Chronic kidney disease progression in kidney transplant recipients: A focus on traditional risk factors

A Pilot Study of Nephrogenic Probiotics to Further Improve an Already Stabilized Graft Function After Kidney Transplantation

BACKGROUND

The majority of kidney recipients are a subset of chronic kidney disease. Our previous study demonstrated that the combination of Lactobacillus plantarum and Lactobacillus paracasei (Lm) had the highest clearance ability of uremic toxins and improved kidney function in a mouse model. This study aimed to evaluate Lm in improving graft function, effects on immunosuppressants, and safety in transplant recipients.

METHODS

We retrospectively reviewed 24 patients. Twelve of them take Lm regularly; we compared the creatinine measurements and estimated glomerular filtration rate 3 months before and after Lm using a 2-tailed Wilcoxon matched-pairs signed-rank test while also evaluating the drug level of immunosuppressants and infection events. Other 12 patients who do not have Lm for evaluation of laboratory calibration and compared the proportion of improving creatinine using Fisher's exact test.

RESULTS

The creatinine decreased by 0.06 mg/dL (P = .02), and the estimated glomerular filtration rate increased by 3.1 mL/min/1.73 m2 (P = .03) after Lm supplementation. This pilot study revealed the association of higher incidence (odds ratio 13.3, 95% CI 1.64-77.2, P = .01) of decreasing creatinine in transplant recipients using Lm. Furthermore, results showed a trend of higher trough levels of tacrolimus and sirolimus, which might provide a potential strategy for reducing the dosages of immunosuppressants.

CONCLUSION

Our findings revealed an association between a higher incidence of decreasing creatinine in kidney transplant recipients using Lm, which may also provide a potential strategy for reducing the acquired dosages of immunosuppressants.

End-stage renal disease patients have comparable results to renal transplant patients after shoulder arthroplasty

Background

End-stage renal disease (ESRD) and renal transplant (RT) patients are known to have more perioperative and postoperative complications after arthroplasty surgeries when compared to patients without. We hypothesize that RT patients undergoing shoulder arthroplasty (SA) have fewer systemic and surgical complications when compared to ESRD patients undergoing SA.

Methods

This was a retrospective review from the PearlDiver Patient Record Database. International Classification of Diseases and Current Procedural Terminology codes were used to identify patients who had undergone primary total and reverse shoulder arthroplasty, respectively, and subsequent surgical revisions. Unadjusted univariate analysis of patient demographics, Charlson Cormorbidty Index, and surgical complications at 90 days, 1 year, and 2 years after was performed using chi-squared testing. Multivariate logistic regression analyses were subsequently performed for systemic complications and prosthesis outcomes at all time points.

Results

Of 1191 patients with ESRD or previous RT and who underwent either total shoulder arthroplasty or reverse total shoulder arthroplasty, 1042 (87.5%) had ESRD and 149 (12.5%) had a previous RT. ESRD SA patients were more likely to have hypertension, liver disease, coronary artery disease, and hypothyroidism. Interestingly no statistical significance was found in multivariate analysis for systemic complications at 90 days, nor for surgical complications at the 90-day, 1-year, or 2-year mark between ESRD and RT cohorts.

Conclusion

SAs have comparable outcomes in ESRD and RT patients. The differing conclusions among studies might be partially accounted for by the demographic differences and comorbidities between these 2 patient populations. Providers should continue to provide appropriate counseling concerning risks, benefits, and timing of SA for these patients.

Sickness Symptoms in Kidney Transplant Recipients: A Scoping Review

Sickness symptoms (depressive symptoms, anxiety, and fatigue) are common among people with chronic illness, often presenting as a symptom cluster. Sickness symptoms persist in many patients with chronic kidney disease, even after kidney transplantation (KT); however, little is known about sickness symptom-induced burden in KT recipients. This scoping review synthesizes available evidence for sickness symptoms in KT recipients, including findings on symptom prevalence, predictors, outcomes, interrelationships, and clustering. Among 38 reviewed studies, none identified sickness symptoms as a cluster, but we observed interrelationships among the symptoms examined. Fatigue was the most prevalent sickness symptom, followed by anxiety and depressive symptoms. Predictors of these symptoms included demographic, clinical, and psychosocial factors, and health-related quality of life was the most researched outcome. Future research should use common data elements to phenotype sickness symptoms, include biological markers, and employ sophisticated statistical methods to identify potential clustering of sickness symptoms in KT recipients.

