Elderly kidney transplant recipients have favorable outcomes but increased infection-related mortality

Global trends of delayed graft function in kidney transplantation from 2013 to 2023: a bibliometric analysis

Delayed graft function (DGF) is an early complication after kidney transplantation. The literature on DGF has experienced substantial growth. However, there is a lack of bibliometric analysis of DGF. This study aimed to analyze the scientific outputs of DGF and explore its hotspots from 2013 to 2023 by using CiteSpace and VOSviewer. The 2058 pieces of literature collected in the Web of Science Core Collection (WOSCC) from 1 January 2013 to 31 December 2023 were visually analyzed in terms of the annual number of publications, authors, countries, journals, literature co-citations, and keyword clustering by using CiteSpace and VOSviewer. We found that the number of papers published in the past ten years showed a trend of first increasing and then decreasing; 2021 was the year with the most posts. The largest number of papers was published by the University of California System, and the largest number of papers was published by the United States. The top five keyword frequency rankings are: 'delayed graft function', 'kidney transplantation', 'renal transplantation', 'survival', and 'recipients'. These emerging trends include 'brain death donors', 'blood absence re-injection injuries', 'tacrolimus', 'older donors and recipients', and 'artificial intelligence and DGF'. In summary, this study reveals the authors and institutions that could be cooperated with and discusses the research hotspots in the past ten years. It provides a reference and direction for future research and application of DGF.

Efficacy of Integrated Risk Score Using Omics-Based Biomarkers for the Prediction of Acute Rejection in Kidney Transplantation: A Randomized Prospective Pilot Study

Acute rejection (AR) is critical for long-term graft survival in kidney transplant recipients (KTRs). This study aimed to evaluate the efficacy of the integrated risk score of omics-based biomarkers in predicting AR in KTRs. This prospective, randomized, controlled, multicenter, pilot study enrolled 40 patients who recently underwent high-immunologic-risk kidney transplantation (KT). Five omics biomarkers were measured, namely, blood mRNA (three-gene signature), urinary exosomal miRNA (three-gene signature), urinary mRNA (six-gene signature), and two urinary exosomal proteins (hemopexin and tetraspanin-1) at 2 weeks and every 4 weeks after KT for 1 year. An integrated risk score was generated by summing each biomarker up. The biomarker group was informed about the integrated risk scores and used to adjust immunosuppression, but not the control group. The outcomes were graft function and frequency of graft biopsy. Sixteen patients in the biomarker group and nineteen in the control group completed the study. The mean estimated glomerular filtration rate after KT did not differ between the groups. Graft biopsy was performed in two patients (12.5%) and nine (47.4%) in the biomarker and control groups, respectively, with the proportion being significantly lower in the biomarker group (p = 0.027). One patient (6.3%) in the biomarker group and two (10.5%) in the control group were diagnosed with AR, and the AR incidence did not differ between the groups. The tacrolimus trough level was significantly lower in the biomarker group than in the control group at 1 year after KT (p = 0.006). Integrated omics biomarker monitoring may help prevent unnecessary or high-complication-risk biopsy and enables tailored immunosuppression by predicting the risk of AR in KTRs.

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.

Influence of diabetes and other risk factors on in-hospital mortality following kidney transplantation: an analysis of the Spanish National Hospital Discharge Database from 2016 to 2020

INTRODUCTION

To assess time trends in incidence, clinical characteristics, complications, and hospital outcomes among patients with type 1 diabetes (T1D), with type 2 diabetes (T2D), and patients without diabetes who underwent kidney transplant (KT); to identify variables associated with in-hospital mortality (IHM); and to determine the impact of the COVID-19 pandemic.

RESEARCH DESIGN AND METHODS

We used a nationwide discharge database to select KT recipients admitted to Spanish hospitals from 2016 to 2020. We stratified patients according to diabetes status. We used multivariable logistic regression to identify the variables associated with IHM.

