What are the key challenges we face in kidney transplantation today?

ABO Incompatible Kidney Transplant in a Patient With Atypical Hemolytic Uremic Syndrome: Case Report

Kidney transplant (KT) or renal transplant is 1 of the preferred treatment options for patients with end-stage renal disease, but the presence of atypical hemolytic uremic syndrome (aHUS) further increases the risk of reoccurrence with graft rejection, and poor outcomes. ABO incompatibility further adds to the rejection risk. Here, we present a case of a young adult with a history of aHUS undergoing a successful ABO-incompatible (ABOi) renal transplant. ABO incompatibility desensitization was carried out, and the antibody titer was reduced to nullify the risk of rejection. Graft acceptance was facilitated by triple immunosuppression (steroid, tacrolimus, and mycophenolate mofetil), and 4-month serum creatinine follow-up indicated the absence of antibody-mediated rejection and recurrence of aHUS. This case demonstrates that in patients with aHUS, ABOi renal transplant can be performed successfully.

Kidney transplant in the next decade: Strategies, challenges and vision of the future

Although the results of kidney transplantation (KT) have improved substantially in recent years, a chronic and inexorable loss of grafts mainly due to the death of the patient and chronic dysfunction of the KT, continues to be observed. The objectives, thus, to optimize this situation in the next decade are fundamentally focused on minimizing the rate of kidney graft loss, improving patient survival, increasing the rate of organ procurement and its distribution, promoting research and training in health professionals and the development of scientific registries providing clinical and reliable information that allow us to optimize our clinical practice in the field of KT. With this perspective, this review will deep into: (1) strategies to avoid chronic dysfunction and graft loss in the medium and long term; (2) to prolong patient survival; (3) strategies to increase the donation, maintenance and allocation of organs; (4) promote clinical and basic research and training activity in KT; and (5) the analysis of the results in KT by optimizing and merging scientific registries.

Transitioning of renal transplant pathology from allograft to xenograft and tissue engineering pathology: Are we prepared?

Currently, the most feasible and widely practiced option for patients with end-stage organ failure is the transplantation of part of or whole organs, either from deceased or living donors. However, organ shortage has posed and is still posing a big challenge in this field. Newer options being explored are xenografts and engineered/bioengineered tissues/organs. Already small steps have been taken in this direction and sooner or later, these will become a norm in this field. However, these developments will pose different challenges for the diagnosis and management of problems as compared with traditional allografts. The approach to pathologic diagnosis of dysfunction in these settings will likely be significantly different. Thus, there is a need to increase awareness and prepare transplant diagnosticians to meet this future challenge in the field of xenotransplantation/ regenerative medicine. This review will focus on the current status of transplant pathology and how it will be changed in the future with the emerging scenario of routine xenotransplantation.

Current Status and Future of Artificial Kidney in Humans

The number of patients needing renal replacement therapy (RRT) is increasing rapidly with an increase in lifestyle diseases such as diabetes, hypertension, and metabolic syndrome. Kidney transplantation, whenever feasible, is the most preferred mode of RRT. However, there is a growing shortage of donor kidneys for transplantation. While dialysis is partially able to perform the filtration and excretion function of the kidneys, it is still not able to perform the other renal tubular and endocrine functions of a normal kidney and has quality-of-life issues with significant long-term morbidity. The need of the hour is to develop an ideal artificial kidney that would be wearable or implantable and would be able to perform the complete excretory, filtration, tubular, endocrine, and metabolic functions of the kidney while preserving the quality of life and minimizing complications. In this review, we discuss the characteristics of an ideal artificial kidney, the challenges of developing such a device, a brief description of the past and current work on this topic, and what the artificial kidney of the future should look like.

Reduced inflammation following human endometrial stromal/stem cell injection into male Wistar rats with cisplatin-induced acute kidney injury

Introduction: Inflammation is one of the most important mechanisms involved in cisplatin-induced acute kidney injury (AKI). Mesenchymal stromal/stem cells (MSCs) exhibit anti-inflammatory and immunomodulatory abilities. Human endometrial stromal/stem cells (hEnSCs) exhibit similar properties to MSCs. These cells secrete immunoregulators, so we investigated the inflammatory aspect of hEnSCs in the treatment of cisplatin-induced AKI in Wistar rats.

Methods: Each group consisted of 6 male Wistar rats. Groups were as follows: sham, model (5 mg/kg cisplatin, IP), and treatment (1 million hEnSCs, IV, 3 hours after cisplatin). Renal function, histopathology, proliferation rate, infiltration of CD3⁺ T cell, and expression of Il-10 and cystatin c (Cst3) were assessed on day 5. DiI-labeled cells were tracked in kidney and liver on days 4 and 14.

Results: HEnSC transplantation improved cisplatin-induced injuries such as renal dysfunction and tissue damage. The highest levels of pathologic scores and hyaline cast formation were observed in the model group while hEnSCs transplantation resulted in their reduction (154.00 ± 14.95, 8.00 ± 1.41 vs. 119.40 ± 5.43, 2.50 ± 1.05). The percentage of Ki-67 positive cells in the treatment group increased while cisplatin decreased proliferation (39.91 ± 5.33 vs. 23.91 ± 3.57 in glomeruli and 39.07 ± 2.95 vs. 16.61 ± 3.25 in tubules). The expression of Cst3 and Il-10 was higher in the model and treatment groups, respectively. DiI-labeled cells were observed in the renal tubules and liver lobes on days 4 and 14.

