Need for optimized immunosuppression in elderly kidney transplant recipients

A Risk Score Using a Cell-based Assay Predicts Long-term Over-immunosuppression Events in Kidney Transplant Recipients

BACKGROUND

Infections and cancer are major causes of premature death in organ recipients. However, there have been few advances in personalized immunosuppressive therapy. We previously reported that a cell-based assay measuring CD14+16+tumor necrosis factor-α+ monocytes after peripheral blood mononuclear cell (PBMC) incubation with Epstein-Barr virus peptides has a high sensitivity for detecting over-immunosuppression (OIS) events in kidney recipients in the short term. We aimed to develop a risk score for predicting long-term events.

METHODS

We studied 551 PBMC samples from 118 kidney recipients. Following random allocation to a testing and training set, we derived a risk function for the delineated tertiles of low, intermediate, and high risk of OIS based on age and CD14+16+tumor necrosis factor-α+ cells.

RESULTS

Patients were followed for a median of 6.3 y (25th-75th percentiles: 3.7-8.3 y). Of these, 40 (34%) experienced an OIS event. The validation indicated that the risk score was well calibrated, with an absolute risk of 21%, 41%, and 61% in the low-, intermediate-, and high-risk categories, respectively (P = 0.03). In sensitivity analyses, the risk score was robust to alternative definitions of OIS ranging from mild to severe. In particular, when restricted to life-threatening OIS, the proportion of events varied from 5% to 27% among the low- and high-risk categories, respectively (P = 0.01).

CONCLUSIONS

Using a combination of age and in vitro PBMC response to Epstein-Barr virus peptides allows a substantial shift in the estimated risk of OIS events.

Assessing Long-Term Adverse Outcomes in Older Kidney Transplant Recipients: A Propensity Score-Matched Comparison of Early Steroid Withdrawal Versus Continuous Steroid Immunosuppression Using a Large Real-World Database

BACKGROUND

Steroids are widely used in maintenance immunosuppression treatment in kidney transplant recipients. Older individuals undergo age-related immunosenescence that consequently decreases their ability to process and evoke a response to foreign antigens. Thus, steroids may not be necessary in preventing allograft rejection and may consequently increase older recipients' risk of long-term steroid-related adverse effects.

OBJECTIVE

The objective of this study was to analyze the adverse outcomes of long-term steroid immunosuppression in older kidney transplant recipients using real-world electronic medical record data.

METHODS

The TriNetX database "US Collaborative Network" was utilized to perform a propensity score-matched case-control study comparing 1-year, 3-year, and 5-year adverse effects of steroid immunosuppression in older adults (aged ≥ 65 years) kidney transplant recipients who underwent either an early-steroid withdrawal (ESW) maintenance regimen or a steroid continuous immunosuppression (SCI) regimen between 31 December, 2010 and 31 December, 2020. Early-steroid withdrawal was defined as tacrolimus plus mycophenolate mofetil maintenance with no prednisone after the seventh day post-transplant. Steroid continuous immunosuppression was defined as tacrolimus plus mycophenolate mofetil plus prednisone maintenance. Cohorts were matched on age, race/ethnicity, and risk factors for adverse steroid-related outcomes and rejection. Outcomes included post-transplant diabetes mellitus, dyslipidemia osteoporosis/fractures, myocardial infarction, glaucoma/cataract, stroke, pulmonary embolism, and malignancy. Secondary outcomes analyzed incidences of infection-related outcomes, graft-related outcomes, and recipient mortality.

RESULTS

After matching, there were 304 recipients in each group (ESW, SCI). Mean age at the time of transplant was 69.2 ± 3.7 years (ESW) and 69.2 ± 3.4 years (SCI, p = 0.96). The Kaplan-Meier analysis showed recipients who underwent SCI had increased incidences of post-transplant diabetes mellitus at 1 year (22.36% vs 30.37%, p = 0.01) and 3 years (34.89% vs 44.29%, p = 0.01), but this became non-significant at 5 years post-transplant (41.97% vs 42.6%, p = 0.34). Incidences of acute pancreatitis were higher for the SCI cohort at 3 years (p = 0.02) as well as incidences of acute myocardial infarction at 5 years post-kidney transplant (6.75% vs 14.39%, p < 0.01). No difference was found for other adverse outcomes. Early-steroid withdrawal recipients experienced significantly fewer infection-related outcomes, such as cytomegalovirus, BK virus, sepsis/bacteremia, and fungal infections, compared with SCI recipients. Last, recipients who underwent ESW experienced fewer incidences of rejection and death-censored graft failure at 5 years post-transplant.

CONCLUSIONS

There is currently no standard maintenance immunosuppression protocol for older kidney transplant recipients. Death-censored graft survival, rejection, and patient survival were improved with ESW. Steroid minimization may be beneficial in this population given that it lowers the risk of drug-induced adverse effects.

Adaptation Process After Kidney Transplantation in Older Adult Recipients: Applied Grounded Theory

Despite the increase in older adults receiving kidney transplantation (KT), little is known about their experience and adaptation process after KT. The current study aimed to explore the process of adaptation after KT in older adult recipients using a qualitative design and grounded theory methodology. Sixteen recipients who had KT at age ≥60 years and received follow-up care were recruited at a university hospital in South Korea. Data were collected from July to December 2017 through in-depth interviews with individual participants. The core theme of the adaptation process after KT in older adult recipients was A Journey of Straining to Save the Last Lifeline. The adaptation process comprised three stages: confusion, depression, and compromise. Tailored interventions based on the in-depth understanding of the adaptation process found in the current study are needed to improve adaptation after KT in older adult recipients. [Research in Gerontological Nursing, 16(4), 183-193.].

