Impact of immunosenescence on transplant outcome

Immunosenescence, immunotolerance and rejection: clinical aspects in solid organ transplantation

As a consequence of increased lifespan and rising number of elderly individuals developing end-stage organ disease, the higher demand for organs along with a growing availability for organs from older donors pose new challenges for transplantation. During aging, dynamic adaptations in the functionality and structure of the biological systems occur. Consistently, immunosenescence (IS) accounts for polydysfunctions within the lymphocyte subsets, and the onset of a basal but persistent systemic inflammation characterized by elevated levels of pro-inflammatory mediators. There is an emerging consensus about a causative link between such hallmarks and increased susceptibility to morbidities and mortality, however the role of IS in solid organ transplantation (SOT) remains loosely addressed. Dissecting the immune-architecture of immunologically-privileged sites may prompt novel insights to extend allograft survival. A deeper comprehension of IS in SOT might unveil key standpoints for the clinical management of transplanted patients.

Allogeneic Ocular Surface Stem Cell Transplantation Outcomes With Decreased or No Systemic Immunosuppression in the Elderly

PURPOSE

The aim of this study was to report outcomes after allogeneic ocular surface stem cell transplantation (OSST) for limbal stem cell deficiency in the setting of decreased or no systemic immunosuppression (SI) in the elderly.

METHODS

A retrospective chart review was performed of all eyes that underwent OSST for limbal stem cell deficiency between 2005 and 2020 at CVP Physicians. Inclusion criteria included patients who were (1) at least 70 years at the time of (2) allogeneic OSST. Postoperative SI regimens were assessed. Outcome measures included improvement in visual acuity, ocular surface stability, and adverse effects.

RESULTS

There were 14 eyes of 14 patients that met the inclusion criteria with mean follow-up of 3.0 (range 0.4-7.0) years. SI was run at a lower level for 6 patients, and 8 patients did not receive any SI. Nine eyes underwent keratolimbal allograft, 1 had a living-related conjunctival limbal allograft, and 4 had combined OSST. Most eyes (85.7%) attained improvement in visual acuity during their follow-up. At the last follow-up, 57.1% maintained a stable ocular surface. Six eyes developed acute rejection or late failure. Minimal adverse events were noted.

CONCLUSIONS

Elderly patients administered less or no SI exhibit overall favorable outcomes after allogeneic OSST. Although not significantly different, surface stability and duration of improved vision was greater with low SI. No SI may be an option that still achieves improved vision in a high proportion for at least part of their follow-up. Decreasing SI after OSST in this population can improve quality of life while minimizing adverse effects.

Review of prognostic factors for kidney transplant survival

Transplantation is the most effective treatment for end-stage chronic kidney disease, as this procedure prolongs and improves the patient's quality of life. One of the key problems is the risk of graft rejection. The purpose of this research was to identify and analyse prognostic factors that will prevent rejection. In particular, the prognostic factors grouped by methods of synthesis, generalisation and statistical processing with calculation and graphical representation of hazard ratio and correlation coefficient were grouped, namely: age of donor and recipient, time of cold kidney ischaemia, duration of preoperative dialysis, body mass index, presence of concomitant diseases (diabetes mellitus, hypertension), primary causes causing transplantation. Several molecular genetic and biochemical prognostic markers (transcription factors, immunocompetent cell signalling and receptors, cytostatin C, creatinine, citrate, lactate, etc.) are annotated. It has been demonstrated that creatinine reduction rate determines the risk of rejection, displaying the dynamics of cystatin C and creatinine changes in the postoperative period. Young recipients who underwent prolonged preoperative dialysis were identified as having the highest risk of rejection. Diabetes and hypertension bear a non-critical but commensurately equal risk of rejection. The survival rate of the graft is better when transplanted from a living donor than from a deceased donor. A correlation between cold ischaemia time, body mass index and the probability of graft failure has been proven, namely, the greater the donor and recipient body mass index and the longer the cold ischaemia time, the lower the chance of successful long-term organ acclimation. The data obtained can be used as prognostic factors for graft accommodation at different intervals after surgery.

