Induction immunosuppressive therapy in the elderly kidney transplant recipient in the United States

Effects of two immunosuppression regimens on T-lymphocyte subsets in elderly kidney transplant recipients

Background

Despite the growing number of elderly kidney transplant (Ktx) recipients, few studies have examined the effects of immunosuppression on their lymphocyte profiles.

Methods

We evaluated the early conversion from mycophenolate sodium (MPS) to everolimus (EVL) after rabbit antithymocyte globulin (rATG) 2 mg/kg induction in elderly kidney recipients. Three groups of KTx patients were compared: (a) Young (n=20, 36 ± 7 y) receiving standard immunosuppression (Group A1) (prednisone, tacrolimus, and MPS), (b) Elderly (n=35, 65 ± 3 y) receiving standard immunosuppression (Group B1), and (c) Elderly (n=16, 65 ± 3 y) with early (mean 30 d) conversion from MPS to EVL (Group B2). Naive, memory, and regulatory peripheral blood TCD4+ lymphocytes were quantified at 0, 30, and 365 d.

Results

Results are reported as [mean(p25-p75)]. Young recipients had higher lymphocyte counts at baseline [2,100(1,630-2,400) vs. 1,310 (1,000-1,600)/mm3, p<0.0001] maintained higher counts within 365 d [1,850(1,590-2,120) vs. 1,130(460-1,325)/mm3, p=0.018 and vs. 1,410(805-1,895)/mm3, p=0.268]. Elderly recipients showed a decrease in lymphocytes within 30 d [1,310(1,000-1,600) vs. 910(700-1,198)/mm3, p=0.0012] with recovery within 365 d. The same pattern was observed in total lymphocytes and TCD4+ counts. Rabbit antithymocyte globulin induced a reduction in central memory T-cell percentages at 30 d in both young recipients [6.2(3.77-10.8) vs. 5.32(2.49-7.28)% of CD4+, p=0.036] and in elderly recipients [8.17(5.28-12.88) vs. 6.74(4.36-11)% of CD4+, p=0.05] on standard immunosuppression, returning to baseline at 365 d in elderly recipients but not in young recipients. Regulatory T CD39+ cells (Treg) percentages decreased at 30 d in elderly recipients [2.1(1.23-3.51) vs. 1.69(0.8-2.66)% of CD4+, p=0.0028] and in young recipients [1.29(0.45-1.85) vs. 0.84(0.18-1.82)% of CD4+, p=0.0038], returning to baseline at 365 d in elderly recipients [2.1(1.23-3.51) vs. 2.042(0.88-2.42)% of CD4+], but not in young recipients [1.29(0.45-1.85) vs. 0.86(0.7-1.34) % of CD4+]. The elderly everolimus conversion group did not show significant changes in cell profile over time or compared to elderly recipients with standard immunosuppression.

Conclusion

Aging favored the maintenance of Treg during the late transplantation period despite ongoing immunosuppression. Lymphocyte depletion due to rATG was more prominent in elderly recipients and affected memory subsets with a temporary reduction in central memory T cells. However, conversion to everolimus did not impact Treg profile. Reducing the dose of rATG in elderly recipients seems necessary for the expected lymphocyte changes with EVL to occur.

Clinical trial registration

nEverOld Trial, identifier NTC01631058.

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.

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

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

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

Background

Basiliximab (BSX) and antithymocyte globulins (ATGs), are two major immunosuppressive agents commonly used as induction therapy for kidney transplant (KT) recipients. The superiority of ATG over BSX has not been well established, especially in elderly KT recipients with low immunological risk.

Methods

A total of 847 elderly (≥60 years old), low-risk KT patients in the Korean Organ Transplantation Registry were propensity score-matched at a 1:2 ratio and compared according to ATG or BSX induction therapy. The primary outcome was patient and graft survival and biopsy-proven acute cellular rejection. The secondary outcome was graft function, BK virus nephropathy, infection, cancer, new-onset diabetes mellitus after transplantation (NODAT), and delayed graft function.

Results

In total, 165 patients in the ATG group were matched with 298 patients in the BSX group with average ages of 64.3 and 64.2 years, respectively. During a follow-up of 28.5 ± 10.4 months, the cumulative probabilities of death-censored graft failure at 3 years posttransplantation were 1.3% and 1.4% in ATG and BSX groups, respectively, without a significant difference (p = 0.72). The cumulative probability of NODAT at 3 years posttransplantation was significantly higher in the BSX group (35.6% vs. 21.6%, p = 0.02). The median tacrolimus trough level was significantly lower at 6 months after KT in the ATG group (5.7 ng/mL vs. 6.4 ng/mL, p = 0.001). There were no differences in the other evaluated outcomes.

Conclusion

Compared with BSX, in elderly, low-risk KT patients, ATG reduced tacrolimus and steroid requirements without differences in all-cause mortality, rejection, or infection, resulting in a reduced NODAT incidence.

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.

Posttransplant Diabetes Mellitus and Immunosuppression Selection in Older and Obese Kidney Recipients

Rationale & Objective

Posttransplant diabetes mellitus (DM) after kidney transplantation increases morbidity and mortality, particularly in older and obese recipients. We aimed to examine the impact of immunosuppression selection on the risk of posttransplant DM among both older and obese kidney transplant recipients.

Study Design

Retrospective database study.

Setting & Participants

Kidney-only transplant recipients aged ≥18 years from 2005 to 2016 in the United States from US Renal Data System records, which integrate Organ Procurement and Transplantation Network/United Network for Organ Sharing records with Medicare billing claims.

Exposures

Various immunosuppression regimens in the first 3 months after transplant.

Outcomes

Development of DM >3 months-to-1 year posttransplant.

Analytical Approach

We used multivariable Cox regression to compare the incidence of posttransplant DM by immunosuppression regimen with the reference regimen of thymoglobulin (TMG) or alemtuzumab (ALEM) with tacrolimus + mycophenolic acid + prednisone using inverse propensity weighting.

