Minimizing immunosuppression, an alternative approach to reducing side effects: objectives and interim result

Incidence, risk factors, outcomes, and clinical management of BK viremia in the modern era of kidney transplantation

BK viremia is endemic among kidney transplant recipients (KTRs). Incidence, risk factors, outcomes, and clinical management of detectable versus high BK viremia have not been considered previously in KTR in the modern era. This observational study examined KTR transplanted between January 1, 2009 and December 31, 2016. Any BK viral load in the serum constituted detectable BK viremia and ≥10³ copies/ml constituted high viremia. Among 1193 KTRs, the cumulative probability of developing detectable and high BK viremia within 2 years posttransplant were 27.8% and 19.6%, respectively. Significant risk factors for detectable BK viremia included recipient age (HR 1.02 [95% CI: 1.01, 1.03]) and donor age (HR 1.01 [95% CI: 1.00, 1.02]). Recipient age also predicted high BK viremia (HR 1.02 [95% CI: 1.01, 1.03]), whereas White race (HR 0.70 [95% CI: 0.52, 0.95]), nondepleting induction therapy (HR 0.61 [95% CI: 0.42, 0.89]), and delayed graft function (HR 0.61 [95% CI: 0.42, 0.88]) were protective. Mean estimated glomerular filtration rates were 4.28 ml/min/1.72 m² (95% CI: 2.71, 5.84) lower with detectable BK viremia. Although low viral load was usually not acted upon at first presentation, antiproliferative dose reductions were the most common initial management. BK viremia remains a common early complication in a modern cohort of KTRs. These findings highlight the benefit of early BKV monitoring in addition to intensive clinical management. Clinical responses beyond first positive BK viremia tests, and their implications for graft outcomes, merit further investigation.

Treatment of early borderline lesions in low immunological risk kidney transplant patients: a Spanish multicenter, randomized, controlled parallel-group study protocol: the TRAINING study

Background

Subclinical inflammation, including borderline lesions (BL), is very common (30–40%) after kidney transplantation (KT), even in low immunological risk patients, and can lead to interstitial fibrosis/tubular atrophy (IFTA) and worsening of renal function with graft loss. Few controlled studies have analyzed the therapeutic benefit of treating these BL on renal function and graft histology. Furthermore, these studies have only used bolus steroids, which may be insufficient to slow the progression of these lesions. Klotho, a transmembrane protein produced mainly in the kidney with antifibrotic properties, plays a crucial role in the senescence-inflammation binomial of kidney tissue. Systemic and local inflammation decrease renal tissue expression and soluble levels of α-klotho. It is therefore important to determine whether treatment of BL prevents a decrease in α-klotho levels, progression of IFTA, and loss of kidney function.

Methods

The TRAINING study will randomize 80 patients with low immunological risk who will receive their first KT. The aim of the study is to determine whether the treatment of early BL (3rd month post-KT) with polyclonal rabbit antithymocyte globulin (Grafalon®) (6 mg/kg/day) prevents or decreases the progression of IFTA and the worsening of graft function compared to conventional therapy after two years post-KT, as well as to analyze whether treatment of BL with Grafalon® can modify the expression and levels of klotho, as well as the pro-inflammatory cytokines that regulate its expression.

Discussion

This phase IV investigator-driven, randomized, placebo-controlled clinical trial will examine the efficacy and safety of Grafalon® treatment in low-immunological-risk KT patients with early BL.

Trial registration

clinicaltrials.gov: NCT04936282. Registered June 23, 2021, https://clinicaltrials.gov/ct2/show/NCT04936282?term=NCT04936282&draw=2&rank=1. Protocol Version 2 of 21 January 2022. Sponsor: Canary Isles Institute for Health Research Foundation, Canary Isles (FIISC). mgomez@fciisc.org.

Immunomodulating Hydrogels as Stealth Platform for Drug Delivery Applications

Non-targeted persistent immune activation or suppression by different drug delivery platforms can cause adverse and chronic physiological effects including cancer and arthritis. Therefore, non-toxic materials that do not trigger an immunogenic response during delivery are crucial for safe and effective in vivo treatment. Hydrogels are excellent candidates that can be engineered to control immune responses by modulating biomolecule release/adsorption, improving regeneration of lymphoid tissues, and enhancing function during antigen presentation. This review discusses the aspects of hydrogel-based systems used as drug delivery platforms for various diseases. A detailed investigation on different immunomodulation strategies for various delivery options and deliberate upon the outlook of such drug delivery platforms are conducted.