Pancreas Donor Risk Index and Preprocurement Pancreas Suitability Score for Prediction of Pancreas Transplant Outcomes

OBJECTIVES

The Pancreas Donor Risk Index and Preprocurement Pancreas Suitability Score were designed to assist in the evaluation of pancreases for transplant. Preprocurement Pancreas Suitability Score <17 and PancreasDonor Risk Index ≤1.57 were deemed ideal.We aimed to determine the ability ofthese scores to predict pancreas transplant outcomes.

MATERIALS AND METHODS

The Pancreas Donor Risk Index and the Preprocurement Pancreas Suitability Score were retrospectively calculated from a prospectively maintained database of consecutive pancreas transplants performed during a 13-year period (December 2004 to November 2017). Outcomes measuredwere rejection rate, graft and patient survival, and duration of hospital stay.

RESULTS

Of 159 pancreas transplants (108 simultaneous pancreas and kidney transplants, 33 pancreas after kidney transplants, 18 pancreas-only transplants), full data were available for 155 (97%) to calculate Pancreas Donor Risk Indexes and 129 (81%) to calculate Preprocurement Pancreas Suitability Scores. Fortyseven patients (30%) experienced at least 1 episode of acute rejection. We calculated Pancreas Donor Risk Indexes for 155 patients, and 19 (23%) and 27 (38%) were in the ≤1.57 and >1.57 groups, respectively (P = .047). We calculated Preprocurement Pancreas Suitability Scores for 129 patients, and 12 (21%) and 27 (32%) were in the <17 and ≥17 groups, respectively (P = .202). Donor age and recipientfemale sex were the main predictors forrejection (binary logistic regression, P < .05). One-year graft survival rates were 95% and 81% forthe ≤1.57 and >1.57 PancreasDonor Risk Index groups,respectively, and 95% and 80% forthe <17 and ≥17 Preprocurement Pancreas Suitability Score groups, respectively (not significant).

CONCLUSIONS

Pancreas Donor Risk Index and Preprocurement Pancreas Suitability Score were not helpful to predict graft/patient survival in our population. A higher Pancreas Donor Risk Index was associated with higher risk of graft rejection. Further studies with larger cohorts are required.

Changes in T and B cell subsets in end stage renal disease patients before and after kidney transplantation

BACKGROUND

The incidence of kidney transplantation performed in elderly patients has increased steadily recently. Higher risk of infection and mortality, but lower rate of rejection, are reported in older kidney transplant patients. This study aims to analyze the effect of transplantation on aging of T and B cells in kidney transplant patients, with the emphasis on age and Cytomegalovirus (CMV) latency.

RESULTS

We included 36 patients before and after (median 2.7 years) kidney transplantation and 27 age- and sex-matched healthy controls (HC). T and B cell subsets were measured by flow cytometry, with a focus on aged T cells (CD28-), and age associated B cells (ABCs, CD19 + CD21-CD11c+). Three years after transplantation a significant increase of total T cells among the lymphocytes was found compared to pre-transplantation and HC. Among the T cells CD4+ cells were decreased, especially naïve CD4+ cells and regulatory T cells. Total CD8+ cell proportions were increased, and proportions of naïve CD8+ cells were significantly decreased after transplantation, while CD8+ effector memory T cells re-expressing CD45RA were increased. CD28- T cells were significantly higher compared to HC after transplantation, especially in CMV seropositive patients. B cells were significantly decreased, while among B cells memory B cells and especially ABCs were increased after transplantation.

CONCLUSIONS

After transplantation T and B cell subsets change towards more terminally differentiated memory cells compared to age-matched HC. Proportions of aged T cells and ABCs were associated with CMV serostatus.

