Outcomes of kidney transplantation over a 16-year period in Korea: An analysis of the National Health Information Database

Impact of sirolimus on long-term adverse cardiovascular outcomes in kidney transplant recipients: A nationwide cohort study

BACKGROUND

Kidney transplant recipients (KTRs) are at high risk for cardiovascular disease due to the long-term use of immunosuppressive therapy. This study aims to evaluate the long-term impact of sirolimus on cardiovascular outcomes in Korean KTRs.

METHODS

From a cohort of 7180 eligible KTRs identified from 2010 to 2021, 387 KTRs who received sirolimus were included. To control for confounding variables, propensity score matching was applied, and the landmark method was used to address immortal time bias. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of myocardial infarction, coronary revascularization, ischaemic stroke and all-cause mortality.

RESULTS

The analysis showed no significant difference in MACE between the sirolimus-treated and untreated groups (hazard ratio, 1.40; 95% confidence interval, .77-2.55), despite a higher incidence of dyslipidaemia in the sirolimus-treated group. However, subgroup analysis revealed an increased MACE risk in KTRs with pre-transplant congestive heart failure (CHF) who were treated with sirolimus (hazard ratio, 6.22; 95% confidence interval, 1.78-21.74), while no significant differences were found in other subgroups.

CONCLUSIONS

These findings suggest that while sirolimus can be a viable option for immunosuppression, it should be used cautiously in those with pre-existing CHF.

Novel association between graft rejection and post-transplant malignancy in solid organ transplantation

BACKGROUND

Advancements in immunosuppressive therapies have improved graft survival by enhancing graft tolerance and preventing organ rejection. However, the risk of malignancy associated with prolonged immunosuppression remains a concern, as it can adversely affect recipients’ quality of life and survival. While the link between immunosuppression and increased cancer risk is well-documented, the specific interactions between graft rejection and post-transplant malignancy (PTM) remain poorly understood. Addressing this knowledge gap is crucial for devising immunosuppressive strategies that balance rejection prevention with cancer risk reduction.

AIM

To investigate whether immunosuppression in PTM reduces rejection risk, while immune activation during rejection protects against malignancy.

METHODS

We analyzed data from the United Network for Organ Sharing’s Organ Procurement and Transplantation Network database (1987–2023) on adult, first-time, single-organ transplant recipients with no prior history of malignancy (in donors or recipients). Landmark analyses at 1, 2, 3, 5, 10, 15, and 20 years post-transplant, Kaplan–Meier analyses, and time-dependent Cox proportional hazards regression models, each incorporating the temporal dimension of outcomes, assessed the association between rejection-induced graft failure (RGF) and PTM. Multivariate models were adjusted for clinical and immunological factors, including immunosuppression regimens.

RESULTS

The cohort included 579905 recipients (kidney: 386878; liver: 108390; heart: 45046; lung: 37643; pancreas: 1948) with a mean follow-up of 7.3 years and a median age of 50.6 ± 13.2 years. RGF was associated with a reduction in PTM risk across all time points [hazard ratio (HR) = 0.07-0.20, P < 0.001], even after excluding mortality cases. Kidney transplant recipients exhibited the most pronounced reduction (HR = 0.22, P < 0.001). Conversely, among recipients with PTM, RGF risk decreased across all time points up to 15 years after excluding mortality cases (HR = 0.49–0.80, P < 0.001). This risk reduction was observed in kidney, liver, heart, and lung transplants (HRs = 0.90, 0.21, 0.21, and 0.18, respectively; P < 0.001) but not in pancreas transplants.

CONCLUSION

RGF reduces PTM risk, particularly in kidney transplants, while PTM decreases RGF risk in kidney, liver, heart, and lung transplants.