The role of Advanced Practice Nurses in creating the Kidney Transplant candidate care map (APN-preKT): a convergent-parallel mixed methods research protocol

BACKGROUND

Waiting time for kidney transplants (KT) is an important health determinant for patients with chronic kidney disease (CKD). During this time, ongoing evaluation and participation is necessary in order to guarantee the quality and suitability of the proposed treatment. There is no existing literature on the potential impact of inclusion of an Advanced Practice Nurse (APN) role in the hospital setting on care for CKD patients who are candidates for KT. The main objectives of this protocol are: to analyse outpatient nursing activity in the care of individuals with KT in Spain; to identify the needs of individuals who are KT candidates; and to measure the impact of the APN role through patient outcomes and experiences. These objectives are fulfilled through 5 specific related substudies.

METHODS

A convergent parallel mixed methods approach will be conducted between July 2021 and April 2024. Quantitative and qualitative data will be collected and analysed separately to ascertain whether the findings confirm or contradict one another. Each of the 5 substudies of the project require a specific design, sampling method, and data collection procedure in order to meet the overall objectives for the project.

DISCUSSION

The results of the project are expected to inform the design of future nursing roles and contribute to future improvements in the quality of care provided. The data that may be obtained from this protocol are limited to the specific context of the study facility and may be extrapolated but not compared to other settings due to the variability of care pathways for KT candidates internationally.

TRIAL REGISTRATION

This project was approved by the Clinical Research Ethics Committee (no.2020/9418/I). The study was supported by the "Strategic Plan for Health Research and Innovation" from the Generalitat de Catalunya, registration number SLT017/20/000001, with a contribution of 57,239 euros.

Diabetic Kidney Disease in Post-Transplant Diabetes Mellitus: Causes, Treatment and Outcomes

Kidney transplant recipients are a unique subgroup of chronic kidney disease patients due to their single functioning kidney, immunosuppressive agent usage, and long-term complications related to transplantation. Post-transplant diabetes mellitus (PTDM) has a significant adverse effect on renal outcomes in particular. As transplantations enable people to live longer, cardiovascular morbidity and mortality become more prevalent, and PTDM is a key risk factor for these complications. Although PTDM results from similar risk factors to those of type 2 diabetes, the conditions differ in their pathophysiology and clinical features. Transplantation itself is a risk factor for diabetes due to chronic exposure to immunosuppressive agents. Considering current evidence, this article describes the risk factors, pathogenesis, diagnostic criteria, prevention strategies, and management of PTDM. The therapeutic options are discussed regarding their safety and potential drug-drug interactions with immunosuppressive agents.

Arterial hypertension in kidney transplantation: huge importance, but few answers

Abstract Arterial hypertension (AH) after renal transplantation (RTX) is correlated with worse cardiovascular and renal outcomes, with loss of renal function, decreased graft survival and higher mortality. RTX recipients have discrepant blood pressure (BP) values when measured in the office or by systematic methodologies, such as Ambulatory Blood Pressure Monitoring (ABPM), with significant prevalence of no nocturnal dipping or nocturnal hypertension, white coat hypertension and masked hypertension. The aim of the present study was to review the issue of hypertension in RTX, addressing its multifactorial pathophysiology and demonstrating the importance of ABPM as a tool for monitoring BP in these patients. Treatment is based on lifestyle changes and antihypertensive drugs, with calcium channel blockers considered first-line treatment. The best blood pressure target and treatment with more favorable outcomes in RTX are yet to be determined, through well-conducted scientific studies, that is, in terms of AH in RTX, we currently have more questions to answer than answers to give.