Immunosuppression in liver and intestinal transplantation

Immunosuppression handling plays a key role in the early and long-term results of transplantation. The development of multiple immunosuppressive drugs led to numerous clincial trials searching to reach the ideal regimen. Due to heterogeneity of the studied patient cohorts and flaws in many, even randomized controlled, study designs, the answer still stands out. Nowadays triple-drug immunosuppression containing a calcineurin inhibitor (preferentially tacrolimus), an antimetabolite (using mycophenolate moffettil or Azathioprine) and short-term steroids with or without induction therapy (using anti-IL2 receptor blocker or anti-lymphocytic serum) is the preferred option in both liver and intestinal transplantation. This chapter aims, based on a critical review of the definitions of rejection, corticoresistant rejection and standard immunosuppression to give some reflections on how to reach an optimal immunosuppressive status and to conduct trials allowing to draw solid conclusions. Endpoints of future trials should not anymore focus on biopsy proven, acute and chronic, rejection but also on graft and patient survival. Correlation between early- and long-term biologic, immunologic and histopathologic findings will be fundamental to reach in much more patients the status of operational tolerance.

Donor HLA Class 1 Evolutionary Divergence Is a Major Predictor of Liver Allograft Rejection : A Retrospective Cohort Study

BACKGROUND

The HLA evolutionary divergence (HED), a continuous metric quantifying the peptidic differences between 2 homologous HLA alleles, reflects the breadth of the immunopeptidome presented to T lymphocytes.

OBJECTIVE

To assess the potential effect of donor or recipient HED on liver transplant rejection.

DESIGN

Retrospective cohort study.

SETTING

Liver transplant units.

PATIENTS

1154 adults and 113 children who had a liver transplant between 2004 and 2018.

MEASUREMENTS

Liver biopsies were done 1, 2, 5, and 10 years after the transplant and in case of liver dysfunction. Donor-specific anti-HLA antibodies (DSAs) were measured in children at the time of biopsy. The HED was calculated using the physicochemical Grantham distance for class I (HLA-A or HLA-B) and class II (HLA-DRB1 or HLA-DQB1) alleles. The influence of HED on the incidence of liver lesions was analyzed through the inverse probability weighting approach based on covariate balancing, generalized propensity scores.

RESULTS

In adults, class I HED of the donor was associated with acute rejection (hazard ratio [HR], 1.09 [95% CI, 1.03 to 1.16]), chronic rejection (HR, 1.20 [CI, 1.10 to 1.31]), and ductopenia of 50% or more (HR, 1.33 [CI, 1.09 to 1.62]) but not with other histologic lesions. In children, class I HED of the donor was also associated with acute rejection (HR, 1.16 [CI, 1.03 to 1.30]) independent of the presence of DSAs. There was no effect of either donor class II HED or recipient class I or class II HED on the incidence of liver lesions in adults and children.

LIMITATION

The DSAs were measured only in children.

CONCLUSION

Class I HED of the donor predicts acute or chronic rejection of liver transplant. This novel and accessible prognostic marker could orientate donor selection and guide immunosuppression.

PRIMARY FUNDING SOURCE

Institut National de la Santé et de la Recherche Médicale.

Fc Receptor-Like Gene Expression in Renal Transplantation Patients

Background:

It has been well-documented that the Fc receptor-like (FCRL) molecule contributes to the pathogenesis of certain autoimmune disorders. FCRL molecules belong to the immunoglobulin superfamily produced by B cells. Also, these molecules induce activating or inhibitory signals of B cells. According to this information and also considering the critical role of immune reactions in organ transplantation, the following experiment was performed to analyze the gene expression level of FCRLs in peripheral blood mononuclear cells of kidney transplant recipients.

Materials and Methods:

Blood samples were obtained from 32 renal transplant patients on days 1, 3, and 7 post-transplantations. Patients were divided into two groups according to the presence or absence of rejection. Also, 24 age-matched healthy subjects were enrolled as control group. After total RNA extraction from peripheral blood mononuclear cells (PBMC) and cDNA synthesis, the gene expression levels of FCRL1, FCRL2, and FCRL4 in each group were measured by real-time polymerase chain reaction.

