Long-Term Results of Kidney Transplantation in the Elderly: Comparison between Different Donor Settings

Effect of increasing age and ureteral stent implantation on urinary tract infections after kidney transplantation - update of recent literature

PURPOSE OF REVIEW

This review aims to present the recent literature regarding effects of aging and ureteral stent implantation (UrS) on the risk of urinary tract infections (UTIs) in kidney transplant (KTX) recipients.

RECENT FINDINGS

UTIs in kidney transplant recipients remain a clinical challenge and represent a leading cause of morbidity, hospitalization rates, and mortality. Higher age was described as a significant risk factor for UTIs in several studies including a recent Brazilian analysis, indicating a 3.6%/years of age increase in UTI risk. Subsequently, a large meta-analysis, published in 2023, confirmed the correlation between older age and elevated UTI risk. The Swiss Transplant Cohort Study in 2022, largest of its kind, similarly confirmed a link between advanced age and heightened risk of recurrent UTIs in KTX. A recent prospective study highlighted UrS placement as a modifiable risk factor, emphasizing the need for careful consideration and antibiotic prophylaxis. Additionally, the type of stents played a crucial role, with external stents associated with a 1.69 times higher UTI risk. The challenge of determining optimal UrS removal timing further complicates posttransplant care, with insufficient evidence to guide practices.

SUMMARY

The aging population of KTX recipients requires a personalized approach to effectively reduce and manage UTIs as one of the most important complications following KTX. Prophylactic stent implantation is successful in lowering ureteral complications, however, is associated with an increased incidence of UTIs. To reduce the increased risk of UTIs, the length of stent insertion requires strict supervision and maintenance.

Intention-to-treat Analysis of Patients Aged 70 Years and Older Awaiting Kidney Transplantation in Post-Kidney Allocation System Era

BACKGROUND

The US population is aging, and so the number of patients treated for end-stage renal disease is on the rise. In the United States, 38% of people over 65 y old have chronic kidney disease. There continues to be a reluctance of clinicians to consider older candidates for transplant, including early referrals.

METHODS

We conducted a retrospective analysis of the Organ Procurement and Transplantation Network database of all adults ≥70 y old undergoing kidney transplants from December 1, 2014, to June 30, 2021. We compared patient and graft survival in candidates who were transplanted while on hemodialysis versus preemptive with a living versus deceased donor kidney transplant.

RESULTS

In 2021, only 43% of the candidates listed for transplant were preemptive. In an intention-to-treat analysis from the time of listing, candidate survival was significantly improved for those transplanted preemptively versus being on dialysis (hazard ratio 0.59; confidence interval, 0.56-0.63). All donor types, donor after circulatory death, donor after brain death, and living donor, had a significant decrease in death over remaining on the waiting list. Patients who were on dialysis or transplanted preemptively with a living donor kidney had significantly better survival than those receiving a deceased donor kidney. However, receiving a deceased donor kidney significantly decreased the chance of death over remaining on the waiting list.

CONCLUSIONS

Patients ≥70 y old who are transplanted preemptively, whether with a deceased donor or a living donor kidney, have a significantly better survival than those who are transplanted after initiating dialysis. Emphasis on timely referral for a kidney transplant should be placed in this population.

Evolving Trends in Kidney Transplant Outcomes Among Older Adults: A Comparative Analysis Before and During the COVID-19 Pandemic

Background

Advancements in medical technology, healthcare delivery, and organ allocation resulted in improved patient/graft survival for older (age ≥65) kidney transplant (KT) recipients. However, the recent trends in these post-KT outcomes are uncertain in light of the mounting burden of cardiovascular disease, changing kidney allocation policies, heterogeneity in candidates' risk profile, and the coronavirus disease 2019 pandemic. Thus, we examined secular trends in post-KT outcomes among older and younger KT recipients over the last 3 decades.

Methods

We identified 73 078 older and 378 800 younger adult (aged 18-64) recipients using Scientific Registry of Transplant Recipients (1990-2022). KTs were grouped into 6 prepandemic eras and 1 postpandemic-onset era. Kaplan-Meier and Cox proportional hazards models were used to examine temporal trends in post-KT mortality and death-censored graft failure.

Results

From 1990 to 2022, a 19-fold increase in the proportion of older KT recipients was observed compared to a 2-fold increase in younger adults despite a slight decline in the absolute number of older recipients in 2020. The mortality risk for older recipients between 2015 and March 14, 2020, was 39% (adjusted hazard ratio [aHR] = 0.61, 95% confidence interval [CI], 0.50-0.75) lower compared to 1990-1994, whereas that for younger adults was 47% lower (aHR = 0.53, 95% CI, 0.48-0.59). However, mortality risk during the pandemic was 25% lower (aHR = 0.75, 95% CI, 0.61-0.93) in older adults and 37% lower in younger adults (aHR = 0.63, 95% CI, 0.56-0.70) relative to 1990-1994. For both populations, the risk of graft failure declined over time and was unaffected during the pandemic relative to the preceding period.

Conclusions

The steady improvements in 5-y mortality and graft survival were disrupted during the pandemic, particularly among older adults. Specifically, mortality among older adults reflected rates seen 20 y prior.

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.

