Benefits of Living Over Deceased Donor Kidney Transplantation in Elderly Recipients. A Propensity Score Matched Analysis of a Large European Registry Cohort.

Although kidney transplantation from living donors (LD) offers better long-term results than from deceased donors (DD), elderly recipients are less likely to receive LD transplants than younger ones. We analyzed renal transplant outcomes from LD versus DD in elderly recipients with a propensity-matched score. This retrospective, observational study included the first single kidney transplants in recipients aged ≥65 years from two European registry cohorts (2013-2020, n = 4,257). Recipients of LD (n = 408), brain death donors (BDD, n = 3,072), and controlled cardiocirculatory death donors (cDCD, n = 777) were matched for donor and recipient age, sex, dialysis time and recipient diabetes. Major graft and patient outcomes were investigated. Unmatched analyses showed that LD recipients were more likely to be transplanted preemptively and had shorter dialysis times than any DD type. The propensity score matched Cox's regression analysis between LD and BDD (387-pairs) and LD and cDCD (259-pairs) revealing a higher hazard ratio for graft failure with BDD (2.19 [95% CI: 1.16-4.15], p = 0.016) and cDCD (3.38 [95% CI: 1.79-6.39], p < 0.001). One-year eGFR was higher in LD transplants than in BDD and cDCD recipients. In elderly recipients, LD transplantation offers superior graft survival and renal function compared to BDD or cDCD. This strategy should be further promoted to improve transplant outcomes.

Death of recipients after kidney living donation triples donors' risk of dropping out from follow-up: a retrospective study.

Although kidney transplantation from the donation of a living donor is a safe treatment for end-stage renal disease, inferences about safety of living kidney donors might be biased by an informative censoring caused by the noninclusion of a substantial percentage of donors lost to follow-up. With the aim of assessing the presence of a potential informative censoring in living kidney donation outcomes of Catalan donors for a period of 12 years, 573 donors followed and lost to follow-up were compared. Losses of follow-up over time were also assessed by univariate and multivariate survival analysis, along with Cox regression. Younger and older ages, and the death of their recipient differentiated those donors who were lost to follow-up over time. The risk of dropping out from follow-up was more than twofold for the youngest and oldest donors, and almost threefold for those donors whose recipient died. Results of studies on postdonation outcomes of Catalan living kidney donors might have overlooked older and younger cases, and, remarkably, a percentage of donors whose recipient died. If these donors showed a higher incidence of psychological problems, conclusions about living donors' safety might be compromised thus emphasizing the necessity of sustained surveillance of donors and prompt identification of these cases.

Does the obesity survival paradox of dialysis patients differ with age?

BACKGROUND: The obesity paradox of hemodialysis patients (the association between obesity and survival) could be modified by age. We hypothesize that whereas obesity associates with survival in elderly patients, it behaves as a mortality risk marker in younger individuals. METHODS: Retrospective study of 2002-2010 adult incident hemodialysis to analyze the relationship between body mass index (BMI) and annual body weight changes with mortality in different age strata. RESULTS: Included in the study were 6,290 individuals. A progressive decrease in mortality was associated with increasing BMI ranges. Both annual body weight gains and losses were associated with mortality. Similar results were observed in elderly individuals, but in the BMI values of young patients, there were no significant differences in mortality. CONCLUSION: There is a survival benefit with increasing BMI in patients overall. However, while these results persist in patients >65 years, in young people there are no changes in mortality. Patients with the highest inter-annual variability in weight have an increased risk.

Evolution of the incidence of chronic kidney disease Stage 5 requiring renal replacement therapy in the diabetic population of Catalonia.

BACKGROUND: Chronic kidney disease due to diabetes (DCKD) is the main known cause of renal replacement therapy (RRT) initiation. A Centers for Disease Control and Prevention study showed that the rate of DCKD cases initiating RRT among the overall DM population has dropped in the USA. Our main objective was to analyse this rate in Catalonia in 1994, 2002, 2006 and 2010. Cardiovascular risk factors (CVRF) in the diabetic population and characteristics and survival of DCKD patients on RRT were also evaluated. METHODS: Data from the Catalan Renal Registry was used to learn the number of DCKD cases on RRT together with their characteristics and survival rates. Data from the Catalonia Health Survey established the diabetic population and also the prevalence of CVRF in this population. RESULTS: The adjusted rate (95% CI) of patients initiating RRT with DCKD was 509.1 (484.6-533.7) pmp in 1994, 645.3 (621.6-669.0) in 2002, 602.6 (581.4-623.9) in 2006 and 600.0 (578.4-621.6) in 2010. Survival of DCKD patients in the 4th year of RRT had increased progressively from 35.9% for DCKD cases versus 64.9% for CKD cases due to other causes in 1994, to 39.9% versus 58.3% in 2002 and to 59.9% versus 65.9% in 2006. CONCLUSIONS: Since 2002, the rates of patients with DCKD initiating RRT among the overall DM population decreased slightly in Catalonia. Survival in these cases has increased progressively and in 2006 is similar to the CKD patients due to other causes. This figure suggests a better overall management, especially of CVRF.