Results

12.7% of kidney transplant recipients developed posttransplant DM with higher incidences in older (≥55 years vs <55 years: 16.7% vs 10.1%) and obese (body mass index [BMI] ≥ 30 kg/m² vs BMI < 30 kg/m²: 17.1% vs 10.9%) patients. The incidence of posttransplant DM was lower with steroid avoidance [TMG/ALEM + no prednisone (8.4%) and IL2rAb + no prednisone (9.7%)] than TMG/ALEM with triple therapy (13.1%). After adjustment for donor and recipient characteristics, TMG/ALEM with steroid avoidance was beneficial for all groups [age < 55 years: adjusted HR (aHR), 0.63 (95% confidence interval [CI], 0.54-0.72); age ≥ 55 years: aHR, 0.69 (95% CI, 0.60-0.79); BMI < 30 kg/m²: aHR, 0.69 (95% CI, 0.60-0.78); BMI ≥ 30 kg/m²: aHR, 0.67 (95% CI, 0.57-0.79)]. However, IL2rAb with steroid avoidance was beneficial only for older patients (aHR, 0.76; 95% CI, 0.58-0.99) and for those with BMI < 30 kg/m² (aHR, 0.63; 95% CI, 0.46-0.87).

Limitations

Retrospective study and lacked data on immunosuppression levels.

Conclusions

The beneficial impact of steroid avoidance using tacrolimus on posttransplant DM appears to differ by patient age and induction regimen.

Outcomes of Kidney Transplantation in the Elderly Recipients

Introduction:

In a developing country with a predominantly young population, the valid assumption is directed toward medical care toward the young. However, as medical technology has advanced, quality care has ensured better survival for the elderly population also. The aim of this study was to determine the clinical outcomes in elderly patients undergoing kidney transplantation.

Materials and Methods:

A retrospective analysis of 1150 patients who had undergone live related renal transplantation was done from January 2006 to December 2014. These patients were divided into two groups; Group 1: age >60 years (N = 150), Group 2: age 18–60 years (N = 1000). The clinical outcomes were compared.

Results:

The mean age in Group 1 was 69 ± 7.5 years (SD ± 7.5), and group 2 was 41 ± 8 years. In groups 1 and 2, males were 80% and 82%; death censored graft survival at 5 years was 82% and 87%; patient survival at 5 years was 86% and 94%, respectively. The incidence of biopsy-proven acute rejection was similar in both groups (11.3 vs. 10.2%, P = 0.12). Urinary tract infection was the most common infectious complication. Sepsis was the primary cause of death in both groups.

Conclusion:

In the elderly patients who underwent kidney transplantation, satisfactory graft function, and patient survival were maintained over a period of 60 months. Urinary tract infections were common, and sepsis was the most common cause of death with a surviving allograft. The acute rejection and mortality rates were comparable to the literature published from India so far.

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.

Immunosuppression Regimen Use and Outcomes in Older and Younger Adult Kidney Transplant Recipients: A National Registry Analysis

BACKGROUND

Although the population of older transplant recipients has increased dramatically, there are limited data describing the impact of immunosuppression regimen choice on outcomes in this recipient group.

METHODS

National data for US Medicare-insured adult kidney recipients (N = 67 362; 2005-2016) were examined to determine early immunosuppression regimen and associations with acute rejection, death-censored graft failure, and mortality using multivariable regression analysis in younger (18-64 y) and older (>65 y) adults.

RESULTS

The use of antithymocyte globulin (TMG) or alemtuzumab (ALEM) induction with triple maintenance immunosuppression (reference) was less common in older compared with younger (36.9% versus 47.0%) recipients, as was TMG/ALEM + steroid avoidance (19.2% versus 20.1%) and mammalian target of rapamycin inhibitor (mTORi)-based (6.7% versus 7.7%) treatments. Conversely, older patients were more likely to receive interleukin (IL)-2-receptor antibody (IL2rAb) + triple maintenance (21.1% versus 14.7%), IL2rAb + steroid avoidance (4.1% versus 1.8%), and cyclosporine-based (8.3% versus 6.6%) immunosuppression. Compared with older recipients treated with TMG/ALEM + triple maintenance (reference regimen), those managed with TMG/ALEM + steroid avoidance (adjusted odds ratio [aOR], 0.440.520.61) and IL2rAb + steroid avoidance (aOR, 0.390.550.79) had lower risk of acute rejection. Older patients experienced more death-censored graft failure when managed with Tac + antimetabolite avoidance (adjusted hazard [aHR], 1.411.782.25), mTORi-based (aHR, 1.702.142.71), and cyclosporine-based (aHR, 1.411.782.25) regimens, versus the reference regimen. mTORi-based and cyclosporine-based regimens were associated with increased mortality in both older and younger patients.

CONCLUSIONS

Lower-intensity immunosuppression regimens (eg, steroid-sparing) appear beneficial for older kidney transplant recipients, while mTORi and cyclosporine-based maintenance immunosuppression are associated with higher risk of adverse outcomes.

Immunosuppression Considerations for Older Kidney Transplant Recipients

PURPOSE OF REVIEW

While kidney transplantation improves the long-term survival of the majority of patients with end-stage kidney disease (ESKD), age-related immune dysfunction and associated comorbidities make older transplant recipients more susceptible to complications related to immunosuppression. In this review, we discuss appropriate management of immunosuppressive agents in older adults to minimize adverse events, avoid acute rejection, and maximize patient and graft survival.

RECENT FINDINGS

Physiological changes associated with senescence can impact drug metabolism and increase the risk of posttransplant infection and malignancy. Clinical trials assessing the safety and efficacy of immunosuppressive agents in older adults are lacking. Recent findings from U.S. transplant registry-based studies suggest that risk-adjusted death-censored graft failure is higher among older patients who received antimetabolite avoidance, mammalian target of rapamycin inhibitor (mTORi)-based, and cyclosporine-based regimens. Observational data suggest that risk-adjusted mortality may be increased in older patients who receive mTORi-based and cyclosporine-based regimens but lower in those managed with T-cell induction and maintenance steroid avoidance/withdrawal.

SUMMARY

Tailored immunosuppression management to improve patient and graft survival in older transplant recipients is an important goal of personalized medicine. Lower intensity immunosuppression, such as steroid-sparing regimens, appear beneficial whereas mTORi- and cyclosporine-based maintenance are associated with greater potential for adverse effects. Prospective clinical trials to assess the safety and efficacy of immunosuppression agents in older recipients are urgently needed.

