Steroid avoidance or withdrawal for kidney transplant recipients

Predicting outcomes after kidney transplantation: Can Pareto's rules help us to do so?

Kidney transplantation is the best option for kidney replacement therapy, even considering that most of the times the grafts do not survive as long as their recipients. In the Khalil et al's experience, published in this issue of the Journal, they analyze their second kidney graft survival and describe those significant predictors of early loss. This editorial comments on the results and put in perspec tive that most of the times, long-term graft survival could be inadvertently jeopardized if the immunosuppressive therapy is reduced or withdrawn for any reason, and that it could happen frequently if the transplant physician intends to innovate with the clinical care without proper evidence-based data.

Current use of antithymoglobulin as induction regimen in kidney transplantation: A review

Currently, various immunosuppressive drugs are used in organ transplantation. In particular, antithymoglobulin is a widely used drug in kidney transplantation in Korea, accounting for 20% of all induction therapy. According to existing studies, antithymoglobulin induction therapy has several advantages and disadvantages compared with other immunotherapies depending on the kidney transplant situation (dead donor, living donor, low-risk recipient, and high-risk recipient) or antithymoglobulin dose. In this review, we summarize the research conducted so far on antithymoglobulin and hope that antithymoglobulin research on kidney transplantation will be actively conducted in the future.

Early post-transplant hyperglycemia and post-transplant diabetes mellitus following heart transplantation

INTRODUCTION

Heart transplantation is an important treatment for end-stage heart failure. Early post-transplant hyperglycemia (EPTH) and post-transplant diabetes mellitus (PTDM) are common following heart transplantation and are associated with increased morbidity and mortality.

AREAS COVERED

This review summarizes the clinical characteristics, diagnosis, and treatment of EPTH and PTDM in cardiac transplant patients, incorporating findings from non-cardiac solid organ transplant studies where relevant due to limited heart-specific research.

EXPERT OPINION

EPTH following heart transplantation is common yet understudied and is associated with the later development of PTDM. PTDM is associated with adverse outcomes including infection, renal dysfunction, microvascular disease, and an increased risk of re-transplantation and mortality. Risk factors for EPTH include the post-operative immunosuppression regimen, recipient and donor age, body mass index, infections, and chronic inflammation. Early insulin treatment is recommended for EPTH, whereas PTDM management is varied and includes lifestyle modification, anti-glycemic agents, and insulin. Given the emerging evidence on the transplant benefits associated with effective glucose control, and the cardioprotective potential of newer anti-glycemic agents, further focus on the management of EPTH and PTDM within heart transplant recipients is imperative.

Do pre-transplant cultural factors predict health-related quality of life after kidney transplantation?

BACKGROUND

Post-transplant health-related quality of life (HRQOL) is associated with health outcomes for kidney transplant (KT) recipients. However, pretransplant predictors of improvements in post-transplant HRQOL remain incompletely understood. Namely, important pretransplant cultural factors, such as experience of discrimination, perceived racism in healthcare, or mistrust of the healthcare system, have not been examined as potential HRQOL predictors. Also, few have examined predictors of decline in HRQOL post-transplant.

METHODS

Using data from a prospective cohort study, we examined HRQOL change pre- to post-transplant, and novel cultural predictors of the change. We measured physical, mental, and kidney-specific HRQOL as outcomes, and used cultural factors as predictors, controlling for demographic, clinical, psychosocial, and transplant knowledge covariates.

RESULTS

Among 166 KT recipients (57% male; mean age 50.6 years; 61.4% > high school graduates; 80% non-Hispanic White), we found mental and physical, but not kidney-specific, HRQOL significantly improved post-transplant. No culturally related factors outside of medical mistrust significantly predicted change in any HRQOL outcome. Instead, demographic, knowledge, and clinical factors significantly predicted decline in each HRQOL domain: physical HRQOL-older age, more post-KT complications, higher pre-KT physical HRQOL; mental HRQOL-having less information pre-KT, greater pre-KT mental HRQOL; and, kidney-specific HRQOL-poorer kidney functioning post-KT, lower expectations for physical condition to improve, and higher pre-KT kidney-specific HRQOL.

CONCLUSIONS

Instead of cultural factors, predictors of HRQOL decline included demographic, knowledge, and clinical factors. These findings are useful for identifying patient groups that may be at greater risk of poorer post-transplant outcomes, in order to target individualized support to patients.

Dual-Organ Transplantation: Indications, Evaluation, and Outcomes for Heart-Kidney and Heart-Liver Transplantation: A Scientific Statement From the American Heart Association

Although heart transplantation is the preferred therapy for appropriate patients with advanced heart failure, the presence of concomitant renal or hepatic dysfunction can pose a barrier to isolated heart transplantation. Because donor organ supply limits the availability of organ transplantation, appropriate allocation of this scarce resource is essential; thus, clear guidance for simultaneous heart-kidney transplantation and simultaneous heart-liver transplantation is urgently required. The purposes of this scientific statement are (1) to describe the impact of pretransplantation renal and hepatic dysfunction on posttransplantation outcomes; (2) to discuss the assessment of pretransplantation renal and hepatic dysfunction; (3) to provide an approach to patient selection for simultaneous heart-kidney transplantation and simultaneous heart-liver transplantation and posttransplantation management; and (4) to explore the ethics of multiorgan transplantation.

Lowering maintenance immune suppression in elderly kidney transplant recipients; connecting the immunological and clinical dots

The management of long-term immune suppressive medication in kidney transplant recipients is a poorly explored field in the area of transplant medicine. In particular, older recipients are at an increased risk for side effects and have an exponentially increased risk of infection-related death. In contrast, an aged immune system decreases the risk of acute T-cell-mediated rejection in older recipients. Recent advances in alloimmunity research have shown a rapid and substantial decline in polyfunctional, high-risk CD4⁺ T cells post-transplantation. This lowers the direct alloreactivity responsible for T-cell-mediated rejection, also known as donor-specific hyporesponsiveness. Chronic antibody-mediated rejection (c-aABMR) is the most frequent cause of kidney graft loss in the long term. However, in older adults, c-aABMR as a cause of graft loss is outnumbered by death with a functioning graft. In addition, DSA development and a diagnosis of c-aABMR plateau ~10 years after transplantation, resulting in a very low risk for rejection thereafter. The intensity of immune suppression regimes could likely be reduced accordingly, but trials in this area are scarce. Tacrolimus monotherapy for 1 year after transplantation seems feasible in older kidney transplant recipients with standard immunological risk, showing the expected benefits of fewer infections and better vaccination responses.

Changes in glucose metabolism among recipients with diabetes 1 year after kidney transplant: a multicenter 1-year prospective study

Background

Diabetes mellitus is a common and crucial metabolic complication in kidney transplantation. It is necessary to analyze the course of glucose metabolism in patients who already have diabetes after receiving a transplant. In this study, we investigated the changes in glucose metabolism after transplantation, and a detailed analysis was performed on some patients whose glycemic status improved.

Methods

The multicenter prospective cohort study was conducted between 1 April 2016 and 31 September 2018. Adult patients (aged 20 to 65 years) who received kidney allografts from living or deceased donors were included. Seventy-four subjects with pre-transplant diabetes were followed up for 1 year after kidney transplantation. Diabetes remission was defined as the results of the oral glucose tolerance test performed one year after transplantation and the presence or absence of diabetes medications. After 1-year post-transplant, 74 recipients were divided into the persistent diabetes group (n = 58) and the remission group (n = 16). Multivariable logistic regression was performed to identify clinical factors associated with diabetes remission.