Results:

Our results showed that FCRL1 expression levels in kidney transplant patients were significantly less than healthy controls. The overall FCRL2 expression level was not significantly different between them. However, at days 1 and 7, following transplantation in the non-rejected group FCRL2 level was significantly higher than the control group. Comparing the FCRL4 gene expression levels of both groups with healthy controls showed a significant decrease in the third and seventh days post-transplantation.

Conclusion:

It can be concluded that mononuclear cells, mainly B cells, have an essential role to play in kidney transplantation.

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.

Frailty and kidney transplant candidates

Frailty is a concept that has been mainly developed in geriatrics and it came from the need of identifying subjects at risk to develop complications when they faced a stressful event. Frail patients have higher risk of mortality, poor outcomes and disability, and this is independent from their age or comorbidities. Chronic kidney disease patients present with high prevalence of frailty, especially those who are in renal replacement therapy. Frail or pre-frail patients on the kidney transplant waiting list represent 20-30%, and these patients are proven to have poorer results after the transplant, which is a stressful event itself. Tools for frailty assessment, both scales or indexes, may be useful to identify which subjects might be at risk for complications after transplant, and this is necessary to adapt our clinical practice and minimize morbidity. The most used frailty scale in kidney patients is Fried scale, which is based in five phenotypic items. Besides that, knowing frail population allows potential interventions such as prehabilitation while the patient is waiting for the kidney transplant, which the aim of improving their vulnerability prior to transplant and, therefore, optimizing results after transplant. More studies are needed amongst kidney patients to improve and prevent frailty.

[Frailty and kidney transplant candidates]

Frailty is a concept that has been mainly developed in geriatrics and it came from the need of identifying subjects at risk to develop complications when they faced a stressful event. Frail patients have higher risk of mortality, poor outcomes and disability, and this is independent from their age or comorbidities. Chronic kidney disease patients present with high prevalence of frailty, especially those who are in renal replacement therapy. Frail or pre-frail patients on the kidney transplant waiting list represent 20-30%, and these patients are proven to have poorer results after the transplant, which is a stressful event itself. Tools for frailty assessment, both scales or indexes, may be useful to identify which subjects might be at risk for complications after transplant, and this is necessary to adapt our clinical practice and minimize morbidity. The most used frailty scale in kidney patients is Fried scale, which is based in five phenotypic items. Besides that, knowing frail population allows potential interventions such as prehabilitation while the patient is waiting for the kidney transplant, which the aim of improving their vulnerability prior to transplant and, therefore, optimizing results after transplant. More studies are needed amongst kidney patients to improve and prevent frailty.

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.

An overview of frailty in kidney transplantation: measurement, management and future considerations

The construct of frailty was first developed in gerontology to help identify older adults with increased vulnerability when confronted with a health stressor. This article is a review of studies in which frailty has been applied to pre- and post-kidney transplantation (KT) populations. Although KT is the optimal treatment for end-stage kidney disease (ESKD), KT candidates often must overcome numerous health challenges associated with ESKD before receiving KT. After KT, the impacts of surgery and immunosuppression represent additional health stressors that disproportionately impact individuals with frailty. Frailty metrics could improve the ability to identify KT candidates and recipients at risk for adverse health outcomes and those who could potentially benefit from interventions to improve their frail status. The Physical Frailty Phenotype (PFP) is the most commonly used frailty metric in ESKD research, and KT recipients who are frail at KT (~20% of recipients) are twice as likely to die as nonfrail recipients. In addition to the PFP, many other metrics are currently used to assess pre- and post-KT vulnerability in research and clinical practice, underscoring the need for a disease-specific frailty metric that can be used to monitor KT candidates and recipients. Although frailty is an independent risk factor for post-transplant adverse outcomes, it is not factored into the current transplant program risk-adjustment equations. Future studies are needed to explore pre- and post-KT interventions to improve or prevent frailty.