Outcomes of ABO-incompatible kidney transplantation in older patients: a national cohort study

BACKGROUND

Outcomes of ABO-incompatible living donor kidney transplantation (ABOi LDKT) in older individuals have not been established.

METHODS

This multicentric observational study, using data from the Korean Organ Transplantation Registry database, included 634 older patients (≥60 years) undergoing kidney transplantation. We compared clinical outcomes of ABOi LDKT (n = 80) with those of ABO-compatible LDKT (ABOc LDKT, n = 222) and deceased donor kidney transplantation (DDKT, n = 332) in older patients.

RESULTS

Death-censored graft survival was similar between the three groups (P = 0.141). Patient survival after ABOi LDKT was similar to that after ABOc LDKT (P = 0.489) but higher than that after DDKT (P = 0.038). In multivariable analysis, ABOi LDKT was not risk factor (hazard ratio [HR] 1.73, 95% confidence interval [CI] 0.29-10.38, P = 0.548), while DDKT was significant risk factor (HR 3.49, 95% CI 1.01-12.23, P = 0.049) for patient survival. Although ABOi LDKT showed higher biopsy-proven acute rejection than ABOc LDKT, the difference was not significant after adjustment with covariates. However, ABOi LDKT was significant risk factor for infection (HR 1.66, 95% CI 1.12-2.45, P = 0.012).

CONCLUSIONS

In older patients, ABOi LDKT was not inferior to ABOc LDKT and was superior to DDKT for patient survival. ABOi LDKT can be recommended for older patients, rather than waiting for DDKT.

Logistic Regression Model in a Machine Learning Application to Predict Elderly Kidney Transplant Recipients with Worse Renal Function One Year after Kidney Transplant: Elderly KTbot

Background

Renal replacement therapy (RRT) is a public health problem worldwide. Kidney transplantation (KT) is the best treatment for elderly patients' longevity and quality of life.

Objectives

The primary endpoint was to compare elderly versus younger KT recipients by analyzing the risk covariables involved in worsening renal function, proteinuria, graft loss, and death one year after KT. The secondary endpoint was to create a robot based on logistic regression capable of predicting the likelihood that elderly recipients will develop worse renal function one year after KT.

Method

Unicentric retrospective analysis of a cohort was performed with individuals aged ≥60 and <60 years old. We analysed medical records of KT recipients from January to December 2017, with a follow-up time of one year after KT. We used multivariable logistic regression to estimate odds ratios for elderly vs younger recipients, controlled for demographic, clinical, laboratory, data pre- and post-KT, and death.

Results

18 elderly and 100 younger KT recipients were included. Pretransplant immune variables were similar between two groups. No significant differences (P > 0.05) between groups were observed after KT on laboratory data means and for the prevalences of diabetes mellitus, hypertension, acute rejection, cytomegalovirus, polyomavirus, and urinary infections. One year after KT, the creatinine clearance was higher (P = 0.006) in youngers (70.9 ± 25.2 mL/min/1.73 m²) versus elderlies (53.3 ± 21.1 mL/min/1.73 m²). There was no difference in death outcome comparison. Multivariable analysis among covariables predisposing chronic kidney disease epidemiology collaboration (CKD-EPI) equation <60 mL/min/1.73 m² presented a statistical significance for age ≥60 years (P = 0.01) and reduction in serum haemoglobin (P = 0.03). The model presented goodness-fit in the evaluation of artificial intelligence metrics (precision: 90%; sensitivity: 71%; and F ₁ score: 0.79).

Conclusion

Renal function in elderly KT recipients was lower than in younger KT recipients. However, patients aged ≥60 years maintained enough renal function to remain off dialysis. Moreover, a learning machine application built a robot (Elderly KTbot) to predict in the elderly populations the likelihood of worse renal function one year after KT.

Assessment of infectious complications in elderly kidney transplant recipients receiving induction with anti-thymocyte globulin vs basiliximab

BACKGROUND

Elderly transplant recipients experience lower rates of acute rejection with higher rates of infectious complications compared to their younger counterparts. While less intensive immunosuppression may be preferable, there are no recommendations for depleting versus non-depleting induction strategies. We sought to compare infectious complications between anti-thymocyte globulin (ATG) and basiliximab (IL2RA) induction in elderly kidney transplant recipients (KTRs).

METHODS

We reviewed 146 KTRs ≥65 years receiving ATG or IL2RA induction. Per institution protocol, ATG was administered to patients with the following characteristics, irrespective of age: African American (AA), PRA ≥20%, and/or re-transplantation. Infectious complications (bacterial, viral, and invasive fungal) at 1 year were compared.

RESULTS

There were significantly more AA, deceased donors, and sensitized KTRs in the ATG group, reflecting criteria for induction agent. ATG KTRs experienced higher rates of overall infectious complications (77% vs 56%, P = .01), driven by increased bacterial (54% vs 39%, P = .08) and viral infections (51% vs 35%, P = .05). Urinary tract infections (UTIs) and CMV in particular occurred at high rates among ATG patients (46% and 32%, respectively). In multivariate analysis, the only independent risk factor associated with increased risk for infection was induction with ATG (adjusted HR 1.71 [95% CI 1.04-2.83], P = .04). Overall rates of immunologic outcomes were low.

CONCLUSION

Elderly KTRs receiving ATG are at an increased risk for infectious complications, largely attributed to high rates of UTIs and CMV. Additional strategies aimed at mitigating these complications in elderly patients requiring ATG may be beneficial.

Transplantation of Marginal Organs: Immunological Aspects and Therapeutic Perspectives in Kidney Transplantation

Recent data from the World Population Prospects projects that, by 2050, nearly all regions in the world will have a quarter or more of the population aged 60 and above. Chronic kidney disease (CKD) has a high global prevalence (~13%) worldwide, and the prevalence of chronic kidney disease and end-stage kidney disease increase with age. Kidney transplantation remains the best therapeutic option for end-stage kidney disease, offering a survival benefit in comparison with dialysis maintenance for most patients. This review focuses on immunological aspects of kidney transplantation in older patients and marginal donors, i.e., 60 years or older deceased kidney donors or 50–59 years old deceased kidney donors with comorbidities. Clinical outcomes of kidney recipients in terms of renal and patient survival are more than acceptable even for patients over 70. In this population, the first cause of graft loss is death with a functional graft. However, the inherent issues of these transplantations are the acceptance or refusal of frail kidney from an old donor and the increased immunogenicity of these organs in balance with potential frail and immunosenescent recipients. Finally, the immunosuppressive regimen itself is a challenge for the future of the transplant, to prevent adverse effects such as nephrotoxicity and higher risk of infections or cancer in a population already at risk. Belatacept may have a good place in the immunosuppressive strategy to improve efficacy and the safety posttransplantation.