Results

Of 74 recipients, 16 (21.6%) showed diabetes remission after 1-year post-transplant. The homeostatic model assessment for insulin resistance numerically increased in both groups throughout the first year after transplantation and significantly increased in the persistent diabetes group. The insulinogenic index (IGI₃₀) value significantly increased only in the remission group, and the IGI₃₀ value remained low in the persistent diabetes group. In univariate analysis, younger age, newly diagnosed diabetes before transplantation, low baseline hemoglobin A1c, and high baseline IGI₃₀ were significantly associated with remission of diabetes. After multivariate analysis, only newly diagnosed diabetes before transplantation and IGI₃₀ at baseline were associated with remission of diabetes (34.00 [1.192-969.84], P = 0.039, and 17.625 [1.412-220.001], P = 0.026, respectively).

Conclusion

In conclusion, some kidney recipients with pre-transplant diabetes have diabetes remission 1 year after transplantation. Our prospective study revealed that preserved insulin secretory function and newly diagnosed diabetes at the time of kidney transplantation were favorable factors for which glucose metabolism did not worsen or improve 1 year after kidney transplantation.

Topical Glucocorticoid Use and the Risk of Posttransplant Diabetes

Systemically administered glucocorticoids constitute an essential part of the immunosuppressive regimen for transplant recipients, yet their known risks of causing hyperglycemia or posttransplant diabetes require close monitoring and minimisation of use, when possible, to prevent detrimental effects on patient morbidity and graft survival. Topical glucocorticoids, on the other hand, are rarely considered to affect glucose metabolism and therefore seldomly monitored, despite their wide and in some cases, long-term use. We report a case of a renal transplant recipient presenting with acute hyperosmolar hyperglycemia after treatment with topical glucocorticoids and present a mini review of the literature.

Oral Glucose Tolerance Test for the Screening of Glucose Intolerance Long Term Post-Heart Transplantation

Post-transplant diabetes mellitus (PTDM) is a frequent complication post-heart transplantation (HT), however long-term prevalence studies are missing. The aim of this study was to determine the prevalence and determinants of PTDM as well as prediabetes long-term post-HT using oral glucose tolerance tests (OGTT). Also, the additional value of OGTT compared to fasting glucose and glycated hemoglobin (HbA1c) was investigated. All patients > 1 year post-HT seen at the outpatient clinic between August 2018 and April 2021 were screened with an OGTT. Patients with known diabetes, an active infection/rejection/malignancy or patients unwilling or unable to undergo OGTT were excluded. In total, 263 patients were screened, 108 were excluded. The included 155 patients had a median age of 54.3 [42.2–64.3] years, and 63 (41%) were female. Median time since HT was 8.5 [4.8–14.5] years. Overall, 51 (33%) had a normal range, 85 (55%) had a prediabetes range and 19 (12%) had a PTDM range test. OGTT identified prediabetes and PTDM in more patients (18% and 50%, respectively), than fasting glucose levels and HbA1c. Age at HT (OR 1.03 (1.00–1.06), p = 0.044) was a significant determinant of an abnormal OGTT. Prediabetes as well as PTDM are frequently seen long-term post-HT. OGTT is the preferred screening method.

Attention2majority: Weak multiple instance learning for regenerative kidney grading on whole slide images

Deep learning consistently demonstrates high performance in classifying and segmenting medical images like CT, PET, and MRI. However, compared to these kinds of images, whole slide images (WSIs) of stained tissue sections are huge and thus much less efficient to process, especially for deep learning algorithms. To overcome these challenges, we present attention2majority, a weak multiple instance learning model to automatically and efficiently process WSIs for classification. Our method initially assigns exhaustively sampled label-free patches with the label of the respective WSIs and trains a convolutional neural network to perform patch-wise classification. Then, an intelligent sampling method is performed in which patches with high confidence are collected to form weak representations of WSIs. Lastly, we apply a multi-head attention-based multiple instance learning model to do slide-level classification based on high-confidence patches (intelligently sampled patches). Attention2majority was trained and tested on classifying the quality of 127 WSIs (of regenerated kidney sections) into three categories. On average, attention2majority resulted in 97.4%±2.4 AUC for the four-fold cross-validation. We demonstrate that the intelligent sampling module within attention2majority is superior to the current state-of-the-art random sampling method. Furthermore, we show that the replacement of random sampling with intelligent sampling in attention2majority results in its performance boost (from 94.9%±3.1 to 97.4%±2.4 average AUC for the four-fold cross-validation). We also tested a variation of attention2majority on the famous Camelyon16 dataset, which resulted in 89.1%±0.8 AUC¹. When compared to random sampling, the attention2majority demonstrated excellent slide-level interpretability. It also provided an efficient framework to arrive at a multi-class slide-level prediction.

Effect of Early Steroid Withdrawal on Posttransplant Diabetes Among Kidney Transplant Recipients Differs by Recipient Age

Supplemental Digital Content is available in the text.

Background.

Posttransplant diabetes (PTD), a major complication after kidney transplantation (KT), is often attributable to immunosuppression. The risk of PTD may increase with more potent steroid maintenance and older recipient age.

Methods.

Using United States Renal Data System data, we studied 12 488 adult first-time KT recipients (2010–2015) with no known pre-KT diabetes. We compared the risk of PTD among recipients who underwent early steroid withdrawal (ESW) versus continued steroid maintenance (CSM) using Cox regression with inverse probability weighting to adjust for confounding. We tested whether the risk of PTD resulting from ESW differed by recipient age (18–29, 30–54, and ≥55 y).

Results.

Of 12 488, 28.3% recipients received ESW. The incidence rate for PTD was 13 per 100 person-y and lower among recipients who received ESW (11 per 100 person-y in ESW; 14 per 100 person-y in CSM). Overall, ESW was associated with lower risk of PTD compared with CSM (adjusted hazard ratio [aHR] = _0.720.79_0.86), but the risk differed by recipient age (P_interaction = 0.09 for comparison between recipients aged 18–29 and those aged 30–54; P_interaction = 0.01 for comparison between recipients aged 18–29 and those aged ≥55). ESW was associated with lower risk of PTD among recipients aged ≥55 (aHR = _0.620.71_0.81) and those aged 30–54 (aHR = _0.730.83_0.95), but not among recipients aged 18–29 (aHR = _0.811.18_1.72). Although recipients who received ESW had a higher risk of acute rejection across the age groups (adjusted odds ratio = _1.011.17_1.34), recipients with no PTD had a lower risk of mortality (aHR = _0.580.66_0.74).

Conclusions.

The beneficial association of ESW with decreased PTD was more pronounced among recipients aged ≥55, supporting an age-specific assessment of the risk-benefit balance regarding ESW.