Conclusion: HEnSCs may ameliorate cisplatin-induced AKI through anti-inflammatory and immunomodulatory effects and/or through paracrine effects.

Bortezomib alleviates antibody-mediated rejection in kidney transplantation by facilitating Atg5 expression

Antibody‐mediated rejection (AMR) is one of the most dominant mechanisms responsible for the loss of kidney grafts. Previous researches have shown that donor‐specific antibodies (DSAs) are the major mediators of AMR. In order to prolong the survival time of grafts, it is vital to reduce the incidence of AMR and inhibit the generation of DSAs. We established an animal model of AMR by performing kidney transplantation in pre‐sensitized rats. Then, we investigated the effect of bortezomib (BTZ) on AMR. We found that BTZ could reduce the serum level of DSAs and alleviate post‐transplantation inflammation in peritubular capillaries (PTCs) and glomeruli, which was demonstrated by the reduction of C4d and IgG deposition in PTCs, and the reduced number of B cell and plasma cell in peripheral blood and the transplanted kidney (p < 0.05). Our results also suggested that BTZ increased the number of regulatory T cell (Treg) and significantly reduced the proportion of T helper (Th17) cell (p < 0.05). Besides, BTZ induced the significant upregulation of anti‐inflammatory cytokines but downregulated pro‐inflammatory cytokines (p < 0.05). After dealing with Atg5 siRNA‐lentivirus, the effect of BTZ alleviating AMR was reversed and Th17/Treg proportions were also significantly modulated. Collectively, these findings show that BTZ slows down the process of AMR and Atg5 may be the key mechanism. Furthermore, Atg5 silencing results may be demonstrated that Atg5 alleviated AMR by modulating the ratio of Th17/Treg.

Protocol Biopsies on de novo Renal-Transplants at 3 Months after Surgery: Impact on 5-Year Transplant Survival

Background: In many centers, a protocol kidney biopsy (PKB) is performed at 3 months post-transplantation (M3), without a demonstrated benefit on death-censored graft survival (DCGS). In this study, we compared DCGS between kidney transplant recipients undergoing a PKB or without such biopsy while accounting for the obvious indication bias. Methods: In this retrospective, single-center study conducted between 2007 and 2013, we compared DCGS with respect to the availability and features of a PKB. We built a propensity score (PS) to account for PKB indication likelihood and adjusted the DCGS analysis on PKB availability and the PS. Results: A total of 615 patients were included: 333 had a PKB, 282 did not. In bivariate Kaplan–Meier survival analysis, adjusting for the availability of a PKB and for the PS, a PKB was associated with a better 5-year DCGS independently of the PS (p < 0.001). Among the PKB+ patients, 87 recipients (26%) had IF/TA > 0. Patients with an IF/TA score of 3 had the worst survival. A total of 144 patients (44%) showed cv lesions. Patients with cv2 and cv3 lesions had the worst 5-year DCGS. Conclusions: A M3 PKB was associated with improved graft survival independently of potential confounders. These results could be explained by the early treatment of subclinical immunological events. It could be due to better management of the immunosuppressive regimen.

Donor genetic variants in interleukin-6 and interleukin-6 receptor associate with biopsy-proven rejection following kidney transplantation

Rejection after kidney transplantation remains an important cause of allograft failure that markedly impacts morbidity. Cytokines are a major player in rejection, and we, therefore, explored the impact of interleukin-6 (IL6) and IL-6 receptor (IL6R) gene polymorphisms on the occurrence of rejection after renal transplantation. We performed an observational cohort study analyzing both donor and recipient DNA in 1271 renal transplant‐pairs from the University Medical Center Groningen in The Netherlands and associated single nucleotide polymorphisms (SNPs) with biopsy-proven rejection after kidney transplantation. The C-allele of the IL6R SNP (Asp358Ala; rs2228145 A > C, formerly rs8192284) in donor kidneys conferred a reduced risk of rejection following renal transplantation (HR 0.78 per C-allele; 95%-CI 0.67–0.90; P = 0.001). On the other hand, the C-allele of the IL6 SNP (at position-174 in the promoter; rs1800795 G > C) in donor kidneys was associated with an increased risk of rejection for male organ donors (HR per C-allele 1.31; 95%-CI 1.08–1.58; P = 0.0006), but not female organ donors (P = 0.33). In contrast, neither the IL6 nor IL6R SNP in the recipient showed an association with renal transplant rejection. In conclusion, donor IL6 and IL6R genotypes but not recipient genotypes represent an independent prognostic marker for biopsy-proven renal allograft rejection.