Evaluation of nefrotoxicity by tacrolimus and micophenolate mofetil associated with kidney ischemia and reperfusion: experimental study in rats

OBJECTIVE

to evaluate the renal toxicity caused by tacrolimus and mycophenolate mofetil (MMF) in a single kidney ischemia and reperfusion model.

METHOD

experimental study using Wistar rats, submitted to right nephrectomy and left renal ischemia for 20 minutes, separated into groups in the postoperative period (PO): 1) Control (nonoperated); 2) Sham (operated, without PO drug); 3) TAC0.1, TAC1 and TAC10, tacrolimus administered PO at doses of 0.1mg/kg, 1mg/kg and 10mg/kg via gavage, respectively; 4) MMF, administered mycophenolate mofetil 20mg/kg; 5) MMF/TAC1 and MMF/TAC0.5, with an association of mycophenolate mofetil 20mg/kg and tacrolimus 1mg/kg and 0.5mg/kg, respectively. They were killed on the 14th PO and the kidney was removed for tissue oxidative stress analysis, by the dosage of reduced glutathione (GSH), lipoperoxidation (LPO) and protein carbonylation (PCO), and histological analysis by glomerular stereology (Glomerular volume density, Numerical density glomerular and mean glomerular volume). Renal function was evaluated by the measurement of serum creatinine and urea.

RESULTS

both drugs caused alterations in renal function, and the toxicity of tacrolimus was dose-dependent. Subacute toxicity did not show significant glomerular histological changes, and there was renal and compensatory glomerular hypertrophy in all groups except TAC10.

CONCLUSION

Both drugs cause changes in renal function. Glomerular morphometry and stereology showed negative interference of immunosuppressants during compensatory glomerular hypertrophy.

A randomized controlled trial to evaluate efficacy and safety of early conversion to a low-dose calcineurin inhibitor combined with sirolimus in renal transplant patients

BACKGROUND

The calcineurin inhibitor (CNI)-based immune maintenance regimen that is commonly used after renal transplantation has greatly improved early graft survival after transplantation; however, the long-term prognosis of grafts has not been significantly improved. The nephrotoxicity of CNI drugs is one of the main risk factors for the poor long-term prognosis of grafts. Sirolimus (SRL) has been employed as an immunosuppressant in clinical practice for over 20 years and has been found to have no nephrotoxic effects on grafts. Presently, the regimen and timing of SRL application after renal transplantation vary, and clinical data are scarce. Multicenter prospective randomized controlled studies are particularly rare. This study aims to investigate the effects of early conversion to a low-dose CNI combined with SRL on the long-term prognosis of renal transplantation.

METHODS

Patients who receive four weeks of a standard regimen with CNI + mycophenolic acid (MPA) + glucocorticoid after renal transplantation in multiple transplant centers across China will be included in this study. At week 5, after the operation, patients in the experimental group will receive an additional administration of SRL, a reduction in the CNI drug doses, withdrawal of MPA medication, and maintenance of glucocorticoids. In addition, patients in the control group will receive the maintained standard of care. The patients' vital signs, routine blood tests, routine urine tests, blood biochemistry, serum creatinine, BK virus (BKV)/ cytomegalovirus (CMV), and trough concentrations of CNI drugs and SRL at the baseline and weeks 12, 24, 36, 48, 72, and 104 after conversion will be recorded. Patient survival, graft survival, and estimated glomerular filtration rate will be calculated, and concomitant medications and adverse events will also be recorded.

CONCLUSION

The study data will be utilized to evaluate the efficacy and safety of early conversion to low-dose CNIs combined with SRL in renal transplant patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1800017277.