Diabetes mellitus in dialysis and renal transplantation

Diabetes mellitus is the commonest cause of end-stage kidney failure worldwide and is a proven and significant risk factor for the development of cardiovascular disease. Renal impairment has a significant impact on the physiology of glucose homeostasis as it reduces tissue sensitivity to insulin and reduces insulin clearance. Renal replacement therapy itself affects glucose control: peritoneal dialysis may induce hyperglycaemia due to glucose-rich dialysate and haemodialysis often causes hypoglycaemia due to the relatively low concentration of glucose in the dialysate. Autonomic neuropathy which is common in chronic kidney disease (CKD) and diabetes increases the risk for asymptomatic hypoglycaemia. Pharmacological options for improving glycaemic control are limited due to alterations to drug metabolism. Impaired glucose tolerance and diabetes are also common in the post-kidney-transplant setting and increase the risk of graft failure and mortality. This review seeks to summarise the literature and tackle the intricacies of glycaemic management in patients with CKD who are either on maintenance haemodialysis or have received a kidney transplant. It outlines changes to glycaemic targets, monitoring of glycaemic control, the use of oral hypoglycaemic agents, the management of severe hyperglycaemia in dialysis and kidney transplantation patients.

Global Epidemiology, Health Outcomes, and Treatment Options for Patients With Type 2 Diabetes and Kidney Failure

The burden of type 2 diabetes and related complications has steadily increased over the last few decades and is one of the foremost global public health threats in the 21st century. Diabetes is one of the leading causes of chronic kidney disease and kidney failure and is an important contributor to the cardiovascular morbidity and mortality in this population. In addition, up to one in three patients who have received kidney transplants develop post-transplant diabetes, but the management of this common complication continues to pose a significant challenge for clinicians. In this review, we will describe the global prevalence and temporal trend of kidney failure attributed to diabetes mellitus in both developing and developed countries. We will examine the survival differences between treated kidney failure patients with and without type 2 diabetes, focusing on the survival differences in those on maintenance dialysis or have received kidney transplants. With the increased availability of novel hypoglycemic agents, we will address the potential impacts of these novel agents in patients with diabetes and kidney failure and in those who have developed post-transplant diabetes.

Belatacept for Simultaneous Calcineurin Inhibitor and Chronic Corticosteroid Immunosuppression Avoidance

Immunosuppressive therapy in kidney transplantation is associated with numerous toxicities. CD28-mediated T cell costimulation blockade using belatacept may reduce long-term nephrotoxicity, compared with calcineurin inhibitor-based immunosuppression. The efficacy and safety of simultaneous calcineurin inhibitor avoidance and rapid steroid withdrawal were tested in a randomized, prospective, multi-center study. Methods All kidney transplants were performed using rapid steroid withdrawal immunosuppression. Recipients were randomized to 1:1:1 to receive belatacept with alemtuzumab induction, belatacept with rabbit antithymocyte globulin (rATG) induction, or tacrolimus with rATG induction. The composite endpoint consisted of death, kidney allograft loss, or an MDRD calculated eGFR of <45 ml/min/1.73m² at 2 years. Results The composite endpoint was observed for 11/107 (10%) participants assigned to belatacept/alemtuzumab, 13/104 (13%) assigned to belatacept /rATG, and 21/105 (21%) assigned to tacrolimus/rATG (belatacept/alemtuzumab vs tacrolimus/rATG p = 0.99: belatacept/rATG vs tacrolimus/rATG p = 0.66). Patient and graft survival rates were similar between all groups. eGFR <45 ml/min/1.73m² was observed for 9/107 (8%) participants assigned to belatacept/alemtuzuab, 8/104 (8%) participants assigned to belatacept/rATG, and 20/105 (19%) participants assigned to tacrolimus/rATG (p<0.05 for each belatacept group vs tacrolimus/rATG). Biopsy-proven acute rejection was observed for 20/107 (19%) participants assigned to belatacept/alemtuzuab, 26/104 (25%) participants assigned to belatacept/rATG, and 7/105 (7%) participants assigned to tacrolimus/rATG (belatacept/alemtuzumab vs tacrolimus/rATG p = 0.006: belatacept/rATG vs tacrolimus/rATG p < 0.001). Gastrointestinal and neurologic adverse events were less frequent with belatacept versus calcineurin based immunosuppression. Conclusions Overall two-year outcomes were similar comparing maintenance immunosuppression based on belatacept versus tacrolimus, each protocol with rapid steroid withdrawal. The incidence of eGFR <45 ml/min/1.73m² was significantly lower but the incidence of biopsy proven acute rejection significantly higher with belatacept compared with tacrolimus.

Foremost Concepts in Mechanisms of De Novo Post-Liver Transplantation Malignancy

In liver transplant patients, solid tumors and post-transplant lymphoproliferative disorders (PTLD) have emerged as significant long-term mortality causes. Additionally, it is assumed that de novo malignancy (DNM) after liver transplantation (LT) is the second-leading cause of death after cardiovascular complications. Well-established risk factors for PTLD and solid tumors are calcineurin inhibitors (CNIs), tacrolimus (TAC), and cyclosporine, the cornerstones of all immunosuppressive (IS) therapies used after LT. The loss of immunocompetence facilitated by the host immune system due to prolonged IS therapy leads to cancer development, including in LT patients. Hindering DNA repair mechanisms, promoting tumor cell invasiveness, and hampering apoptosis are critical events in tumorigenesis and tumor growth in LT patients resulting from IS administration. This paper aims to overview the refined mechanisms of IS-induced tumorigenesis after LT and the loss of immunocompetence facilitated by the host immune system due to prolonged IS therapy. In addition, we also discuss in detail the mechanisms of action in different types of IS regimen used after LT, and their putative effect on DNM.

Changes in cancer incidence and outcomes among kidney transplant recipients in the United States over a thirty-year period

Recipients of kidney transplants have elevated cancer risk compared with the general population. Improvements over time in transplant care and cancer treatment may have affected incidence and outcomes of cancer among recipients of kidney transplant. To evaluate this, we used linked United States transplant and cancer registry data to study 101,014 adult recipients of kidney transplants over three decades (1987-1996, 1997-2006, 2007-2016). Poisson regression was used to assess trends in incidence for cancer overall and seven common cancers. Associations of cancer with risk of death-censored graft failure (DCGF) and death with functioning graft (DWFG) were evaluated with Cox regression. We also estimated absolute risks of DCGF and graft failure following cancer for recipients transplanted in 2007-2016. There was no significant change in the incidence of cancer overall or for six common cancers in recipients across the 1987-2016 period. Only the incidence of prostate cancer significantly decreased across this period after multivariate adjustment. Among recipients of kidney transplants with non-Hodgkin lymphoma, there were significant declines over time in elevated risks for DCGF and DWFG but no significant changes for other combined cancers. For recipients transplanted in the most recent period (2007-2016), risks following cancer diagnosis remained high, with 38% experiencing DWFG and 14% graft failure within four years of diagnosis. Absolute risk of DWFG was especially high following lung cancer (78%), non-Hodgkin lymphoma (38%), melanoma (35%), and colorectal cancer (49%). Thus, across a 30-year period in the United States, there was no overall change in cancer incidence among recipients of kidney transplants. Despite improvements for non-Hodgkin lymphoma, cancer remains a major cause of morbidity and mortality.