Hipertensão arterial no transplante renal: grande importância, mas poucas respostas

Resumo Hipertensão arterial (HA) no póstransplante renal (TXR) se correlaciona com piores desfechos cardiovasculares e renais, com perda de função renal, diminuição da sobrevida do enxerto e maior mortalidade. Receptores de TXR apresentam valores discrepantes de pressão arterial (PA) quando ela é obtida em consultório ou por metodologias sistematizadas, como a Monitorização Ambulatorial da PA (MAPA), com prevalências significantes de ausência de descenso noturno ou hipertensão noturna, hipertensão do avental branco e hipertensão mascarada. O objetivo do presente estudo foi rever a temática da hipertensão no TXR, abordando sua fisiopatologia multifatorial e demonstrando a importância da MAPA como ferramenta de acompanhamento da PA nesses pacientes. O tratamento é baseado em mudanças no estilo de vida e em fármacos anti-hipertensivos, sendo os bloqueadores de canais de cálcio considerados de primeira linha. A melhor meta pressórica e o tratamento com desfechos mais favoráveis no TXR ainda estão por ser determinados, por meio de estudos bem conduzidos cientificamente, ou seja, em termos de HA no TXR temos atualmente mais questões a responder do que respostas a dar.

Management of long-term cardiovascular risk factors post organ transplant

PURPOSE OF REVIEW

Cardiovascular disease is one of the leading causes of death in solid organ transplant (SOT) recipients. Early identification of cardiovascular risk factors and their adequate management in this population is key for prevention and improved outcomes.

RECENT FINDINGS

Approximately 80% of SOT present one or more cardiovascular risk factors, with increasing prevalence with time posttransplantation. They are due to the interplay of pretransplant conditions and metabolic consequences of immunosuppressive agents, mainly corticosteroids and calcineurin inhibitors. Among the pharmacological management strategies, statins have shown an important protective effect in SOT.

SUMMARY

Strict surveillance of cardiovascular risk factors is recommended in SOT due to their high prevalence and prognostic implications. Further studies on the best managements strategies in this population are needed.

Association of Post Transplantation Anaemia and Persistent Secondary Hyperparathyroidism with Diastolic Function in Stable Kidney Transplant Recipients

Introduction

We hypothesized that post transplantation anaemia and persistent secondary hyperparathyroidism are potential determinants of diastolic function in stable kidney transplant recipients.

Methods

We assessed traditional and non-traditional cardiovascular risk factors and determined carotid artery intima-media thickness and plaque by ultrasound, arterial function by applanation tonometry using SphygmoCor software and diastolic function by echocardiography in 43 kidney transplant recipients with a transplant duration of ≥6 months, no acute rejection and a glomerular filtration rate of ≥15 mL/min/1.73m².

Results

Mean (SD; range) transplant duration was 12.3 (8.0; 0.5–33.8) years. Post transplantation anaemia and persistent secondary hyperparathyroidism were identified in 27.9% and 30.8% of the patients, respectively; 67.5% of the participants were overweight or obese. In established confounder adjusted analysis, haemoglobin (partial R=−0.394, p=0.01) and parathyroid hormone concentrations (partial R=0.382, p=0.02) were associated with E/e’. In multivariable analysis, haemoglobin (partial R=−0.278, p=0.01) and parathyroid levels (partial R=0.324, p=0.04) were independently associated with E/e’. Waist–height ratio (partial R=−0.526, p=0.001 and partial R=−0.355, p=0.03), waist circumference (partial R=−0.433, p=0.008 and partial R=−0.393, p=0.02) and body mass index (partial R=−0.332, p=0.04 and partial R=−0.489, p=0.002) were associated with both e’ and E/A, respectively, in established confounder adjusted analysis. The haemoglobin-E/e’ (partial R=−0.422, p=0.02), parathyroid hormone-E/e’ (partial R=0.434, p=0.03), waist–height ratio-e’ (partial R=−0.497, p=0.007) and body mass index-E/A (partial R=−0.386, p=0.04) relationships remained consistent after additional adjustment for left ventricular mass index and cardiac preload and afterload measures.

