Death with graft function after kidney transplantation: a single-center experience

Effect of metformin use on graft and patient survival in kidney transplant recipients with type 2 diabetes: a systematic review protocol

INTRODUCTION

Metformin is a first-line antihyperglycaemic agent for type 2 diabetes (T2DM). In addition to glycaemic control, it offers benefits related to cardiovascular health, weight neutrality and metabolic syndrome. However, its benefits in kidney transplant recipients remain unclear as metformin use is controversial in this population due to a lack of evidence and there are recommendations against its use in patients with poor kidney function. Hence, we seek to describe a protocol for a systematic review, which will assess the impact of metformin use on graft survival and mortality in kidney transplant recipients.

METHODS

This protocol was guided by the standards of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols 2015. We will search empirical databases such as MEDLINE, Embase, Cochrane Library, CINAHL and Web of Science Core Collection for relevant studies conducted in kidney transplant recipients using metformin, which report outcomes related to graft and patient survival. All studies meeting these criteria in adults and published in English from inception to 2023 will be included in our review. We will employ the Cochrane Risk of Bias Tool 2 for randomised controlled trials and the Risk of Bias in Non-randomised Studies of Intervention for non-randomised studies. We will present our data and study characteristics in a table format and determine if a meta-analysis can be performed by clinical and methodological heterogeneity, using the I2 statistics. If a meta-analysis cannot be performed, we will provide a narrative synthesis of included studies using the Synthesis Without Meta-Analysis Reporting Guideline.

ETHICS AND DISSEMINATION

Ethical approval will not be required for this review as the data used will be extracted from already published studies with publicly accessible data. As this study will assess the impact of metformin use on graft and patient survival in kidney transplant recipients, evidence gathered through it will be disseminated using traditional approaches that include open-access peer-reviewed publication, scientific presentations and a report. We will also disseminate our findings to appropriate academic bodies in charge of publishing guidelines related to T2DM and transplantation, as well as patient and research centred groups.

PROSPERO REGISTRATION NUMBER

CRD42023421799.

Impact of Immunosenescence in Older Kidney Transplant Recipients: Associated Clinical Outcomes and Possible Risk Stratification for Immunosuppression Reduction

The number of older individuals receiving a kidney transplant as replacement therapy has significantly increased in the past decades and this increase is expected to continue. Older patients have a lower rate of acute rejection but an increased incidence of death with a functioning graft. Several factors, including an increased incidence of infections, post-transplant malignancy and cardiovascular comorbidity and mortality, contribute to this increased risk. Notwithstanding, kidney transplantation is still the best form of kidney replacement therapy in all patients with chronic kidney disease, including in older individuals. The best form of immunosuppression and the optimal dose of these medications in older recipients remains a topic of discussion. Pharmacological studies have usually excluded older patients and when included, patients were highly selected and their numbers insignificant to draw a reasonable conclusion. The reduced incidence of acute rejection in older recipients has largely been attributed to immunosenescence. Immunosenescence refers to the aging of the innate and adaptive immunity, accumulating in phenotypic and functional changes. These changes influences the response of the immune system to new challenges. In older individuals, immunosenescence is associated with increased susceptibility to infectious pathogens, a decreased response after vaccinations, increased risk of malignancies and cardiovascular morbidity and mortality. Chronic kidney disease is associated with premature immunosenescent changes, and these are independent of aging. The immunosenescent state is associated with low-grade sterile inflammation termed inflammaging. This chronic low-grade inflammation triggers a compensatory immunosuppressive state to avoid further tissue damage, leaving older individuals with chronic kidney disease in an immune-impaired state before kidney transplantation. Immunosuppression after transplantation may further enhance progression of this immunosenescent state. This review covers the role of immunosenescence in older kidney transplant recipients and it details present knowledge of the changes in chronic kidney disease and after transplantation. The impact of immunosuppression on the progression and complications of an immunosenescent state are discussed, and the future direction of a possible clinical implementation of immunosenescence to individualize/reduce immunosuppression in older recipients is laid out.