Clinical Relevance of Corticosteroid Withdrawal on Graft Histological Lesions in Low-Immunological-Risk Kidney Transplant Patients

The impact of corticosteroid withdrawal on medium-term graft histological changes in kidney transplant (KT) recipients under standard immunosuppression is uncertain. As part of an open-label, multicenter, prospective, phase IV, 24-month clinical trial (ClinicalTrials.gov, NCT02284464) in low-immunological-risk KT recipients, 105 patients were randomized, after a protocol-biopsy at 3 months, to corticosteroid continuation (CSC, n = 52) or corticosteroid withdrawal (CSW, n = 53). Both groups received tacrolimus and MMF and had another protocol-biopsy at 24 months. The acute rejection rate, including subclinical inflammation (SCI), was comparable between groups (21.2 vs. 24.5%). No patients developed dnDSA. Inflammatory and chronicity scores increased from 3 to 24 months in patients with, at baseline, no inflammation (NI) or SCI, regardless of treatment. CSW patients with SCI at 3 months had a significantly increased chronicity score at 24 months. HbA1c levels were lower in CSW patients (6.4 ± 1.2 vs. 5.7 ± 0.6%; p = 0.013) at 24 months, as was systolic blood pressure (134.2 ± 14.9 vs. 125.7 ± 15.3 mmHg; p = 0.016). Allograft function was comparable between groups and no patients died or lost their graft. An increase in chronicity scores at 2-years post-transplantation was observed in low-immunological-risk KT recipients with initial NI or SCI, but CSW may accelerate chronicity changes, especially in patients with early SCI. This strategy did, however, improve the cardiovascular profiles of patients.

Individual Lymphocyte Sensitivity to Steroids as a Reliable Biomarker for Clinical Outcome after Steroid Withdrawal in Japanese Renal Transplantation

Recently, steroid reduction/withdrawal regimens have been attempted to minimize the side effects of steroids in renal transplantation. However, some recipients have experienced an increase/resumption of steroid administrations and acute graft rejection (AR). Therefore, we investigated the relationship between the individual lymphocyte sensitivity to steroids and the clinical outcome after steroid reduction/withdrawal. We cultured peripheral blood mononuclear cells (PBMCs) isolated from 24 recipients with concanavalin A (Con A) in the presence of methylprednisolone (MPSL) or cortisol (COR) for four days, and the 50% of PBMC proliferation (IC₅₀) values and the PBMC sensitivity to steroids were calculated. Regarding the experience of steroid increase/resumption and incidence of AR within one year of steroid reduction/withdrawal, the IC₅₀ values of these drugs before transplantation in the clinical event group were significantly higher than those in the event-free group. The cumulative incidence of steroid increase/resumption and AR in the PBMC high-sensitivity groups to these drugs before transplantation were significantly lower than those in the low-sensitivity groups. These observations suggested that an individual’s lymphocyte sensitivity to steroids could be a reliable biomarker to predict the clinical outcome after steroid reduction/withdrawal and to select the patients whose dose of steroids can be decreased and/or withdrawn after transplantation.

On Path to Informing Hierarchy of Eplet Mismatches as Determinants of Kidney Transplant Loss

Introduction

To mitigate risks related to human leukocyte antigen (HLA) incompatibility, we assessed whether certain structurally defined HLA targets present in donors but absent from recipients, known as eplet mismatches (EMM), are associated with death-censored graft failure (DCGF).

Methods

We studied a cohort of 118,313 American 0% panel reactive antibodies (PRA) first kidney transplant recipients (2000 to 2015) from the Scientific Registry of Transplant Recipients. Imputed allele-level donor and recipient HLA-A, -B, -C, -DRB1, and -DQB1 genotypes were converted to the repertoire of EMM. We fit survival models for each EMM with significance thresholds corrected for false discovery rate and validated those in an independent PRA > 0% cohort. We conducted network-based analyses to model relationships among EMM and developed models to select the subset of EMM most predictive of DCGF.

Results

Of 412 EMM observed, 119 class I and 118 class II EMM were associated with DCGF. Network analysis showed that although 210 eplets formed profiles of 2 to 12 simultaneously occurring EMMs, 202 were singleton EMMs that were not involved in any profile. A variable selection procedure identified 55 single HLA class I and II EMMs in 70% of the dataset; of those, 15 EMMs (9 singleton and 6 involved in profiles) were predictive of DCGF in the remaining dataset.

Conclusion

Our analysis distinguished increasingly smaller subsets of EMMs associated with increased risk of DCGF. Validation of these EMMs as important predictors of transplant outcomes (in contrast to acceptable EMMs) in datasets with measured allele-level genotypes will support their role as immunodominant EMMs worthy of consideration in organ allocation schemes.

Gut microbiota alterations associated with antibody-mediated rejection after kidney transplantation

Antibody-mediated rejection (AMR) has become the major challenge for kidney transplantation, and the efficacy of existing therapies was limited to prevent AMR. Increasing evidences have demonstrated the link between gut microbiota alterations and allograft outcome. However, there has been no comprehensive analysis to profile the gut microbiota associated with AMR after kidney transplantation. We performed this study to characterize the gut microbiota possibly associated with AMR. Fecal specimens were collected from 24 kidney transplantation recipients with AMR and 29 controls. DNA extracted from the specimens was processed for 16S rRNA gene sequencing using Illumina MiSeq. Gut microbial community of recipients with AMR was significantly different from that of controls based on unweighted (P = 0.001) and weighted (P = 0.02) UniFrac distances, and the bacterial richness (observed species: P = 0.0448; Chao1 index: P = 0.0450; ACE index: P = 0.0331) significantly decreased in the AMR group. LEfSe showed that 1 phylum, 5 classes, 7 families, and 10 genera were increased, whereas 1 class, 2 order, 3 families, and 4 genera were decreased in the AMR group. Specific taxa such as Clostridiales could be potentially used as biomarkers to distinguish the recipients with AMR from the controls (AUC = 0.77). PICRUSt analysis illustrated that 16 functional pathways were with significantly different abundances in the AMR and control groups. Our findings provide a foundation for further investigation on the role of gut microbiota in AMR after kidney transplantation, and potentially support novel diagnostic biomarkers and therapeutic options for AMR. KEY POINTS: • Gut microbial community of kidney recipients with AMR was different from that of controls. • Clostridiales is a potential marker to distinguish recipients with AMR from controls.

Cytomegalovirus antiviral stewardship in the COVID-19 Era: Increasing complexity of prophylaxis and treatment and potential mitigation strategies

Cytomegalovirus (CMV) infection is one of the most common and significant complications after solid organ transplant (SOT). Severe acute respiratory coronavirus 2 (SARS‐CoV‐2), which causes the novel betacoronavirus 2019 disease (COVID‐19), has become the first global pandemic in 100 years. The world's attention has turned to address this unanticipated development; however, the viral infection that has long plagued outcomes after solid organ transplantation still requires vigilance. With physical distancing as the key intervention to reduce the healthcare burden, and the unease related to healthcare contact within the transplant population given the associated morbidity and mortality of COVID‐19 in transplant recipients, providers have struggled to evaluate and streamline essential in‐person healthcare contact, including laboratory visits. Owing to this, the COVID‐19 pandemic has placed a significant strain on the delivery of CMV prophylaxis and treatment after solid organ transplantation. In this piece, we will describe issues our CMV antiviral stewardship service has encountered in the care of the transplant recipient with CMV during the this unprecedented time and share our expert opinion to approaches to providing optimal, evidenced based care during a pandemic associated with a seemingly unrelated viral infection.