Long-term outcome of antineutrophil cytoplasmic antibody-associated small vessel vasculitis after renal transplantation.

The survival after renal transplantation of patients with antineutrophil cytoplasmic antibody (ANCA)-associated to systemic vasculitis is as good as in other diseases, although most of the reports are based on small numbers of patients. Furthermore, it is not known whether comorbidities (cardiovascular [CV] disease and cancer) are more frequent than in general population. We report our experience and the analysis of the published data on this topic. The outcome after transplantation in 49 patients with ANCA-associated small vessel vasculitis was compared with a control group. The relapse rate of vasculitis was 0.01 per patient per year. Comparison with the control patients revealed no difference in long-term outcome, CV mortality or incidence of malignancies. In the published literature, patients with ANCA at transplantation and with Wegener's granulomatosis are at greater risk of relapse. Taking our own results together with the review of the literature, we conclude that patient and graft survival rates compare favorably with those in control group that the recurrence rate is very low and that there is no increase in the incidence of cancer or in CV mortality. Patients with ANCA at transplantation and with Wegener's granulomatosis have a higher relapse rate.

Renal replacement therapy in ADPKD patients: a 25-year survey based on the Catalan registry.

BACKGROUND: Some 7-10% of patients on replacement renal therapy (RRT) are receiving it because of autosomal dominant polycystic kidney disease (ADPKD). The age at initiation of RRT is expected to increase over time. METHODS: Clinical data of 1,586 patients (7.9%) with ADPKD and 18,447 (92.1%) patients with other nephropathies were analysed from 1984 through 2009 (1984-1991, 1992-1999 and 2000-2009). RESULTS: The age at initiation of RRT remained stable over the three periods in the ADPKD group (56.7 ± 10.9 (mean ± SD) vs 57.5 ± 12.1 vs 57.8 ± 13.3 years), whereas it increased significantly in the non-ADPKD group (from 54.8 ± 16.8 to 63.9 ± 16.3 years, p < 0.001). The ratio of males to females was higher for non-ADPKD than for ADPKD patients (1.6-1.8 vs 1.1-1.2). The prevalence of diabetes was significantly lower in the ADPKD group (6.76% vs 11.89%, p < 0.001), as were most of the co-morbidities studied, with the exception of hypertension. The survival rate of the ADPKD patients on RRT was higher than that of the non-ADPKD patients (p < 0.001). CONCLUSIONS: Over time neither changes in age nor alterations in male to female ratio have occurred among ADPKD patients who have started RRT, probably because of the impact of unmodifiable genetic factors in the absence of a specific treatment.

Haemodialysis access profile in failed kidney transplant patients: Analysis of data from the Catalan Renal Registry (1998-2016).

BACKGROUND: Data about vascular access (VA) use in failed kidney transplant (KT) patients returning to haemodialysis (HD) are limited. We analysed the VA profile of these patients, the factors associated with the likelihood of HD re-initiation through fistula (AVF) and the effect of VA in use at the time of KT on kidney graft (KTx) outcome. METHOD: Data from the Catalan Registry on failed KT patients restarting HD and incident HD patients with native kidney failure were examined over an 18-year period. RESULTS: The VA profile of 675 failed KT patients at HD re-initiation compared with that before KT and with 16,731 incident patients starting HD was (%): AVF 79.3 versus 88.6 and 46.2 (p = 0.001 and p < 0.001), graft AVG 4.4 versus 2.6 and 1.1 (p = 0.08 and p < 0.001), tunnelled catheter TCC 12.4 versus 5.5 and 18.0 (p = 0.001 and p < 0.001) and non-tunnelled catheter 3.9 versus 3.3 and 34.7 (p = 0.56 and p < 0.001). The likelihood of HD re-initiation by AVF was significantly lower in patients with cardiovascular disease, KT duration >5 years, dialysed through AVG or TCC before KT, and females. The analysis of Kaplan-Meier curves showed a greater KTx survival in patients dialysed through arteriovenous access than in patients using catheter just before KT (λ2 = 5.59, p = 0.0181, log-rank test). Cox regression analysis showed that patients on HD through arteriovenous access at the time of KT had lower probability of KTx loss compared to those with catheter (hazard ratio 0.71, 95% CI 0.55-0.90, p = 0.005). CONCLUSIONS: The VA profile of failed KT patients returning to HD and incident patients starting HD was different. Compared to before KT, the proportion of failed KT patients restarting HD with AVF decreased significantly at the expense of TCC. Patients on HD through arteriovenous access at the time of KT showed greater KTx survival compared with those using catheter.

Impact of obesity on the evolution of outcomes in peritoneal dialysis patients.

