Personalized immunosuppression in elderly renal transplant recipients

Association of Senescence Markers with Age and Allograft Rejection in Renal Transplant Recipients

BACKGROUND/OBJECTIVES

Renal transplantation is the treatment of choice for patients with end-stage renal disease. In the last decade, the number of older renal transplant recipients has significantly increased. However, these patients are at a higher risk of developing post-transplant complications. Therefore, identifying the suitable biomarkers to predict which older patients are at risk of complications is crucial. Cellular senescence could provide insights into the increased vulnerability in this population and guide personalized post-transplant care.

METHODS

This preliminary study involved biopsies from 25 patients with renal allograft rejection and 18 patients without rejection, further divided into older (50-65 years) and younger (29-40 years) groups. Biopsies were collected at different time points after transplantation, and rejection was classified according to the histological Banff 07 criteria. Additionally, immunohistochemistry for the markers of cellular senescence, p27kip1 and p16INK4a, was performed.

RESULTS

We observed that the number of p27kip1-positive glomeruli was higher in the older patients with rejection compared to the younger patients with rejection, and a similar pattern was found in the patients without rejection. However, the number of p27kip1-positive tubules was higher in the older patients with rejection compared to the younger patients with rejection, as well as compared to both the older and younger patients without rejection. Tubular p16INK4a expression was not significantly different in the older patients with rejection compared to the younger patients with rejection, and the same pattern was observed in the patients without rejection. However, it was increased in the older patients with rejection in comparison to the older patients without rejection.

CONCLUSIONS

Our preliminary data suggest the strong potential of both p16INK4a and p27kip1 as biomarkers of renal graft rejection, particularly in older renal transplant recipients.

Kidney transplants from elderly donors: what we have learned 20 years after the Crystal City consensus criteria meeting

Based on the current projection of the general population and the combined increase in end-stage kidney disease with age, the number of elderly donors and recipients is increasing, raising crucial questions about how to minimize the discard rate of organs from elderly donors and improve graft and patient outcomes. In 2002, extended criteria donors were the focus of a meeting in Crystal City (VA, USA), with a goal of maximizing the use of organs from deceased donors. Since then, extended criteria donors have progressively contributed to a large number of transplanted grafts worldwide, posing specific issues for allocation systems, recipient management, and therapeutic approaches. This review analyzes what we have learned in the last 20 years about extended criteria donor utilization, the promising innovations in immunosuppressive management, and the molecular pathways involved in the aging process, which constitute potential targets for novel therapies.

Seronegative Rheumatoid Arthritis in an Elderly Dialysis Patient With Multiple Comorbidities: A Case Report

The diagnosis of autoimmune diseases in elderly, immunocompromised patients undergoing dialysis poses significant challenges due to the diverse etiology of symptoms such as fever and systemic pain. This case study reports on a 79-year-old man undergoing hemodialysis with a history of multiple comorbidities, including diabetes, heart failure, and pure red cell aplasia. He presented with subacute polyarthritis and fever and was ultimately diagnosed with seronegative rheumatoid arthritis. The case illustrates the complexities of differential diagnosis in this population, emphasizing the need for a systematic approach to distinguish between possible infectious and autoimmune causes. Despite the absence of rheumatoid factor and anti-citrullinated protein antibody, the patient's clinical presentation and response to steroids supported the diagnosis of seronegative rheumatoid arthritis. Treatment with prednisolone resulted in significant improvement in symptoms and quality of life, demonstrating the effectiveness of steroids in managing autoimmune conditions in elderly, high-risk patients. However, such treatment necessitates careful monitoring due to potential adverse effects. This case underlines the importance of considering autoimmune diseases in differential diagnoses and customizing treatment strategies to accommodate the unique needs of elderly, immunocompromised patients on dialysis. Insights from this case contribute to better understanding and management of complex clinical scenarios in similar patient populations.