Conclusion

Haemoglobin and parathyroid hormone concentrations as well as adiposity measures are independently associated with diastolic function in kidney transplant recipients. Whether adequate management of post transplantation anaemia, persistent secondary hyperparathyroidism and excess adiposity can prevent the development of heart failure with preserved ejection fraction in kidney transplant recipients merits further investigation.

The association between severe or death COVID-19 and solid organ transplantation: A systematic review and meta-analysis

Background

The effect of solid organ transplantation (SOT) on the severity and mortality of coronavirus disease 2019 (COVID-19) remained controversial. There is still no consensus on whether solid organ transplantation (SOT) recipients with COVID-19 are at greater risk of developing severe or fatal COVID-19. Therefore, we conducted a systematic review and meta-analysis to investigate the association between SOT, severe COVID-19 illness, and mortality.

Methods

A systemically comprehensive search in Pubmed, Embase, the Cochrane Library, Web of Science, and China National Knowledge Infrastructure was performed for relevant studies and articles. Consequently, we pooled the odds ratio (OR) from individual studies and performed heterogeneity, quality assessment and subgroup/sensitivity analysis.

Results

A total number of 15 articles with 265,839 participants were included in this study. Among the total number of participants, 1485 were SOT recipients. The meta-analysis results showed that transplant patients with COVID-19 were remarkably associated with a higher risk of intensive care unit admission than non-transplant patients (OR = 1.57, 95%CI: 1.07 to 2.31, P = 0.02). On the other hand, there were no statistically significant differences between SOT recipients and non-SOT recipients in mechanical ventilation need (OR = 1.55, 95%CI: 0.98 to 2.44, P = 0.06). In addition, we found that SOT recipients with COVID-19 had 1.40-fold increased odds of mortality than non-SOT recipients (OR = 1.40, 95%CI: 1.10 to 1.79, P = 0.007). Moreover, pooled analysis of adjusted results revealed that SOT recipients had a greater risk of mortality compared with non-SOT patients (HR = 1.54, 95%CI: 1.03 to 2.32, P = 0.037).

Limitations

The main limitations in our study are attributed to the relatively small sample size, short follow-up period, and the fact that most of the studies included were retrospective in design.

Conclusions

The results of this study indicate that SOT recipients with COVID-19 had a more significant risk of COVID-19 severity and mortality than the general population.

Targeting Premature Renal Aging: from Molecular Mechanisms of Cellular Senescence to Senolytic Trials

The biological process of renal aging is characterized by progressive structural and functional deterioration of the kidney leading to end-stage renal disease, requiring renal replacement therapy. Since the discovery of pivotal mechanisms of senescence such as cell cycle arrest, apoptosis inhibition, and the development of a senescence-associated secretory phenotype (SASP), efforts in the understanding of how senescent cells participate in renal physiological and pathological aging have grown exponentially. This has been encouraged by both preclinical studies in animal models with senescent cell clearance or genetic depletion as well as due to evidence coming from the clinical oncologic experience. This review considers the molecular mechanism and pathways that trigger premature renal aging from mitochondrial dysfunction, epigenetic modifications to autophagy, DNA damage repair (DDR), and the involvement of extracellular vesicles. We also discuss the different pharmaceutical approaches to selectively target senescent cells (namely, senolytics) or the development of systemic SASP (called senomorphics) in basic models of CKD and clinical trials. Finally, an overview will be provided on the potential opportunities for their use in renal transplantation during ex vivo machine perfusion to improve the quality of the graft.

Long-term outcomes after kidney transplant failure and variables related to risk of death and probability of retransplant: Results from a single-center cohort study in Brazil

Background

Returning to dialysis after kidney graft loss (GL) is associated with a high risk of mortality, mainly in the first 3–6 months. The follow-up of patients with GL should be extended to better understand crude patient outcomes, mainly in emerging countries, where the transplantation activity has increased.