Impact of HLA compatibility in recipients of kidneys from expanded criteria donors: A Collaborative Transplant Study Report

Due to a widespread organ shortage, the use of expanded criteria donors (ECDs) in kidney transplantation has increased persistently, reaching approximately 40% in recent years. Whether human leucocyte antigen (HLA) matching between donor and recipient should be part of allocation algorithms in transplantation of ECD kidneys, and especially of ECD kidneys from ≥70-year-old donors, is still in question. To this end, 135,529 kidney transplantations performed between 2000 and 2017 and reported to the Collaborative Transplant Study were analysed and the impact of HLA-A+B+DR mismatches on death-censored graft and patient survival as well as on rejection episodes was investigated. Results were stratified according to donor status (standard criteria donor (SCD) versus ECD) and age of ECD. HLA incompatibility increased the five-year death-censored graft failure risk similarly strong in recipients of ECD and SCD transplants (hazard ratio (HR) per HLA mismatch 1.078 and 1.075, respectively; p < .001 for both). Its impact on rejection treatments during the first post-transplant year was also significant but slightly weaker for recipients of ECD transplants (risk ratio (RR) per HLA mismatch 1.10 for ECD transplants and 1.13 for SCD transplants; p < .001 for both). Mortality increased gradually from zero to six HLA mismatches in recipients of SCD transplants, whereas for ECD transplants a significant increase was notable only from zero to more than zero mismatches. A significant but slightly less pronounced impact of HLA incompatibility on graft failure was observed in transplants from ≥70- compared with <70-year-old ECDs (HR per mismatch 1.047 and 1.093; p = .009 and < 0.001, respectively). The influence of HLA mismatches on rejection treatments was the same for both ECD age groups (RR = 1.10, p < .001 and p = .004, respectively). Our data indicate that HLA matching should be part of allocation algorithms not only in transplantation of kidneys from SCDs but also from ECDs.

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

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

Methods

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

Results

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

Conclusions

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

Transplanting Marginal Organs in the Era of Modern Machine Perfusion and Advanced Organ Monitoring

Organ transplantation is undergoing profound changes. Contraindications for donation have been revised in order to better meet the organ demand. The use of lower-quality organs and organs with greater preoperative damage, including those from donation after cardiac death (DCD), has become an established routine but increases the risk of graft malfunction. This risk is further aggravated by ischemia and reperfusion injury (IRI) in the process of transplantation. These circumstances demand a preservation technology that ameliorates IRI and allows for assessment of viability and function prior to transplantation. Oxygenated hypothermic and normothermic machine perfusion (MP) have emerged as valid novel modalities for advanced organ preservation and conditioning. Ex vivo prolonged lung preservation has resulted in successful transplantation of high-risk donor lungs. Normothermic MP of hearts and livers has displayed safe (heart) and superior (liver) preservation in randomized controlled trials (RCT). Normothermic kidney preservation for 24 h was recently established. Early clinical outcomes beyond the market entry trials indicate bioenergetics reconditioning, improved preservation of structures subject to IRI, and significant prolongation of the preservation time. The monitoring of perfusion parameters, the biochemical investigation of preservation fluids, and the assessment of tissue viability and bioenergetics function now offer a comprehensive assessment of organ quality and function ex situ. Gene and protein expression profiling, investigation of passenger leukocytes, and advanced imaging may further enhance the understanding of the condition of an organ during MP. In addition, MP offers a platform for organ reconditioning and regeneration and hence catalyzes the clinical realization of tissue engineering. Organ modification may include immunological modification and the generation of chimeric organs. While these ideas are not conceptually new, MP now offers a platform for clinical realization. Defatting of steatotic livers, modulation of inflammation during preservation in lungs, vasodilatation of livers, and hepatitis C elimination have been successfully demonstrated in experimental and clinical trials. Targeted treatment of lesions and surgical treatment or graft modification have been attempted. In this review, we address the current state of MP and advanced organ monitoring and speculate about logical future steps and how this evolution of a novel technology can result in a medial revolution.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

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

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

Graft Pre-conditioning by Peri-Operative Perfusion of Kidney Allografts With Rabbit Anti-human T-lymphocyte Globulin Results in Improved Kidney Graft Function in the Early Post-transplantation Period-a Prospective, Randomized Placebo-Controlled Trial

Introduction: Although prone to a higher degree of ischemia reperfusion injury (IRI), the use of extended criteria donor (ECD) organs has become reality in transplantation. We therefore postulated that peri-operative perfusion of renal transplants with anti-human T-lymphocyte globulin (ATLG) ameliorates IRI and results in improved graft function.