Curcumin Blunts IL-6 Dependent Endothelial-to-Mesenchymal Transition to Alleviate Renal Allograft Fibrosis Through Autophagy Activation

Fibrosis contributes to graft loss in chronic renal allograft injury. Endothelial-to-mesenchymal transition (EndMT) plays an important role in the development of fibrosis following kidney transplantation. Autophagy plays an important role in the homeostasis of diverse cell types including endothelial cells. Here we demonstrate that inhibition of autophagy by treatment with 3-methyladenine (3-MA) or by silencing autophagy-related (ATG)5 promoted interleukin (IL)-6-dependent EndMT in human umbilical vein endothelial cells (HUVECs) and human renal glomerular endothelial cells (HRGECs), and autophagy inactivation was associated with EndMT in patients with chronic allograft dysfunction. IL-6 level was significantly higher in the culture medium of HUVECs transfected with ATG5 siRNA or treated with 3-MA compared to the respective control groups. IL-6 application induced EndMT in HUVECs and HRGECs, whereas antibody-mediated neutralization of IL-6 suppressed EndMT induced by ATG5 silencing. The protective role of curcumin (Cur) against allograft fibrosis was confirmed in a rat kidney transplantation model of F344 donors to Lewis recipients. Curcumin-a natural polyphenol compound with known antifibrotic effects in various tissues-alleviated IL-6-induced EndMT and promoted autophagy in the allografted organ and in HUVECs. This is the first demonstration of the role of autophagy in renal allograft fibrosis; our findings indicate that curcumin can alleviate chronic renal allograft injury by suppressing IL-6-dependent EndMT via activation of autophagy.

The Genetic Polymorphism of CYP3A4 rs2242480 is Associated with Sirolimus Trough Concentrations Among Adult Renal Transplant Recipients

BACKGROUND

The large interindividual variability in the genetic polymorphisms of sirolimus (SIR)- metabolizing enzymes, transporters, and receptors can lead to qualitatively and quantitatively distinct therapeutic responses.

OBJECTIVE

We examined the impact of numerous candidate single-nucleotide polymorphisms (SNPs) involved in the trough concentration of SIR-based immunosuppressant regimen.

METHODS

This is a retrospective, long-term cohort study involving 69 renal allograft recipients. Total DNA was isolated from recipient blood samples and trough SIR concentrations were measured by microparticle enzyme immunoassay. Genome sequence reading was targeted based on next-generation sequencing. The association of tagger SNPs to SIR trough concentrations with non-genetic covariate adjusting was analyzed using logistic regression.

RESULTS

A total of 300 SNPs were genotyped in the recipient DNA samples using target sequencing analysis. Only the SNP of CYP3A4 (Ch7: 99361466 C>T, rs2242480) had a significantly higher association with SIR trough concentration as compared to the other 36 tagger SNPs. The mean trough SIR concentration of patients in the CYP3A4 rs2242480-CC group was more significant compared to that of the CYP3A4 rs2242480-TC and TT group, respectively 533.3; 157.4 and 142.5 (ng/ml)/mg/kg, P<0.0001. After adjusting the SNPs, there was no significant association between clinical factors such as age, follow-up period, the incidence of delayed graft function, immunosuppression protocol, and sex with SIR trough concentration.

CONCLUSION

These findings indicated a significant association of polymorphism in the CYP3A4 (Ch7: 99361466 C>T, rs2242480) with SIR trough concentration after 1-year administration in patients who have undergone kidney transplantation.

Perioperative blood usage and therapeutic plasma exchange in kidney transplantation during a 16-year period in South Korea

BACKGROUND

The frequency of kidney transplantation (KT) is increasing. Blood transfusion plays an important role in the success of KT. Therapeutic plasma exchange (TPE) is also used for desensitisation in ABO-incompatible KT and treatment of antibody-mediated rejection.

MATERIALS AND METHODS

We analysed red blood cell (RBC), platelet, and fresh frozen plasma (FFP) usage and the number of TPE procedures performed during the hospitalisation of KT patients from 2002 to 2017 using the Korean National Health Insurance Service-National Health Information Database.

RESULTS

A total of 18,331 KT patients were included in this study. The number of transfused RBCs continued to increase from 4,806 units in 2002-2005 to 12,390 units in 2014-2017. However, the average number of RBCs transfused per patient decreased from 2.17 to 1.79 units. Estimated platelet usage increased from 4,259 units in 2002-2005 to 11,519 units in 2014-2017, and the proportion of filtered platelets increased from 72.6% to 83.4% during the same period. There was a huge increase in the total number of FFP units used, from 2,255 units in 2002-2005 to 51,531 units in 2014-2017. The number of TPE procedures performed also increased from 296 to 6,479 during the same period. Patients with acute rejection accounted for 8.8% of all KT patients, and more RBC and FFP were used for these patients and a greater number of TPE procedures were performed compared to those who did not experience rejection.

DISCUSSION

Blood usage and TPE have increased steadily with the increasing numbers of KTs. Therefore, continuous efforts are needed to ensure appropriate perioperative blood preparation and usage for KT patients.