Complications Associated with Immunosuppressive Agents in Solid Organ Transplant Recipients: A Nationwide Analysis

Background: Immunosuppressive therapies are vital for solid organ transplant (SOT) recipients to ensure graft survival, but long-term use can lead to complications. This study aimed to comprehensively evaluate the complications associated with immunosuppressive agents across different types of major SOTs. Methods: In a retrospective cohort study using a national claims database, we analyzed adult SOT recipients who began immunosuppressive therapy from 2007 to 2018. We identified complications such as infections, acute kidney injury, hypertensive emergencies, chronic kidney disease, hypertension, diabetes, dyslipidemia, and osteoporosis. These outcomes were determined through diagnostic codes, medication usage data, and hospital or emergency department visits. Results: Among 30,997 transplants with three-year follow up, complication rates varied by transplant type. Pancreatic transplant recipients had the lowest complication rate (225.9 per 1000 patient-years), while lung transplant recipients experienced the highest rate (823.9 per 1000 patient-years). Serious infections and chronic kidney disease were most common 2 to 6 months post transplant. Other complications, like acute kidney injury, hypertensive emergencies, hypertension, diabetes, dyslipidemia, and osteoporosis, were predominantly observed in the first month. Opportunistic infections peaked between 7 months and 1 year after transplantation. Conclusions: This study emphasizes the varied complications related to immunosuppressive therapy among different SOT recipients, delineating specific timeframes for each complication and maintenance regimen.

Time-dependent impact of immunosuppressant regimens on cardiovascular outcomes in kidney transplant recipients: a nationwide cohort study

Objectives

We aimed to evaluate the effect of different immunosuppressive regimens on the risk of major adverse cardiovascular events (MACEs) in kidney transplant recipients (KTRs).

Methods

This retrospective cohort study used nationwide claims data from the Korean Health Insurance Review and Assessment Service from between 2010 and 2021. Immunosuppressive medications were analyzed as time-dependent variables, and the primary outcome was MACEs, defined as a composite of myocardial infarction, coronary revascularization, ischemic stroke, and all-cause mortality.

Results

A total of 8,056 KTRs were included in the analysis, with significant risk factors for MACEs identified as male sex, older age, longer dialysis duration, lower economic status, and greater comorbidity. At the time of the kidney transplant, 86.7% of the KTRs were administered standard triple therapy, after which various immunosuppressive regimens, including sirolimus-inclusive regimens, were employed. The risk of MACE was lower or comparable in KTRs standard triple therapy than in those receiving most other immunosuppressive regimens. However, corticosteroid withdrawal was associated with a significant reduction in cardiovascular risk, particularly in KTRs with preexisting diabetes or dyslipidemia.

Conclusion

These findings suggest that early consideration should be given to minimizing steroid use in KTRs with dyslipidemia or diabetes to optimize cardiovascular outcomes.

Evaluation of efficacy and safety of generic tacrolimus (Suprotac®) compared to reference tacrolimus (Prograf®) in kidney transplantation: a phase IV study

Transplant recipients are given an immunosuppressive regimen such as tacrolimus to prevent organ rejection. Suprotac® is a generic tacrolimus that is utilized in kidney transplantation regimen in Iran. This post-market study was conducted to evaluate the safety and efficacy of Suprotac® in comparison with Prograf®. In this two-armed, open-label, parallel, active-controlled, and cohort study, de novo kidney transplant recipients aging 18 to 65 years were prescribed Suprotac® or Prograf® as part of the immunosuppressant protocol. The primary outcome was comparing the mean estimated glomerular filtration rate (eGFR) at month 12. The secondary outcomes were the assessment of patient and graft survival, acute rejections during hospitalization, tacrolimus dose, trough concentration, and Trough Concentration/dose (C/D) ratio, and Adverse Events (AEs) during the study period. A total of 201 patients were enrolled in this study. At discharge, the eGFR was lower in the Suprotac® group compared to the Prograf® group (51.70 ml/min/1.73m2 and 57.48 ml/min/1.73m2, respectively; p=0.042). However, at month 12, there was no significant difference in mean eGFR between the two groups (58.94 ml/min/1.73m2 and 59.78 ml/min/1.73m2, respectively; p=0.772). Other outcomes, including patient and graft survival, acute rejection during hospitalization, tacrolimus dose, trough concentration, and C/D ratio, and overall incidence of AEs were similar between the two groups (p >0.05). The efficacy and safety profile of the generic tacrolimus were shown to be comparable to the reference tacrolimus at month 12.

Sex Differences in the Risk of Bladder Cancer among Kidney Transplant Recipients and Patients with Kidney Failure Receiving Hemodialysis: A Nationwide Cohort Study

INTRODUCTION

Although both patients with kidney failure (KF) receiving hemodialysis (HD) and kidney transplantation (KT) recipients (KTRs) have a high risk of bladder cancer, how this risk changes in the transition from dialysis to KT is unknown. In this study, we aimed to investigate the risk of bladder cancer in KTRs and patients on HD.