Immunosuppression for older liver transplant recipients

Older liver transplant recipients have a lower risk of acute rejection than younger patients (9% for patients aged ≥65 years versus 23% for those aged 18-34 years) and are more vulnerable to immunosuppression-related complications. The number of liver transplant recipients ≥65 years has risen to 22% in Europe and the US, but limited information is available on the optimal immunosuppressive regimen for these patients. In this review, we discuss the appropriate management of immunosuppressive agents in older adults to minimize adverse events while avoiding acute rejection. The way the body processes drugs greatly depends on age. In the case of calcineurin inhibitor drugs, aging reduces hepatic metabolism, leading to changes in their pharmacokinetics. Corticosteroids also show decreased clearance as the patient ages. In severe cases of hypoalbuminemia, dose adjustment of mycophenolate acid derivatives may be necessary. However, the pharmacokinetic profiles of the mammalian target of rapamycin inhibitors, basiliximab, and rabbit anti-thymocyte globulin remain unaffected by age. Furthermore, age-related frailty may impact drug metabolism and require tailored interventions and closer follow-up. Although there is limited research, elderly liver transplant recipients require less immunosuppression with double or triple-agent regimens, lower exposure to calcineurin inhibitors, and a shorter course of corticosteroids. The usage of mammalian target of rapamycin inhibitors in older transplant populations has not been specifically investigated, and thus their usage should align with indications for younger patient groups.

Challenges and opportunities in the islet transplantation microenvironment: a comprehensive summary of inflammatory cytokine, immune cells, and vascular endothelial cells

It is now understood that islet transplantation serves as a β-cell replacement therapy for type 1 diabetes. Many factors impact the survival of transplanted islets, especially those related to the microenvironment. This review explored microenvironmental components, including vascular endothelial cells, inflammatory cytokines, and immune cells, and their profound effects on post-islet transplantation survival rates. Furthermore, it revealed therapeutic strategies aimed at targeting these elements. Current evidence suggests that vascular endothelial cells are pivotal in facilitating vascularization and nutrient supply and establishing a new microcirculation network for transplanted islets. Consequently, preserving the functionality of vascular endothelial cells emerges as a crucial strategy to enhance the survival of islet transplantation. Release of cytokines will lead to activation of immune cells and production and release of further cytokines. While immune cells hold undeniable significance in regulating immune responses, their activation can result in rejection reactions. Thus, establishing immunological tolerance within the recipient's body is essential for sustaining graft functionality. Indeed, future research endeavors should be directed toward developing precise strategies for modulating the microenvironment to achieve higher survival rates and more sustained transplantation outcomes. While acknowledging certain limitations inherent to this review, it provides valuable insights that can guide further exploration in the field of islet transplantation. In conclusion, the microenvironment plays a paramount role in islet transplantation. Importantly, we discuss novel perspectives that could lead to broader clinical applications and improved patient outcomes in islet transplantation.

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.].

Effects of NR1I2 and ABCB1 Genetic Polymorphisms on Everolimus Pharmacokinetics in Japanese Renal Transplant Patients

The purpose of this study was to evaluate the effects of NR1I2 (7635G>A and 8055C>T) and ABCB1 (1236C>T, 2677G>T/A, and 3435C>T) genetic polymorphisms on everolimus pharmacokinetics in 98 Japanese renal transplant patients. On day 15 after everolimus administration, blood samples were collected just prior to and 1, 2, 3, 4, 6, 9, and 12 h after administration. The dose-adjusted area under the blood concentration−time curve (AUC0-12) of everolimus was significantly lower in patients with the NR1I2 8055C/C genotype than in those with other genotypes (p = 0.022) and was significantly higher in male patients than female patients (p = 0.045). Significant correlations between the dose-adjusted AUC0-12 of everolimus and age (p = 0.001), aspartate transaminase (p = 0.001), and alanine transaminase (p = 0.005) were found. In multivariate analysis, aging (p = 0.008) and higher alanine transaminase levels (p = 0.032) were independently predictive of a higher dose-adjusted everolimus AUC0-12. Aging and hepatic dysfunction in patients may need to be considered when evaluating dose reductions in everolimus. In renal transplant patients, management using everolimus blood concentrations after administration may be more important than analysis of NR1I2 8055C>T polymorphism before administration.