A Single-Nucleotide Polymorphism (rs1131243) of the Transforming Growth Factor Beta Signaling Pathway Contributes to Risk of Acute Rejection in Chinese Renal Transplant Recipients

BACKGROUND Acute rejection (AR) is a common complication of kidney transplantation. The transforming growth factor beta (TGF-ß) signaling pathway has been observed to be involved in several cellular functions. Our study aimed to investigate the correlations between single-nucleotide polymorphisms (SNPs) in TGF-ß-related genes and the risk of AR in renal transplant recipients. MATERIAL AND METHODS This retrospective, single-center study included 200 Chinese renal transplant recipients. All exons, exon/intron boundaries, and flanking regions of the TGF-ß signaling pathway were detected by targeting sequencing (TS) based on next-generation sequencing technology. Tagger SNPs and haplotypes were identified after adjustment. A general linear model (GLM) was used to explore the confounding effect of clinical variables. Five adjusted inheritance models were utilized to investigate the influence of SNPs on AR, and Banff score was applied to evaluate the effect of related SNPs on pathological changes. RESULTS A total of 188 SNPs on TGF-ß genes were detected. Analysis of adjustment led to identification of 31 tagger SNPs and 10 haplotype blocks. After the analysis of a general linear model and 5 sirolimus-adjusted multiple inheritance models, 1 of the SNPs - rs1131243 on the TGF-ßR3 gene - was observed to be significantly associated with the occurrence of AR. Based on Banff score, no significant association was observed between SNPs and pathological changes. CONCLUSIONS In this study, we observed that the SNP rs1131243 on the TGF-ßR3 gene was significantly associated with the occurrence of AR in Chinese renal transplant recipients.

Bortezomib attenuates renal interstitial fibrosis in kidney transplantation via regulating the EMT induced by TNF-α-Smurf1-Akt-mTOR-P70S6K pathway

Allograft interstitial fibrosis was characterized by massive extracellular matrix deposition caused by activated fibroblasts and myofibroblasts. Epithelial‐mesenchymal transition (EMT) is recognized as an important source of myofibroblasts contributing to the pathogenesis of allograft interstitial fibrosis. Smad ubiquitination regulatory factor 1 (Smurf1) has been recently reported to be involved in the progression of EMT. Our study was to detect the effect of Bortezomib and Smurf1 in the EMT and allograft interstitial fibrosis. Biomarkers of EMT, as well as Smurf1, were examined in human proximal tubular epithelial cells (HK‐2) treated with tumour necrosis factor‐alpha (TNF‐α) in various doses or at various time points by Western Blotting or qRT‐PCR. We knockdown or overexpressed Smurf1 in HK‐2 cells. Furthermore, rat renal transplant model was established and intervened by Bortezomib. Allograft tissues from human and rats were also collected and prepared for HE, Masson's trichrome, immunohistochemical staining and western blotting assays. As a result, we found that TNF‐α significantly promoted the development of EMT in a time‐dependent and dose‐dependent manner through Smurf1/Akt/mTOR/P70S6K signalling pathway. More importantly, Bortezomib alleviated the progression of EMT and allograft interstitial fibrosis in vivo and in vitro by inhibiting the production of TNF‐α and expression of Smurf1. In conclusion, Smurf1 plays a critical role in the development of EMT induced by TNF‐α. Bortezomib can attenuate the Sumrf1‐mediated progression of EMT and renal allograft interstitial fibrosis, which could be suggested as a novel choice for the prevention and treatment of renal allograft interstitial fibrosis.

Enteroparasitosis infections among renal transplant recipients in Khartoum state, Sudan 2012-2013

Objectives

Renal transplantation procedure markedly increased over the past few decades. The risk of harboring parasitic diseases may affect transplant recipients during life expectancy. We aimed in this study to determine the enteroparasitosis frequency among renal transplant recipients in Khartoum state, Sudan. A case–control hospital-based study performed between November 2012 and May 2013, on 300 renal transplant recipients attending Sudanese Kidney Association hospital in Khartoum state, Sudan, along with 300 normal healthy individuals matching the case in age and sex. Stool samples were collected for parasitological studies.

Results

Out of the 300 renal transplant recipients: 242 (80.7%) were males mean age 43 ± 11.28 and 58 (19.3%) were females mean age 41 ± 13.41. Intestinal parasitic infection was observed in 118 participants and the overall frequency was 19.7%; of which 64 were cases (21.3%) and 54 (18.0%) were controls. Eight different species of intestinal parasites were identified; Entamoeba histolytica/dispar (7.5%), Entamoeba coli (6.5%), Giardia lambelia (3.2%), Cryptosporidium parvum (1.2%), Ascaris lumbricoides (0.6%), Enterobius vermicularis (0.3%), (0.2%) for each of Strongyloides stercoralis and Hymenolepis nana.

Deleting Death and Dialysis: Conservative Care of Cardio-Vascular Risk and Kidney Function Loss in Chronic Kidney Disease (CKD)

The uremic syndrome, which is the clinical expression of chronic kidney disease (CKD), is a complex amalgam of accelerated aging and organ dysfunctions, whereby cardio-vascular disease plays a capital role. In this narrative review, we offer a summary of the current conservative (medical) treatment options for cardio-vascular and overall morbidity and mortality risk in CKD. Since the progression of CKD is also associated with a higher cardio-vascular risk, we summarize the interventions that may prevent the progression of CKD as well. We pay attention to established therapies, as well as to novel promising options. Approaches that have been considered are not limited to pharmacological approaches but take into account lifestyle measures and diet as well. We took as many randomized controlled hard endpoint outcome trials as possible into account, although observational studies and post hoc analyses were included where appropriate. We also considered health economic aspects. Based on this information, we constructed comprehensive tables summarizing the available therapeutic options and the number and kind of studies (controlled or not, contradictory outcomes or not) with regard to each approach. Our review underscores the scarcity of well-designed large controlled trials in CKD. Nevertheless, based on the controlled and observational data, a therapeutic algorithm can be developed for this complex and multifactorial condition. It is likely that interventions should be aimed at targeting several modifiable factors simultaneously.