METHODS

This was a nationwide longitudinal cohort study of 66,547 participants from the National Health Insurance Service cohort who started HD for patients with KF or who received KT from 2002 to 2020. The primary outcome was the diagnosis of bladder cancer, which was defined as the composite of diagnostic codes and either hospitalization or ≥2 outpatient visits for bladder cancer.

RESULTS

During mean follow-ups of 4.2 and 7.9 years in the HD and KT groups, respectively, the incidence rates of bladder cancer were 1.1/1,000 and 0.3/1,000 person-years, respectively. In the time-dependent multivariable Cox models, compared to patients on HD, the adjusted hazard ratio (aHR) for bladder cancer among KTRs was 0.36 (95% confidence interval [CI], 0.21-0.60; p < 0.001). Among men, this aHR was 0.29 (95% CI, 0.15-0.55; p < 0.001); however, no statistically significant association between the kidney replacement therapy modality and the risk of bladder cancer was observed among women. Landmark analysis performed to avoid immortal time bias by redefining time zero as a specific landmark time (2 and 5 years after HD initiation or KT) revealed similar results.

CONCLUSION

The risk of bladder cancer was significantly lower among KTRs than that among patients receiving HD, particularly among men.

Report on post-transplantation cancer in southeast Asia from the Thai kidney transplantation cohort

Post-transplantation cancer is a significant cause of mortality among kidney transplant recipients (KTR). The incidence of post-transplantation cancer varies based on geographic region and ethnicity. However, data on KTR from South East Asia, where characteristics differ from other parts of Asia, is lacking. We conducted a retrospective cohort study at a transplant center in Thailand to investigate the incidence of post-transplantation cancer and mortality rates. Factors associated with post-transplantation cancer and patient outcomes were analyzed using competing-risks regression. The study included 1156 KTR with a post-transplant follow-up duration of 5.1 (2.7-9.4) years. The age- and sex-adjusted incidence rate of post-transplant cancer was highest for urothelial cancer (6.9 per 1000 person-years), which also resulted in the highest standardized incidence ratio (SIR) of 42.5 when compared to the general population. Kidney cancer had the second-highest SIR of 24.4. Increasing age was the factor associated with an increased risk of post-transplant cancer (SHR 1.03; 95% CI 1.01-1.05). Human leukocyte antigen (HLA) DR mismatch was associated with a decreased risk of post-transplant cancer (SHR 0.72; 95% CI 0.52-0.98). Post-transplantation cancer was significantly associated with patient mortality (HR 3.16; 95% CI 2.21-4.52). Cancer significantly contributes to KTR mortality, and the risk profile for cancer development in Thai KTRs differs from that of Western and most Asian counterparts. Further research is essential to explore appropriate screening protocols for countries with high rates of urothelial and kidney cancer, including Thailand.

Impact of Induction Immunosuppressants on T Lymphocyte Subsets after Kidney Transplantation: A Prospective Observational Study with Focus on Anti-Thymocyte Globulin and Basiliximab Induction Therapies

Induction immunosuppressive therapy for kidney transplant recipients (KTRs) primarily includes interleukin-2 receptor antagonists, such as basiliximab (BXM) or lymphocyte-depleting agents, and anti-thymocyte globulin (ATG). This study aimed to investigate their effects on T cell dynamics during the early post-transplantation period. This prospective observational study included 157 KTRs. Peripheral blood samples were collected from each patient within 5 days before and 4 and 12 weeks after transplantation. Flow cytometric analysis was performed to assess various T cell subsets whose changes were then analyzed. In the ATG group, CD4+ T cell expression decreased significantly compared with that in the BXM group. However, CD4+CD161+ and CD4+CD25+CD127low T cell expression levels increased significantly. In the CD8+ T cell subset, a decrease in CD8+CD28nullCD57+ and CD8+CCR7+ T cell expression was observed in the ATG group. However, among patients diagnosed with biopsy-proven acute rejection, T cell subset expression did not significantly differ relative to non-rejection cases. In conclusion, ATG induction therapy resulted in more pronounced changes in T lymphocyte subsets than BXM induction, with increased CD4+CD161+ and CD4+CD25+CD127low T cells and an early decrease in CD8+CD28nullCD57+ and CD8+CCR7+ T cells, some of which are associated with acute rejection.