Methods

This is a historical single-center cohort study conducted in an emerging country (Brazil) that included 115 transplant patients with kidney allograft failure who were followed for 44.1 (21.4; 72.6) months after GL. The outcomes were death or retransplantation after GL calculated by Kaplan-Meier and log-rank tests. Proportional hazard ratios for death and retransplantation were assessed by Cox regression.

Results

The 5-year probability of retransplantation was 38.7% (95% CI: 26.1%-51.2%) and that of death was 37.7% (95% CI: 24.9%-50.5%); OR = 1.03 (95% CI: 0.71–1.70) and P = 0.66. The likelihood of retransplantation was higher in patients who resumed dialysis with higher levels of hemoglobin (HR = 1.22; 95% CI = 1.04–1.43; P = 0.01) and lower in blood type O patients (HR = 0.48; 95% CI = 0.25–0.93; P = 0.03), which was associated with a lower frequency of retransplantation with a subsequent living-donor kidney. On the other hand, the risk of death was significantly associated with Charlson comorbidity index (HR for each point = 1.37; 95% CI 1.19–1.50; P<0.001), and residual eGFR at the time when patients had resumed to dialysis (HR for each mL = 1.14; 95% CI = 1.05–1.25; P = 0.002). The trend toward a lower risk of death when patients had resumed to dialysis using AV fistula access was observed (HR = 0.50; 95% CI 0.25–1.02; P = 0.06), while a higher risk seems to be associated with the number of previous engraftment (HR = 2.01; 95% CI 0.99–4.07; P = 0.05).

Conclusions

The 5-year probability of retransplantation was not less than that of death. Variables related to the probability of retransplantation were hemoglobin level before resuming dialysis and ABO blood type, while the risk of death was associated with comorbidities and residual eGFR.

Differentially expressed urinary exo-miRs and clinical outcomes in kidney recipients on short-term tacrolimus therapy: a pilot study

Aim: To analyze the expression of urinary exosome-derived miRNAs (exo-miRs) in kidney recipients on tacrolimus-based therapy. Patients & methods: Clinical and drug monitoring data were recorded from 23 kidney recipients. Expression of 93 exo-miRs was measured by quantitative PCR array and mRNA targets were explored. Results: 16 exo-miRs were differentially expressed, including marked upregulation of miR-155-5p, and downregulation of miR-223-3p and miR-1228-3p. Expression of miR-155-5p and miR-223-3p correlated with tacrolimus dose (p < 0.05), miR-223-3p with serum creatinine (p < 0.05), and miR-223-3p and miR-1228-3p with blood leukocytes (p < 0.05). 12 miRNAs have predicted targets involved in cell proliferation, apoptosis, stress response, PIK3/AKT/mTOR and TGF-β signaling pathways. Conclusion: Differentially expressed urinary exo-miRs may be useful markers to monitor tacrolimus therapy and graft function in kidney transplantation.

Differential expression of genes related to calcineurin and mTOR signaling and regulatory miRNAs in peripheral blood from kidney recipients under tacrolimus-based therapy

Background

Genetic and epigenetics factors have been implicated in drug response, graft function and rejection in solid organ transplantation. Differential expression of genes involved in calcineurin and mTOR signaling pathway and regulatory miRNAs was analyzed in the peripheral blood of kidney recipient cohort (n=36) under tacrolimus-based therapy.

Methods

PPP3CA, PPP3CB, MTOR, FKBP1A, FKBP1B and FKBP5 mRNA expression and polymorphisms in PPP3CA and MTOR were analyzed by qPCR. Expression of miRNAs targeting PPP3CA (miR-30a, miR-145), PPP3CB (miR-10b), MTOR (miR-99a, miR-100), and FKBP1A (miR-103a) was measured by qPCR array.