Renal Replacement Therapy For Elderly Patients with ESKD Through Shared Decision-Making

The incidence and prevalence of end-stage kidney disease (ESKD) in Korea are increasing, and ESKD constitutes a very important medical and social issue. Elderly dialysis patients have the highest risk of early mortality within 3 months after initiating dialysis, and geriatric syndromes such as aging, frailty, functional impairment, and cognitive impairment are crucial for the prognosis of elderly patients. Shared decision-making (SDM) is an approach through which clinicians and patients can achieve informed preferences, thereby yielding better clinical outcomes and quality of life. Through SDM-based, close consultation among patients, families, and healthcare providers, an ESKD Life-Plan for elderly patients should be established. A multidisciplinary approach led by nephrologists can help them to provide proper vascular access for dialysis at the right time, with the right evidence, and to the right patient. Strategies that can improve peritoneal dialysis in elderly patients include assisted peritoneal dialysis, homecare support programs, and automated peritoneal dialysis. In order to enhance the role of kidney transplantation in elderly patients with ESKD, it is necessary to accurately identify patients' clinical conditions before transplantation and to perform active rehabilitation activities and postoperative management to promote recovery after transplantation. With the aging population and the increase in ESKD in the elderly, clinicians must identify factors affecting the mortality and quality of life of elderly dialysis patients.

Frailty in kidney transplant candidates and recipients: pathogenesis and intervention strategies

ABSTRACT

With the rapid aging of the global population posing a serious problem, frailty, a non-specific state that reflects physiological senescence rather than aging in time, has become more widely addressed by researchers in various medical fields. A high prevalence of frailty is found among kidney transplant (KT) candidates and recipients. Therefore, their frailty has become a research hotspot in the field of transplantation. However, current studies mainly focus on the cross-sectional survey of the incidence of frailty among KT candidates and recipients and the relationship between frailty and transplantation. Research on the pathogenesis and intervention is scattered, and relevant review literature is scarce. Exploring the pathogenesis of frailty in KT candidates and recipients and determining effective intervention measures may reduce waiting list mortality and improve the long-term quality of life of KT recipients. Therefore, this review explains the pathogenesis and intervention measures for frailty in KT candidates and recipients to provide a reference for the formulation of effective intervention strategies.

The Most Promising Biomarkers of Allogeneic Kidney Transplant Rejection

Clinical transplantology is a constantly evolving field of medicine. Kidney transplantation has become standard clinical practice, and it has a significant impact on reducing mortality and improving the quality of life of patients. Allogenic transplantation induces an immune response, which may lead to the rejection of the transplanted organ. The gold standard for evaluating rejection of the transplanted kidney by the recipient's organism is a biopsy of this organ. However, due to the high invasiveness of this procedure, alternative diagnostic methods are being sought. Therefore, the biomarkers may play an essential predictive role in transplant rejection. A review of the most promising biomarkers for early diagnosis and prognosis prediction of allogenic kidney transplant rejection summarizes novel data on neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), C-X-C motif chemokine 10 (CXCL-10), cystatin C (CysC), osteopontin (OPN), and clusterin (CLU) and analyses the dynamics of changes of the biomarkers mentioned above in kidney diseases and the mechanism of rejection of the transplanted kidney.

Therapeutic and tectonic keratoplasty with simple cryopreserved remnants of donor corneas: an 11 year retrospective case series

This study sought to describe the use of deep-frozen donor corneal remnants preserved after keratoplasty procedures for therapeutic or tectonic keratoplasty without subsequent optical keratoplasty. This single-center retrospective consecutive case series analyzed the electronic medical records of patients who had undergone therapeutic or tectonic keratoplasty using deep-frozen donor remains preserved in Optisol-GS, for the past 11 years at Keimyung University Dongsan Medical Center. Fifty-five surgical cases in 46 patients were included. Twenty-three surgical cases in 18 patients underwent therapeutic keratoplasty for refractory infectious corneal ulcer. Complete eradication of primary infection was achieved in 14 patients (77.8%). Tectonic keratoplasty were performed 32 cases in 28 patients. Twenty-seven of 28 patients were ultimately able to maintain anatomical integrity (96.4%). Mean uncorrected visual acuity improved from 1.77 ± 0.94 preoperatively to 1.31 ± 0.95 at the last follow-up postoperatively in the tectonic graft group by logarithm of the minimal angle of resolution (P = 0.002). There were no cases of graft rejection. Keratoplasty using cryopreserved donor tissue is a suitable surgical alternative for infectious or non-infectious corneal ulcers in elderly patients or patients with poor general condition. It could be a viable alternative to overcome the shortage of corneal donors.

Elderly kidney transplant recipients have favorable outcomes but increased infection-related mortality

Background

The number of elderly patients with end-stage kidney disease has been increasing, but the outcomes of kidney transplants (KT) remain poorly understood in elderly patients. Therefore, we evaluated the clinical outcomes of elderly KT recipients and analyzed the impact of elderly donors.

Methods

This retrospective cohort study included patients who underwent KT between 2000 and 2019. KT recipients were divided into four groups according to a combination of recipient and donor age (≥60 or <60 years); elderly recipients: old-to-old (n = 46) and young-to-old (n = 83); young recipients: old-to-young (n = 98) and young-to-young (n = 796). We compared the risks of mortality, graft failure, and acute rejection between groups using Cox regression analysis.