Predictors of graft function and survival in second kidney transplantation: A single center experience

BACKGROUND

The increasing kidney retransplantation rate has created a parallel field of research, including the risk factors and outcomes of this advanced form of renal replacement therapy. The presentation of experiences from different kidney transplantation centers may help enrich the literature on kidney retransplantation, as a specific topic in the field of kidney transplantation.

AIM

To identify the risk factors affecting primary graft function and graft survival rates after second kidney transplantation (SKT).

METHODS

The records of SKT cases performed between January 1977 and December 2014 at a European tertiary-level kidney transplantation center were retrospectively reviewed and analyzed. Beside the descriptive characteristics, the survivals of patients and both the first and second grafts were described using Kaplan-Meier curves. In addition, Kaplan-Meier analyses were also used to estimate the survival probabilities at 1, 3, 5, and 10 post-operative years, as well as at the longest follow-up duration available. Moreover, bivariate associations between various predictors and the categorical outcomes were assessed, using the suitable biostatistical tests, according to the predictor type.

RESULTS

Out of 1861 cases of kidney transplantation, only 48 cases with SKT were eligible for studying, including 33 men and 15 women with a mean age of 42.1 ± 13 years. The primary non-function (PNF) graft occurred in five patients (10.4%). In bivariate analyses, a high body mass index (P = 0.009) and first graft loss due to acute rejection (P = 0.025) were the only significant predictors of PNF graft. The second graft survival was reduced by delayed graft function in the first (P = 0.008) and second (P < 0.001) grafts. However, the effect of acute rejection within the first year after the first transplant did not reach the threshold of significance (P = 0.053). The mean follow-up period was 59.8 ± 48.6 mo. Censored graft/patient survival rates at 1, 3, 5 and 10 years were 90.5%/97.9%, 79.9%/95.6%, 73.7%/91.9%, and 51.6%/83.0%, respectively.

CONCLUSION

Non-immediate recovery modes of the first and second graft functions were significantly associated with unfavorable second graft survival rates. Patient and graft survival rates of SKT were similar to those of the first kidney transplantation.

A multinational cohort study uncovered sex differences in excess mortality after kidney transplant

Worldwide and at all ages, males have a higher mortality risk than females. This mortality bias should be preserved in kidney transplant recipients unless there are sex differences in the effects of transplantation. Here we compared the excess risk of mortality (risk above the general population) in female versus male recipients of all ages recorded in three large transplant databases. This included first deceased donor kidney transplant recipients and accounted for the modifying effects of donor sex and recipient age. After harmonization of variables across cohorts, relative survival models were fitted in each cohort separately and results were combined using individual patient data meta-analysis among 466,892 individuals (1988-2019). When the donor was male, female recipients 0-12 years (Relative Excess Risk 1.54, 95% Confidence Interval 1.20-1.99), 13-24 years (1.17, 1.01-1.34), 25-44 years (1.11, 1.05-1.18) and 60 years and older (1.05, 1.02-1.08) showed higher excess mortality risks than male recipients of the same age. When the donor was female, the Relative Excess Risk for those over 12 years were similar to those when the donor was male. There is a higher excess mortality risk in female than male recipients with differences larger at younger than older ages and only statistically significant when the donor was male. While these findings may be partly explained by the known sex differences in graft loss risks, sex differences in the risks of death with graft function may also contribute. Thus, higher risks in females than males suggest that management needs to be modified to optimize transplant outcomes among females.

Long-term mortality in pediatric solid organ recipients-A nationwide study

BACKGROUND

The present study aimed at investigating long-term mortality of patients who underwent solid organ transplantation during childhood and at identifying their causes of death.

METHODS

A cohort of 233 pediatric solid organ transplant recipients who had a kidney, liver, or heart transplantation between 1982 and 2015 in Finland were studied. Year of birth-, sex-, and hometown-matched controls (n = 1157) were identified using the Population Register Center registry. The Causes of Death Registry was utilized to identify the causes of death.