Results

PPP3CA and MTOR mRNA levels were reduced in the first three months of treatment compared to pre-transplant (P<0.05). PPP3CB, FKBP1A, FKBP1B, and FKBP5 expression was not changed. In the 3^rd month of treatment, the expression of miR-99a, which targets MTOR, increased compared to pre-transplant (P<0.05). PPP3CA c.249G>A (GG genotype) and MTOR c.2997C>T (TT genotype) were associated with reduced expression of PPP3CA mRNA and MTOR, respectively. FKBP1B mRNA levels were higher in patients with acute rejection (P=0.026).

Conclusions

The expression of PPP3CA, MTOR and miR-99a in the peripheral blood of renal recipients is influenced by tacrolimus-based therapy and by PPP3CA and MTOR variants. These molecules can be potential biomarkers for pharmacotherapy monitoring.

Inflammaging and Complement System: A Link Between Acute Kidney Injury and Chronic Graft Damage

The aberrant activation of complement system in several kidney diseases suggests that this pillar of innate immunity has a critical role in the pathophysiology of renal damage of different etiologies. A growing body of experimental evidence indicates that complement activation contributes to the pathogenesis of acute kidney injury (AKI) such as delayed graft function (DGF) in transplant patients. AKI is characterized by the rapid loss of the kidney's excretory function and is a complex syndrome currently lacking a specific medical treatment to arrest or attenuate progression in chronic kidney disease (CKD). Recent evidence suggests that independently from the initial trigger (i.e., sepsis or ischemia/reperfusions injury), an episode of AKI is strongly associated with an increased risk of subsequent CKD. The AKI-to-CKD transition may involve a wide range of mechanisms including scar-forming myofibroblasts generated from different sources, microvascular rarefaction, mitochondrial dysfunction, or cell cycle arrest by the involvement of epigenetic, gene, and protein alterations leading to common final signaling pathways [i.e., transforming growth factor beta (TGF-β), p16 ink4a , Wnt/β-catenin pathway] involved in renal aging. Research in recent years has revealed that several stressors or complications such as rejection after renal transplantation can lead to accelerated renal aging with detrimental effects with the establishment of chronic proinflammatory cellular phenotypes within the kidney. Despite a greater understanding of these mechanisms, the role of complement system in the context of the AKI-to-CKD transition and renal inflammaging is still poorly explored. The purpose of this review is to summarize recent findings describing the role of complement in AKI-to-CKD transition. We will also address how and when complement inhibitors might be used to prevent AKI and CKD progression, therefore improving graft function.

Serum Adipocyte Fatty Acid-Binding Protein Level is Negatively Associated with Vascular Reactivity Index Measured by Digital Thermal Monitoring in Kidney Transplant Patients

Adipocyte fatty acid-binding protein (A-FABP) is abundantly found in mature adipocytes and is involved in cardiovascular disease. Our aim is to investigate the association between serum A-FABP levels and endothelial function among kidney transplant (KT) patients. Fasting blood samples were obtained from 80 KT patients. Serum A-FABP levels were measured using a commercially available enzyme immunoassay kit. Endothelial function and vascular reactivity index (VRI) were measured using digital thermal monitoring test. In this study, VRI < 1.0, VRI 1.0-1.9, and VRI ≥ 2.0 were defined as poor, intermediate, and good vascular reactivity, respectively. There were 12 (15.0%), 30 (37.5%), and 38 (47.5%) KT patients categorized as having poor, intermediate, and good vascular reactivity, respectively. Increased serum levels of alkaline phosphatase (p = 0.012), γ-glutamyltranspeptidase (GGT; p = 0.032), and A-FABP (p < 0.001) were associated with decreased vascular reactivity. Multivariable forward stepwise linear regression analysis revealed that age (β = -0.283, adjusted R2 change = 0.072; p = 0.003) and serum log-A-FABP level (β = -0.514, adjusted R2 change = 0.268; p < 0.001) were significantly associated with VRI values in KT patients. We concluded that serum fasting A-FABP level is negatively associated with VRI values and plays a role in endothelial dysfunction of KT patients.