Outcomes of induction antibody therapies in the nonbroadly sensitized adult deceased donor kidney transplant recipients: a retrospective cohort registry analysis

The outcomes of lymphocyte-depleting antibody induction therapy (LDAIT), [thymoglobulin (ATG) or alemtuzumab (ALM)] versus interleukin-2 receptor antagonist (IL-2RA) in the nonbroadly-sensitized [pretransplant calculated panel reactive antibody (cPRA), <80%] adult deceased donor kidney transplant recipients (adult-DDKTRs) are understudied. In this registry, study of 55 593 adult-DD-KTRs, outcomes of LDAIT [(ATG, N = 32 985) and (ALM, N = 9429)], and IL-2RA (N = 13 179) in <10% and 10-79% cPRA groups was analyzed. Adjusted odds ratio (aOR) of one-year biopsy-proven acute rejection (BPAR) was lower; while, aOR of 1-year composite of re-hospitalization, graft loss, or death was higher with LDAIT than IL2-RA in both cPRA groups. Adjusted odds ratio (aOR) of delayed graft function was higher with LDAIT than IL-2RA in the <10% cPRA group. Adjusted hazard ratio (aHR) of 5-year death-censored graft loss (DCGL) in both <80% cPRA groups seemed higher with ALM than other inductions [(<10% cPRA: ALM versus IL2RA, aHR = 1.11, 95% CI = 1.00-1.23 and ATG versus ALM: aHR = 0.84, 95% CI = 0.77-0.91; 10-79% cPRA: ALM versus IL2RA, aHR = 1.29, 95% CI = 1.02-1.64; and ATG versus ALM, aHR = 0.83, 95% CI = 0.70-0.98)]. Five-year aHR of death did not differ among induction therapies in both cPRA groups. In nonbroadly sensitized adult-DDKTRs, LDAIT is more protective against 1-year BPAR (not 5-year mortality) than IL-2RA; the trend of a higher 5-year DCGL risk with ALM than ATG or IL-2RA needs further investigation.

Reconstitution of T-Cell Subsets Following Thymoglobulin-Induced Depletion in High Immunologic Risk and Donation After Cardiac Death Renal Transplant Recipients

INTRODUCTION

Depletion therapy in high immunologic risk (HR) patients by antithymocyte globulin (rATG) induces lymphopenia and subsequent compartmental repopulation of T-cell subsets. rATG is also given to patients receiving kidneys from donations after cardiac death (DCDs) to mitigate innate immune activation associated with the DCD process.

METHODS

We compared the T-cell response with rATG in both HR and DCD kidney recipients. We examined the reconstitution of T-cell subsets after rATG treatment in HR and DCD recipients (n = 19 per group) by multicolor flow cytometry.

RESULTS

Following treatment, there was a rapid drop in the frequency of T cells in both groups, which persisted over 28 days. HR patients had an early surge in the frequency of CD4⁺ naïve, effector-memory, and regulatory T cells. Although we found a significant proliferation of the T cells in both groups, the DCD cohort had a blunted response as well as reduced CD4⁺ T-cell immune-reactivity compare with the HR group.

CONCLUSIONS

Our data suggest that there is a lack of significant homeostatic proliferative response in DCD recipients following rATG, and CD4⁺ T cells may be less reactive in the DCD group than previously thought, indicating that rATG treatment may not have to be considered a first-line induction therapy in DCD recipients.

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.

Comparison of Alemtuzumab Versus Basiliximab Induction Therapy in Elderly Kidney Transplant Recipients: A Single-Center Experience

BACKGROUND

The optimal choice of induction immunosuppression for elderly kidney transplant recipients remains unclear. Although alemtuzumab has been associated with escalating risk of death and graft loss in this population, this risk has not been adequately explored. The purpose of this study was to compare the safety and efficacy of alemtuzumab with basiliximab induction in this population.

METHODS

This is a retrospective matched cohort study of kidney transplant recipients aged ≥65 years. Patients who received alemtuzumab induction were matched (1:2) to a basiliximab control. The primary outcome was allograft survival. The incidence of acute rejection, infection, and all-cause mortality was measured.

RESULTS

Fifty-one and 102 patients were included in the alemtuzumab and basiliximab groups, respectively. Baseline demographics were similar between groups, except for more living donor transplant recipients in the alemtuzumab group (26/51 [51%] vs 31/102 [30.4%], P = .02). Acute cellular rejection occurred more frequently within the first year in the basiliximab group (P = .02). There was no difference in rates of infection within the first year. Graft and patient survival rates were similar over the follow-up period. Patients receiving basiliximab had a higher glomerular filtration rate at 2 years posttransplant (59 mL/min/1.73 m² vs 49 mL/min/1.73 m², P = .03).

CONCLUSIONS

Alemtuzumab induction is associated with similar outcomes to basiliximab in elderly kidney transplant recipients.

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.

Alemtuzumab Induction Is Associated With Equalization of Graft Outcomes Between Elderly and Nonelderly Kidney Transplant Recipients: A Single-Center Report

OBJECTIVES

Alemtuzumab (monoclonal anti-CD52 antibody) provides profound lymphocyte depletion and offers numerous advantages as an induction agent. Elderly recipients (> 65 years old) traditionally have inferior posttransplant outcomes versus younger recipients. We investigated short-term and long-term patient and graft survival rates following alemtuzumab induction in elderly recipients.

MATERIALS AND METHODS

This retrospective analysis, which included 676 renal allograft transplant recipients with alemtuzumab induction, was conducted at the University of Toledo Medical Center between March 2006 and November 2015. We used 2-sided t test, Pearson chi-square test, Fisher exact test, and Cox proportional hazard regressions with 95% confidence interval for analyses. P < .05 was significant.

