAC/MMF combination therapy.

Risk Due to ABO Incompatibility and Donor-Recipient Weight Mismatch in Living Donor Kidney Transplantation: A National Cohort Study.

The effect of donor-recipient weight mismatch is not well established in ABO-incompatible living donor kidney transplantation (LDKT). A total of 2584 LDKT patients in the Korean Organ Transplantation Registry were classified into four groups according to the presence or absence of ABO incompatibility and donor-recipient weight mismatch (donor-to-recipient weight ratio (DRWR) < 0.8). In a multivariable Cox analysis, the combination of ABO incompatibility and DRWR incompatibility (n = 124) was an independent risk factor for graft survival (HR = 2.73, 95% CI = 1.11-6.70) and patient survival (HR = 3.55, 95% CI = 1.39-9.04), whereas neither factor alone was a significant risk factor for either outcome. The combination of ABO incompatibility and DRWR incompatibility was not an independent risk factor for biopsy-proven graft rejection (HR = 1.27, 95% CI = 0.88-1.82); however, it was an independent risk factor for pneumonia (HR = 2.94, 95% CI = 1.64-5.57). The mortality rate due to infection was higher among patients with both ABO incompatibility and DRWR incompatibility than among patients with neither factor or with either factor alone. The combination of ABO incompatibility and DRWR incompatibility was an independent risk factor for graft and patient survival after LDKT, whereas neither factor alone significantly affected graft or patient survival. Thus, donor-recipient weight matching should be cautiously considered in LDKT with ABO incompatibility.

Perioperative, short-, and long-term outcomes of gastric cancer surgery: Propensity score-matched analysis of patients with or without prior solid organ transplantation.

BACKGROUND: Details of perioperative outcomes and survival after gastric cancer surgery in prior transplant recipients have received minimal research attention. METHODS: We performed an observational cohort study using the database of 20,147 gastric cancer patients who underwent gastrectomy at a single gastric cancer center in Korea. Forty-one solid organ recipients [kidney (n = 35), liver (n = 5), or heart (n = 1)] were matched with 205 controls using propensity score matching. RESULTS: Operation time, blood loss, and postoperative pain were similar between groups. Short-term complication rates were similar between transplantation and control groups (22.0% vs. 20.1%, P = 0.777). Transplantation group patients with stage 1 gastric cancer experienced no recurrence, while those with stage 2/3 cancer had significantly higher recurrence risk compared to the controls (P = 0.049). For patients with stage 1 cancer, the transplantation group had a significantly higher rate of non-gastric cancer-related deaths compared to the controls (19.2% vs. 1.4%, P = 0.001). For those with stage 2/3 cancer, significantly lower proportion of the transplantation group received adjuvant chemotherapy compared to the control group (26.7% vs. 80.3%, P < 0.001). The transplantation group had a higher (albeit not statistically significant) rate of gastric cancer-related deaths compared to the controls (40.0% vs. 18.0%, P = 0.087). CONCLUSION: Transplant recipients and non-transplant recipients exhibited similar perioperative and short-term outcomes after gastric cancer surgery. From long-term outcome analyses, we suggest active surveillance for non-gastric cancer-related deaths in patients with early gastric cancer, as well as strict oncologic care in patients with advanced cancer, as effective strategies for transplant recipients.

Outcomes after liver transplantation in Korea: Incidence and risk factors from Korean transplantation registry.

BACKGROUND/AIMS: To analyze the incidence and risk factors of outcomes after liver transplantation (LT) in the Korean population. METHODS: This study analyzed data from the liver cohort of Korean Organ Transplantation Registry (KOTRY) who had LT between May 2014 and December 2017. Study measures included the incidence of post-LT outcomes in recipients of living donor LT (LDLT) and deceased donor LT (DDLT). Cox multivariate proportional hazards model was used to determine the potential risk factors predicting the outcomes. RESULTS: A total of 2,563 adult recipients with LT (LDLT, n=1,956; DDLT, n=607) were included, with mean±standard deviation age of 53.9±8.9 years, and 72.2% were male. The post-LT outcomes observed in each LDLT and DDLT recipients were death (4.0% and 14.7%), graft loss (5.0% and 16.1%), rejection (7.0% and 12.0%), renal failure (2.7% and 13.8%), new onset of diabetes (12.5% and 15.4%), and hepatocellular carcinoma (HCC) recurrence (both 6.7%). In both LDLT and DDLT recipients, the most common post-LT complications were renal dysfunction (33.6% and 51.4%), infection (26.7% and 48.4%), and surgical complication (22.5% and 23.9%). Incidence of these outcomes were generally higher among recipients of DDLT than LDLT. Multivariate analysis indicated recipient age and DDLT as significant risk factors associated with death and graft loss. DDLT and ABO incompatible transplant were prognostic factors for rejection, and HCC beyond Milan criteria at pre-transplant was a strong predictor of HCC recurrence. CONCLUSION: This study is a good indicator of the post-LT prognosis in the Korean population and suggests a significant burden of post-LT complications.