Early steroid withdrawal in HIV-infected kidney transplant recipients: Utilization and outcomes

Kidney transplant (KT) outcomes for HIV-infected (HIV+) persons are excellent, yet acute rejection (AR) is common and optimal immunosuppressive regimens remain unclear. Early steroid withdrawal (ESW) is associated with AR in other populations, but its utilization and impact are unknown in HIV+ KT. Using SRTR, we identified 1225 HIV+ KT recipients between January 1, 2000, and December 31, 2017, without AR, graft failure, or mortality during KT admission, and compared those with ESW with those with steroid continuation (SC). We quantified associations between ESW and AR using multivariable logistic regression and interval-censored survival analysis, as well as with graft failure and mortality using Cox regression, adjusting for donor, recipient, and immunologic factors. ESW utilization was 20.4%, with more zero HLA mismatch (8% vs 4%), living donors (26% vs 20%), and lymphodepleting induction (64% vs 46%) compared to the SC group. ESW utilization varied widely across 129 centers, with less use at high- versus moderate-volume centers (6% vs 21%, P < .001). AR was more common with ESW by 1 year (18.4% vs 12.3%; aOR: _1.08 1.61_2.41 , P = .04) and over the study period (aHR: _1.02 1.39_1.90 , P = .03), without difference in death-censored graft failure (aHR _0.60 0.91_1.36 , P = .33) or mortality (aHR: _0.75 1.15_1.77 , P = .45). To reduce AR after HIV+ KT, tailoring of ESW utilization is reasonable.

Management of post-transplant diabetes: immunosuppression, early prevention, and novel antidiabetics

Post‐transplant diabetes mellitus (PTDM) shows a relationship with risk factors including obesity and tacrolimus‐based immunosuppression, which decreases pancreatic insulin secretion. Several of the sodium–glucose‐linked transporter 2 inhibitors (SGLT2is) and glucagon‐like peptide 1 receptor agonists (GLP1‐RAs) dramatically improve outcomes of individuals with type 2 diabetes with and without chronic kidney disease, which is, as heart failure and atherosclerotic cardiovascular disease, differentially affected by both drug classes (presumably). Here, we discuss SGLT2is and GLP1‐RAs in context with other PTDM management strategies, including modification of immunosuppression, active lifestyle intervention, and early postoperative insulin administration. We also review recent studies with SGLT2is in PTDM, reporting their safety and antihyperglycemic efficacy, which is moderate to low, depending on kidney function. Finally, we reference retrospective case reports with GLP1‐RAs that have not brought forth major concerns, likely indicating that GLP1‐RAs are ideal for PTDM patients suffering from obesity. Although our article encompasses PTDM after solid organ transplantation in general, data from kidney transplant recipients constitute the largest proportion. The PTDM research community still requires data that treating and preventing PTDM will improve clinical conditions beyond hyperglycemia. We therefore suggest that it is time to collaborate, in testing novel antidiabetics among patients of all transplant disciplines.

Early steroid withdrawal has a positive effect on bone in kidney transplant recipients: a propensity score study with inverse probability-of-treatment weighting

Background:

Long-term corticosteroid use after kidney transplantation is associated with a decrease in bone mineral density (BMD) and a high fracture risk. We hypothesized that patients with early steroid withdrawal (ESW) would display a gain in BMD in the year following kidney transplantation, when compared with patients on long-term corticosteroid therapy.

Methods:

In a cohort of kidney transplant recipients, 356 patients were included between 2012 and 2019. Dual-energy X-ray absorptiometry was performed 1 and 12 months after transplantation. The data were analyzed using linear regression with inverse probability-of-treatment weighting (based on a propensity score).

Results:

At 1 year after transplantation, the gain in BMD was significantly greater in recipients with ESW than in recipients on long-term corticosteroid therapy for the lumbar spine (+0.036 g/cm², p < 0.001) and the femoral neck (+0.020 g/cm², p = 0.035). Among patients with ESW, (i) none had osteoporosis, (ii) the percentage with normal BMD increased from 33.3% at month 1 to 54.4% at month 12, and (iii) the percentage with osteopenia fell from 56.2% to 45.6%. In patients undergoing long-term corticosteroid therapy, the fracture incidence was 13.5 per 1000 person-years. None of the patients in the ESW group experienced a fracture.

Conclusion:

ESW has a positive effect on bone in kidney transplant recipients.

Practical recommendations for kidney transplantation in the COVID-19 pandemic

Kidney transplantation at the time of a global viral pandemic has become challenging in many aspects. Firstly, we must reassess deceased donor safety (for the recipient) especially in communities with a relatively high incidence of coronavirus disease 19 (COVID-19). With respect to elective live donors, if one decides to do them at all, similar considerations must be made that may impose undue hardship on the donor. Recipient selection is also problematic since there is clear evidence of a much higher morbidity and mortality from COVID-19 for patients older than 60 and those with comorbidities such as hypertension, diabetes, obesity and lung disease. Unfortunately, many, if not most of dialysis patients fit that mold. We may and indeed must reassess our allocation policies, but this must be done based on data rather than conjecture. Follow-up routines must be re-engineered to minimize patient travel and exposure. Reliance on technology and telemedicine is paramount. Making this technology available to patients is extremely important. Modifying or changing immunosuppression protocols is controversial and not based on clinical studies. Nevertheless, we should reassess the need for induction therapy across the board for ordinary patients and the more liberal use of mammalian target of rapamycin inhibitors in transplant patients with proven infection.

A case of successful late steroid withdrawal after ABO-incompatible kidney transplantation

Few data exist regarding steroid withdrawal in ABO-incompatible (ABO-i) kidney transplantation (KT). Here, we report a case of steroid withdrawal after ABO-i KT. A 46-year-old man diagnosed with Henoch-Schonlein purpura received ABO-i KT from his 42-year-old sister. The recipient and donor blood types were O and AB, respectively. His preoperative ABO antibody titers were anti-A of 1:16 and anti-B of 1:8 in isoagglutinin test. HLA mismatch was 0 and he received a single 325 mg/m² dose of intravenous (IV) rituximab 4 weeks before KT. Three sessions of plasma exchange were undertaken before KT and low-dose IV immunoglobulin of 0.1 g/kg was administered after plasma exchange. On the day of the operation, ABO antibody titer decreased to anti-A of 1:4 and anti-B of 1:2. Renal function remained stable after KT. The patient wished to stop steroid treatment despite the risk of rejection after withdrawal. Steroid tapering was initiated at 20 months and accomplished at 26 months after KT. At that time, serum creatinine level was 1.13 mg/dL, and anti-A and anti-B titers were 1:8 and 1:2, respectively. No issues were observed after steroid withdrawal. At 48 months after KT, serum creatinine level was 1.21 mg/dL, and anti-A and anti-B antibody titers were 1:32 and 1:2, respectively. Steroid withdrawal in ABO-i KT might be considered in immunologically low-risk patients.

Autosomal Dominant Polycystic Kidney Disease Is a Risk Factor for Posttransplantation Diabetes Mellitus: An Updated Systematic Review and Meta-analysis

Supplemental Digital Content is available in the text.

Autosomal dominant polycystic kidney disease (ADPKD) is linked with risk for posttransplantation diabetes mellitus (PTDM), but this association has methodologic limitations like diagnostic criteria. The aim of this study was to use contemporary diagnostic criteria for PTDM and explore any risk association for kidney transplant recipients with ADPKD.