Results

The incidence of delayed graft function, graft failure, and acute rejection was not different among groups. Annual mean tacrolimus trough level was not lower in elderly recipients than young recipients during 10-year follow-up. Mortality was significantly higher in elderly recipients (p = 0.001), particularly infection-related mortality (p < 0.001). In multivariable Cox regression analysis, old-to-old and young-to-old groups had increased risk of mortality (adjusted hazard ratio [aHR], 2.89; 95% confidence interval [CI], 1.14–7.32; p = 0.03; aHR, 3.06; 95% CI, 1.51–6.20; p = 0.002). However, graft failure and acute rejection risks were not increased in elderly recipients.

Conclusion

In elderly recipients, graft survival and acute rejection-free survival were not inferior to those of young recipients. However, mortality, especially risk of infection-related death, was increased in elderly recipients. Thus, low immunosuppression intensity might help decrease mortality in elderly recipients.

Immunosenescence as a reason of individualizing immunosuppressive therapy in kidney transplantation

Transplantation in elderly patients is obviously more challenging due to existing underlying diseases, changes in pharmacokinetics of immunosuppressive drugs, polypragmasy, and transformation of immunoreactivity (immunosenescence). Our review presents data on modification of adaptive and innate immunity during aging. It also considers the possibility of both reduced and adapted immunosuppressive therapy in elderly renal transplant recipients in achieving an optimal balance between efficacy and complications.

Pharmacokinetic and Pharmacodynamic Considerations in Relation to Calcineurin Usage in Elderly Kidney Transplant Recipients

This review summarizes how possible age-related changes in tacrolimus and cyclosporine pharmacokinetics and pharmacodynamics may influence drug dosing and monitoring in the elderly, and highlights how micro-sampling may be useful in this cohort in the future. Advancing biological age leads to physiological changes that can affect drug absorption, distribution, metabolism and excretion, as well as immune system responsiveness. Some studies have shown that elderly recipients may have higher dose-adjusted exposure and/or lower clearance of the calcineurin inhibitors, suggesting that doses may need to be lowered in elderly recipients. Only one study has examined how aging effects drug target enzyme activity and demonstrated that age does not correlate with the calcineurin inhibitor half-maximal inhibitory concentration. Several studies have shown elderly kidney transplant recipients have increased risk of both morbidity and mortality, compared to younger adults due to increased susceptibility to immunosuppressant side effects, particularly cardiovascular disease, infection and malignancy. Current immunosuppressant dosing and monitoring protocols often make no adjustments for age. Lower maintenance immunosuppressant targets in elderly recipients may decrease patient susceptibility to drug side effects, however, further studies are required and appropriate targets need to be established. Blood draw by micro-sampling may be useful for drug monitoring in this cohort in the future, as blood collection is minimally invasive and less painful than venepuncture. Micro-sampling could also make further pharmacokinetic, pharmacodynamics and outcome studies in the elderly more feasible.

Longitudinal immune profile reveals reduced function of pro-inflammatory monocytes with age following kidney transplantation

Toxicity of immunosuppression, notably the risk of infection, increases with age. However, the dynamic changes in innate immune response following transplantation are unclear. Based on recent observations, we hypothesized that pro-inflammatory capacity would decrease with age. We analyzed approximately 300 PBMC samples collected longitudinally in 45 de novo, adult kidney recipients and performed detailed phenotypic and functional profiling of monocytes and T cell subsets. Inflammatory response to TLR4 stimulation and indirect allostimulation using mismatched HLA peptides were assessed. In patients aged ≥56 years, TNF-α production by intermediate monocytes was similar to that in younger patients early posttransplant, but diminished substantially later. Adjusted analyses suggested that this was not attributable to confounding factors. In contrast, the alloimmune response to HLA peptides measured by IFN-γ in CD4⁺ T cells and TNF-α in monocytes was stable over time, but was low in older recipients. Measurement of CD80-86 surface expression revealed no signal for a lower costimulation capacity of APCs. These results suggest that older recipients have a reduced function of their innate pro-inflammatory immune cells posttransplant while maintaining a stable, low alloimmune response over time. The effect of reduced immunosuppressant doses on preventing this phenomenon needs to be clarified.

A Sequential Two-Step Cell-Based Assay Predicts Immunosuppression-Related Adverse Events

Immunosuppressants are associated with serious and often life-threatening adverse effects. To optimize immunotherapy, a tool that measures the immune reserve is necessary. We validated that a cell-based assay that measures TNF-α production by CD14⁺16⁺ intermediate monocytes following stimulation with EBV peptides has high sensitivity for the detection of over-immunosuppression (OIS) events. To develop a sequential, two-step assay with high specificity, we used PBMCs from kidney recipients (n = 87). Patients were classified as cases or controls, according to the occurrence of opportunistic infection, recurring bacterial infections, or de novo neoplasia. Patients who tested positive in the first step were randomly allocated to a training or a testing set for the development of the second step. In the discovery phase, an assay based on the examination of early mature B (eBm5) cells was able to discriminate OIS patients from controls with a specificity of 88%. The testing set also revealed a specificity of 88%. The interassay coefficient of variability between the experiments was 6.1%. Stratified analyses showed good diagnostic accuracy across tertiles of age and time posttransplant. In the adjusted model, the risk of OIS was more than 12 times higher in patients classified as positive than in those who tested negative (adjusted hazard ratio, 12.2; 95% confidence interval: 4.3-34.6). This sequential cell-based assay, which examines the monocyte and eBm5 cell response to EBV peptides, may be useful for identifying OIS in immunosuppressed patients.