RESULTS

Among the transplant recipients, there were 60 (25.8%) deaths (median follow-up 18.0 years, interquartile range of 11.0-23.0 years). Transplant recipients' risk of death was nearly 130-fold higher than that of the controls (95% CI 51.9-1784.6). The 20-year survival rates for kidney, liver, and heart recipients were 86.1% (95% CI 79.9%-92.3%), 58.5% (95% CI 46.2%-74.1%), and 61.4% (95% CI 48.1%-78.4%), respectively. The most common causes of death were cardiovascular diseases (23%), infections (22%), and malignancies (17%). There were no significant differences in survival based on sex or transplantation era.

CONCLUSION

The late mortality is still significantly higher among pediatric solid organ recipients in comparison with controls. Cardiovascular complications, infections, and cancers are the main causes of late mortality for all studied transplant groups. These findings emphasize the cruciality of careful monitoring of pediatric transplant recipients in order to reduce long-term mortality.

[Analysis of causes of graft loss in 135 kidney transplant recipients]

OBJECTIVE

To investigate the causes of graft loss in kidney transplant recipients.

METHODS

We retrospectively analyzed the clinical data of 135 recipients with graft loss after renal transplantation in the Eighth Medical Center of Chinese PLA General Hospital from January 1, 2002 to January 1, 2022.

RESULTS

A total of 135 kidney transplant recipients experienced graft failure. The causes of graft loss included graft rejection (70 cases, 51.8%), death of the recipients with functional graft (37 cases, 27.4%), surgical complications (12 cases, 8.9%), drug toxicity (4 cases, 3.0%), carbapenem-resistant Klebsiella pneumoniae infection (4 cases, 3.0%), polyoma BK virus-related nephropathy (3 cases, 2.2%), primary nonfunctioning kidney (2 cases, 1.5%), recurrence of primary disease (2 cases, 1.5%), and prerenal acute renal failure (1 case, 0.7%).

CONCLUSION

The main cause of graft loss after renal transplantation is graft rejection, and the secondary cause is death of the recipient with functional graft, and other reasons can be rare.

Experiences of performing ABO-incompatible kidney transplantation in Bangladesh

Background

The number of end-stage renal disease (ESRD) patients is increasing in Bangladesh. Currently, living kidney donation is the only viable option for transplantation in Bangladesh, and it is further restricted by ABO compatibility issues. We have performed ABO-incompatible kidney transplantations (ABOi KTs) in Bangladesh since 2018. This study examines our experiences with seven cases of ABOi KT.

Methods

The desensitization protocol included low-dose rituximab (100 mg/body) followed by plasma exchange (PEX), which was followed by a 5-g dose of intravenous immunoglobulin. Immunosuppression was undertaken using tacrolimus (0.1 mg/kg/day), mycophenolate mofetil (1,500 mg/day), and prednisolone (0.5 mg/kg/day). All patients received basiliximab for induction therapy.

Results

The median baseline anti-ABO antibody titer was 164 (range, 132–1128). Transplantation was performed at a titer of ≤18. Our patients attended three to five PEX sessions before transplantation. Graft survival was 100% in the seven cases over a mean period of 22 months. The mean creatinine level was 204.6±47.4 µmol/L. Two patients were suspected of having developed acute rejection and received intravenous methylprednisolone, resulting in improved kidney function. One patient required posttransplant hemodialysis due to delayed graft function and subsequently improved. Infection was the most common complication experienced by ABOi KT patients. Two patients developed severe cytomegalovirus pneumonia and died with functioning grafts.

Conclusions

ABOi KT in Bangladesh will substantially expand the living kidney donor pool and bring hope to a large number of ESRD patients without ABO-compatible donors. However, the high cost and risk of acute rejection and infection remain major concerns.

Death With a Functioning Graft Kidney: A Single-Center Experience of More Than 4 Decades

OBJECTIVES

Death with graft function is one of the most catastrophic events after kidney transplant. Various pre and posttransplant risk factors have been linked to death with graft function. Characterization of this event is crucial to set successful preventive measures. Here, we reported on death with graft function among living donor kidney transplant recipients seen at the Urology and Nephrology Centre at Mansoura University (Mansoura, Egypt) throughout a period of >4 decades.