BACKGROUND: Some studies reveal that obesity is associated with a decrease in mortality in haemodialysis (HD) patients. However, few studies have addressed the association between body mass index (BMI) and peritoneal dialysis (PD) patients. METHODS: We performed this longitudinal, retrospective study to evaluate the impact of obesity on PD patients, using data from the Catalan Registry of Renal Patients from 2002 to 2015 (n = 1573). Obesity was defined as BMI ≥30; low weight: BMI <18.5; normal range: BMI = 18.5-24.99; and pre-obesity: BMI = 25-29.99 kg/m2. Variations in BMI were calculated during follow-up. The main outcomes evaluated were the technique and patient survival. RESULTS: Obesity was observed in 20% of patients starting PD. We did not find differences in sex or PD modality, with the obesity group being older (65.9% are ≥55 years versus 59% non-obese, P = 0.003) and presenting more diabetes mellitus and cardiovascular disease (CVD) (47.9% obese versus 25.1% non-obese and 41.7% versus 31.5%, respectively). We did not observe differences in haemoglobin, albumin and Kt/V in obese patients. Regarding peritonitis rate, we did not find any difference between groups, presenting more peritonitis patients on continuous ambulatory peritoneal dialysis and aged ≥65 years [sub-hazard ratio (SHR) = 1.75, P = 0.000 and SHR = 1.56, P = 0.009]. In relation to technique survival, we found higher transfer to HD in the obese group of patients in the univariate analysis, which was not confirmed in the multivariate analysis (SHR = 1.12, P = 0.4), and we did not find differences in mortality rate. In relation to being transplanted, the underweight group, elderly and patients with CVD or diabetic nephropathy presented less probability to undergo kidney transplantation (SHR = 0.65, 0.24, 0.5 and 0.54, P < 0.05). Obese patients did not present differences in survival with weight changes but in normal-weight patients, a gain of 7% of the basal weight during the first year had a protective effect on death risk (hazard ratio 0.6, P = 0.034). CONCLUSIONS: Obese and non-obese patients starting on PD had similar outcomes.

The Spanish Version of the Fear of Kidney Failure Questionnaire: Validity, Reliability, and Characterization of Living Donors With the Highest Fear of Kidney Failure.

BACKGROUND: Measures of fear of progression or recurrence of illnesses have been criticized for neglecting cross-cultural validity. Therefore, we assessed the psychometric properties of the Spanish version of the Fear of Kidney Failure Questionnaire (FKFQ), to determine whether postdonation fear of kidney failure (FKF) influenced the donors' psychosocial status, and define variables that characterized donors with high FKFQ scores. METHODS: We included 492 participants (211 donors) in a multicenter, 11-year, retrospective, cross-sectional study. Donors were classified with a Latent Class Analysis of the FKFQ-item scores and characterized with a multivariable logistic regression analysis. We calculated the risk ratio based on predicted marginal probabilities. RESULTS: The Spanish version of the FKFQ showed acceptable psychometric properties. FKF was uncommon among donors, but we detected a small subgroup (n = 21, 9.9%) with high FKF (mean FKFQ score = 14.5, 3.1 SD). Compared with other donors, these donors reported higher anxiety and depression (38% and 29% of potential anxiety and depressive disorders), worse quality of life, and less satisfaction with the donation. Donors with high FKFQ scores were characterized by higher neuroticism combined with postdonation physical symptoms that interfered with daily activities. CONCLUSIONS: The FKFQ was cross-culturally valid, and thus, it may be used to assess the FKF in Spanish-speaking donors. New interventions that promote positive affectivity and evidence-based treatments for worry could be adapted for treating FKF.

Assessing the Limits in Kidney Transplantation: Use of Extremely Elderly Donors and Outcomes in Elderly Recipients.

BACKGROUND: Patient survival with end-stage renal disease is longer after kidney transplantation (KT) compared with those remaining on dialysis. Nevertheless, this remains uncertain when receiving a kidney from a donor ≥80 years old. METHODS: In a longitudinal mortality study in the Catalan Renal Registry including 2585 patients ≥60 years old on dialysis and placed on the KT waiting list, 1084 received a first KT from a deceased donor aged 60 to 79 years and 128 from a deceased donor ≥80 years. We calculated adjusted risk of graft loss by means of competing-risks regression, considering patient death with functioning graft as a competing event. To assess patient survival benefit from KT, we calculated the adjusted risk of death by nonproportional hazard analysis, taking the fact of being transplanted as a time-dependent effect. Considering all KT ≥60 (n = 1212), we assessed whether the benefit of KT varied per different recipient characteristics by calculating the interaction effect between all potential mortality risk factors and the treatment group. RESULTS: Compared with kidneys from donors 60 to 79 years old, graft survival was significantly lower for kidneys from donors aged ≥80 years (subhazard ratio = 1.55; 95% confidence interval, 1.00-2.38; P = 0.048). In comparison with those who remained on dialysis, adjusted risk of death 12 months after transplantation in recipients with a kidney from donors ≥80 years was 0.54 (95% confidence interval, 0.38-0.77; P < 0.0001). CONCLUSIONS: Despite KT from octogenarian deceased donors being associated with reduced graft survival, recipients had lower mortality rates than those remaining on dialysis, even if the kidney came from an extremely aged donor.