Factors Influencing Long-Term Patient and Allograft Outcomes in Elderly Kidney Transplant Recipients

Introduction

Individuals aged ≥65 years are increasingly prevalent on the waitlist for kidney transplantation, yet evidence on recipient and donor factors that define optimal outcomes in elderly patients after kidney transplantation is scarce.

Methods

We used multivariable Cox regression modeling to determine the factors associated with all-cause death, death with a functioning graft, and overall and death-censored graft survival, using data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry.

Results

A total of 802 kidney transplant recipients aged ≥65 years underwent their first transplantation between June 2006 and December 2016. Median age at transplantation was 68 years (interquartile range = 66−69 years). The 1-year and 5-year overall patient and graft survivals (95% confidence interval [CI]) were 95.1 (93.5−96.7) and 79.0 (75.1−82.9), and 92.9 (91.1−94.7) and 75.4 (71.3−79.5), respectively. Factors associated with higher risks of all-cause death included prevalent coronary artery disease (adjusted hazard ratio [95% confidence interval] = 1.47 [1.03–2.11]), cerebrovascular disease (1.99 [1.26–3.16]), increasing graft ischemic time (1.06 per hour [1.03–1.09]), donor age (1.02 per year [1.01–1.03]), delayed graft function (1.64 [1.13−2.39]), and peritoneal dialysis pretransplantation (1.71 [1.17–2.51]).

Conclusion

Prevalent vascular disease and peritoneal dialysis as a pretransplantation dialysis modality are risk factors associated with poorer outcomes in transplant recipients aged ≥65 years. Careful selection and evaluation of potential candidates may improve graft and patient outcomes in older patients.

Induction immunosuppression and the risk of incident malignancies among older and younger kidney transplant recipients: A prospective cohort study

BACKGROUND

Older (≥65) KT recipients differ from their younger counterparts in their immune response to immunosuppression (IS) and may have a different risk of malignancy after receiving induction.

METHODS

We identified 66 700 adult KT recipients treated with anti-thymocyte globulin (ATG) (n = 40 443) or interleukin-2 receptor antagonist (IL-2RA) (n = 26 327) induction (1/1/1999-12/31/2014) using USRDS/Medicare data. We estimated the risk of first-diagnosed post-KT malignancy associated with induction (ATG vs. IL-2RA) using Cox proportional hazard models. We then tested whether these risks differed between older and younger recipients (Wald test for interaction). Models incorporated inverse probability of treatment weights to adjust for confounders.

RESULTS

The 3-year cumulative incidences of any diagnosed malignancy were 11.5%. ATG was associated with a higher malignancy risk (HR = 1.12, 95%CI:1.06-1.18). This association differed (p_interaction  = 0.04) between younger (HR = 1.12, 95%CI:1.06-1.18) and older recipients (HR = 1.03, 95%CI:0.96-1.09). ATG was also associated with higher risk of skin (HR = 1.18, 95%CI:1.08-1.29), lung (HR = 1.24, 95%CI:1.05-1.47), and ovary malignancies (HR = 1.94, 95%CI:1.08-3.48). However, only the association of ATG with post-KT skin malignancy differed (p_interaction  = 0.01) between younger (HR = 1.18; 95%CI:1.08-1.29) and older (HR = 1.01; 95%CI:0.93-1.09) recipients.

CONCLUSIONS

Compared with IL-2RA induction, ATG was associated with elevated post-KT malignancy risk but only among younger recipients. Transplant centers may need to tailor induction IS for younger recipients to mitigate malignancy risk.

DNA Methylation Age Is More Closely Associated With Infection Risk Than Chronological Age in Kidney Transplant Recipients

Older kidney transplant recipients demonstrate increased rates of infection but decreased rates of rejection compared with younger recipients, suggesting that older transplant patients are functionally overimmunosuppressed. We hypothesized that this is a consequence of reduction in immunological activity due to biological aging and that an immune biological age, as determined by DNA methylation (DNAm), would be associated more strongly with incidence of infection than chronological age.

METHODS

DNAm analysis was performed on peripheral blood mononuclear cell collected from 60 kidney transplant recipients representing older (≥age 60 y) and younger (aged 30-59 y) patients 3 months after transplantation. DNAm age was calculated based on methylation status of a panel of CpG sites, which have been previously identified as indicative of biological age.

RESULTS

Correlation was seen between chronological and DNAm age; however, there were many patients with significant differences (either acceleration or slowing) between DNAm age and chronological age. A statistically significant association was seen between increased DNAm age and incidence of infection in the first year after kidney transplantation, whereas no significant association was seen between chronological age and infection.

CONCLUSIONS

Assessment of DNAm age holds promise as an approach for patient evaluation and individualization of immune suppression regimens. This analysis may provide insights into the immunological mechanism behind increased incidence of infection observed in older transplant patients. The ability to measure biological age would allow for patient risk stratification and individualization of immunosuppression, improving outcomes for the growing numbers of older patients undergoing kidney transplantation.