RESULTS

Elderly recipients were more likely to receive a kidney from an inferior donor (deceased donor: 82% vs 72.4%; P = .030) and have higher mean kidney donor profile index (46.2 vs 38.4; P = .024) than nonelderly recipients. Elderly recipients were more likely to experience delayed graft function (15.1% vs 8.5%; P = .038). Elderly recipients demonstrated death-censored graft survival (1 year: 95.4% vs 93.1%; 3 years: 88.5% vs 93.3%; 5 years: 83.1% vs 86.4%) and rejection rates (1 year: 19.8% vs 21.2%; 3 years: 22.1% vs 25.3%; 5 years: 23.8% vs 26.9%) similar to nonelderly recipients. Elderly recipients had significantly higher overall mortality rates than recipients under 65 years old (29.8% vs. 13.2%; P = .001). Although 1-year patient survival was similar to younger recipients (94.8% vs 96.3%; P = .431), 3-year (80.0% vs 91.5%; P = .006) and 5-year (72.9% vs 86.2%; P = .19) rates were significantly decreased in elderly recipients.

CONCLUSIONS

Elderly age is not a predictor of rejection or death-censored graft loss in individuals who receive alemtuzumab induction. Despite elevated overall mortality, elderly recipients induced with alemtuzumab demonstrated rejection, graft, and short-term patient survival rates similar to younger recipients.

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.

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.

Long-Term Outcomes of Kidney Transplantation From Expanded-Criteria Deceased Donors: A Single-Center Experience

BACKGROUND

Organ shortage has prompted the use of expanded-criteria donors (ECDs). Our objective was to compare long-term outcomes of kidney transplants from ECDs with those from concurrent standard-criteria donors (SCDs). In addition, we evaluated variables associated with graft survival in both groups.

METHODS

We retrospectively reviewed all 617 deceased-donor kidney transplantations performed from 2005 to 2009 in our department. The population was divided according to donor status into ECD or SCD. Patients were followed until 5 years after transplantation, death, graft failure, or loss to follow-up.

RESULTS

We transplanted 150 deceased-donor kidneys from ECDs and 467 from SCDs. ECD were older, more frequently women, had a lower pre-retrieval glomerular filtration rate, and more frequently died due to cerebrovascular accident. ECD recipients were older, presented a lower proportion of black race, more frequently were on hemodialysis, and presented a higher rate of first kidney transplants. Mean glomerular filtration rate was consistently lower in the ECD group. Patient and graft survivals were lower in the ECD group, but statistical significance was present only in graft survival censored for death with a functioning graft at 3 years and graft survival noncensored for death with a functioning graft at 5 years. Younger recipient ages, longer time on dialysis, acute rejection episodes, and glomerular filtration rate at 1 year after transplantation were independent risk factors for lower graft survival.

CONCLUSIONS

Transplantation with the use of ECD kidneys provide quite satisfactory patient and graft survival rates despite their poorer long-term outcomes.

[Focusing on kidney transplantation in the elderly]

Due to the increase in life expectancy and the ageing of end-stage renal disease patients, the number of patients older than 65 years receiving a kidney transplant has been continuously growing over the last fifteen years. The benefits of renal transplantation compared to dialysis in terms of survival and quality of life have been shown in selected recipients over 65, or 70 years. However, the age remains the main limiting factor for the access to the waiting list, and the reluctance of the clinicians can be explained by the multiple comorbidities of these candidates, their limited life expectancy or the shortage of grafts. The challenge is to select the candidates who can benefit from renal transplantation, thanks to rigorous cardiovascular and neoplastic evaluation before enrolment and by taking into account the specific characteristics of elderly patients. The living donor appears to be the ideal option for elderly recipients, the alternative being the extended criteria donor, allowing waiting times to be limited. The choice of immunosuppressive therapy is also crucial in these patients at high risk of infectious and cardiovascular complications in whom the occurrence of acute rejection can have severe consequences. There are currently no specific recommendations for immunosuppression in elderly recipients, and we would need large-scale randomized studies to improve the prognosis of renal transplantation in this population.

Cost-Effectiveness of Antibody-Based Induction Therapy in Deceased Donor Kidney Transplantation in the United States

BACKGROUND

Induction therapy in deceased donor kidney transplantation is costly, with wide discrepancy in utilization and a limited evidence base, particularly regarding cost-effectiveness.

METHODS

We linked the United States Renal Data System data set to Medicare claims to estimate cumulative costs, graft survival, and incremental cost-effectiveness ratio (ICER - cost per additional year of graft survival) within 3 years of transplantation in 19 450 deceased donor kidney transplantation recipients with Medicare as primary payer from 2000 to 2008. We divided the study cohort into high-risk (age > 60 years, panel-reactive antibody > 20%, African American race, Kidney Donor Profile Index > 50%, cold ischemia time > 24 hours) and low-risk (not having any risk factors, comprising approximately 15% of the cohort). After the elimination of dominated options, we estimated expected ICER among induction categories: no-induction, alemtuzumab, rabbit antithymocyte globulin (r-ATG), and interleukin-2 receptor-antagonist.

RESULTS

No-induction was the least effective and most costly option in both risk groups. Depletional antibodies (r-ATG and alemtuzumab) were more cost-effective across all willingness-to-pay thresholds in the low-risk group. For the high-risk group and its subcategories, the ICER was very sensitive to the graft survival; overall both depletional antibodies were more cost-effective, mainly for higher willingness to pay threshold (US $100 000 and US $150 000). Rabbit ATG appears to achieve excellent cost-effectiveness acceptability curves (80% of the recipients) in both risk groups at US $50 000 threshold (except age > 60 years). In addition, only r-ATG was associated with graft survival benefit over no-induction category (hazard ratio, 0.91; 95% confidence interval, 0.84-0.99) in a multivariable Cox regression analysis.

CONCLUSIONS

Antibody-based induction appears to offer substantial advantages in both cost and outcome compared with no-induction. Overall, depletional induction (preferably r-ATG) appears to offer the greatest benefits.

How does age affect the outcome of kidney transplantation in elderly recipients?