Impact of Machine Perfusion on the Immune Response After Liver Transplantation – A Primary Treatment or Just a Delivery Tool

The frequent use of marginal livers forces transplant centres to explore novel technologies to improve organ quality and outcomes after implantation. Organ perfusion techniques are therefore frequently discussed with an ever-increasing number of experimental and clinical studies. Two main approaches, hypothermic and normothermic perfusion, are the leading strategies to be introduced in clinical practice in many western countries today. Despite this success, the number of studies, which provide robust data on the underlying mechanisms of protection conveyed through this technology remains scarce, particularly in context of different stages of ischemia-reperfusion-injury (IRI). Prior to a successful clinical implementation of machine perfusion, the concept of IRI and potential key molecules, which should be addressed to reduce IRI-associated inflammation, requires a better exploration. During ischemia, Krebs cycle metabolites, including succinate play a crucial role with their direct impact on the production of reactive oxygen species (ROS) at mitochondrial complex I upon reperfusion. Such features are even more pronounced under normothermic conditions and lead to even higher levels of downstream inflammation. The direct consequence appears with an activation of the innate immune system. The number of articles, which focus on the impact of machine perfusion with and without the use of specific perfusate additives to modulate the inflammatory cascade after transplantation is very small. This review describes first, the subcellular processes found in mitochondria, which instigate the IRI cascade together with proinflammatory downstream effects and their link to the innate immune system. Next, the impact of currently established machine perfusion strategies is described with a focus on protective mechanisms known for the different perfusion approaches. Finally, the role of such dynamic preservation techniques to deliver specific agents, which appear currently of interest to modulate this posttransplant inflammation, is discussed together with future aspects in this field.

Avaliação da nefrotoxicidade pelo tacrolimus e micofenolato mofetil associados à isquemia e reperfusão renal: estudo experimental em ratos

RESUMO Objetivo: avaliar a toxicidade renal causada pelo tacrolimus e micofenolato mofetil (MMF) em um modelo de isquemia e reperfusão de rim único. Método: estudo experimental utilizando ratos Wistar, submetidos á nefrectomia direita e isquemia renal esquerda por 20 minutos, separados em grupos no pós- operatório (PO): 1) Controle (não operados); 2) Sham (operados, sem droga PO); 3) TAC0.1, TAC1 e TAC10, administrado tacrolimus no PO nas doses 0,1mg/kg, 1mg/kg e 10mg/kg via gavagem, respectivamentae; 4) MMF, administrado micofenolato mofetil 20mg/kg; 5) MMF/TAC1 e MMF/TAC0.5, com associação de micofenolato mofetil 20mg/kg e tacrolimus 1mg/kg e 0,5mg/kg, respectivamente. Foram mortos no 14º PO e retirado rim para análise do estresse oxidativo tecidual, pela dosagem de glutationa reduzida (GSH), lipoperoxidação (LPO) e carbonilação de proteínas (PCO), e análise histológica por estereologia glomerular (Densidade de volume glomerular, Densidade numérica glomerular e Volume glomerular médio). Foi avaliada função renal pela dosagem de creatinina e uréia séricas. Resultados: ambas drogas provocaram alteração na função renal, sendo a toxicidade do tacrolimus dosedependente. A toxicidade subaguda não mostrou alterações histológicas glomerulares significativas, sendo que houve hipertrofia renal e glomerular compensatória em todos os grupos exceto em TAC10. Conclusão: Ambas drogas provocam alteração na função renal. A morfometria e a estereologia glomerular mostraram interferência negativa dos imunossupressores durante a hipertrofia glomerular compensatória..

Impact of kidney transplantation on functional status

BACKGROUND AND AIMS

Functional capacity (FC) is known to affect morbidity and mortality in kidney transplantation. Despite this important role, little is known about the variables influencing post-transplant FC. Our study aims at identifying these crucial associations.

METHOD

Our study included 16,684 renal transplant recipients (RTR). Patients had transplant between 1 September 2018 and 1 September 2019. Mild functional impairment was defined as those with a KPSS score > or = 80; moderate functional impairment was defined as those with a KPSS score between 50 and 70 and severe functional impairment was defined as those with a KPSS score < or =40. The outcome measured was FC at follow-up one-year post-transplant. Abnormal FC at follow-up was defined as those with KPSS score less than 80%. Normal FC at follow-up was defined as those with KPSS score equal or above 80%. Multivariate logistic regression was used to assess with the relationship between patient characteristics and abnormal functional status post-transplant.