Methods: We performed a randomized, single-blinded, placebo-controlled trial involving 50 kidneys (KTx). Prior to implantation organs were perfused and incubated with ATLG (AP) (n = 24 kidney). Control organs (CP) were perfused with saline only (n = 26 kidney). Primary endpoint was defined as graft function reflected by serum creatinine at day 7 post transplantation (post-tx).

Results: AP-KTx recipients illustrated significantly better graft function at day 7 post-tx as reflected by lower creatinine levels, whereas no treatment effect was observed after 12 months surveillance. During the early hospitalization phase, 16 of the 26 CP-KTx patients required dialysis during the first 7 days post-tx, whereas only 10 of the 24 AP-KTx patients underwent dialysis. No treatment-specific differences were detected for various lymphocytes subsets in the peripheral blood of patients. Additionally, mRNA analysis of 0-h biopsies post incubation with ATLG revealed no changes of intragraft inflammatory expression patterns between AP and CP organs.

Conclusion: We here present the first clinical study on peri-operative organ perfusion with ATLG illustrating improved graft function in the early period post kidney transplantation.

Clinical Trial Registration:www.ClinicalTrials.gov, NCT03377283

Differences in Proinflammatory Cytokines and Monocyte Subtypes in Older as Compared With Younger Kidney Transplant Recipients

Supplemental digital content is available in the text.

Background

The number of elderly patients with end-stage kidney disease requiring kidney transplantation continues to grow. Evaluation of healthy older adults has revealed proinflammatory changes in the immune system, which are posited to contribute to age-associated illnesses via “inflamm-aging.” Immunologic dysfunction is also associated with impaired control of infections. Whether these immunologic changes are found in older kidney transplant recipients is not currently known, but may have important implications for risk for adverse clinical outcomes.

Methods

Three months after transplant, innate immune phenotype was evaluated by flow cytometry from 60 kidney transplant recipients (22 older [≥60 years] and 38 younger [<60 years old]). Multiplex cytokine testing was used to evaluate plasma cytokine levels. Younger patients were matched to older patients based on transplant type and induction immune suppression.

Results

Older kidney transplant recipients demonstrated decreased frequency of intermediate monocytes (CD14++CD16+) compared with younger patients (1.2% vs 3.3%, P = 0.007), and a trend toward increased frequency of proinflammatory classical monocytes (CD14++CD16−) (94.5% vs 92.1%) (P = 0.065). Increased levels of interferon-gamma (IFN-γ) were seen in older patients.

Conclusions

In this pilot study of kidney transplant recipients, we identified differences in the innate immune system in older as compared with younger patients, including increased levels of IFN-γ. This suggests that age-associated nonspecific inflammation persists despite immune suppression. The ability to apply noninvasive testing to transplant recipients will provide tools for patient risk stratification and individualization of immune suppression regimens to improve outcomes after transplantation.

Differences in Phenotypes and Liver Transplantation Outcomes by Age Group in Patients with Primary Sclerosing Cholangitis

BACKGROUND

There is increasing evidence for a heterogeneity of phenotypes in primary sclerosing cholangitis (PSC), but differences across the age spectrum in adults with PSC have not been well characterized.

AIMS

To characterize phenotypic variations and liver transplantation outcomes by age group in adults with PSC.

METHODS

The United Network for Organ Sharing database was used to identify waitlist registrations for primary liver transplantation in adults with PSC. Patients were split into three age groups: 18-39 (young), 40-59 (middle-aged), and ≥60 (older). Their clinical characteristics and outcomes on the waitlist and post-transplant were compared.