RESULTS

A total of 14 594 KTs were performed in Spain (T2D, 22.28%; T1D, 3.72%). The number of KTs rose between 2016 and 2019 and and decreased from 2019 to 2020 in all groups. In patients with T2D, the frequency of KT complications increased from 21.08% in 2016 to 34.17% in 2020 (p<0.001). Patients with T2D had significantly more comorbidity than patients with T1D and patients without diabetes (p<0.001). Patients with T1D experienced KT rejection significantly more frequently (8.09%) than patients with T2D (5.57%).COVID-19 was recorded in 26 out of the 2444 KTs performed in 2020, being found in 6 of the 39 patients deceased that year (15.38%) and in 0.83% of the survivors.The variables associated with IHM were comorbidity and complications of KT. The presence of T1D was associated with IHM (OR 2.6; 95% CI 1.36 to 5.16) when patients without diabetes were the reference category. However, T2D was not associated with a higher IHM (OR 0.86; 95% CI 0.61 to 1.2).

CONCLUSIONS

The COVID-19 pandemic led to a decrease in the number of transplants. Patients with T1D have more rejection of the transplanted organ than patients with T2D. Fewer women with T2D undergo KT. The presence of T1D is a risk factor for IHM.

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.

Incidence and Causes of Early Hospital Readmissions After Living-Donor Renal Transplant at King Abdulaziz Medical City, Riyadh

BACKGROUND

 Living-donor organ transplant has a higher long-term survival rate compared to deceased-donor organ transplant, with kidney transplantation being the optimal treatment for most kidney failure patients. However, early hospital readmission within 30 days of discharge can occur due to various factors and can negatively affect long-term outcomes. Effective communication with patients pre-and post-transplant is crucial for a better quality of life and for reducing readmissions. Chronic kidney disease and co-morbid conditions must also be addressed for better long-term outcomes. The incidence and causes of early hospital readmission vary depending on local characteristics and other factors.

METHODS

 A retrospective cohort study of outcomes in patients who underwent living-donor renal transplantation at King Abdulaziz Medical City (KAMC) between 2015 and 2022. Data were collected by chart review using the BestCare system. The data collected included patients' demographics, comorbidities, surgery-related data, and the outcome of transplantation. The categorical data were presented using percentages and frequencies, while the numerical data were presented as mean and standard deviation. The Chi-square test was used for inferential statistics to find the association between categorical variables.

RESULTS

 Regarding sociodemographic characteristics, the majority of patients were male, aged 19-50 years, and either overweight or had obesity class 1. The incidence of complications, graft failure, and mortality after renal transplant was low, with only a small percentage of patients experiencing these outcomes within one year of transplant. There is no significant association between gender, age, BMI, and the likelihood of readmission after renal transplantation. Patients with comorbidities such as hypertension, diabetes, and coronary artery disease had a higher likelihood of readmission after renal transplantation. The study provides an association between readmission after renal transplantation and various factors such as surgical complications, previous transplant, age at transplant, graft failure, and mortality. Out of the 107 readmitted patients, 2.8% had surgical complications, and 5.6% had a previous transplant, but the association was not statistically significant.

CONCLUSION

 Early hospital readmission within 30 days of discharge can be a concern for patients undergoing renal transplants. While the incidence of complications, graft failure, and mortality after renal transplant was low, patients with comorbidities such as hypertension, diabetes, and coronary artery disease had a higher likelihood of readmission after renal transplantation. Although the association between surgical complications and readmission was not statistically significant, it is important to continue monitoring this factor in future studies. Effective communication with patients pre-and post-transplant can play a crucial role in reducing readmissions and improving long-term outcomes.

Discovery of cellular and genetic signatures of immune tolerance in kidney transplant recipients through single cell RNA sequencing analysis