MATERIALS AND METHODS

This single-center study included 2953 patients who received living donor kidney transplant between March 1976 and December 2018. Patient data were retrospectively analyzed. Patients who had death with graft function were compared with other patients with regard to pre- and posttransplant data. Causes of death with graft function were also studied.

RESULTS

Among our patients (1654 male [56%] and 1299 female [44%] patients), death with graft function was reported in 9.9% of patients and responsible for 58.3% of deaths and 24.6% of graft losses. Male sex, pretransplant dialysis and blood transfusion, pre- and posttransplant diabetes and hypertension, high HLA mismatches, antithymocyte globulin induction, steroid and cyclosporine use, steroid dose, acute rejection episodes, and posttransplant infections and malignancy were significantly higher among the death with graft function group. However, multivariate analyses showed that only pretransplant diabetes, steroid dose, and posttransplant infections were risk factors for death with graft function. The most common causes of death with graft function were cardiovascular disease, infections, and malignancy.

CONCLUSIONS

Death with graft function remains a significant hindrance to competent kidney transplant outcomes. We found that the most common contributors to this major event were cardiovascular disease, infections, and malignancy. More attention is needed to modify risk factors of cardiovascular disease, to update implementation policies for posttransplant vaccinations, and to conduct increased malignancy surveillance, as well to adopt less aggressive immunosuppression regimens.

Time-Varying Proteinuria and the Risk of Cardiovascular Disease and Graft Failure in Kidney Transplant Recipients

Introduction: Proteinuria is recognized as an independent risk factor for cardiovascular disease in kidney transplant recipients, but previous studies have not considered the impact of changes in urine protein over time. Research Question and Design: We used time-dependent, multivariable Cox proportional hazards models in this observational cohort study of adult kidney transplant recipients to evaluate whether proteinuria measured by dipstick on random spot urine samples starting from 1-month post-transplant was associated with the risk of major adverse cardiac events and graft loss. Results: A total of 144 major adverse cardiac events, defined as acute myocardial infarction, cerebrovascular accident, revascularization, or all-cause mortality, were observed in 1106 patients over 5728.7 person-years. Any level of proteinuria greater or equal to trace resulted in a two-fold increase in the risk of major adverse cardiac events (hazard ratio 2.00 [95% confidence interval 1.41, 2.84]). This relationship was not found to be dose-dependent (hazard ratios of 2.98, 1.76, 1.63, and 1.54 for trace, 1+, 2+, and 3+ urine protein, respectively). There was an increased risk of graft failure with greater urine protein concentration (hazard ratios 2.22, 2.85, 6.41, and 19.71 for trace, 1+, 2+, and 3+, respectively). Conclusion: Urine protein is associated with major adverse cardiac events and graft loss in kidney transplant recipients. The role of interventions to reduce proteinuria on decreasing the risk of adverse cardiovascular and graft outcomes in kidney transplant recipients requires further study.

Oral/oesophageal candidiasis is a risk factor for severe infection after kidney transplantation

Aim

Bacterial and fungal infections are serious, life‐threatening conditions after kidney transplantation. The development of oral/oesophageal candidiasis after kidney transplantation is not a reported risk factor for subsequent severe infection. This study was performed to investigate the relationship between oral/oesophageal candidiasis after kidney transplantation and the development of subsequent infection requiring hospitalization.

Methods

This retrospective study included 522 consecutive patients who underwent kidney transplantation at Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital from 1 January 2010 to 1 February 2019. Ninety‐five percentage of patients were living donor transplant recipients. Visual examination was performed to detect oral candidiasis, beginning immediately after kidney transplantation; upper gastrointestinal endoscopy was performed 8–10 months after kidney transplantation. Twenty‐five patients developed candidiasis (Candida‐onset group) and 497 did not (non‐Candida‐onset group). The follow‐up periods were 67 (37–86) months in the Candida‐onset group and 55 (34–89) months in the non‐Candida‐onset group. Severe infection was defined as bacterial or fungal infection requiring hospitalization; viral infections were excluded.