Associations of Perioperative Red Blood Cell Transfusion With Outcomes of Kidney Transplantation in Korea Over a 16-Year Period

BACKGROUND

This study investigated the associations between transfusion of different types of red blood cell (RBC) preparations and kidney allograft outcomes after kidney transplantation (KT) over a 16-year period in Korea using a nationwide population-based cohort.

METHODS

We investigated the reported use of RBCs during hospitalization for KT surgery, rejection, and graft failure status using nationwide data from the National Health Information Database (2002-2017). The associations between the type of perioperative RBC product and transplant outcomes were evaluated among four predefined groups: no RBC transfusion, filtered RBCs, washed RBCs, and packed RBCs (pRBCs).

RESULTS

A total of 17,754 KT patients was included, among which 8,530 (48.0%) received some type of RBC transfusion. Of the patients who received RBC transfusion, 74.9%, 19.7%, and 5.4% received filtered RBCs, pRBCs, or washed RBCs, respectively. Regardless of the type of RBC products, the proportions of acute rejection and graft failure was significantly greater in patients receiving transfusion (P < 0.001). Cox proportional hazards regression analyses showed that the filtered RBC and pRBC groups were significantly associated with both rejection and graft failure. The washed RBC group also had hazard ratios greater than 1.0 for rejection and graft failure, but the association was not significant. Rejection-free survival of the pRBC group was significantly lower than that of the other groups (P < 0.001, log-rank test), and graft survival for the no RBC transfusion group was significantly greater than in the other groups (P < 0.001, log-rank test).

CONCLUSION

Perioperative RBC transfusion was associated with poor graft outcomes. Notably, transfusion of pRBCs significantly increased transplant rejection. Therefore, careful consideration of indications for RBC transfusion and selection of the appropriate type of RBCs is necessary, especially for patients at high risk of rejection or graft failure.

Predictor factor for worse outcomes in kidney transplant recipients infected with coronavirus disease 2019: A systematic review and meta-analysis

INTRODUCTION

The pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a massive impact on the health sector, especially in patients with pre-existing comorbidities. This study aims to define the predictor factors for worse outcomes in kidney transplant patients infected with SARS-CoV-2 and affected by coronavirus disease 2019 (COVID-19). We have analyzed in these patients their prior medical history, their clinical symptoms, and their laboratory results.

METHOD

We assessed outcomes of kidney transplant patients with confirmed COVID-19 until July 2021 from PubMed, Medline, Science Direct, Cochrane databases, EMBASE, Scopus, and EBSCO. We performed meta-analyses of nine published studies to estimate predictor factors. The analysis was analyzed by the Newcastle-Ottawa Scale (NOS) and then using the Review Manager 5.4 software.

RESULT

Our analysis demonstrated that the most significant risk factors for the worse COVID-19 outcomes for kidney transplant patients included: age of 60 and older [MD 9.31(95% CI, 6.31-12.30), p < 0.0001, I2 = 76%], diabetic nephropathy [OR 2.13 (95% CI, 1.49-3.04), p < 0.0001, I2 = 76%], dyspnea [OR 4.53, (95% CI, 2.22-9.22), p < 0.0001, I2 = 76%], acute kidney injury (AKI) [OR 4.53 (95% CI, 1.10-5.21), p = 0.03, I2 = 58%], and some laboratory markers. Many patients had two or multiple risk factors in combination.

CONCLUSION

Age and several comorbidities were the most significant factors for COVID-19 outcomes for kidney transplant recipients.

Characteristics of stroke after liver and kidney transplantation

Background

The mechanism and characteristics of a post-transplantation stroke may differ between liver (LT) and kidney transplantation (KT), as the associated comorbidities and peri-surgical conditions are different. Herein, we investigated the characteristics and etiologies of stroke occurring after LT and KT.

Methods

Consecutive patients who received LT or KT between January 2005 to December 2020 who were diagnosed with ischemic or hemorrhagic stroke after transplantation were enrolled. Ischemic strokes were further classified according to the etiologies. The characteristics of stroke, including in-hospital stroke, perioperative stroke, stroke etiology, and timing of stroke, were compared between the LT and KT groups.