Comparison of kidney allograft survival in the Eurotransplant senior program after changing the allocation criteria in 2010-A single center experience

Aims

The European Senior Program (ESP) aims to avoid waiting list competition between younger and elderly patients applying for renal transplantation. By listing patients ≥65 years on a separate waiting list and locally allocating of grafts ≥65 years exclusively to this cohort, waiting and cold ischemia times are predicted to be shortened, potentially resulting in improved kidney transplantation outcomes. This study compared a historic cohort of renal transplant recipients being simultaneously listed on the general and the ESP waiting lists with a collective exclusively listed on the ESP list in terms of surrogates of the transplantation outcome.

Methods

Total 151 eligible patients ≥ 65 years from Münster transplant Center, Germany, between 1999 and 2014 were included. Graft function, graft and patient survival were compared using surrogate markers of short- and long-term graft function. Patients were grouped according to their time of transplantation.

Results

Recipients and donors in the newESP (nESP) cohort were significantly older (69.6 ± 3.5 years vs 67.1 ± 2 years, p<0.05; 72.0 ± 5.0 years vs 70.3 ± 5.0 years, p = 0.039), had significantly shorter dialysis vintage (19.6 ± 21.7 months vs 60.2 ± 28.1 months, p<0.001) and suffered from significantly more comorbidities (2.2 ± 0.9 vs 1.8 ± 0.8, p = 0.009) than the historic cohort (HC). Five-year death-censored graft survival was better than in the HC, but 5-year graft and patient survival were better in the ESP cohort. After 2005, cold ischemia time between groups was comparable. nESP grafts showed more primary function and significantly better long-term graft function 18 months after transplantation and onwards.

Conclusion

nESP recipients received significantly older grafts, but experienced significantly shorter time on dialysis. Cold ischemia times were comparable, but graft function in the nESP cohort was significantly better in the long term.

The Frailty Risk Score predicts length of stay and need for rehospitalization after kidney transplantation in a retrospective cohort: a pilot study

Background

Frailty is a widely used measure in older patients as a predictor of poor outcomes after hospitalization and surgery. There is a growing body of data in kidney transplantation suggesting frailty can predict adverse outcomes. There is interest in using chart review measures of frailty and multimorbidity, as they may be equally predictive as physical measurement. This approach holds promise for patient evaluation, identifying candidates for prehabilitation, and targeting resources towards those anticipated to have an increased rate of clinical challenges after kidney transplantation. Frail patients who are often older may place a large resource and economic burden on transplant programs.

Methods

We applied a previously published chart review–based approach in a retrospective, pilot study to calculate the Frailty Risk Score (FRS) utilizing a cohort of kidney transplant patients. We reviewed concurrent comorbidities using the Charlson comorbidity (CM) score to determine the feasibility and utility of applying this approach in transplant patients to predict post-transplant outcomes such as length of hospitalization and the need for rehospitalization.

Results

Sixty kidney transplant recipients were evaluated by chart review, 23 characterized as older (> = 60) and 37 younger (ages 30–59). Median FRS score was 3 (range 1–7). Higher FRS was significantly associated with increased patient age (high FRS 19% in younger patients, 43% in older patients). Increased CM score was also associated with increased patient age. Patients with a high FRS stayed in the hospital for an average of 8 days, compared with 5.7 days for a low FRS. Patients with high FRS were readmitted an average of 2.9 times compared with an average of 1.1 for those with a low FRS. FRS score remained significant for predicting outcomes after adjustment for patient age.

Conclusion

Elevated FRS prior to transplantation was associated with increased hospital stay and the need for readmission in kidney transplant recipients. This analysis demonstrates the potential strength of chart review in evaluating frailty prior to transplantation, permitting risk stratification and targeting of resources for rehabilitation and close post-transplant monitoring. Frail patients may benefit from targeted “prehabilitation” to attenuate the associated adverse clinical outcomes.

Everolimus in de novo kidney transplant recipients participating in the Eurotransplant senior program: Results of a prospective randomized multicenter study (SENATOR)

Early conversion to everolimus was assessed in kidney transplant recipients participating in the Eurotransplant Senior Program (ESP), a population in whom data are lacking. The SENATOR multicenter study enrolled 207 kidney transplant recipients undergoing steroid withdrawal at week 2 post-transplant (ClinicalTrials.gov [NCT00956293]). At week 7, patients were randomized (1:2 ratio) to continue the previous calcineurin inhibitor (CNI)-based regimen with mycophenolic acid (MPA) and cyclosporine or switch to a CNI-free regimen with MPA, everolimus (5–10 ng/mL) and basiliximab at weeks 7 and 12, then followed for 18 weeks to month 6 post-transplant. The primary endpoint was estimated GFR (eGFR). At week 7, 77/207 (37.2%) patients were randomized (53 everolimus, 24 control). At month 6, eGFR was comparable: 36.5±10.8ml/min with everolimus versus 42.0±13.0ml/min in the control group (p = 0.784). Discontinuation due to adverse events occurred in 27.8% of everolimus-treated patients and 0.0% of control patients (p = 0005). Efficacy profiles showed no difference. In conclusion, eGFR, safety and efficacy outcomes at month 6 post-transplant showed no difference between groups. The everolimus group experienced a higher rate of discontinuation due to adverse events. However, the high rate of non-randomization is highly relevant, indicating this to be a somewhat unstable patient population regardless of treatment.

Infection-Related Mortality in Recipients of a Kidney Transplant in Australia and New Zealand

BACKGROUND AND OBJECTIVES

The burden of infectious disease is high among kidney transplant recipients because of concomitant immunosuppression. In this study the incidence of infectious-related mortality and associated factors were evaluated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this registry-based retrospective, longitudinal cohort study, recipients of a first kidney transplant in Australia and New Zealand between 1997 and 2015 were included. Cumulative incidence of infectious-related mortality was estimated using competing risk regression (using noninfectious mortality as a competing risk event), and compared with age-matched, populated-based data using standardized incidence ratios.