Endogenous urinary glucocorticoid metabolites and mortality in prednisolone-treated renal transplant recipients

BACKGROUND

Chronic corticosteroid treatment suppresses HPA-axis activity and might alter activity of 11β hydroxysteroid dehydrogenases (11β-HSD). We aimed to investigate whether the endogenous glucocorticoid production and 11β-HSD activities are altered in prednisolone-treated renal transplant recipients (RTR) compared with healthy controls and whether this has implications for long-term survival in RTR.

METHODS

In a longitudinal cohort of 693 stable RTR and 275 healthy controls, 24-hour urinary cortisol, cortisone, tetrahydrocorisol (THF), allotetrahydrocortisol (alloTHF), and tetrahydrocortisone (THE) were measured using liquid chromatography tandem-mass spectrometry. Twenty-four-hour urinary excretion of cortisol and metabolites were used as measures of endogenous glucocorticoid production; (THF + alloTHF)/THE and cortisol/cortisone ratios were used as measures of 11β-HSD activity.

RESULTS

Urinary cortisol and metabolite excretion were significantly lower in RTR compared with healthy controls (P < .001), whereas (THF + alloTHF)/THE and cortisol/cortisone ratios were significantly higher (P < .001 and P = .002). Lower total urinary metabolite excretion and higher urinary (THF + alloTHF)/THE ratios were associated with increased risk of mortality, independent of age, sex, estimated glomerular filtration rate, C-reactive protein, body surface area, and daily prednisolone dose, respectively.

CONCLUSIONS

Endogenous glucocorticoid production and 11β-HSD activities are altered in prednisolone-treated RTR. Decreased total urinary endogenous glucocorticoid metabolite excretion and increased urinary (THF + alloTHF)/THE ratios are associated with increased risk of mortality.

Early Steroid Withdrawal in Deceased-Donor Kidney Transplant Recipients with Delayed Graft Function

BACKGROUND

Early steroid withdrawal (ESW) is associated with acceptable outcomes in kidney transplant (KT) recipients. Recipients with delayed graft function (DGF), however, often have a suboptimal allograft milieu, which may alter the risk/benefit equation for ESW. This may contribute to varying practices across transplant centers.

METHODS

Using the Scientific Registry of Transplant Recipients, we studied 110,019 adult deceased-donor KT recipients between 2005 and 2017. We characterized the association of DGF with the use of ESW versus continued steroid maintenance across KT centers, and quantified the association of ESW with acute rejection, graft failure, and mortality using multivariable logistic and Cox regression with DGF-ESW interaction terms.

RESULTS

Overall 29.2% of KT recipients underwent ESW. Recipients with DGF had lower odds of ESW (aOR=_0.600.67_0.75). The strength of this association varied across 261 KT centers, with center-specific aOR of <0.5 at 31 (11.9%) and >1.0 at 22 (8.4%) centers. ESW was associated with benefits and harms among recipients with immediate graft function (IGF), but only with harms among recipients with DGF. ESW was associated with increased acute rejection (aOR=_1.091.16_1.23), slightly increased graft failure (aHR=_1.011.06_1.12), but decreased mortality (aHR=_0.860.89_0.93) among recipients with IGF. Among recipients with DGF, ESW was associated with a similar increase in rejection (aOR=1.12; 95% CI, 1.02 to 1.23), a more pronounced increase in graft failure (aHR=1.16; 95% CI, 1.08 to 1.26), and no improvement in mortality (aHR=1.00; 95% CI, 0.94 to 1.07). DGF-ESW interaction was statistically significant for graft failure (P=0.04) and mortality (P=0.003), but not for rejection (P=0.6).

CONCLUSIONS

KT centers in the United States use ESW inconsistently in recipients with DGF. Our findings suggest ESW may lead to worse KT outcomes in recipients with DGF.

Everolimus in de novo kidney transplant recipients participating in the Eurotransplant senior program: Results of a prospective randomized multicenter study (SENATOR)

Early conversion to everolimus was assessed in kidney transplant recipients participating in the Eurotransplant Senior Program (ESP), a population in whom data are lacking. The SENATOR multicenter study enrolled 207 kidney transplant recipients undergoing steroid withdrawal at week 2 post-transplant (ClinicalTrials.gov [NCT00956293]). At week 7, patients were randomized (1:2 ratio) to continue the previous calcineurin inhibitor (CNI)-based regimen with mycophenolic acid (MPA) and cyclosporine or switch to a CNI-free regimen with MPA, everolimus (5–10 ng/mL) and basiliximab at weeks 7 and 12, then followed for 18 weeks to month 6 post-transplant. The primary endpoint was estimated GFR (eGFR). At week 7, 77/207 (37.2%) patients were randomized (53 everolimus, 24 control). At month 6, eGFR was comparable: 36.5±10.8ml/min with everolimus versus 42.0±13.0ml/min in the control group (p = 0.784). Discontinuation due to adverse events occurred in 27.8% of everolimus-treated patients and 0.0% of control patients (p = 0005). Efficacy profiles showed no difference. In conclusion, eGFR, safety and efficacy outcomes at month 6 post-transplant showed no difference between groups. The everolimus group experienced a higher rate of discontinuation due to adverse events. However, the high rate of non-randomization is highly relevant, indicating this to be a somewhat unstable patient population regardless of treatment.

Peripheral blood lymphocyte subsets change after steroid withdrawal in renal allograft recipients: a prospective study

Several studies have assessed clinical outcomes after steroid withdrawal (SW) in kidney transplant (KT) recipients, but little is known about its potential impact on lymphocyte subpopulations. We designed a prospective study to evaluate the long-term impact of SW in 19 KT recipients compared to 16 KT recipients without changes in immunosuppression (steroid maintenance, SM). We assessed renal function, presence of HLA antibodies and peripheral blood lymphocyte subsets at time of inclusion, and 3, 12 and 24 months later. The immunophenotype of 20 healthy subjects was also analyzed. Serum creatinine and proteinuria remained stable in SW and SM patients. SW did not associate with generation of de novo donor-specific antibodies. SW patients showed decreases in T-lymphocytes (p < 0.001), and in the CD4+ T cell subpopulation (p = 0.046). The proportion of B-lymphocytes (p = 0.017), and both naïve and transitional B cells increased compared to SM patients (p < 0.001). Changes in B cell subsets were detected 3 months after SW and persisted for 24 months. No changes were observed in NK cells related to steroid withdrawal. SW patients displayed significant changes in peripheral T and B cell subsets, transitioning to the phenotype detected in healthy subjects. This may be considered as a maintained positive effect of SW previously unnoticed.