Personalized immunosuppression after kidney transplantation

With advances in immunosuppressive therapy, there have been significant improvements in acute rejection rates and short-term allograft survival in kidney transplant recipients. However, this success has not been translated into long-term benefits by the same magnitude. Optimization of immunosuppression is important to improve the clinical outcome of transplant recipients. It is important to note that each patient has unique attributes and immunosuppression management should not be a one-size-fits-all approach. Elderly transplant patients are less likely to develop acute rejection but more likely to die from infectious and cardiovascular causes than younger patients. For those with post-transplant cancers and BK polyomavirus-associated nephropathy, reduction of immunosuppression can increase the risk of rejection. Therapeutic drug monitoring (TDM) is routinely used for dosage adjustment of several immunosuppressive drugs. It has been hoped that pharmacogenetics can be used to complement TDM in optimizing drug exposure. Among the various drug-genotype pairs being investigated, tacrolimus and CYP3A5 gives the most promising results. Different studies have consistently shown that CYP3A5 expressers require a higher tacrolimus dose and take longer time to achieve target blood tacrolimus levels than nonexpressers. However, for pharmacogenetics to be widely used clinically, further trials are necessary to demonstrate the clinical benefits of genotype-guided dosing such as reduction of rejection and drug-related toxicities. The development of different biomarkers in recent years may help to achieve true personalized therapy in transplant patients.

Survival Rate of Renal Transplant and Factors Affecting Renal Transplant Failure

OBJECTIVES

The most important complication in kidney transplant is acute/chronic rejection. In this study, we investigated the factors affecting kidney rejection and transplant survival.

MATERIALS AND METHODS

In this survival analysis study, 352 patients (mean follow-up of 12.9 ± 4.4 years) who underwent renal biopsy due to increased creatinine level from 2012 to 2016 were identified by glomerular filtration rate level and rejection. Probable factors affecting renal function and survival rate after transplant rejection were assessed. P < .05 was considered as significant.

RESULTS

Among our study patients, 40.9% developed early and 59.1% developed late acute kidney injury. Graft survival rates at 1 and 5 years were 98.9% and 68.5%, respectively, which was significant when rejection type was considered (P = .002). In addition, patient survival rates at 1 and 5 years were 99.7% and 98.6%, respectively. Graft survival at 5 years was significantly lower among older subjects, those with diabetes, those who received deceased donor organs, and those with late acute kidney injury (P < .002). Patient survival was significantly higher among young patients, those with systemic lupus erythematosus, those who received living donor organs, and those without cytomegalovirus infection (P < .003).

CONCLUSIONS

We observed that recipient age, type of donor, underlying disease, infection, and late acute kidney injury had great negative impacts on renal dysfunction and survival. In our center, because of the large number of kidney transplants from deceased donors, the necessity of antithymocyte globulin induction therapy was considered, since this study showed that patients who received rabbit antithymocyte globulin induction had better outcomes.

Heart Transplant in Older Adults

Purpose of Review

Older adults with end-stage heart failure may be candidates for heart transplantation (HT) and changing guidelines and institutional policies have increased the availability of HT for septuagenarians. This review explores historical, pre-HT evaluation, and post-HT outcomes for older adult HT recipients.

Recent Findings

Rates of HT in older adults have increased in the past decade and more than 800 septuagenarians have undergone HT. Older adult HT recipients have similar survival, rehospitalization, and graft failure rates when compared to younger patients despite additional comorbidities and higher risk donors.

Summary

HT is feasible in carefully selected older adults. As the number of older adults who are considered for HT increases, additional research into population-specific assessment tools will be needed. Furthermore, age-related immune changes warrant population-specific studies on immunosuppressive regimens.

Evaluation of rejection, infection, and malignancy outcomes in elderly liver transplant recipients receiving a similar level of immunosuppression compared to a younger group

Elderly liver transplant (LTx) recipients at a lower risk of acute rejection compared to younger recipients due to immunosenescence. As such, they may benefit from reduced immunosuppression (IS) to minimize infectious and malignant complications. We aimed to evaluate outcomes in LTx recipients ≥60 years compared to a younger group of LTx recipients aged 18-59 years maintained on a similar level of IS. This was a single-center retrospective evaluation of adult LTx recipients from 2013 to 2018 who received methylprednisolone induction and were maintained on tacrolimus, mycophenolate mofetil (MMF), and a prednisone taper. A total of 143 LTx recipients were evaluated. Mean age in the older group was 65 ± 3.8 compared to 49 ± 10.4 years in the younger group (p < 0.0001). Mean tacrolimus levels and the duration of MMF and steroids were comparable. Both groups had a similar incidence of first rejection within 1 year (19.2% in the elderly group vs. 23.1% in the younger group, p = 0.57). There were no statistical difference in terms of infection, malignancy, or patient survival. In conclusion, our data suggests that elderly LTx recipients, when treated with a similar level of IS, had similar 1 year incidence of rejection, infection, malignancy, and patient survival as younger LTx 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.