RESULTS

Among 12,519 patients, (median age 46 years, 63% men, 15% diabetic, 6% Indigenous ethnicity), 2197 (18%) died, of whom 416 (19%) died from infection. The incidence of infection-related mortality during the study period (1997-2015) was 45.8 (95% confidence interval [95% CI], 41.6 to 50.4) per 10,000 patient-years. The incidence of infection-related mortality reduced from 53.1 (95% CI, 45.0 to 62.5) per 10,000 person-years in 1997-2000 to 43.9 (95% CI, 32.5 to 59.1) per 10,000 person-years in 2011-2015 (P<0.001) Compared with the age-matched general population, kidney transplant recipients had a markedly higher risk of infectious-related death (standardized incidence ratio, 7.8; 95% CI, 7.1 to 8.6). Infectious mortality was associated with older age (≥60 years adjusted subdistribution hazard ratio [SHR], 4.16; 95% CI, 2.15 to 8.05; reference 20-30 years), female sex (SHR, 1.62; 95% CI, 1.19 to 2.29), Indigenous ethnicity (SHR, 2.87; 95% CI, 1.84 to 4.46; reference white), earlier transplant era (2011-2015: SHR, 0.39; 95% CI, 0.20 to 0.76; reference 1997-2000), and use of T cell-depleting therapy (SHR, 2.43; 95% CI, 1.36 to 4.33). Live donor transplantation was associated with lower risk of infection-related mortality (SHR, 0.53; 95% CI, 0.37 to 0.76).

CONCLUSIONS

Infection-related mortality in kidney transplant recipients is significantly higher than the general population, but has reduced over time. Risk factors include older age, female sex, Indigenous ethnicity, T cell-depleting therapy, and deceased donor transplantation.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_08_27_CJN03200319.mp3.

Outcomes of sirolimus regimens in 65-year-old and older kidney transplant recipients: a registry-based observational study

PURPOSE

In large observational studies of adult kidney transplant recipients (KTRs) where older adults (65 years old and older) were not well represented, the mammalian target of rapamycin inhibitors (mTOR inhibitors) has poorer outcomes than the standard tacrolimus-mycophenolate-steroids (TAC-MPA-S) regimen. We conducted this study to compare the outcomes of regimens containing the common mTOR inhibitor, sirolimus (SRL) against TAC-MPA-S in older adult KTRs.

METHODS

Using the 2000-2016 Scientific Registry of Transplant Recipients, Cox multivariable regression models were conducted to analyze the patient and graft outcomes associated with regimens containing SRL, steroids (S) and cyclosporine (CSA), tacrolimus (TAC), or mycophenolate (MPA) vs. the standard (TAC-MPA-S) regimen in older adult KTRs.

RESULTS

Included in the analysis were 15,008 (95.19%) older adult KTRs on standard (TAC-MPA-S) regimen, 242 (1.53%) on SRL-MPA-S, 300 (1.90%) on SRL-TAC-S, and 217 (1.38%) on SRL-CSA-S. Compared with the standard regimen, the adjusted risks of all-cause death and overall graft loss over a maximum 5-year follow-up were highest with SRL-MPA-S, intermediate with SRL-TAC-S and not significantly different with SRL-CSA-S. The adjusted risks of all-cause death and overall graft loss were modified by a pre-transplant history of malignancy in older adult KTRs on SRL-TAC-S, not in those on SRL-MPA-S or SRL-CSA-S.

CONCLUSIONS

In older adult kidney transplant recipients, SRL-TAC-S or SRL-MPA-S, but not SRL-CSA-S is associated with higher risks of death and allograft loss than standard TAC-MPA-S regimen and a pre-transplant malignancy history worsens these risks in patients on SRL-TAC-S. Confirmation of our findings by a prospective randomized trial is needed before translation into clinical practice can be recommended.

Effect of initial immunosuppression on long-term kidney transplant outcome in immunological low-risk patients

BACKGROUND

Few studies have evaluated the effect of different immunosuppressive strategies on long-term kidney transplant outcomes. Moreover, as they were usually based on historical data, it was not possible to account for the presence of pretransplant donor-specific human-leukocyte antigen antibodies (DSA), a currently recognized risk marker for impaired graft survival. The aim of this study was to evaluate to what extent frequently used initial immunosuppressive therapies increase graft survival in immunological low-risk patients.

METHODS

We performed an analysis on the PROCARE cohort, a Dutch multicentre study including all transplantations performed in the Netherlands between 1995 and 2005 with available pretransplant serum (n = 4724). All sera were assessed for the presence of DSA by a luminex single-antigen bead assay. Patients with a previous kidney transplantation, pretransplant DSA or receiving induction therapy were excluded from the analysis.

RESULTS

Three regimes were used in over 200 patients: cyclosporine (CsA)/prednisolone (Pred) (n = 542), CsA/mycophenolate mofetil (MMF)/Pred (n = 857) and tacrolimus (TAC)/MMF/Pred (n = 811). Covariate-adjusted analysis revealed no significant differences in 10-year death-censored graft survival between patients on TAC/MMF/Pred therapy (79%) compared with patients on CsA/MMF/Pred (82%, P = 0.88) or CsA/Pred (79%, P = 0.21). However, 1-year rejection-free survival censored for death and failure unrelated to rejection was significantly higher for TAC/MMF/Pred (81%) when compared with CsA/MMF/Pred (67%, P < 0.0001) and CsA/Pred (64%, P < 0.0001).