RESULTS

Three groups were identified; those with none-to-mild functional impairment at time of transplant (Group A; n = 8388), those who had moderate impairment at time of transplant (Group B; n = 7694) and those who had severe impairment at time of transplant (Group C; n = 602). Abnormal FC at one-year post transplant was present in 7.69%, 28.89%, 49.49% of patients in group A, B and C, respectively. Glucocorticoid withdrawal was associated with lower risk of developing abnormal FC post-transplant (OR = 0.75, p value = .02, 95% confidence intervals: 0.64 to 0.97), while recipient diabetes was associated with higher risk of abnormal FC (OR = 1.44, p value <.01, 95% confidence intervals: 1.20 to 1.74) in adjusted model.

CONCLUSION

Kidney transplantation is associated with substantial improvement in all stages of FC in KTRs. Glucocorticoid withdrawal and diabetes mellitus are potentially modifiable factors of FC and merit further considerations during pre-transplant workup and post-transplant immunosuppressive therapeutic planning.Key messagesKidney transplantation is associated with substantial improvement in all stages of FC in KTRs.Glucocorticoid withdrawal and diabetes mellitus are potentially modifiable factors of FC and merit further considerations during pre-transplant workup and post-transplant immunosuppressive therapeutic planning.

Genetic Engineering in Combination with Semi-Synthesis Leads to a New Route for Gram-Scale Production of the Immunosuppressive Natural Product Brasilicardin A

Brasilicardin A (1) consists of an unusual anti/syn/anti-perhydrophenanthrene skeleton with a carbohydrate side chain and an amino acid moiety. It exhibits potent immunosuppressive activity, yet its mode of action differs from standard drugs that are currently in use. Further pre-clinical evaluation of this promising, biologically active natural product is hampered by restricted access to the ready material, as its synthesis requires both a low-yielding fermentation process using a pathogenic organism and an elaborate, multi-step total synthesis. Our semi-synthetic approach included a) the heterologous expression of the brasilicardin A gene cluster in different non-pathogenic bacterial strains producing brasilicardin A aglycone (5) in excellent yield and b) the chemical transformation of the aglycone 5 into the trifluoroacetic acid salt of brasilicardin A (1 a) via a short and straightforward five-steps synthetic route. Additionally, we report the first preclinical data for brasilicardin A.

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.

The Role of Regulatory Myeloid Cell Therapy in Renal Allograft Rejection

Kidney transplantation is a primary therapy for end-stage renal disease (ESRD) all the time. But it does not mean that we have fully unraveling the mystery of kidney transplantation and confer every patient favorable prognosis. Immune rejection has always been a stumbling block when we try to increase the success rate of kidney transplantation and improve long-term outcomes. Even if the immune rejection is effectively controlled in acute phase, there is a high possibility that the immune response mediated by chronically activated antibodies will trigger chronic rejection and ultimately lead to graft failure. At present, immunosuppressive agent prepared chemically is mainly used to prevent acute or chronic rejection, but it failed to increase the long-term survival rate of allografts or reduce the incidence of chronic rejection after acute rejection, and is accompanied by many adverse reactions. Therefore, many studies have begun to use immune cells to regulate the immune response in order to control allograft rejection. This article will focus on the latest study and prospects of more popular regulatory myeloid cells in the direction of renal transplantation immunotherapy and introduce their respective progress from experimental research to clinical research.

Immune Protection of Stem Cell-Derived Islet Cell Therapy for Treating Diabetes

Insulin injection is currently the main therapy for type 1 diabetes (T1D) or late stage of severe type 2 diabetes (T2D). Human pancreatic islet transplantation confers a significant improvement in glycemic control and prevents life-threatening severe hypoglycemia in T1D patients. However, the shortage of cadaveric human islets limits their therapeutic potential. In addition, chronic immunosuppression, which is required to avoid rejection of transplanted islets, is associated with severe complications, such as an increased risk of malignancies and infections. Thus, there is a significant need for novel approaches to the large-scale generation of functional human islets protected from autoimmune rejection in order to ensure durable graft acceptance without immunosuppression. An important step in addressing this need is to strengthen our understanding of transplant immune tolerance mechanisms for both graft rejection and autoimmune rejection. Engineering of functional human pancreatic islets that can avoid attacks from host immune cells would provide an alternative safe resource for transplantation therapy. Human pluripotent stem cells (hPSCs) offer a potentially limitless supply of cells because of their self-renewal ability and pluripotency. Therefore, studying immune tolerance induction in hPSC-derived human pancreatic islets will directly contribute toward the goal of generating a functional cure for insulin-dependent diabetes. In this review, we will discuss the current progress in the immune protection of stem cell-derived islet cell therapy for treating diabetes.