Results

Severe infection developed in 9/25 (36%) patients in the Candida‐onset group and in 77/497 (15%) patients in the non‐Candida‐onset group (p = .006). Binomial logistic analysis revealed that Candida infection (odds ratio [OR] 2.53, 95% confidence interval [CI] 1.06–6.06; p = .037) and use of rituximab (OR 1.81, 95% CI 1.12–2.93; p = .016) were significant predictors of subsequent severe infection.

Conclusion

Oral/oesophageal candidiasis is a risk factor for severe infection after kidney transplantation and suggests an over‐immunosuppressive state, which should prompt evaluation of immunosuppression.

This paper concludes that oral/oesophageal candidiasis is a risk factor for severe infection following kidney transplantation. The authors suggest that the presence of oral/oesophageal candidiasis indicates an over‐immunosuppressed state, which should prompt a review of immunosuppression.

Trends in the effects of pre-transplant diabetes on mortality and cardiovascular events after kidney transplantation

AIMS/INTRODUCTION

It is not clear whether survival in kidney transplant recipients with pre-transplant diabetes has improved over the past decades. We compared the rates of mortality and major adverse cardiovascular events (MACE) after renal transplantation in patients with and without pre-transplant diabetes. Furthermore, we investigated whether transplant era and recipient age affected the association between diabetes status and adverse events.

MATERIALS AND METHODS

This retrospective cohort study included 691 patients who underwent renal transplantation between 1994 and 2016 at a single tertiary center. We compared the incidences of post-transplant mortality and four-point MACE in patients with and without pre-transplant diabetes using Kaplan-Meier analysis and the Cox proportional hazard model, and assessed the interactions between diabetes status and transplant era and recipient age.

RESULTS

Of 691 kidney recipients, 143 (20.7%) had pre-transplant diabetes. The mean follow-up duration was 94.5 months. Kaplan-Meier analysis showed that patients with pre-transplant diabetes had higher incidences of post-transplant mortality and four-point MACE compared with those without pre-transplant diabetes (log-rank test, P < 0.001 for both). After adjusting for potential confounding factors, pre-transplant diabetes was associated with an increased risk of post-transplant mortality and four-point MACE (hazard ratio 1.90, 95% confidence interval 1.05-3.44, P = 0.034; and hazard ratio 1.75; 95% confidence interval 1.02-3.00, P = 0.043, respectively). The associations between pre-transplant diabetes status and all-cause mortality and four-point MACE were not affected by transplant era or recipient age.

CONCLUSIONS

Pre-transplant diabetes remains a significant risk factor for mortality and four-point MACE in kidney transplant recipients.

Subcutaneous phaeohyphomycosis caused by Hongkongmyces snookiorum in a kidney transplant patient: a case report

BACKGROUND

Morbidity and mortality in transplant patients is increased by infection caused mainly by rare opportunistic pathogens. The present study reports a case where Hongkongmyces snookiorum caused subcutaneous phaeohyphomycosis in a kidney transplant patient.

CASE PRESENTATION

A 47-year old Chinese woman with chronic kidney disease 5 underwent kidney transplantation 3 years ago. Her regular medications included Tacrolimus (1 mg, two times daily), Mycophenolate Mofetil (two times 250 mg, twice daily) and Prednisone acetate tablets (5 mg daily). Eighteen months ago, her proximal right index finger was red, painful and swollen. After admission, a hard and fluctuating 1 cm × 1 cm abscess was found on the dorsal side of the right index finger. Gram and fluorescence staining of a direct smear of a syringe extraction from the abscess revealed presence of filamentous fungi. White velvet colonies (2-3 mm) were found on blood plate and Sabouraud glucose agar (SGA) after 1 week, and grey aerial hyphae were observed. After 15 days, a 26 mm gray colony was also observed on SGA. The homology between this filamentous fungus and Hongkongmyces snookiorum ILLS00125755 (Genbank Sequence ID: MH161189.1) was 99.66%. An in vitro antifungal susceptibility test showed that this filamentous fungus was sensitive to azoles such as itraconazole and voriconazole.

CONCLUSIONS

We report an opportunistic fungus infection caused by Hongkongmyces snookiorum in a transplant patient. Our finding shows that prevention of subcutaneous fungal infection is necessary for kidney transplantation patients.