CONCLUSION

These results suggest that in immunological low-risk patients excellent long-term kidney graft survival can be achieved irrespective of the type of initial immunosuppressive therapy (CsA or TAC; with or without MMF), despite differences in 1-year rejection-free survival.

Age-associated decrease in de novo donor-specific antibodies in renal transplant recipients reflects changing humoral immunity

Background

Older age at organ transplantation is associated with increased risk of infection and malignancy but reduced risk of cellular rejection. De novo donor-specific anti-HLA antibodies (dnDSA), are key biomarkers associated with reduced long-term allograft survival, yet there is a lack of data focusing on age-associated changes.

Methods

Development of dnDSA was restrospectively analyzed in all subjects who received a kidney transplant at the University Hospital Zurich between 01/2006 and 02/2015. Follow up continued until 03/2016. The incidence of dnDSA in different age categories was compared with special focus on the extremes of age: children < 10 years (n = 19) and adults ≥60 years of age (n = 110).

Results

Incidence of dnDSA gradually decreased with age, with older recipients having a significantly lower risk (HR 0.21, p = 0.0224) compared to pediatric recipients. Cumulative incidence of dnDSA at 2, 5 and 10 years was 6.2, 9.1 and 36% in the older recipients versus 5.3, 29.5 and 47.1% in pediatric recipients. Median time to development of dnDSA was similar (older 720 days, min 356, max 3646 days; children 1086 days, min 42, max 2474 days). Annual incidence was highest within the first two years after transplantation in the older recipients and peaked in years two to four in pediatric recipients. DnDSA were predominantly class II. More dnDSA were observed with cyclosporine as compared to tacrolimus.

Conclusion

Older kidney transplant recipients have a lower risk of developing dnDSA than pediatric recipients, pointing towards reduced humoral immune reactivity with increasing age. This observation raises the question of adjustment in immunosuppression.

Characterizing the pharmacokinetics and pharmacodynamics of immunosuppressant medicines and patient outcomes in elderly renal transplant patients

This review examines what is currently known about the pharmacokinetics and pharmacodynamics of commonly prescribed immunosuppressant medicines, tacrolimus, cyclosporine, mycophenolate and prednisolone, in elderly renal transplant recipients, and reported patient outcomes in this cohort. Renal transplantation is increasing rapidly in the elderly, however, currently, long-term patient outcomes are relatively poor compared to younger adults. Some studies have suggested that elderly recipients may have higher dose-adjusted exposure and/or lower clearance of the calcineurin inhibitors tacrolimus and cyclosporine; with one study reporting up to 50% reduction in tacrolimus exposure in the elderly. Elderly transplant recipients do not appear to have higher dosage-adjusted exposure to mycophenolic acid (MPA). The effects of ageing on the pharmacokinetics of prednisolone are unknown. Only one study has examined how aging effects drug target enzymes, reporting no difference in baseline inosine 5'-monophosphate dehydrogenase (IMPDH) activity and MPA-induced IMPDH activity in elderly compared to younger adult renal transplant recipients. In elderly transplant recipients, immunosenescence likely lowers the risk of acute rejection, but increases the risk of drug-related adverse effects. Currently, the three main causes of death in elderly renal transplant recipients are cardiovascular disease, infection and malignancy. One study has showed that renal transplant recipients aged over 65 years are seven times more likely to die with a functioning graft compared with young adults (aged 18-29 years). This suggests that an optimal balance between immunosuppressant medicine efficacy and toxicity is not achieved in elderly recipients, and further studies are needed to foster long-term graft and patient survival. Lower maintenance immunosuppressant targets in elderly recipients may decrease patient susceptibility to drug side effects, however, further studies are required and appropriate targets need to be established.

Risk Factors for Early Graft Failure and Death After Kidney Transplantation in Recipients Older Than 70 Years

INTRODUCTION

Although kidney transplantation carries a survival benefit compared with dialysis, mortality, especially the first year after transplantation, is high in recipients older than 70. The aim of this study was to evaluate early death and graft failure, and to determine the risk factors associated with these events in this specific population.

METHODS

All patients older than 70 years who received a kidney transplant between January 2000 and December 2014 in the North-West of France were included (n = 171). Baseline characteristics and outcomes after transplantation were studied. Kaplan-Meier analysis was performed to assess patient and graft survival, and Cox regression analysis to evaluate risk factors for graft failure and patient death.

RESULTS

The mean recipient age was 73.3 ± 2.5 years. Death-censored graft survival at 1, 3, and 5 years were 82.6%, 78.7%, and 75.4%, respectively. Patient survival at 1, 3, and 5 years was 90.1%, 82.5%, and 68.1%, respectively. One year after transplantation, 17 patients (9.9%) were dead, mainly from infectious (58.5%) or cardiovascular disease (29.4%). According to the Cox multivariate analysis, the independent risk factors for death or graft failure during the first year were arrhythmia (odds ratio [OR] 2.26; 95% confidence interval [CI] 1.08-4.8), left-ventricular ejection fraction (LVEF) under 56% (OR 2.38; 95% CI 1.18-4.83), human leucocyte antigen (HLA) antibodies (OR 2.1; 95% CI 1.04-4.2), deceased donor from cardiovascular cause (OR 5.18; 95% CI 1.22-6.3), and acute rejection (OR 2.77; 95% CI 1.2-6.3).