Cholesterol Embolization Syndrome After Kidney Transplantation: A Case Series and Systematic Review

Supplemental Digital Content is available in the text.

Background.

Cholesterol embolization syndrome (CES) is an uncommon but well-known cause of renal failure in native kidneys, but little is known about CES in kidney transplant recipients. The aim of this study was to determine the incidence, clinical characteristics, histopathology, and prognosis of CES after kidney transplantation.

Methods.

CES cases in both transplanted and native kidneys (control group) were identified by searching the databases of the divisions of Nephrology and Pathology of our institution. Clinical data were retrospectively collected. Biopsies were classified according to the latest Banff 2019 Update. Second, a systematic literature search was performed (December 01, 2020) of Ovid MEDLINE, EMBASE, the Cochrane Central Register of controlled trials, Google Scholar, and Web of Science.

Results.

CES was observed in for-cause biopsies of 11 out of 2350 (0.47%) kidney transplant recipients transplanted between January 1, 2006, and December 31, 2018 (0.0009 cases per person-year). All patients had ≥1 cardiovascular risk factor, and 9 donors were expanded criteria donors. Graft loss occurred in 27.3% of the patients diagnosed with CES. Eight transplant biopsies with CES were also classified as biopsy-proven acute rejection. Transplant biopsies showed signs of inflammation (arteritis, n = 7; interstitial inflammation, n = 5; tubulitis, n = 7). One patient with CES in a native kidney was identified. The biopsy of the native kidney only showed arteritis and classified as an isolated “v” lesion. The literature search resulted in 188 unique articles of which 20 were included. A total of 47 cases of CES after kidney transplantation was reported. Cholesterol emboli were found in <1% of all kidney transplant biopsies. In 57.8% of the kidney transplant biopsies with CES described in literature, concomitant inflammation was present.

Conclusions.

CES is an uncommon cause of kidney transplant failure, although the incidence of CES may be underestimated. CES may mimic rejection as it can be accompanied by arteritis.

The Risk of Postkidney Transplant Outcomes by Induction Choice Differs by Recipient Age

Supplemental Digital Content is available in the text.

Background.

Among adult kidney transplant (KT) recipients, the risk of post-KT adverse outcomes differs by type of induction immunosuppression. Immune response to induction differs as recipients age; yet, choice of induction is barely tailored by age likely due to a lack of evidence of the risks and benefits.

Methods.

Using Scientific Registry of Transplant Recipients data, we identified 39336 first-time KT recipients (2010–2016). We estimated the length of stay (LOS), acute rejection (AR), graft failure, and death by induction type using logistic and Cox regression weighted by propensity score to adjust for confounders. We tested whether these estimates differed by age (65+ versus 18–64 y) using a Wald test.

Results.

Overall, rabbit antithymocyte globulin (rATG) was associated with a decreased risk of AR (odds ratio = 0.79, 95% confidence interval [CI], 0.72-0.85) compared with basiliximab. The effect of induction on LOS and death (interaction P = 0.03 and 0.003) differed by recipient age. Discharge was on average 11% shorter in rATG among younger recipients (relative time = 0.89; 95% confidence interval [CI], 0.81-0.99) but not among older recipients (relative time = 1.01; 95% CI, 0.95-1.08). rATG was not associated with mortality among older (hazard ratio = 1.05; 95% CI, 0.96-1.15), but among younger recipients (hazard ratio = 0.87; 95% CI, 0.80-0.95), it was associated with reduced mortality risk.

Conclusions.

rATG should be considered to prevent AR, especially among recipients with high-immunologic risk regardless of age; however, choice of induction should be tailored to reduce LOS and risk of mortality, particularly among younger recipients.

Pharmacokinetics of Mycophenolate Mofetil Metabolites in Older Patients on the Seventh Day After Renal Transplantation

BACKGROUND

Currently, immunosuppression schemes are age-independent; however, physiological changes may alter drugs' pharmacokinetics in the older population. We compared mycophenolic acid (MPA) and its glucuronide metabolite (MPAG) pharmacokinetics among patients aged <60 and >60 years on the seventh day after renal transplantation.