Graft outcomes following immunosuppressive therapy with different combinations in kidney transplant recipients: a nationwide cohort study

Background

Immunosuppression plays an essential role to overcome immune-related allograft rejection, but it also causes some nephrotoxicity. This study aimed to investigate how the immunosuppressant combinations affect graft outcomes in kidney transplant recipients.

Methods

A nationwide population-based cohort study using the Taiwan National Health Insurance Database was conducted. A total of 3,441 kidney transplant recipients who underwent kidney transplantation during the targeted period were included. The effects on graft outcomes contributed by conventional immunosuppressants, including corticosteroid, calcineurin inhibitors, antimetabolite purine antagonists, and mammalian target of rapamycin inhibitors, were compared.

Results

A total of 423 graft failures developed after the index date. Therapy regimens incorporated with purine antagonists had a comparable reduction of graft failure among four main drug groups regardless of whether they were given as monotherapy or in combination (adjusted hazard ratio: 0.52, 95% confidence interval: 0.42–0.63). Corticosteroid was found to have inferior effects among four groups (adjusted hazard ratio: 1.67, 95% confidence interval: 1.28–2.21). Furthermore, all 15 arrangements of mutually exclusive treatment combinations were analyzed by referencing with corticosteroid monotherapy. As referenced with steroid-based treatment, regimens incorporated with purine antagonists all have superior advantage on graft survival regardless of whether given in monotherapy (65% of graft failure reduced), dual therapy (48%–67% reduced), or quadruple therapy (43% reduced). In all triple therapies, only corticosteroid combined with calcineurin inhibitor and purine antagonist demonstrated superior protection on graft survival (52% of graft failure reduced).

Conclusion

The results may recommend several superior regimens for contributing to graft survival, and for supporting a steroid-minimizing strategy in immunosuppression maintenance.

Intraoperative blood transfusion in pediatric patients undergoing renal transplant-Effect of renal graft size

In pediatric RT, donor allograft size often exceeds the expected recipient norms, especially in younger recipients. An "oversize" graft might not only present a technical- and space-related challenge, but may possibly lead to increased demands in perioperative volume requirements due to the disparity between donor and recipient in renal blood flow. We evaluated transfusion practices at a single tertiary institution with special consideration of kidney graft size, hypothesizing that oversize graft kidneys might lead to a quantifiable increased need of blood transfusion in smaller recipients. Retrospective analysis of all patients who underwent pediatric RT from January 2004 to June 2014 at a tertiary pediatric centre was performed. Variables analyzed included patient age, weight, pre- and postoperative Hb concentration, graft size, EBL, amount of intraoperative blood transfusion, and preoperative use of erythropoietin. Based on graft size in relation to patient's age, a SMR and an OvR were identified. A subcohort of age-matched pairs was used to allow for comparison between groups. We calculated the expected procedure- and transfusion-induced changes in Hb and compared these changes to the observed difference in pre- vs postoperative Hb to assess the influence of graft size on transfusion requirements. RT was performed in 188 pediatric recipients during the study period. In the matched cohort, percentage of transfused patients during transplantation in the OvR group was more than double compared with SMR (89% vs 39%, P < .001); similarly, the median number of transfused PRBC units in OvR was 1, while the median of SMR did not receive transfusion (P < .001). The difference between expected (calculated) and observed change in Hb was significantly higher in OvR with a median of 1.9 g/dL compared with SMR with a median of 1.0 g/dL (P = .026). Correspondingly, the calculated median volume taken up by a regular size kidney was significantly higher with 213 mL compared with 313 mL (P = .031) taken up by an oversize graft kidney. Median estimated intraoperative blood loss was significantly higher in OvR than in SMR (6.9 mL/kg, vs 5.3 mL/kg, respectively; P = .04). Median postoperative Hb was similar among groups (10.4 g/dL vs 10.6 g/dL for SMR vs OvR, respectively). Transplantation of an oversized kidney in pediatric RT recipients is associated with a quantifiable higher need for blood transfusion. This may be caused by a higher intraoperative EBL and/or greater blood volume sequestered by the larger renal allograft and requires further evaluation.

From portable dialysis to a bioengineered kidney

INTRODUCTION

Since the advent of peritoneal dialysis (PD) in the 1970s, the principles of dialysis have changed little. In the coming decades, several major breakthroughs are expected.

AREAS COVERED

Novel wearable and portable dialysis devices for both hemodialysis (HD) and PD are expected first. The HD devices could facilitate more frequent and longer dialysis outside of the hospital, while improving patient's mobility and autonomy. The PD devices could enhance blood purification and increase technique survival of PD. Further away from clinical application is the bioartificial kidney, containing renal cells. Initially, the bioartificial kidney could be applied for extracorporeal treatment, to partly replace renal tubular endocrine, metabolic, immunoregulatory and secretory functions. Subsequently, intracorporeal treatment may become possible.