The aging of the on-dialysis population raises the issue of whether to propose elderly patients for kidney transplantation and how to manage their immunosuppression. This study aimed to analyze the outcome of kidney transplantation on an Italian series of elderly recipients. We included in this retrospective study all patients over 60 years, receiving a deceased-donor kidney transplantation from January 2004 to December 2014 in two north Italian Centers. We analyzed the correlation of recipient age with graft's and patient's survival, delayed graft function, acute cellular rejection (ACR), surgical complications, infections, and glomerular filtration rate. Four hundred and fifty-two patients with a median age of 65 years were included in the study. One-, 3-, and 5-year patient's and graft's survival were, respectively, of 98.7%, 93%, 89% and 94.4%, 87.9%, 81.4%. The increasing recipient age was an independent risk factor only for the patient's (P=.008) and graft's survival (P=.002). ACR and neoplasia were also associated to a worse graft survival. The reduced graft survival in elderly kidney recipients seems to be related more to the increasing recipient's age than to the donor's features. In this population, the optimization of organ allocation and immunosuppression may be the key factors to endorse improvements.

Strategies for an Expanded Use of Kidneys From Elderly Donors

The old-for-old allocation policy used for kidney transplantation (KT) has confirmed the survival benefit compared to remaining listed on dialysis. Shortage of standard donors has stimulated the development of strategies aimed to expand acceptance criteria, particularly of kidneys from elderly donors. We have systematically reviewed the literature on those different strategies. In addition to the review of outcomes of expanded criteria donor or advanced age kidneys, we assessed the value of the Kidney Donor Profile Index policy, preimplantation biopsy, dual KT, machine perfusion and special immunosuppressive protocols. Survival and functional outcomes achieved with expanded criteria donor, high Kidney Donor Profile Index or advanced age kidneys are poorer than those with standard ones. Outcomes using advanced age brain-dead or cardiac-dead donor kidneys are similar. Preimplantation biopsies and related scores have been useful to predict function, but their applicability to transplant or refuse a kidney graft has probably been overestimated. Machine perfusion techniques have decreased delayed graft function and could improve graft survival. Investing 2 kidneys in 1 recipient does not make sense when a single KT would be enough, particularly in elderly recipients. Tailored immunosuppression when transplanting an old kidney may be useful, but no formal trials are available.Old donors constitute an enormous source of useful kidneys, but their retrieval in many countries is infrequent. The assumption of limited but precious functional expectancy for an old kidney and substantial reduction of discard rates should be generalized to mitigate these limitations.

Comparing Outcomes between Antibody Induction Therapies in Kidney Transplantation

Kidney transplant recipients often receive antibody induction. Previous studies of induction therapy were often limited by short follow-up and/or absence of information about complications. After linking Organ Procurement and Transplantation Network data with Medicare claims, we compared outcomes between three induction therapies for kidney recipients. Using novel matching techniques developed on the basis of 15 clinical and demographic characteristics, we generated 1:1 pairs of alemtuzumab-rabbit antithymocyte globulin (rATG) (5330 pairs) and basiliximab-rATG (9378 pairs) recipients. We used paired Cox regression to analyze the primary outcomes of death and death or allograft failure. Secondary outcomes included death or sepsis, death or lymphoma, death or melanoma, and healthcare resource utilization within 1 year. Compared with rATG recipients, alemtuzumab recipients had higher risk of death (hazard ratio [HR], 1.14; 95% confidence interval [95% CI], 1.03 to 1.26; P<0.01) and death or allograft failure (HR, 1.18; 95% CI, 1.09 to 1.28; P<0.001). Results for death as well as death or allograft failure were generally consistent among elderly and nonelderly subgroups and among pairs receiving oral prednisone. Compared with rATG recipients, basiliximab recipients had higher risk of death (HR, 1.08; 95% CI, 1.01 to 1.16; P=0.03) and death or lymphoma (HR, 1.12; 95% CI, 1.01 to 1.23; P=0.03), although these differences were not confirmed in subgroup analyses. One-year resource utilization was slightly lower among alemtuzumab recipients than among rATG recipients, but did not differ between basiliximab and rATG recipients. This observational evidence indicates that, compared with alemtuzumab and basiliximab, rATG associates with lower risk of adverse outcomes, including mortality.

[Deceased donation in renal transplantation]

OBJECTIVES

To review epidemiologic data's and medical results of deceased donation in renal transplantation.

MATERIAL AND METHODS

Relevant publications were identified through Medline (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) database using the following keywords, alone or in association, "brain death; cardiac arrest; deceased donation; organ procurement; transplantation". Articles were selected according to methods, language of publication and relevance. The reference lists were used to identify additional historical studies of interest. Both prospective and retrospective series, in French and English, as well as review articles and recommendations were selected. In addition, French national transplant and health agencies (http://www.agence-biomedecine.fr and http://www.has-sante.fr) databases were screened using identical keywords. A total of 2498 articles, 8 official reports and 17 newspaper articles were identified; after careful selection 157 publications were eligible for our review.

RESULTS

Deceased donation may involve either brain death or non-heartbeating donors (NHBD). Organ shortage led to the procurement of organs from expanded-criteria donors, with an increased age at donation and extended vascular disease, leading to inferior results after transplantation and underlining the need for careful donor management during brain death or cardiac arrest. Evolution of French legislation covering bioethics allowed procurement from Maastricht categories II and recently III non-heartbeating donors.

CONCLUSION

The increase of organ shortage emphasizes the need for a rigorous surgical technique during procurement to avoid loss of transplants. A history or current neoplasm in deceased-donors, requires attention to increase the pool of organs without putting the recipients at risk for cancer transmission. French NHBD program, especially from Maastricht category III, may stand for a potential source of valuable organs.