5-Year outcomes of the prospective and randomized CISTCERT study comparing steroid withdrawal to replacement of cyclosporine with everolimus in de novo kidney transplant patients

Withdrawal of either steroids or calcineurin inhibitors are two strategies to reduce treatment-related side effects and improve long-term outcomes of kidney transplantation. The CISTCERT study compared the efficacy and safety of these two strategies. In this multicenter, randomized controlled trial, 151 incident kidney transplant recipients received cyclosporine (CsA), mycophenolic acid (MPA), and steroids during three months, followed by either steroid withdrawal (CsA/MPA) or replacement of cyclosporine with everolimus (EVL) (EVL/MPA/steroids). 5-year patient survival (89% vs. 86%; P = NS) and death-censored graft survival (95% vs. 96%; P = NS) were comparable in the CsA/MPA and EVL/MPA/steroids arm, respectively. ⁵¹ CrEDTA clearance was comparable in the intention-to-treat analysis, but in the on-treatment population, the EVL/MPA/steroids arm exhibited a superior ⁵¹ CrEDTA clearance at 1 and 5 years after transplantation (61.6 vs. 52.4, P = 0.05 and 59.1 vs. 46.2ml/min/1.73 m² , P = 0.042). Numerically more and more severe rejections were observed in the EVL/MPA/steroids arm, which also experienced a higher incidence of posttransplant diabetes (26% vs. 6%, P = 0.0016) and infections. No significant differences were observed in cardiovascular outcomes and malignancy. Both regimens provide an excellent long-term patient survival and graft survival. Regarding graft function, EVL/MPA/steroids is an attractive strategy for patients with good tolerability who remain free of rejection. (ClinicalTrials.gov number: NCT00903188; EudraCT Number 2007-005844-26).

Role of mesenchymal stem cell derived extracellular vesicles in autoimmunity: A systematic review

BACKGROUND

Mesenchymal stem cells (MSCs) have been reported to possess immune regulatory effects in innate and adaptive immune reactions. MSCs can mediate intercellular communications by releasing extracellular vesicles (EVs), which deliver functional molecules to targeted cells. MSC derived EVs (MSC-EVs) confer altering effects on many immune cells, including T lymphocytes, B lymphocytes, natural killer cells, dendritic cells, and macrophages. A large number of studies have suggested that MSC-EVs participate in regulating autoimmunity related diseases. This characteristic of MSC-EVs makes them be potential biomarkers for the diagnosis and treatment of autoimmunity related diseases.

AIM

To verify the potential of MSC-EVs for molecular targeted therapy of autoimmunity related diseases.

METHODS

Literature search was conducted in PubMed to retrieve the articles published between 2010 and 2020 in the English language. The keywords, such as “MSCs,” “EVs,” “exosome,” “autoimmunity,” “tumor immunity,” and “transplantation immunity,” and Boolean operator “AND” and “NOT” coalesced admirably to be used for searching studies on the specific molecular mechanisms of MSC-EVs in many immune cell types and many autoimmunity related diseases. Studies that did not investigate the molecular mechanisms of MSC-EVs in the occurrence and development of autoimmune diseases were excluded.

RESULTS

A total of 96 articles were chosen for final reference lists. After analyzing those publications, we found that it had been well documented that MSC-EVs have the ability to induce multiple immune cells, like T lymphocytes, B lymphocytes, natural killer cells, dendritic cells, and macrophages, to regulate immune responses in innate immunity and adaptive immunity. Many validated EVs-delivered molecules have been identified as key biomarkers, such as proteins, lipids, and nucleotides. Some EVs-encapsulated functional molecules can serve as promising therapeutic targets particularly for autoimmune disease.

CONCLUSION

MSC-EVs play an equally important part in the differentiation, activation, and proliferation of immune cells, and they may become potential biomarkers for diagnosis and treatment of autoimmunity related diseases.

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.