CONCLUSION

In kidney transplant recipients older than 70 years, cardiac evaluation and immunosuppression optimization seem to be crucial to improve short-term patient and graft survival.

Differences in Gene Expression in Older Compared With Younger Kidney Transplant Recipients

BACKGROUND

For the growing numbers of older transplant patients, increased incidence of infection and death compared with younger patients may limit the many benefits provided by transplantation. However, little is known about age-associated immune dysfunction in the older transplant recipient.

METHODS

A cohort of 60 kidney transplant recipients, 23 older (≥ 60y) and 37 younger (30-59y), matched on antithymocyte induction and donor type (living vs deceased) was evaluated. Gene expression in peripheral blood mononuclear cells 3 months after kidney transplantation was analyzed to compare differences between older and younger patients.

RESULTS

Proinflammatory genes were upregulated in older kidney transplant patients, including cytokines IL1-β and IL-6. Downregulated genes were associated with B-cell and T-cell function, including CCR7 and CD27. Analysis of predicted transcription factor binding suggested an increase in proinflammatory transcription factor CCAAT/enhancer binding protein β-binding sites in older patients, whereas interferon regulatory factor 2 transcription factor binding sites were less prevalent.

CONCLUSIONS

Older kidney transplant recipients exhibited multiple differences in gene expression compared with younger patients, with upregulation of proinflammatory genes and downregulation of adaptive immune response genes. These findings may explain the mechanism of increased vulnerability to infection and malignancy observed in older transplant patients.

Natural killer cell function predicts severe infection in kidney transplant recipients

The aim of this study was to determine if natural killer cell number (CD3^- /CD16^± /CD56^± ) and cytotoxic killing function predicts severity and frequency of infection in kidney transplant recipients. A cohort of 168 kidney transplant recipients with stable graft function underwent assessment of natural killer cell number and functional killing capacity immediately prior to entry into this prospective study. Participants were followed for 2 years for development of severe infection, defined as hospitalization for infection. Area under receiver operating characteristic (AUROC) curves were used to evaluate the accuracy of natural killer cell number and function for predicting severe infection. Adjusted odds ratios were determined by logistic regression. Fifty-nine kidney transplant recipients (35%) developed severe infection and 7 (4%) died. Natural killer cell function was a better predictor of severe infection than natural killer cell number: AUROC 0.84 and 0.75, respectively (P = .018). Logistic regression demonstrated that after adjustment for age, transplant function, transplant duration, mycophenolate use, and increasing natural killer function (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.74-0.90; P < .0001) but not natural killer number (OR 0.96, 95% CI 0.93-1.00; P = .051) remained significantly associated with a reduced likelihood of severe infection. Natural killer cell function predicts severe infection in kidney transplant recipients.

Increased T cell immunosenescence and accelerated maturation phenotypes in older kidney transplant recipients

Older kidney transplant recipients experience increased rates of infection and death, and less rejection, compared with younger patients. However, little is known about immune dysfunction in older compared with younger kidney transplant recipients and whether it is associated with infection. We evaluated T cell phenotypes including maturation, immune senescence, and exhaustion in a novel investigation into differences in older compared with younger patients receiving identical immune suppression regimens. We evaluated PBMC from 60 kidney transplant recipients (23 older and 37 matched younger patients) by multiparameter immune phenotyping. Older kidney transplant recipients demonstrated decreased frequency of naïve CD4+ and CD8+ T cells, and increased frequency of terminally differentiated, immune senescent, and NK T cells expressing KLRG1. There was a trend towards increased frequency of T cell immune senescence in patients experiencing infection in the first year after transplantation, which reached statistical significance in a multivariate analysis. This pilot study reveals immune dysfunction in older compared with younger transplant recipients, and suggests a likely mechanism for increased vulnerability to infection. The ability to assess T cell maturation and immune senescence in transplant recipients offers the potential for risk stratification and customization of immune suppression to prevent infection and rejection after transplantation.

Seroprevalence of Toxoplasma gondii and Toxocara canis in a human rural population of Southern Rio Grande do Sul

Due to the growing population of pets, especially homeless dogs and cats, zoonoses still represent a significant public health problem. Toxoplasma gondii and Toxocara spp. are epidemiologically important zoonotic agents as they are etiological factors of human toxoplasmosis and toxocariasis, respectively. These parasites remain neglected even though they are substantially prevalent in rural areas. The aim of this study was to investigate T. gondii and T. canis seroprevalence and risk factors of seropositivity in a rural population in Pelotas municipality, Brazil. The study participants (n=344) were patients of a Basic Healthcare Unit (BHU) located in Cerrito Alegre. Blood samples were collected and tested for T. gondii antibodies by indirect immunofluorescence and T. canis antibodies by an indirect ELISA that targets an excreted-secreted antigen (TES). T. gondii seropositivity was 53.2%, with higher titers (1:256 - 1:1,024) in individuals who habitually eat pork, beef, or chicken, while T. canis seropositivity was 71.8% and concomitant T. gondii and T. canis seropositivity was 38.3%. Among the seropositivity risk factors assessed, only habitual undercooked meat consumption was significant (p = 0.046; OR = 3.7) for T. gondii and none of them were associated with T. canis seropositivity. Both parasites have a high prevalence in rural areas, which reinforces the need to invest in rural community education and health.