The objective of this study was to uncover distinct cellular and genetic signatures of transplant operational tolerance (TOT) in kidney transplant recipients (KTRs) through single cell RNA sequencing (scRNA-seq) using peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from 12 KTRs, including those with TOT (TOT, n = 4), stable allograft function on maintenance immunosuppression (STA, n = 4) and biopsy-proven allograft rejection (BPAR, n = 4). ScRNA-seq of PBMCs was analyzed using 20 cell surface marker antibody sequencing to annotate clusters and 399 immune response panel to identify gene expression. Differences in cellular distribution and gene expression were compared among the three groups. Heatmap hierarchical clustering showed that overall cellular distribution pattern was distinct in TOT in comparison with those in the other two groups, with the proportion of B cells being higher in TOT, attributed to immature B cell fraction (TOT vs. STA vs. BPAR: 4.61% vs. 1.27% vs. 2.53%, p = 0.01). Transcript analysis of B cells revealed that genes involved in allo-immune pathway were downregulated in TOT. In T cell subset analysis, the proportion of naïve T cells and regulatory T cells (Tregs) was increased. In transcript analysis, genes associated with inflammation were decreased, while expression levels of CCR6 in Tregs were increased in TOT. Proportions of NKT and NK cells were increased in TOT than in the other two groups. This study showed that TOT has distinct cellular and genetic signatures such as increases of immature B cells, naïve T cells and Tregs and high expression levels of CCR6 in Tregs.

Kidney Transplant Outcomes in Recipients Over the Age of 70

BACKGROUND

Patients older than 70 years are the fastest-growing age group of patients requiring renal replacement therapy. This has resulted in a corresponding increase in the number of elderly transplant recipients. We hypothesized that graft survival in this population would be comparable to that seen in the literature on kidney transplant recipients under 70 years of age.

METHODS

This was a retrospective, single-center review of outcomes of kidney transplant recipients aged ≥70 years. Patients were dichotomized based on whether their allograft originated from a living or deceased donor.

RESULTS

A total of 59 recipients aged ≥70 years underwent kidney transplantation. Of these, five (8.5%) were lost to follow-up within the first year post transplant and excluded from the analysis. History of cerebrovascular accident (p = 0.003), coronary artery disease (p = 0.03), postoperative return to the operating room (p = 0.03), and readmission within one year of transplant were predictive of graft loss (p = 0.003). Overall graft survival in our cohort declined from 92.6% at one year to 53.8% at five years. Death-censored graft survival was 100% at one year and decreased to 80.8% at five years. There were no differences seen in patient, graft, or death-censored graft survival based on donor type.

CONCLUSIONS

Kidney transplant patients over 70 years, as seen in our cohort, had good short-term outcomes. Graft survival is similar to rates seen in younger cohorts but the decline in this rate over time is steeper in the older age group, possibly due to decreased patient survival. These findings could be validated further in larger multi-center studies.

Social support mediates the relationship between illness perception and psychosocial adaptation among young and middle-aged kidney transplant recipients in China

Background

No research has yet been done on social support's influence on the association between illness perception and psychosocial adaptation among young and middle-aged kidney transplant recipients in China. Accordingly, it remains unclear how medical personnel can assist patients in successfully adjusting to the early postoperative period and improving their health.

Objective

This study sought to explore the influence of illness perception and social support on the psychosocial adaptation of young and middle-aged recipients of kidney transplants in China during the early postoperative period.

Methods

This study adopted a cross-sectional design. The study included 236 young and middle-aged kidney transplant recipients from a tertiary hospital in China. Demographic and disease-related data were collected. Additionally, the Psychosocial Adjustment to Illness Scale-Self-Report, the Brief Illness Perception Questionnaire, and the Multidimensional Scale of Perceived Social Support were used to assess participants' psychosocial adaptation, illness perception, and social support, respectively. The model was examined using descriptive analysis, Pearson's correlation analysis, hierarchical multiple regression analysis, and the PROCESS Macro in SPSS 26.0.

Results

A total of 176 (74.56%) participants reported an average psychosocial adaptation score >50, which is relatively negative. Marital status, education level, residence, per capita monthly income (in Chinese yuan), medical insurance, work status, post-transplant time, body mass index, creatinine status, and complications were all related to psychosocial adaptation (p < 0.05). The more negative their illness perception and the worse their social support, the worse the psychosocial adaptation of young and middle-aged kidney transplant recipients. Further, the effect of illness perception on psychosocial adaptation was partially mediated by social support (36.56%).

Conclusion

In general, the psychosocial adaption level of young and middle-aged kidney transplant recipients was negative during the early postoperative period. Healthcare teams should assist patients in building a positive illness perception shortly following kidney transplantation, while also providing psychological care and support to help them cope with the onset of psychosocial issues.