Clinical outcomes between elderly ESKD patients under peritoneal dialysis and hemodialysis: a national cohort study

With ageing populations, new elderly end-stage kidney disease (ESKD) cases rise. Unlike younger patients, elderly ESKD patients are less likely to undergo kidney transplant, and therefore the decision of receiving peritoneal dialysis (PD) and hemodialysis (HD) is more crucial. A total of 36,852 patients, aged more than 65, who were newly diagnosed with ESKD and initiated renal replacement therapy between 2013 and 2019 were identified. These patients were categorized into two groups: the PD group and the HD group according to their long-term renal replacement treatment. After propensity score matching, the PD group (n = 1628) displayed a lower incidence of major adverse cardiac and cerebrovascular events (MACCE) (10.09% vs. 13.03%, hazard ratio (HR): 0.74, 95% confidence interval (CI): 0.66-0.83), malignancy (1.23% vs. 2.14%, HR: 0.55, 95% CI: 0.40-0.76), and MACCE-associated mortality (1.35% vs. 2.25%, HR: 0.62, 95% CI: 0.46-0.84) compared to the HD group (n = 6512). However, the PD group demonstrated a higher rate of infection (34.09% vs. 24.14%, HR: 1.28, 95% CI: 1.20-1.37). The risks of all-cause mortality and infection-associated mortality were not different. This study may provide valuable clinical information to assist elderly ESKD patients to choose HD or PD as their renal replacement therapy.

Factors Influencing Short-Term Patient Survival in Elderly Kidney Transplant Recipients

BACKGROUND

For the average patient with end-stage renal disease, kidney transplantation improves quality of life and prolongs survival compared with patients on the transplant waiting list who remain on dialysis. Patients ≥65 years of age represent an increasing proportion of adults with end-stage renal disease, and kidney transplantation outcomes remain controversial in this population. The aim of this study was to evaluate factors that may increase 1-year mortality after renal transplantation in older recipients.

METHODS

A retrospective study that included 147 patients (75.5% men) ≥65 years old (mean age 67.5 ± 2 years) who were transplanted between January 2011 and December 2020. The mean follow-up was 52.6 ± 27.2 months.

RESULTS

Rehospitalization (<1 year) occurred in 39.5% of patients. Infectious complications were present in 18.4% of patients. The overall mortality rate was 23.1%, and 1-year mortality was 6.8%. As 1-year mortality predictors, we found a positive correlation with factors related to kidney transplant, such as cold ischemia time (P = .003), increasing donor age (P = .001); and factors related to the receptor such as pretransplantation dialysis modality as peritoneal dialysis (P = .04), cardiovascular disease (P = .004), delayed graft function (P = .002), early cardiovascular complications after kidney transplant (P < .001), and early rehospitalizations (P < .001). No correlation was found between 1-year mortality and age, sex, race, body mass index, and type of kidney transplant.

CONCLUSION

A more rigorous pretransplant evaluation, focusing on cardiovascular disease and strict exclusion criteria, is recommended for patients ≥65 years old.

Human Leucocyte Antigen-Matching Can Improve Long Term Outcome of Renal Allografts from Donors Older Than 75 Years

BACKGROUND

Renal transplantation is the therapy of choice for kidney failure. The Eurotransplant Senior Program (ESP) has been established to allocate kidneys ≥65 years to recipients of the same age group considered a regional allocation with short cold ischemia (CIT) but not human-leukocyte-antigen (HLA)-matching. The acceptance of organs aged ≥75 years is also still controversial within the ESP.

METHODS

In a multicenter approach, 179 kidney grafts ≥75 years (mean donor age 78 years) that were transplanted in 174 patients in 5 German transplant centers were analyzed. The primary focus of the analysis was long-term outcome of the grafts and the impact of CIT, HLA matching, and recipient related risk factors.

RESULTS

The mean graft survival was 59 months (median 67 months) with a mean donor age of 78.3 ± 2.9 years. Grafts with 0 to 3 HLA-mismatches had a significantly better overall graft survival compared to grafts with ≥4 mismatches (69 months vs 54 months; P = .008). The mean CIT was short (11.9 ± 5.3 hours) and had no impact on graft survival.

CONCLUSION

Recipients receiving a kidney graft from donors aged ≥75 years can benefit from nearly 5 years of survival with a functioning graft. Even minimal HLA matching may improve long term allograft survival.

An enhanced level of VCAM in transplant preservation fluid is an independent predictor of early kidney allograft dysfunction

Background

We aimed to evaluate whether donor-related inflammatory markers found in kidney transplant preservation fluid can associate with early development of kidney allograft dysfunction.

Methods

Our prospective study enrolled 74 consecutive donated organs who underwent kidney transplantation in our center between September 2020 and June 2021. Kidneys from 27 standard criteria donors were allocated to static cold storage and kidneys from 47 extended criteria donors to hypothermic machine perfusion. ELISA assessment of inflammatory biomarkers (IL-6, IL6-R, ICAM, VCAM, TNFα, IFN-g, CXCL1 and Fractalkine) was analyzed in view of a primary endpoint defined as the occurrence of delayed graft function or slow graft function during the first week following transplantation.

Results

Soluble VCAM levels measured in transplant conservation fluid were significantly associated with recipient serum creatinine on day 7. Multivariate stepwise logistic regression analysis identified VCAM as an independent non-invasive predictor of early graft dysfunction, both at 1 week (OR: 3.57, p = .04, 95% CI: 1.06-12.03) and 3 Months (OR: 4.039, p = .034, 95% CI: 1.11-14.73) after transplant surgery.

Conclusions

This prospective pilot study suggests that pre-transplant evaluation of VCAM levels could constitute a valuable indicator of transplant health and identify the VCAM-CD49d pathway as a target to limit donor-related vascular injury of marginal transplants.