National Variation in Use of Immunosuppression for Kidney Transplantation: A Call for Evidence-Based Regimen Selection

Immunosuppression management in kidney transplantation has evolved to include an increasingly diverse choice of medications. Although informed by patient and donor characteristics, choice of immunosuppression regimen varies widely across transplant programs. Using a novel database integrating national transplant registry and pharmacy fill records, immunosuppression use at 6-12 and 12-24 mo after transplant was evaluated for 22 453 patients transplanted in 249 U.S. programs in 2005-2010. Use of triple immunosuppression comprising tacrolimus, mycophenolic acid or azathioprine, and steroids varied widely (0-100% of patients per program), as did use of steroid-sparing regimens (0-77%), sirolimus-based regimens (0-100%) and cyclosporine-based regimens (0-78%). Use of triple therapy was more common in highly sensitized patients, women and recipients with dialysis duration >5 years. Sirolimus use appeared to diminish over the study period. Patient and donor characteristics explained only a limited amount of the observed variation in regimen use, whereas center choice explained 30-46% of the use of non-triple-therapy immunosuppression. The majority of patients who received triple-therapy (79%), cyclosporine-based (87.6%) and sirolimus-based (84.3%) regimens continued them in the second year after transplant. This population-based study of immunosuppression practice demonstrates substantial variation in center practice beyond that explained by differences in patient and donor characteristics.

Immunosuppression in the elderly renal allograft recipient: a systematic review

BACKGROUND

The Elderly are the fastest growing part of kidney transplant recipients. The best immunosuppressive strategy is unknown.

METHODS

We performed a systematic search of randomized controlled trials and observational studies focused on safety and efficacy of different immunosuppression strategies in elderly kidney recipients. Data extraction and risk of bias evaluation were systematically performed.

RESULTS

Ten studies were included: 2 randomized clinical trials and 8 observational. A marginal benefit was found for early renal function with delayed tacrolimus or complete tacrolimus avoidance using mycophenolate mofetil (MMF). Observational cohort studies looked at different antibody induction strategies, calcineurin-inhibitors based maintenance immunosuppression, calcineurin-inhibitor-free sirolimus-based therapy and use of MMF versus azathioprine. Treatment with interleukin-2 receptor antibody induction, calcineurin-inhibitor minimization with MMF and steroid minimization is advisable in the low immunologic risk elderly recipient, considering the increased risk of toxicities, infection and malignancies. In the high immunologic risk elderly recipient, taking into account the morbid consequences of acute rejection in the elderly, observational studies support antibody induction with depletive antibodies, calcineurin-inhibitor, MMF and steroids; calcineurin-inhibitor-minimization is not recommended.

CONCLUSIONS

There is very limited evidence for the benefits and harms of different immunosuppression strategies in the elderly. Most of the published literature are observational studies, and randomized controlled trials are urgently needed.

Renal transplantation with expanded criteria donors: Which is the optimal immunosuppression?

The growing gap between demand and supply for kidney transplants has led to renewed interest in the use of expanded criteria donor (ECD) kidneys in an effort to increase the donor pool. Although most studies of ECD kidney transplantation confirm lower allograft survival rates and, generally, worse outcomes than standard criteria donor kidneys, recipients of ECD kidneys generally have improved survival compared with wait-listed dialysis patients, thus encouraging the pursuit of this type of kidney transplantation. The relative benefits of transplantation using kidneys from ECDs are dependent on patient characteristics and the waiting time on dialysis. Because of the increased risk of poor graft function, calcineurin inhibitor (CNI)-induced nephrotoxicity, increased incidence of infections, cardiovascular risk, and malignancies, elderly recipients of an ECD kidney transplant are a special population that requires a tailored immunosuppressive regimen. Recipients of ECD kidneys often are excluded from transplant trials and, therefore, the optimal induction and maintenance immunosuppressive regimen for them is not known. Approaches are largely center specific and based upon expert opinion. Some data suggest that antithymocyte globulin might be the preferred induction agent for elderly recipients of ECD kidneys. Maintenance regimens that spare CNIs have been advocated, especially for older recipients of ECD kidneys. CNI-free regimens are not universally accepted due to occasionally high rejection rates. However, reduced CNI exposure and CNI-free regimens based on mammalian target of rapamycin inhibitors have shown acceptable outcomes in appropriately selected ECD transplant recipients.

A Rationale for Age-Adapted Immunosuppression in Organ Transplantation

Demographic changes are associated with a steady increase of older patients with end-stage organ failure in need for transplantation. As a result, the majority of transplant recipients are currently older than 50 years, and organs from elderly donors are more frequently used. Nevertheless, the benefit of transplantation in older patients is well recognized, whereas the most frequent causes of death among older recipients are potentially linked to side effects of their immunosuppressants.Immunosenescence is a physiological part of aging linked to higher rates of diabetes, bacterial infections, and malignancies representing the major causes of death in older patients. These age-related changes impact older transplant candidates and may have significant implications for an age-adapted immunosuppression. For instance, immunosenescence is linked to lower rates of acute rejections in older recipients, whereas the engraftment of older organs has been associated with higher rejection rates. Moreover, new-onset diabetes mellitus after transplantation is more frequent in the elderly, potentially related to corticosteroids, calcineurin inhibitors, and mechanistic target of rapamycin inhibitors.This review presents current knowledge for an age-adapted immunosuppression based on both, experimental and clinical studies in and beyond transplantation. Recommendations of maintenance and induction therapy may help to improve graft function and to design future clinical trials in the elderly.

Kidney Transplantation Among the Elderly: Challenges and Opportunities to Improve Outcomes

Elderly patients (>65 years old) represent the fastest growing population among the ESRD patients and those awaiting kidney transplantation. There is ample evidence to suggest that kidney transplant in the elderly population offers the best chance of survival and improves health-related quality of life compared to remaining on dialysis. Although all these emerging facts are encouraging, this population brings with them complex medical problems including frailty, cognitive impairment, and multiple comorbidities. These issues can be barriers to transplantation and threaten the well-being of the patients after transplantation. Furthermore, aging results in changes to the immune system and affects the pharmacokinetics of immunosuppressants. All these changes can increase risk of complications such as infections and malignancy. Because death with a functioning graft is a common cause of graft loss, the new kidney allocation system has been implemented in an attempt to maximize allograft utilization and minimize unrealized graft years. This may result in longer wait-times for the elderly. In this review, we will highlight the barriers to kidney transplant, characterize transplant-related issues in the elderly, and propose alternative strategies under the new allocation system.

What immunosuppression should be used for old-to-old recipients?