METHODS

We included 7 and 10 renal transplant recipients, aged >60 and <60 years, respectively, treated with mycophenolate mofetil. MPA and MPAG concentrations were determined using the high-performance liquid chromatography method with ultraviolet detection (HPLC-UV). Noncompartmental pharmacokinetic analysis was performed.

RESULTS

In patients aged >60 years, mean MPA and MPAG concentrations before the next dose and ratio of MPAG area under the concentration-time curve (AUC_0-12) to MPA AUC_0-12 were higher by 1.6-fold, 1.4-fold, and 1.9-fold, respectively. Other MPAG concentrations appeared to be slightly higher (1.2- to 1.5-fold) in older patients. MPA apparent clearance was similar in both groups, whereas volume of distribution at steady state was slightly higher (1.6-fold) in patients aged >60 years. The variability of most MPA and some MPAG pharmacokinetics was greater in patients aged >60 years. The MPA AUC_0-12 target was achieved in 40% and 14% of patients aged <60 and >60 years, respectively. The highest MPAG concentrations and AUC_0-12 were observed for patients with the lowest glomerular filtration rate.

CONCLUSIONS

Higher variability of MPA and MPAG pharmacokinetic parameters, MPA AUC_0-12 above the reference range, higher values of MPAG pharmacokinetics in patients with lower glomerular filtration rates, as well as lower proportion of patients achieving MPA targets all indicate the need for therapeutic drug monitoring in renal transplant recipients aged >60 years and to verify target MPA AUC_0-12 for this population.

Clinical Experience with Extended-Release Tacrolimus in Older Adult Kidney Transplant Recipients: A Retrospective Cohort Study

BACKGROUND

Extended-release tacrolimus (LCP-Tac) prescribing information states that there is insufficient data in older adult patients from which to make recommendations on use in this population. This study sought to provide information on de novo use of LCP-Tac in the older adult kidney transplant population.

METHODS

This single-center retrospective study had two distinct objectives; to determine if weight-based doses of LCP-Tac differ based on recipient age and to compare safety and efficacy between LCP-Tac and immediate-release tacrolimus (IR-Tac) in older adult transplant recipients. Data was obtained through electronic chart review up to 2 years after transplant with censoring for graft loss and death.

RESULTS

Weight-based doses were compared between patients aged ≥ 65 years (n = 84), 36-64 years (n = 64), and ≤35 years (n = 44). LCP-Tac weight-based doses were lower at all time points in patients ≥ 65 years of age. Both age and race significantly impacted required dose on linear regression. The doses required to achieve therapeutic tacrolimus troughs were significantly lower in all age groups compared with the current FDA de novo dosing recommendation. In the older adult population, graft outcomes and infectious and metabolic complications were compared between recipients of LCP-Tac (n = 84) and IR-Tac (n = 42). Within this cohort, there were no differences between LCP-Tac and IR-Tac on graft function, rejection, graft loss, death, cytomegalovirus viremia, BK viremia, hypertension, diabetes, alopecia, or tremor up to 2 years after transplant.

CONCLUSIONS

Older adult recipients required significantly lower LCP-Tac doses compared with younger recipients and with the FDA-labeled starting dose. There were no differences in graft outcomes or adverse effects in older adult patients who received LCP-Tac versus IR-Tac.

Molecular mechanisms and therapeutic implications of tetrandrine and cepharanthine in T cell acute lymphoblastic leukemia and autoimmune diseases