Long-Term Kidney Transplant Outcomes: Role of Prolonged-Release Tacrolimus

Tacrolimus has significantly improved outcomes for kidney transplant patients and remains the cornerstone of immunosuppressive therapy. While improvements in short-term outcomes in transplantation have been achieved in recent years, maintaining long-term graft survival remains a challenge in kidney transplantation. Minimizing risk factors for poor long-term kidney graft function and survival, and modifying tacrolimus regimens in the early and maintenance phases post-transplantation are essential to maintain long-term kidney transplant outcomes. Tacrolimus has a narrow therapeutic window, resulting in a tightly defined range of optimal drug exposure. Underimmunosuppression is associated with long-term risks, such as the development of donor-specific antibodies and antibody-mediated rejection, with a high possibility of a decline in kidney function and progression to graft failure. Conversely, prolonged overimmunosuppression carries a risk of drug-related adverse events. This review provides an overview of the differences in the formulation, delivery, and pharmacokinetic profiles between immediate- and prolonged-release tacrolimus and evaluates the effect of prolonged-release tacrolimus on the risk factors for poor outcomes in kidney transplantation. Recent evidence is used to provide guidance on target tacrolimus trough levels in the early and maintenance phases post-transplantation, with a view to improving long-term kidney graft function.

Nanodelivery of Mycophenolate Mofetil to the Organ Improves Transplant Vasculopathy

Inflammation occurring within the transplanted organ from the time of harvest is an important stimulus of early alloimmune reactivity and promotes chronic allograft rejection. Chronic immune-mediated injury remains the primary obstacle to the long-term success of organ transplantation. However, organ transplantation represents a rare clinical setting in which the organ is accessible ex vivo, providing an opportunity to use nanotechnology to deliver therapeutics directly to the graft. This approach facilitates the directed delivery of immunosuppressive agents (ISA) to target local pathogenic immune responses prior to the transplantation. Here, we have developed a system of direct delivery and sustained release of mycophenolate mofetil (MMF) to treat the donor organ prior to transplantation. Perfusion of a donor mouse heart with MMF-loaded PEG-PLGA nanoparticles (MMF-NPs) prior to transplantation abrogated cardiac transplant vasculopathy by suppressing intragraft pro-inflammatory cytokines and chemokines. Our findings demonstrate that ex vivo delivery of an ISA to donor organs using a nanocarrier can serve as a clinically feasible approach to reduce transplant immunity.

High Dimensional Renal Profiling: Towards a Better Understanding or Renal Transplant Immune Suppression

PURPOSE OF REVIEW

The goal of this review is to discuss new approaches to avoid CNI/CCS toxicities with a focus on new biologics and new methods to understand transplant rejection at the single-cell level.

RECENT FINDINGS

Recently developed biologics hold significant promise as the next wave of therapeutics designed to promote CNI/CCS-free long-term allograft acceptance. Indeed, belatacept, soluble CTLA4-Ig, is largely devoid of CNI-like toxicities, although it is accompanied by an increased frequency of acute rejection. Besides belatacept, other biologics hold promise as CNI-free immune suppressive approaches. Finally, powerful new single cell approaches can enable characterization of cellular populations that drive rejection within the rejecting allograft.

SUMMARY

We propose that the incorporated single cell profiling into studies investigating new biologics in transplantation, could be tailored to each patient, correlated with potential biomarkers in the blood and urine, and provide a platform where therapeutic targets can be rationally defined, mechanistically-based, and exploited.

Preventive Role of mTOR Inhibitor in Post-Kidney Transplant Urothelial Carcinoma

BACKGROUND

There is little evidence about whether mammalian target of rapamycin (mTOR) inhibitor could prevent post-kidney transplant (KT) urothelial carcinoma (UC) or not. The aim of this study is to analyze the role of mTOR inhibitor add-on in tacrolimus-based kidney transplant recipients.

METHOD

The data were obtained from the Kaohsiung Chang Gung Memorial Hospital using the Chang Gung Research Database and retrospectively reviewed from January 2000 to December 2015. Patients then were categorized into 2 groups: group FK (more than 2-year tacrolimus [FK] prescription) and group FK + mTOR inhibitor (more than 2-year tacrolimus plus at least 6-month continued sirolimus prescription). The primary end point is post-KT UC development. The secondary end point is mTOR inhibitor add-on effect on renal function deterioration episode.