RESULTS

Overall, 8272 adults with PSC were listed for liver transplantation during the study period, of which 28.9% were young, 52.0% were middle-aged, and 19.1% were older. The young age group had the greatest male predominance (70.0 vs. 66.2 vs. 65.1%, p = 0.001), the highest proportion of black individuals (20.0 vs. 11.0 vs. 5.5%, p < 0.001), and the most patients listed with concomitant autoimmune hepatitis (2.2 vs. 1.0 vs. 0.8%, p < 0.001). Older patients experienced the greatest waitlist and post-transplant mortality. Graft survival was greatest in the middle-aged group. Young patients were most likely to experience acute rejection (31 vs. 22.8 vs. 18.0%, p < 0.001) and have graft failure due to chronic rejection or PSC recurrence (47.8 vs. 42.3 vs. 17.9%, p < 0.001).

CONCLUSIONS

Age-related differences exist among adults with PSC and are associated with outcomes pre- and post-transplant. Young patients may have a more robust immune-related phenotype that is associated with poorer graft survival. Future studies are needed to further investigate these findings.

Shifts in subsets of CD8+ T-cells as evidence of immunosenescence in patients with cancers affecting the lungs: an observational case-control study

Background

Shifts in CD8+ T-cell subsets that are hallmarks of immunosenescence are observed in ageing and in conditions of chronic immune stimulation. Presently, there is limited documentation of such changes in lung cancer and other malignancies affecting the lungs.

Methods

Changes in CD8+ T-cell subsets, based on the expression of CD28 and CD57, were analysed in patients with various forms of cancer affecting the lungs, undergoing chemotherapy and in a control group over six months, using multi-colour flow cytometry.

Results

The differences between patients and controls, and the changes in the frequency of CD8+ T-cell subpopulations among lung cancer patients corresponded to those seen in immunosenescence: lower CD8-/CD8+ ratio, lower proportions of CD28+CD57- cells consisting of naïve and central memory cells, and higher proportions of senescent-enriched CD28-CD57+ cells among the lung cancer patients, with the stage IV lung cancer patients showing the most pronounced changes. Also observed was a tendency of chemotherapy to induce the formation of CD28+CD57+ cells, which, in line with the capacity of chemotherapy to induce the formation of senescent cells, might provide more evidence supporting CD28+CD57+ cells as senescent cells.

Conclusion

Immunosenescence was present before the start of the treatment; it appeared to be pronounced in patients with advanced cases of malignancies affecting the lungs, and might not be averted by chemotherapy.

Th-17 Alloimmune Responses in Renal Allograft Biopsies From Recipients of Kidney Transplants Using Extended Criteria Donors During Acute T Cell-Mediated Rejection

Although renal transplantation using expanded criteria donors has become a common practice, immune responses related to immunosenescence in those kidney allografts have not been studied yet in humans. We performed a retrospective molecular analysis of the T cell immune response in 43 kidney biopsies from patients with acute T cell-mediated rejection including 25 from recipients engrafted with a kidney from expanded criteria donor and 18 from recipients grafted with optimal kidney allograft. The clinical, transplant and acute T cell-mediated rejection characteristics of both groups were similar at baseline. The expression of RORγt, Il-17 and T-bet mRNA was significantly higher in the elderly than in the optimal group (p = 0.02, p = 0.036, and p = 0.01, respectively). Foxp3 mRNA levels were significantly higher in elderly patients experiencing successful acute T cell-mediated rejection reversal (p = 0.03). The presence of IL-17 mRNA was strongly associated with nonsuccessful reversal in elderly patients (p = 0.008). Patients with mRNA IL17 expression detection and low mRNA Foxp3 expression experienced significantly more treatment failure (87.5%) than patients with no mRNA IL17 expression and/or high mRNA Foxp3 expression (26.7%; p = 0.017). Our study suggests that the Th17 pathway is involved in pathogenesis and prognosis of acute T cell-mediated rejection in recipients of expanded criteria allograft.