Inappropriately activated T cells mediate autoimmune diseases and T cell acute lymphoblastic leukemia (T-ALL). Glucocorticoid and chemotherapeutic agents have largely extended lives of these patients. However, serious side effects and drug resistance often limit the prognosis of considerable number of the patients. The efficient treatment of autoimmune diseases or T-ALL with drug resistance remains an important unmet demand clinically. Bisbenzylisoquinoline alkaloids tetrandrine and cepharanthine have been applied for the treatment of certain types of autoimmune diseases and cancers, while studies on their action mechanisms and their further applications combined with glucocorticoids or chemotherapeutic agents remains to be expanded. This review introduced molecular mechanisms of tetrandrine and cepharanthine in T cells, including their therapeutic implications. Both tetrandrine and cepharnthine influence the growth of activated T cells via several kinds of signaling pathways, such as NF-κB, caspase cascades, cell cycle, MAPK, and PI3K/Akt/mTOR. According to recent preclinical and clinical studies, P-glycoprotein inhibitory effect of tetrandrine and cepharnthine could play a significant role on T cell-involved refractory diseases. Therefore, tetrandrine or cepharanthine combined with glucocorticoid or other anti-leukemia drugs would bring a new hope for patients with glucocorticoid-resistant autoimmune disease or refractory T-ALL accompanied with functional P-glycoprotein. In conclusion, bisbenzylisoquinoline alkaloids tetrandrine and cepharanthine can regulate several signaling pathways in abnormally activated T cells with low toxicity. Bisbenzylisoquinoline alkaloids deserve to be paid more attention as a lead compound to develop new drugs for the treatment of T cell-involved diseases in the future.

Recent Advances on Biomarkers of Early and Late Kidney Graft Dysfunction

New biomarkers of early and late graft dysfunction are needed in renal transplant to improve management of complications and prolong graft survival. A wide range of potential diagnostic and prognostic biomarkers, measured in different biological fluids (serum, plasma, urine) and in renal tissues, have been proposed for post-transplant delayed graft function (DGF), acute rejection (AR), and chronic allograft dysfunction (CAD). This review investigates old and new potential biomarkers for each of these clinical domains, seeking to underline their limits and strengths. OMICs technology has allowed identifying many candidate biomarkers, providing diagnostic and prognostic information at very early stages of pathological processes, such as AR. Donor-derived cell-free DNA (ddcfDNA) and extracellular vesicles (EVs) are further promising tools. Although most of these biomarkers still need to be validated in multiple independent cohorts and standardized, they are paving the way for substantial advances, such as the possibility of accurately predicting risk of DGF before graft is implanted, of making a “molecular” diagnosis of subclinical rejection even before histological lesions develop, or of dissecting etiology of CAD. Identification of “immunoquiescent” or even tolerant patients to guide minimization of immunosuppressive therapy is another area of active research. The parallel progress in imaging techniques, bioinformatics, and artificial intelligence (AI) is helping to fully exploit the wealth of information provided by biomarkers, leading to improved disease nosology of old entities such as transplant glomerulopathy. Prospective studies are needed to assess whether introduction of these new sets of biomarkers into clinical practice could actually reduce the need for renal biopsy, integrate traditional tools, and ultimately improve graft survival compared to current management.

An interdisciplinary approach to the older transplant patient: strategies for improving clinical outcomes

PURPOSE OF REVIEW

To describe the latest investigations into the role of frailty and assessment of other aging-related issues in the solid organ transplant candidate and recipient. This information is relevant for all involved in the care of transplant patients, but is especially relevant in infectious diseases, given the increased burden of infection seen in older and frailer patients.

RECENT FINDINGS

The Fried Frailty Phenotype (FFP) and Short Performance Physical Battery (SPPB) are well validated tools for measuring frailty in older adults. Recently, these frailty tools have also been used to predict a range of clinical outcomes in adults with endstage organ disease undergoing advanced therapies including mechanical circulatory device (MCSD) or transplantation including death on the waiting list, length of hospital stay, need for readmission, infection, and death. Frailty may also be estimated by chart review and comorbidity assessment. Other aging-related evaluations of interest are cognitive function, sarcopenia, and nutritional status. The strength of association for each tool varies by the type of end organ disease, although there are many findings in common across organ types.

SUMMARY

As trends in the aging of the population continue to impact transplant and MCSD candidates and recipients, it is increasingly important for providers to be cognizant of the methods for assessment of aging-associated dysfunction including frailty and sarcopenia.