RESULTS

There were 140 patients with tacrolimus-based immunosuppressant (group FK) and 82 patients with tacrolimus-based and add-on mTOR inhibitor regimen (group FK + mTOR inhibitor). The follow-up duration, sex distribution, and combined mycophenolate mofetil rate are similar in both groups. Younger age, lower tacrolimus trough level, lower UC incidence, and longer KT-to-UC interval were observed. Short- to intermediate-term results revealed noninferior graft outcome by creatinine level or creatinine deterioration.

CONCLUSIONS

In our preliminary result, mTOR inhibitor add-on in patients with tacrolimus-based regimen revealed less post-KT UC occurrence. In addition, noninferior graft outcome was also observed. In Taiwan, a high UC prevalence area, mTOR inhibitor add-on strategy can be considered as a preventive strategy for UC after KT.

False Immunosuppressant Measurement by LC-MS/MS Method Due to Radiopaque Agents

BACKGROUND

Although liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is preferred as a reliable method, some molecules in the blood matrix may lead to false positive or false negative results. False positive or negative results show the direction of the deviation rate from the target value.

AIM

The aim of this study was to investigate the effect of seven different radiopaque agents on four immunosuppressant drugs.

METHODS

Every agent coded with RM1 to RM7 was added to control materials containing tacrolimus, everolimus, sirolimus, and cyclosporine A drugs. Measurements were performed using an LC-MS/MS instrument. Bias values were calculated to detect the deviation rates.

RESULTS

All RMs led to false negative results in the tacrolimus and cyclosporine A levels at a rate of -19.77% (95% CI, -27.16 to 12.52) to -44.45% (95% CI, -49.20 to -39.69). The smallest deviations were seen in the everolimus levels with the administration of RM6 (gadodiamide) and in the sirolimus levels with RM1 (gadobutrol) at the rates of 4.04% (95% CI, -11.36 to -3.17) and 2.11% (95% CI, -7.18 to 7.11), respectively. The most affected drug by RM4 (gadopentetate dimeglumine salt) was sirolimus at the rate of 114.01% (95% CI, 97.31 - 130.76). RM5 (gadodiamide) interfered cyclosporine A at the most. The highest deviations were observed with the administration of RM3 (iohexol) in the everolimus and sirolimus levels at the rates of 153.72% (95% CI, 142.44 to 164.78) and 171.41% (95% CI, 157.91 to 184.97), respectively.

CONCLUSION

Radiopaque agents interfered the measurement of immunosuppressant drugs. Especially, everolimus and sirolimus levels were affected due to using iohexol. The choice of gadodiamide or ioversol is important to reduce the risk of interference for everolimus measurement. The blood samples should be obtained for measurement of drug levels before contrast-enhanced imaging.

Active targeted delivery of immune therapeutics to lymph nodes

PURPOSE OF REVIEW

Organ transplantation is a life-saving procedure and the only option for patients with end-organ failure. Immune therapeutics have been key to the success of organ transplantation. However, immune therapeutics are still unable to eliminate graft rejection and their toxicity has been implicated in poorer long-term transplant outcomes. Targeted nanodelivery has the potential to enhance not only the therapeutic index but also the bioavailability of the immune therapeutics. One of the key sites of immune therapeutics delivery is lymph node where the priming of immune cells occur. The focus of this review is on nanomedicine research to develop the targeted delivery of immune therapeutics to lymph nodes for controlling immune activation.

RECENT FINDINGS

As nanomedicine creates its niche in clinical care, it provides novel immunotherapy platforms for transplant recipients. Draining lymph nodes are the primary loci of immune activation and represent a formidable site for delivery of wide variety of immune therapeutics. There have been relentless efforts to improve the properties of nanomedicines, to have in-depth knowledge of antigen and drug loading, and, finally, to explore various routes of passive and active targeted delivery to lymph nodes.

SUMMARY

The application of nanotechnology principles in the delivery of immune therapeutics to the lymph node has created enormous excitement as a paradigm shifting approach that enables targeted delivery of a gamut of molecules to achieve a desired immune response. Therefore, innovative strategies that improve their efficacy while reducing their toxicity are among the highest unmet needs in transplantation.