Results

There were 105 (1.8%) and 58 (1.3%) post-transplantation stroke patients in 5,950 LT and 4,475 KT recipients, respectively. Diabetes, hypertension, and coronary arterial disease were less frequent in the LT than the KT group. In-hospital and perioperative strokes were more common in LT than in the KT group (LT, 57.9%; KT, 39.7%; p = 0.03, and LT, 43.9%; KT, 27.6%; p = 0.04, respectively). Hemorrhagic strokes were also more common in the LT group (LT, 25.2%; KT, 8.6%; p = 0.01). Analysis of ischemic stroke etiology did not reveal significant difference between the two groups; undetermined etiology was the most common, followed by small vessel occlusion and cardioembolism. The 3-month mortality was similar between the two groups (both LT and KT, 10.3%) and was independently associated with in-hospital stroke and elevated C-reactive protein.

Conclusions

In-hospital, perioperative, and hemorrhagic strokes were more common in the LT group than in the KT group. Ischemic stroke subtypes did not differ significantly between the two groups and undetermined etiology was the most common cause of ischemic stroke in both groups. High mortality after stroke was noted in transplantation patients and was associated with in-hospital stroke.

Pregnancy outcomes after living kidney donation from a nationwide population-based cohort study from Korea

While most living kidney donors experience good outcomes and high rates of satisfaction, kidney donation can increase the risk of gestational hypertension or preeclampsia. However, pregnancy outcomes in non-white donors are limited. We conducted a nationwide cohort study of 112 living kidney donors and 672 matched healthy non-donors using the Korean National Health Insurance Claims Database. Donors and healthy non-donors were matched according to age, year of cohort entry, residency, income, number of pregnancies, and the time to the first pregnancy after cohort entry. We assessed pregnancy outcomes of live kidney donors compared with matched healthy non-donors using the nationwide database. Gestational hypertension or preeclampsia was more common in kidney donors than in non-donors (8.9% vs. 1.8%; adjusted odds ratio, 2.68; 95% confidence interval, 1.11-6.50). However, the incidence of severe gestational hypertension or preeclampsia that required antihypertensive medication was comparable (2.7% vs. 0.9%; P = 0.121). The time from donation to delivery within 5 years and primiparity were risk factors for preeclampsia in donors. Low birth weight, stillbirth, and ectopic pregnancy were not significantly different between the two groups. Maternal death occurred in two non-donor cases, but none occurred in donors compared to non-donors. Our findings indicate that kidney donors are associated with an increased risk of gestational hypertension or preeclampsia than matched healthy non-donors. However, the probabilities of serious maternal and fetal outcomes remained low and are not increased significantly after kidney donation.

Impact of donor hypertension on graft survival and function in living and deceased donor kidney transplantation: a nationwide prospective cohort study

OBJECTIVES

Hypertensive living donors are potential candidates to expand the kidney donor pool. However, the impact of donor hypertension on graft survival and function remains to be clarified.

METHODS

We analyzed 3907 kidney transplant recipients registered in a nationwide prospective cohort from 2014 to 2018. Patients were divided by donor types and the presence of donor hypertension. The primary and secondary outcome was the occurrence of death-censored graft failure and renal allograft function, respectively.

RESULTS

The prevalence of hypertension was 9.4% (258/2740) and 19.9% (232/1167) in living and deceased donors, respectively. During a median follow-up of 21.8 months, death-censored graft survival rate was significantly worse in recipients of hypertensive living donors than in those of normotensive living donors ( P  = 0.008). In multivariable analysis, recipients of hypertensive living donors had a significantly increased risk of graft loss (adjusted hazard ratio 2.91; P  = 0.009). The risk of allograft loss was not different between recipients of hypertensive living and normotensive deceased donors. Propensity score-matched analyses had consistent worse graft survival rate in recipients of hypertensive living donors compared to those of normotensive living donors ( P  = 0.027), while it was not different between recipients of hypertensive living and normotensive deceased donors. Hypertension in living donors had a significant negative impact on one-year graft function (adjusted unstandardized β -3.64; P  = 0.011).

CONCLUSIONS

Hypertensive living donor recipients have significantly higher risks of renal allograft loss than normotensive living donor recipients, and showed similar outcomes compared to recipients of normotensive deceased donors.