The TreaT-Assay: A Novel Urine-Derived Donor Kidney Cell-Based Assay for Prediction of Kidney Transplantation Outcome

Donor-reactive immunity plays a major role in rejection after kidney transplantation, but analysis of donor-reactive T-cells is not applied routinely. However, it has been shown that this could help to identify patients at risk of acute rejection. A major obstacle is the limited quantity or quality of the required allogenic stimulator cells, including a limited availability of donor-splenocytes or an insufficient HLA-matching with HLA-bank cells. To overcome these limitations, we developed a novel assay, termed the TreaT (Transplant reactive T-cells)-assay. We cultivated renal tubular epithelial cells from the urine of kidney transplant patients and used them as stimulators for donor-reactive T-cells, which we analyzed by flow cytometry. We could demonstrate that using the TreaT-assay the quantification and characterization of alloreactive T-cells is superior to other stimulators. In a pilot study, the number of pre-transplant alloreactive T-cells negatively correlated with the post-transplant eGFR. Frequencies of pre-transplant CD161⁺ alloreactive CD4⁺ T-cells and granzyme B producing alloreactive CD8⁺ T-cells were substantially higher in patients with early acute rejection compared to patients without complications. In conclusion, we established a novel assay for the assessment of donor-reactive memory T-cells based on kidney cells with the potential to predict early acute rejection and post-transplant eGFR.

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.

Induction Therapy in Elderly Kidney Transplant Recipients With Low Immunological Risk

BACKGROUND

In nonimmunized patients, similar rejection rates are observed for patients who have undergone thymoglobulin (antithymocyte globulins [ATG]) or basiliximab (BSX) therapy. While ATG may improve delayed graft function, it may also be associated with higher infection rates and malignancy risk. We compared survival and clinical outcomes in elderly recipients with low immunological risk according to their induction therapy.

METHODS

We conducted a multicentric study on nonimmunized patients ≥65 years of age receiving a first kidney transplant between 2010 and 2017. The principal outcome was patient and graft survival. Secondary outcomes were cumulative probabilities of infection, first acute rejection episode, malignancy, de novo donor specific antibody, posttransplant diabetes (PTD), cardiac complications, estimated glomerular filtration rate, and occurrence of delayed graft function. Cox, logistic, or linear statistical models were used depending on the outcome studied, and models were weighted on the propensity scores.

RESULTS

Two hundred and four patients were included in the BSX group and 179 in the ATG group with the average age of 71.0 and 70.5 years, respectively. Patient and graft survival at 3 years posttransplantation were 74% (95% CI, 65%-84%) and 68% (95% CI, 60%-78%) in ATG and BSX group, respectively, without significant difference. Occurrence of PTD was significatively higher in BSX group (23% versus 15%, P = 0.04) due to higher trough levels of Tacrolimus on month 3 (9.48 versus 7.30 ng/mL, P = 0.023). There was no difference in other evaluated outcomes.

CONCLUSIONS

In elderly recipients, ATG does not lead to poorer outcomes compared with BSX and could permit lower trough levels of Tacrolimus, thus reducing occurrence of PTD.

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.

Infections after kidney transplantation. Does age matter?

Infections threaten successful outcomes after kidney transplantation. Our aim was to determine if the number, types of infections and the risk factors for common infections differed between older compared to younger kidney transplant (KT) recipients in the first year after surgery. We performed a single-center retrospective cohort study. Between 2011 and 2015, 91 KTs were performed in patients ≥65 years of age; these were matched 1:1 (by year of transplantation, sex and race) to controls aged 40-60 years. Over 90% of both groups had an infectious complication. Urinary tract infections (UTIs) and cytomegalovirus (CMV) viremia were significantly more frequent in older recipients. Older adults had more late onset UTIs, including after stent removal. CMV viremia was more frequent in older adults in the 1-6 months post-transplant period. Due to our center-specific protocol utilizing pre-emptive monitoring in the CMV recipient-seropositive population, the higher CMV incidence in the aged recipient was driven by this subpopulation of older adults. No difference in pneumonias or bloodstream infections were found, nor in surgical complications, rejection or graft loss. Mortality was higher at 1-year post-transplant in the older recipients (9.9% vs 1.1%; P = 0.018). Prophylactic and immunosuppressive strategies may need to be altered for older KT recipients.

Solid organ transplantation in older adults. Infectious and other age-related considerations

In the U.S., older adults aged 65 or above comprise nearly one quarter of the solid organ transplant (SOT) waitlists, and the number of transplants performed in this age group continues to increase. There are no specific guidelines for the assessment and follow up of the older SOT candidate or recipient. Older adults are at increased risk of infectious complications after SOT. Despite these complications and even with the use of suboptimal donors, overall outcomes are favorable. We provide an overview to specific consideration as they relate to the older SOT candidate and recipient.