Characterizing the pharmacokinetics and pharmacodynamics of immunosuppressant medicines and patient outcomes in elderly renal transplant patients

This review examines what is currently known about the pharmacokinetics and pharmacodynamics of commonly prescribed immunosuppressant medicines, tacrolimus, cyclosporine, mycophenolate and prednisolone, in elderly renal transplant recipients, and reported patient outcomes in this cohort. Renal transplantation is increasing rapidly in the elderly, however, currently, long-term patient outcomes are relatively poor compared to younger adults. Some studies have suggested that elderly recipients may have higher dose-adjusted exposure and/or lower clearance of the calcineurin inhibitors tacrolimus and cyclosporine; with one study reporting up to 50% reduction in tacrolimus exposure in the elderly. Elderly transplant recipients do not appear to have higher dosage-adjusted exposure to mycophenolic acid (MPA). The effects of ageing on the pharmacokinetics of prednisolone are unknown. Only one study has examined how aging effects drug target enzymes, reporting no difference in baseline inosine 5'-monophosphate dehydrogenase (IMPDH) activity and MPA-induced IMPDH activity in elderly compared to younger adult renal transplant recipients. In elderly transplant recipients, immunosenescence likely lowers the risk of acute rejection, but increases the risk of drug-related adverse effects. Currently, the three main causes of death in elderly renal transplant recipients are cardiovascular disease, infection and malignancy. One study has showed that renal transplant recipients aged over 65 years are seven times more likely to die with a functioning graft compared with young adults (aged 18-29 years). This suggests that an optimal balance between immunosuppressant medicine efficacy and toxicity is not achieved in elderly recipients, and further studies are needed to foster long-term graft and patient survival. Lower maintenance immunosuppressant targets in elderly recipients may decrease patient susceptibility to drug side effects, however, further studies are required and appropriate targets need to be established.

Dissecting the Multiplicity of Immune Effects of Immunosuppressive Drugs to Better Predict the Risk of de novo Malignancies in Solid Organ Transplant Patients

De novo malignancies constitute an emerging cause of morbidity after solid organ transplant (SOT), significantly affecting the long-term survival of transplant recipients. Pharmacologic immunosuppression may functionally impair the immunosurveillance in these patients, thereby increasing the risk of cancer development. Nevertheless, the multiplicity and heterogeneity of the immune effects induced by immunosuppressive drugs limit the current possibilities to reliably predict the risk of de novo malignancy in SOT patients. Therefore, there is the pressing need to better characterize the immune dysfunctions induced by the different immunosuppressive regimens administered to prevent allograft rejection to tailor more precisely the therapeutic schedule and decrease the risk of de novo malignancies. We herein highlight the impact exerted by different classes of immunosuppressants on the most relevant immune cells, with a particular focus on the effects on dendritic cells (DCs), the main regulators of the balance between immunosurveillance and tolerance.

State-of-the-art immunosuppression protocols for pediatric renal transplant recipients

Immunosuppressive protocols used in pediatric kidney transplantation have changed substantially within the last decade. Many transplant centers now focus on the use of tacrolimus and mycophenolate mofetil in combination with early steroid withdrawal, frequently combined with antibody induction therapy. However, this approach is mainly based on treatment efficacy and-compared to other immunosuppressive regimens used in this context-leads to higher rates of viral infections in patients. In this review I assess data from prospective, interventional trials of immunosuppressive therapy in pediatric kidney transplantation. However, since there is a paucity of randomized controlled trials, I also describe the results of studies with weaker designs. The advantages and disadvantages of different immunosuppressive strategies are discussed. Within this framework I suggest ideas for individualized immunosuppressive regimens based on different stratificators that could effect a change from a 'one size fits all' to a tailored approach for initial and maintenance immunosuppressive therapy after renal transplantation in the pediatric setting.

Recent advances in kidney transplantation: a viewpoint from the Descartes advisory board

Transplantation medicine is a rapidly evolving field. Keeping afloat of the published literature to offer the best clinical care to our patients is a daunting task. As part of its educational mission, the Descartes advisory board identified seven topics in kidney transplantation where there has been substantial progresses over the last years: kidney allocation within Eurotransplant; kidney exchange strategies; kidney machine perfusion strategies; the changing landscape of anti-human leukocyte antigen (HLA) antibodies; the new immunosuppressive drugs in the pipeline; strategies for immunosuppression minimization; and the continuous enigma of focal segmental glomerular sclerosis recurrence after transplantation. Here, we have summarized the main knowledge and the main challenges of these seven topics with the aim to provide transplant professionals at large with key bullet points to successfully understand these new concepts.

Post-transplantation diabetes in kidney transplant recipients: an update on management and prevention

Post-transplantation diabetes mellitus (PTDM) may severely impact both short- and long-term outcomes of kidney transplant recipients in terms of graft and patient survival. However, PTDM often goes undiagnosed is underestimated or poorly managed. A diagnosis of PTDM should be delayed until the patient is on stable maintenance doses of immunosuppressive drugs, with stable kidney graft function and in the absence of acute infections. Risk factors for PTDM should be assessed during the pre-transplant evaluation period, in order to reduce the likelihood of developing diabetes. The oral glucose tolerance test is considered as the gold standard for diagnosing PTDM, whereas HbA1c is not reliable during the first months after transplantation. Glycaemic targets should be individualised, and comorbidities such as dyslipidaemia and hypertension should be treated with drugs that have the least possible impact on glucose metabolism, at doses that do not interact with immunosuppressants. While insulin is the preferred agent for treating inpatient hyperglycaemia in the immediate post-transplantation period, little evidence is available to guide therapeutic choices in the management of PTDM. Metformin and incretins may offer some advantage over other glucose-lowering agents, particularly with respect to risk of hypoglycaemia and weight gain. Tailoring immunosuppressive regimens may be of help, although maintenance of good kidney function should be prioritised over prevention/treatment of PTDM. The aim of this narrative review is to provide an overview of the available evidence on management and prevention of PTDM, with a focus on the available therapeutic options.

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.

Recipient rs1045642 Polymorphism Is Associated With Office Blood Pressure at 1-Year Post Kidney Transplantation: A Single Center Pharmacogenetic Cohort Pilot Study

Background: Corticosteroids are associated with reduced bone mineral density (BMD), as well as water and salt retention, leading to hypertension. They are substrates for P-glycoprotein, a protein coded by the highly polymorphic ABCB1 gene. We hypothesized that one ABCB1 polymorphism, rs1045642, is associated with blood pressure and BMD parameters at 1-year post kidney transplantation (KT).

Methods: Rs1045642 was genotyped using pyrosequencing in 40 KT recipients. Both dominant (CC vs. CT + TT) and codominant (CC vs. CT vs. TT) genetic models (analysis of variance from linear regressions) were adjusted for confounding variables (age, sex, type of nephropathy, glomerular filtration rate, and corticosteroid use at 1 year).

Results: Rs1045642 genotypes were significantly associated with systolic (SBP) and diastolic (DBP) blood pressure 1-year post-transplantation, independent of the genetic model used (adjusted codominant model: SBP p-value = 0.015, DBP p-value = 0.038; adjusted dominant model: SBP p-value = 0.003, DBP p-value = 0.011). A non-statistically significant trend was observed for an association between rs1045642 and BMD change at 1-year post-KT.

Conclusions: Rs1045642 is significantly associated with higher BP 1 year after KT. Further investigations are necessary to confirm the role of rs1045642 in corticosteroid-related adverse effects.

Impact of immunosuppressive therapy on arterial stiffness in kidney transplantation: are all treatments the same?