Elderly patients receiving a kidney from old donors (old-to-old) are a growing population of transplant recipients. This population cumulates risks of complications due to the co-morbidities and the immunodeficiency state and the frailty of the recipients together with the kidney senescence of the donors. In this context, the choice of immunosuppression is complicated and must take into account some contradictory principles explaining why no consensus exists today.

Pharmacokinetics and pharmacodynamics of immunosuppressive drugs in elderly kidney transplant recipients

Elderly patients are a fast growing population among transplant recipients over the past decades. Both the innate and adaptive immune reactivity decrease with age, which is believed to contribute to the decreased incidence of acute rejection and increased infectious death rate in elderly transplant recipients. In contrast to recipient age, donor age is associated with a higher incidence of acute rejection. Pharmacokinetic studies in renal transplant recipients show that CNI troughs are >5% higher in elderly compared to younger patients given the same dose normalized by body weight. This may impact the starting dose of tacrolimus and cyclosporine. Possibly in elderly patients the intracellular (in lymphocyte) concentrations are relatively high in relation to the whole blood concentration, resulting in a stronger pharmacodynamic effect at the same whole blood trough concentration. For cyclosporine this has been shown, but it is not clear if the same is true for other immunosuppressive drugs. Pharmacodynamic studies have compared the inhibition of target enzymes, or more downstream effects of immunosuppressive drugs, in younger and older patients. Measurement of nuclear factor of activated T-cell (NFAT)-regulated gene expression (RGE), a pharmacodynamic read-out of CNI, is a promising biomarker of immunosuppression. Low levels of NFAT RGE are associated with increased risk of infection and non-melanoma skin cancer in elderly patients. Clinical trials to evaluate the safety and efficacy of immunosuppression regimens in this specific patient population, which is underrepresented in published trials, are lacking. More studies in elderly patients are needed to investigate the impact of age on the pharmacokinetics or pharmacodynamics of immunosuppressive drugs, and to decide on the optimal regimen and target levels for elderly transplant recipients.

Managing transplant rejection in the elderly: the benefits of less aggressive immunosuppressive regimens

Organ transplantation is increasingly common in the older population, particularly among end-stage renal disease patients. The outcomes of transplantation are often inferior in older people compared with younger recipients, partly because of the side effects of immunosuppressive medication used after organ transplantation. In this paper, we explore treatment considerations for older transplant patients. The current commonly used immunosuppressive protocols have not been validated sufficiently in older organ recipients. The primary objective for the management of transplant recipients of all ages is to prevent rejection without increasing the risk of infection or other long-term complications. To avoid serious side effects related to immunosuppressive treatment, the clinician should consider modifying and tailoring the long-term regimen for individual patients. Modifications for older recipients include reduction in the dosage or avoidance of calcineurin inhibitors, with or without the introduction of a mammalian target of rapamycin inhibitor and discontinuing the use of corticosteroids. Such modifications must consider the individual risks and needs of each recipient. Treatment of an acute rejection episode should follow the same protocol as for younger recipients, but special attention is needed to ensure reduction in the total immunosuppressive load. One way to achieve this is to avoid anti-thymocyte globulin (ATG) induction and to use on-demand ATG treatment of rejection on the basis of the patient's CD3 T cell count.

How immunosuppressive therapy affects T cells from kidney transplanted patients of different age: the role of latent cytomegalovirus infection

The average age of patients receiving renal transplantation is increasing as programmes have been established which support the donation of organs from elderly donors to older recipients. Little is known about the effect of immunosuppressive therapy on the immune system of older patients. In this study, T cell function and the composition of the T cell repertoire were analysed in immunosuppressed renal transplant recipients of different age and cytomegalovirus (CMV) status in comparison to age- and CMV-matched controls. Independent of age and CMV status, the production of interleukin (IL)-2 and interferon (IFN)-γ by T cells was decreased in the patient groups and autologous serum from patients was capable of inhibiting the proliferation of CD3⁺ T cells. CXCR5 expression on T cells was increased in patients versus controls reflecting reduced endogenous IL-2 signalling under immunosuppressive therapy. In CMV-seronegative patients kidney transplantation and immunosuppressive therapy did not induce changes in the CD8⁺ T cell pool, but there was a moderate increase in CD4⁺CD28⁻ effector T cells when compared to age-matched controls. In contrast, latent CMV infection triggered a shift from early to late differentiated CD4⁺ and CD8⁺ T cells in patients and controls. This shift was most pronounced in elderly transplant patients under immunosuppressive therapy. In conclusion, our results demonstrate that immunosuppressive therapy following kidney transplantation is effective in patients older than 65 years. Latent CMV infection, however, accelerates age-related changes in the T cell repertoire in elderly people under immunosuppressive therapy. These patients should therefore be monitored with special care.

Effect of different immunosuppressive drugs on immune cells from young and old healthy persons

BACKGROUND

Life expectancy, as well as the average age of patients undergoing solid organ transplantation, increases constantly. Consequently, immunosuppressive therapy is no longer limited to young organ recipients.

OBJECTIVE

Here, we investigate how different types of immunosuppressive therapy, namely the calcineurin inhibitors cyclosporin A and tacrolimus, as well as the mTOR inhibitor rapamycin, affect the function of immune cells in young and elderly persons.

METHODS

Proliferation, cell viability, cytokine production (IL-2, IFN-γ), H2O2 production and telomere length of phytohemagglutinin (PHA)-stimulated human peripheral blood mononuclear cells (PBMCs) of young (n = 13; median age 27 years) and old (n = 19; median age 71 years) healthy donors were analyzed.

RESULTS

The inhibition of proliferation was dampened in PBMCs from elderly donors, especially after incubation with rapamycin. All three immunosuppressive drugs inhibited the production of IL-2 equally well, whereas the production of IFN-γ was less well inhibited by rapamycin. Both calcineurin inhibitors increased H2O2 concentrations after stimulation with PHA and led to a shortening of telomeres in PBMCs from young and old individuals. Rapamycin had only minor effects on H2O2 production and telomere length.

CONCLUSION

Our results demonstrate that the effects of immunosuppressive drugs on PBMCs differ between young and elderly persons. Calcineurin inhibitors compared to rapamycin have a more pronounced prosenescence effect. These data indicate that specific treatment regimens for the elderly might therefore be considered.