Lack of agreement for defining 'clinical suspicion of rejection' in liver transplantation: a model to select candidates for liver biopsy

The gold standard to diagnose acute cellular rejection (ACR) after liver transplantation (LT) is histological evaluation, but there is no consensus to select patients for liver biopsy. We aimed to evaluate the agreement among clinicians to select candidates for liver biopsy early after LT. From a protocol biopsy population (n = 690), we randomly selected 100 LT patients in whom the biopsy was taken 7-10 days after LT. The clinical information between LT and protocol biopsy was given to nine clinicians from three transplant centres who decided whether a liver biopsy was needed. The agreement among clinicians to select candidates for liver biopsy was poor: κ = 0.06-0.62, being κ < 0.40 in 76% of comparisons. The concordance between indication for liver biopsy and moderate-severe ACR in the protocol biopsy was κ < 0.30 in all cases. A multivariate model based on the product age-by-MELD (OR = 0.81; P = 0.013), delta eosinophils (OR = 1.5; P = 0.002) and mean tacrolimus trough concentrations <6 ng/ml within the prior 4 days (OR = 11.4; P = 0.047) had an AUROC = 0.84 to diagnose moderate-severe histological ACR. In conclusion, the agreement among clinicians to select patients for liver biopsy is very poor. If further validated the proposed model would provide an objective method to select candidates for liver biopsy after LT.

Impact of recipient aging on kidney allograft in living donor transplantation

BACKGROUND

The aging of recipients is becoming increasingly important in organ transplantation.

PATIENTS AND METHODS

We analyzed outcomes in 215 consecutive adult kidney transplant recipients from living donors who underwent transplantation at our center between November 1988 and March 2012. The list of recipients was divided by age at transplantation into those aged 16 to 29 years (n = 61), 30 to 39 years (n = 69), 40 to 49 years (n = 33), 50 to 59 years (n = 29), and those 60 years or older (elderly group, n = 23). Cox proportional hazards analysis was used to calculate the relative risk (RR) of patient death and graft failure, with recipient age included as a continuous variable.

RESULTS

Univariate analysis showed that recipient age did not significantly affect the risk of graft failure, either uncensored (RR = 1.01, P = .312) or censored for death (RR = 0.993, P = .587). Multivariate analysis, however, showed that recipient age was an independent risk factor for patient death (RR = 1.053, P = .024). The patient survival rate was the poorest in elderly group (87.0%, P = .036), whereas the both death uncensored and censored graft survival rates of this group were 78.1% and 91.3%, respectively, comparable to those of other age groups (P = .567 and P = .696). Mean estimated glomerular filtration rate (eGFR) 1 year after transplantation was lower in elderly groups than in other groups (46.1 ± 13.0 mL/min/1.73 m(2), P = .014). However, mean δeGFR, defined as the difference between pretransplantation eGFR of the donor and eGFR of the recipient 1 year post-transplantation, did not differ significantly among age groups.

CONCLUSION

Recipient age did not affect allograft deterioration in living donor kidney transplantation, although it was an independent risk factor of recipient death.

An analysis of pancreas transplantation outcomes based on age groupings--an update of the UNOS database

INTRODUCTION

Previously, increasing age has been a part of the exclusion criteria used when determining eligibility for a pancreas transplant. However, the analysis of pancreas transplantation outcomes based on age groupings has largely been based on single-center reports.

METHODS

A UNOS database review of all adult pancreas and kidney-pancreas transplants between 1996 and 2012 was performed. Patients were divided into groups based on age categories: 18-29 (n = 1823), 30-39 (n = 7624), 40-49 (n = 7967), 50-59 (n = 3160), and ≥60 (n = 280). We compared survival outcomes and demographic variables between each age grouping.

RESULTS

Of the 20 854 pancreas transplants, 3440 of the recipients were 50 yr of age or above. Graft survival was consistently the greatest in adults 40-49 yr of age. Graft survival was least in adults age 18-29 at one-, three-, and five-yr intervals. At 10- and 15-yr intervals, graft survival was the poorest in adults >60 yr old. Patient survival and age were found to be inversely proportional; as the patient population's age increased, survival decreased.

CONCLUSION

Pancreas transplants performed in patients of increasing age demonstrate decreased patient and graft survival when compared to pancreas transplants in patients <50 yr of age.