EXPERT COMMENTARY

Key factors for successful implementation of miniature dialysis devices are patient attitudes and cost-effectiveness. A well-functioning and safe extracorporeal blood circuit is required for HD. For PD, a double lumen PD catheter would optimize performance. Future research should focus on further miniaturization of the urea removal strategy. For the bio-artificial kidney (BAK), cost effectiveness should be determined and a general set of functional requirements should be defined for future studies. For intracorporeal application, water reabsorption will become a major challenge.

Human Cytomegalovirus-Encoded Receptor US28 Is Expressed in Renal Allografts and Facilitates Viral Spreading In Vitro

BACKGROUND

Renal transplantation is the preferred treatment for patients with end-stage renal disease. Human cytomegalovirus (HCMV) activation is associated with decreased renal graft function and survival. Human cytomegalovirus encodes several immune modulatory proteins, including the G protein-coupled receptor US28, which scavenges human chemokines and modulates intracellular signaling.

METHODS

Our aim was to identify the expression and localization of US28 in renal allograft biopsies by immunohistochemistry and determine its role in viral spreading in vitro.

RESULTS

Immunohistochemistry revealed US28 in 31 of 34 renal transplant biopsies from HCMV-seropositive donors. Expression was independent of HCMV viremia or IgG serostatus. US28 was predominantly expressed in the cytoplasm of vascular smooth muscle cells (VSMCs) and tubular epithelial cells, with a median positivity of 20% and 40%, respectively. Also, US28-positive cells were present within arterial neointima. In contrast to US28, HCMV-encoded immediate early antigen was detected in less than 5% of VSMCs, tubular epithelial cells, interstitial endothelium, interstitial inflammatory infiltrates, and glomerular cells.Primary VSMCs were infected with green fluorescent protein-tagged wild type or US28-deficient HCMV. The viral spreading of US28-deficient HCMV, via culture medium or cell-to-cell transmission, was significantly impeded as shown by green fluorescent protein (ie, infected) cell quantification and quantitative real-time polymerase chain reaction. Additionally, the number and size of foci was smaller.

CONCLUSIONS

In summary, HCMV-encoded US28 was detected in renal allografts from HCMV-positive donors independent of viremia and serostatus. Also, US28 facilitates HCMV spreading in VSMCs in vitro. Because the vasculature is affected in chronic renal transplant dysfunction, US28 may provide a potential target for therapeutic intervention.

Bioartificial Kidneys

Purpose of Review

Historically, there have been many advances in the ways in which we treat kidney diseases. In particular, hemodialysis has set the standard for treatment since the early 1960s and continues today as the most common form of treatment for acute, chronic, and end-stage conditions. However, the rising global prevalence of kidney diseases and our limited understanding of their etiologies have placed significant burdens on current clinical management regimens. This has resulted in a desperate need to improve the ways in which we treat the underlying and ensuing causes of kidney diseases for those who are unable to receive transplants.

Recent Findings

One way of possibly addressing these issues is through the use of improved bioartificial kidneys. Bioartificial kidneys provide an extension to conventional artificial kidneys and dialysis systems, by incorporating aspects of living cellular and tissue function, in an attempt to better mimic normal kidneys. Recent advancements in genomic, cellular, and tissue engineering technologies are facilitating the improved design of these systems.

Summary

In this review, we outline various research efforts that have focused on the development of regenerated organs, implantable constructs, and whole bioengineered kidneys, as well as the transitions from conventional dialysis to these novel alternatives. As a result, we envision that these pioneering efforts can one day produce bioartificial renal technologies that can either perform or reintroduce essential function, and thus provide practical options to treat and potentially prevent kidney diseases.

Role of endothelial-to-mesenchymal transition induced by TGF-β1 in transplant kidney interstitial fibrosis

Chronic allograft dysfunction (CAD) induced by kidney interstitial fibrosis is the main cause of allograft failure in kidney transplantation. Endothelial‐to‐mesenchymal transition (EndMT) may play an important role in kidney fibrosis. We, therefore, undertook this study to characterize the functions and potential mechanism of EndMT in transplant kidney interstitial fibrosis. Proteins and mRNAs associated with EndMT were examined in human umbilical vein endothelial cells (HUVECs) treated with transforming growth factor‐beta1 (TGF‐β1) at different doses or at different intervals with western blotting, qRT‐PCR and ELISA assays. Cell motility and migration were evaluated with motility and migration assays. The mechanism of EndMT induced by TGF‐β1 was determined by western blotting analysis of factors involved in various canonical and non‐canonical pathways. In addition, human kidney tissues from control and CAD group were also examined for these proteins by HE, Masson's trichrome, immunohistochemical, indirect immunofluorescence double staining and western blotting assays. TGF‐β1 significantly promoted the development of EndMT in a time‐dependent and dose‐dependent manner and promoted the motility and migration ability of HUVECs. The TGF‐β/Smad and Akt/mTOR/p70S6K signalling pathways were found to be associated with the pathogenesis of EndMT induced by TGF‐β1, which was also proven in vivo by the analysis of specimens from the control and CAD groups. EndMT may promote transplant kidney interstitial fibrosis by targetting the TGF‐β/Smad and Akt/mTOR/p70S6K signalling pathways, and hence, result in the development of CAD in kidney transplant recipients.