Arterial stiffness is a biologic process related to ageing and its relationship with cardiovascular risk is well established. Several methods are currently available for non-invasive measurement of arterial stiffness that provide valuable information to further assess patients’ vascular status in real time. In kidney transplantation recipients, several factors could accelerate the stiffness process, such as the use of calcineurin inhibitors (CNIs), the presence of chronic kidney disease and other classical cardiovascular factors, which would explain, at least in part, the high cardiovascular mortality and morbidity. Despite the importance of arterial stiffness as a biomarker of cardiovascular risk, and unlike other cardiovascular risk factors (e.g. left ventricular hypertrophy), only a few clinical trials or retrospective studies of kidney recipients have evaluated its impact. In this review we describe the clinical impact of arterial stiffness as a prognostic marker of cardiovascular disease and the effects of different immunosuppressive regimens on its progression, focusing on the potential benefits of CNI-sparing protocols and supporting the rationale for individualization of immunosuppression in patients with lower arterial elasticity. Among the immunosuppressive drugs, a belatacept-based regimen seems to offer better vascular protection compared with CNIs, although further studies are needed to confirm the preliminary positive results.

One-Year Outcomes of a Cohort of Renal Transplant Patients Related to BMI in a Steroid-Sparing Regimen

Background

The prevalence of overweight and obese kidney transplant recipients (KTR) has risen in parallel to the obesity epidemic that has affected the general population over the last two decades. At present, there is an ongoing debate regarding the suitability for transplantation of obese patients.

Methods

Data were prospectively collected on consecutive single organ KTR transplanted between January 2014 and March 2016. The patients were stratified according to their body mass index (BMI) using the World Health Organization classification. As a measure of allograft function Modification of Diet in Renal Disease, estimated glomerular filtration rate was used at 3, 6, and 12 months posttransplant.

Results

We included 370 KTR: 126 of 370 women; median age, 52.7 years (range, 19-77 years), followed up for a median of 19.5 ± 8.6 months. In total, 155 (41.9%) KTR were underweight or of normal BMI at transplant, whereas 148 (40%) were overweight, and 67 (18.1%) were classified as obese (47 [12.7%] class 1, 11 [3%] class 2, 9 [2.4%] class 3). Overweight and obese KTR had a higher incidence of pretransplant diabetes (P = 0.021), but no difference was found in new-onset hyperglycemia posttransplant (P = 0.35). There was also no difference in posttransplant hospital length of stay (P = 0.386). Obese and overweight KTR had a significantly lower estimated glomerular filtration rate than underweight and normal BMI KTR at 3 and 6 months posttransplant, a finding that did not persist at 1 year follow-up. Overall, 23 patients lost their grafts, and 20 patients died during follow-up. Kaplan Meier analysis showed no difference in allograft loss between the different BMI groups (log rank P = 0.7).

Conclusions

In this single-center study, which used short-term data, overweight and obese patients were shown not to have inferior outcomes regarding renal function 1 year posttransplant.

Recurrence of IgA nephropathy after kidney transplantation in steroid continuation versus early steroid-withdrawal regimens: a retrospective analysis of the UNOS/OPTN database

In the past 20 years, there has been an increase in use of steroid-withdrawal regimens in kidney transplantation. However, steroid withdrawal may be associated with an increased risk of recurrent IgA nephropathy (IgAN). Using United Network of (Organ Sharing/Organ Procurement and Transplantation Network) UNOS/OPTN data, we analyzed adult patients with end-stage renal disease (ESRD) due to IgAN who received their first kidney transplant between 2000 and 2014. For the primary outcome, we used a competing risk analysis to compare the cumulative incidence of graft loss due to IgAN recurrence between early steroid-withdrawal (ESW) and steroid continuation groups. The secondary outcomes were patient survival and death-censored graft survival (DCGS). A total of 9690 recipients were included (2831 in ESW group and 6859 in steroid continuation group). In total, 1238 recipients experienced graft loss, of which 191 (15.43%) were due to IgAN recurrence. In multivariable analysis, steroid use was associated with a decreased risk of recurrence (subdistribution hazard ratio 0.666, 95% CI 0.482-0.921; P = 0.014). Patient survival and DCGS were not different between the two groups. In the USA, ESW in transplant for ESRD due to IgAN is associated with a higher risk of graft loss due to disease recurrence. Future prospective studies are warranted to further address which patients with IgAN would benefit from steroid continuation.

Steroid free immunosuppression is associated with enhanced Th1 transcripts in kidney transplantation

BACKGROUND

Steroid avoidance in immunosuppression in kidney transplantation offers several metabolic advantages, however it is associated with higher early acute rejection rate. Cellular and molecular mechanisms of this phenomenon remain poorly understood.

METHODS

In this single center observational study, low-risk kidney transplant recipients randomized into large multicenter prospective ADVANCE trial with steroid avoidance/early withdrawal and center standard of care treated patients were monitored for 12months. The expressions of 28 transcripts, associated with alloimmune response and operational tolerance, were evaluated in the peripheral blood using RT-qPCR at 0, 7, 14, 90 and 365 postoperative days (POD) and in the protocol graft biopsy at 3months while lymphocyte subpopulations were analyzed by flow-cytometry within the follow-up.

RESULTS

Both steroid avoidance and withdrawal regimens were associated with significantly higher granzyme B (GZMB) transcript at POD 14 and perforin 1 (PRF1) transcript at POD 7. The higher interleukin 2 (IL-2) expression at POD 7 was detected only in the steroid avoidance group. Initial steroids decreased the expression SH2D1B transcript at POD14 and there were no further differences in other operational tolerance transcripts among groups. The statistically significant decrease in absolute numbers of peripheral NK cells in the first 14days was observed in the standard of care group only. There were no differences in analyzed intrarenal transcripts in 3-month biopsies among groups.

CONCLUSIONS

The enhanced expression of some of Th1 associated transcripts and limited effects on NK cells of steroid avoidance immunosuppression suggest higher susceptibility for early acute rejection.

Steroid withdrawal after renal transplantation: a retrospective cohort study

BACKGROUND

Immunosuppressive regimens in renal transplantation frequently contain corticosteroids, but many centers withdraw steroids as a consequence of unwanted side effects of steroids. The optimal timing to withdraw steroids after transplantation, however, remains unclear. The aim of this study was to determine an optimal time point following kidney transplantation that is associated with reduced mortality without jeopardizing the allograft to allow safe discontinuation of steroids.

METHODS

We conducted a retrospective cohort study and computed a concatenated landmark-stratified Cox supermodel to estimate hazard ratios and 95% confidence intervals for mortality and graft loss using dynamic propensity score matching to adjust for confounding by indication.

RESULTS

A total of 6070 first kidney transplant recipients in the Austrian Dialysis and Transplant Registry who were transplanted between 1990 and 2012 were evaluated and classified according to steroid treatment status throughout follow-up after kidney transplantation; 2142 patients were withdrawn from steroids during the study period. Overall, 1131 patients lost their graft and 821 patients in the study cohort died. Steroid withdrawal within 18 months after transplantation was associated with an increased rate of graft loss compared to steroid maintenance during that time (6 months after transplantation: HR = 1.8; 95% CI, 1.3 to 2.6; 18 months after transplantation: HR = 1.3; 95% CI, 1.1 to 1.6; 24 months after transplantation: HR = 1.2; 95% CI, 0.9 to 1.5), while mortality was not different between groups.

CONCLUSIONS

Our findings suggest that steroid withdrawal after anti-IL-2 induction in the first 18 months after transplantation is associated with an increased risk of allograft loss.