Do the Benefits of Transplant Tourism Amongst Nigerian Patients Outweigh the Risks? A Single-Center Experience

BACKGROUND

Transplant tourism (TT) is the term used to describe travel outside one's country of abode for the sole purpose of obtaining organ transplantation services.

OBJECTIVE

This study describes the characteristics and outcomes of kidney transplant tourists who were followed up in our institution.

METHODS

A retrospective study was conducted on patients who underwent kidney transplantation outside the country and were followed up in our institution from 2007 to 2015.

RESULTS

26 patients were followed up; 19 (73%) were males. The mean±SD age of patients was 40.5±10.3 years. The majority (n=20) of the transplantations were carried out in India. Living-unrelated transplants were most common (54%). Complications encountered were infections in 11 (42%) patients, new-onset diabetes after transplantation in 9 (35%), chronic allograft nephropathy in 8 (31%), biopsy-proven acute rejections in 3 (12%), and primary non-function in 2 (8%). 1-year graft survival was 81% and 1-year patient survival was 85%.

CONCLUSION

Kidney transplant tourism is still common among Nigerian patients with end-stage renal disease. Short-term graft and patient survival rates were poorer than values recommended for living kidney transplants. We therefore advise that TT should be discouraged in Nigeria, given the availability of transplantation services in the country, and also in line with international efforts to curb the practice.

Senescence in chronic allograft nephropathy

Despite increasing numbers of patients on dialysis, the numbers of renal transplants performed yearly have remained relatively static. During the last 50 years, there have been many advances in the pharmacology of prevention of organ rejection. However, most patients will suffer from a slow but steady decline in renal function leading to graft loss. The most common cause of long-term graft loss is chronic allograft nephropathy (CAN). Therefore, elucidating and understanding the mechanisms involved in CAN is crucial for achieving better posttransplant outcomes. It is thought that the development of epithelial to mesenchymal transition (EMT) in proximal tubules is one of the first steps towards CAN, and has been shown to be a result of cellular senescence. Cells undergoing senescence acquire a senescence associated secretory phenotype (SASP) leading to the production of interleukin-1 alpha (IL-1α), which has been implicated in several degenerative and inflammatory processes including renal disease. A central mediator in SASP activation is the production of reactive oxygen species (ROS), which are produced in response to numerous physiological and pathological stimuli. This review explores the connection between SASP and the development of EMT/CAN in an effort to suggest future directions for research leading to improved long-term graft outcomes.

Magnesium and infection risk after kidney transplantation: An observational cohort study

OBJECTIVES

Magnesium is a co-factor in natural killer and T cell reactivity and may modify the course of infections. We examined the association between baseline serum magnesium concentration and infections requiring admission the first year after kidney transplantation.

METHODS

Inclusion of adults transplant recipients between January 2003 and 31 December 2013. Cox piecewise linear regression model estimating the hazard ratio for first admission for infection. Outcomes until one year post-transplantation or up to May 1, 2014.

RESULTS

Overall, 371 of 873 persons were admitted at least once the first year after transplantation (65 events per 100 person-years). The infection-specific cumulative incidence increased with lower serum magnesium concentration (P = 0.008). After adjustment for confounders, a low serum magnesium was associated with an increased hazard of infection (P < 0.0001 in type 3 test). With 2 mg/dL as the reference value, every 0.1 mg/dL reduction in serum magnesium at baseline below 2 mg/dL (N = 165) increased the hazard ratio by 15% (HR 1.15, 95%CI 1.05-1.27; P = 0.002) while every increase of 0.1 mg/dL in those with a serum magnesium between 2 and 3 mg/dL (N = 661) decreased the hazard ratio by 4% (HR 0.96, 95%CI 0.93-1.00; P = 0.08).

CONCLUSION

A lower baseline serum magnesium concentration is associated with an increased risk of infection after kidney transplantation.

Retrospective analysis of perioperative transfusion requirements in living donor renal transplantation

BACKGROUND

Extensive bleeding in solid organ transplantation is a major challenge faced by transplant surgeons. Our aim was to audit the peri-operative transfusion requirements in our patients.

MATERIALS AND METHODS

A retrospective analysis of living donor renal transplant surgeries performed from 1st May 2014 to 31st December 2014 was done. The blood/blood component usage during the peri-operative period was obtained. Univariate analysis was performed and the significant factors identified were further analyzed through multivariate regression analysis.

RESULTS

A total of 510 patients (398 males: 78%, and 112 females: 22%) ranging from 18 to 77 years in age were included in the study. Of these, 269 (52.7%) patients were not transfused, while 241 (47.3%) patients received a total of 845 units of blood/blood components. The mean pre-operative hemoglobin in the transfused group was 8.7g/dl while in the non-transfused group it was 10.3g/dl. Leukoreduced packed red blood cell (PRBC) was the major blood component transfused during the peri-operative period. Multivariate regression analysis revealed that pre-operative hemoglobin was a major predictor of intra-operative PRBC transfusion (p = <0.001). Average post-operative length of stay (PLOS) was 10 ± 6 days. There was no significant difference in the PLOS between the transfused and non-transfused groups of patients; however, a statistical significant increase in utilization for both PRBC (p = 0.044) and fresh frozen plasma (p = 0.002) was observed with increased PLOS.

CONCLUSION

Nearly 47.3% of patients undergoing living donor renal transplant received transfusion. PRBC was the most common product transfused and pre-operative hemoglobin was identified as strong predictor of blood consumption.

Clinical management of the uraemic syndrome in chronic kidney disease

The clinical picture of the uraemic syndrome is a complex amalgam of accelerated ageing and organ dysfunction, which progress in parallel to chronic kidney disease. The uraemic syndrome is associated with cardiovascular disease, metabolic bone disease, inflammation, protein energy wasting, intestinal dysbiosis, anaemia, and neurological and endocrine dysfunction. In this Review, we summarise specific, modern management options for the uraemic syndrome in chronic kidney disease. Although large randomised controlled trials are scarce, based on data from randomised controlled trials and observational studies, as well as pathophysiological reasoning, a therapeutic algorithm can be developed for this complex and multifactorial condition, with interventions targeting several modifiable factors simultaneously.

Sleep apnea syndrome and restless legs syndrome in kidney transplant recipients

Background:

This study was aimed to evaluate the prevalence of obstructive sleep apnea (OSA) and restless legs syndrome (RLS) in patients with end-stage renal disease (ESRD) after kidney transplantation.

Materials and Methods:

Two hundred kidney transplant recipients were enrolled in this cross-sectional study. Data on age, gender, etiology of ESRD, history of previous kidney transplantation, serum creatinine, and the presence or absence of OSA and RLS were collected. Symptoms of RLS were identified using the RLS questionnaire which was completed by the patients. The Berlin questionnaire and polysomnography were used for diagnosing OSA.

Results:

The mean age of the studied patients was 45.86 ± 10.24 years. The prevalence of OSA was 26% (52 of 200 studied patients) and of RLS was 51.5% (103 of 200 studied patients). Majority of the patients with high-risk OSA were male and significantly older than the patients with low-risk OSA (P < 0.05). The prevalence of RLS was higher in patients with high-risk OSA and a higher level of creatinine compared to that in those with a low risk of OSA (P < 0.0001). Level of creatinine in patients with positive RLS was significantly higher than in those with negative RLS (P < 0.0001). OSA was observed in almost 42% of patients with positive RLS, compared to 9% of patients with negative RLS (P < 0.0001).

Conclusion:

In summary, our results indicate that the prevalence of OSA and RLS in kidney transplant recipients was higher than in the general population. Also, there was a significant association between OSA and RLS in these patients.

Chronic Renal Transplant Rejection and Possible Anti-Proliferative Drug Targets

The global prevalence of renal transplants is increasing with time, and renal transplantation is the only definite treatment for end-stage renal disease. We have limited the acute and late acute rejection of kidney allografts, but the long-term survival of renal tissues still remains a difficult and unanswered question as most of the renal transplants undergo failure within a decade of their transplantation. Among various histopathological changes that signify chronic allograft nephropathy (CAN), tubular atrophy, fibrous thickening of the arteries, fibrosis of the kidney interstitium, and glomerulosclerosis are the most important. Moreover, these structural changes are followed by a decline in the kidney function as well. The underlying mechanism that triggers the long-term rejection of renal transplants involves both humoral and cell-mediated immunity. T cells, with their related cytokines, cause tissue damage. In addition, CD 20+ B cells and their antibodies play an important role in the long-term graft rejection. Other risk factors that predispose a recipient to long-term graft rejection include HLA-mismatching, acute episodes of graft rejection, mismatch in donor-recipient age, and smoking. The purpose of this review article is the analyze current literature and find different anti-proliferative agents that can suppress the immune system and can thus contribute to the long-term survival of renal transplants. The findings of this review paper can be helpful in understanding the long-term survival of renal transplants and various ways to improve it.

The diagnosis of posttransplantation diabetes mellitus: meeting the challenges

Posttransplantation diabetes mellitus (PTDM) is a major complication after renal transplantation due to its negative impact on patient and graft survival, and affects up to 40% of renal transplant recipients. The generation of evidence regarding its optimal treatment is now progressing with some emphasis on early postoperative insulin treatment that targets β-cell failure. This therapy seems to benefit renal transplant patients but contrasts with previous PTDM guidelines that were following treatment of type 2 diabetes mellitus (DM): oral antidiabetics first, insulin last. Similarly, in the current PTDM consensus recommendations, diagnostic procedures are in accordance with the American Diabetes Association (ADA) recommendations for diagnosis of DM. PTDM and type 2 DM, however, are distinct disease entities with different pathophysiological backgrounds. This review will discuss the significance of the standard diagnostic criteria for DM in patients after renal transplantation without prior DM. In particular, the role of glycated hemoglobin (HbA1c) and oral glucose tolerance testing (OGTT) will be reviewed. In addition, the potential role of other glycated proteins and continuous glucose monitoring will be covered, although these parameters are not yet part of the consensus recommendations.