Integrated Kidney Exosome Analysis for the Detection of Kidney Transplant Rejection

Kidney transplant patients require life-long surveillance to detect allograft rejection. Repeated biopsy, albeit the clinical gold standard, is an invasive procedure with the risk of complications and comparatively high cost. Conversely, serum creatinine or urinary proteins are noninvasive alternatives but are late markers with low specificity. We report a urine-based platform to detect kidney transplant rejection. Termed iKEA (integrated kidney exosome analysis), the approach detects extracellular vesicles (EVs) released by immune cells into urine; we reasoned that T cells, attacking kidney allografts, would shed EVs, which in turn can be used as a surrogate marker for inflammation. We optimized iKEA to detect T-cell-derived EVs and implemented a portable sensing system. When applied to clinical urine samples, iKEA revealed high level of CD3-positive EVs in kidney rejection patients and achieved high detection accuracy (91.1%). Fast, noninvasive, and cost-effective, iKEA could offer new opportunities in managing transplant recipients, perhaps even in a home setting.

Twenty-four hour urinary cortisol excretion and the metabolic syndrome in prednisolone-treated renal transplant recipients

Chronic prednisolone treatment in renal transplant recipients (RTR) causes metabolic abnormalities, which cluster in the metabolic syndrome (MS). It also suppresses the hypothalamic-pituitaryadrenal (HPA)-axis. We investigated whether HPA-axis suppression, as measured by 24h urinary cortisol excretion, is associated with presence of the MS and its individual components, in outpatient RTR with a functioning graft for >1year. Urinary cortisol was measured in 24h urine, using LC-MS/MS (LOQ 0.30nmol/L). We included 563 RTR (age 51±12years; 54% male) at median 6.0 [IQR, 2.6-11.5] years post-transplantation. MS was present in 439/563 RTR (78%). Median 24h urinary cortisol excretion was 2.0 [IQR, 0.9-5.1]nmol/24h. Twenty-four hour urinary cortisol excretion was independently associated with MS presence (OR=0.80 [95% CI, 0.66-0.98], P=0.02). It was also independently associated with bodyweight (st.β=-0.11, P=0.007), waist circumference (st.β=-0.10, P=0.01), BMI (st.β=-0.14, P=0.001), fasting triglycerides (st.β=-0.15, P=0.001), diabetes (st.β=-0.12, P=0.005), and number of antihypertensives used (st.β=-0.13, P=0.003). Suppressed HPA-axis activity, as reflected by decreased 24h urinary cortisol excretion, is associated with higher prevalence of MS and its individual components (i.e. central obesity, dyslipidemia, diabetes, hypertension) in prednisolone-treated RTR. Assessment of 24h urinary cortisol excretion by LC-MS/MS may be a tool to monitor metabolic side-effects of prednisolone in RTR.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.

Immunosuppression Minimization and Avoidance Protocols: When Less Is Not More

Kidney transplantation is well established as the best treatment option for end-stage kidney disease. It confers not only a better quality of life but also a significant survival advantage compared to dialysis. However, despite significant improvement in short-term kidney transplant graft survival over the past three decades, long-term graft survival remains suboptimal. Concerns about the possible contribution of chronic calcineurin inhibitor (CNI) nephrotoxicity to late allograft failure and other serious adverse effects of currently used immunosuppressive agents (especially corticosteroids) have led to increasing interest in developing regimens which may better preserve kidney allograft function and minimize other immunosuppression-related problems without increasing the risk of rejection. The availability of newer immunosuppressive agents has provided the opportunity to formulate such regimens. Approaches to this end include minimization, withdrawal, or avoidance of corticosteroids and CNIs. Currently, replacement of a CNI with a mammalian target of rapamycin inhibitor while continuing mycophenolate and discontinuation of corticosteroids within the first post-transplant week is being increasingly utilized. Belatacept-based, CNI-free immunosuppression is an emerging alternative approach to avoiding CNI-mediated nephrotoxicity. We also discuss the evolution, results, and pros and cons of corticosteroid- and CNI minimization protocols. Recent studies suggest that chronic alloimmune damage rather than chronic CNI nephrotoxicity is the major contributor to late kidney allograft failure. The implications of this finding for the use of CNI minimization protocols are also discussed.

Treatment with Tacrolimus and Sirolimus Reveals No Additional Adverse Effects on Human Islets In Vitro Compared to Each Drug Alone but They Are Reduced by Adding Glucocorticoids

Tacrolimus and sirolimus are important immunosuppressive drugs used in human islet transplantation; however, they are linked to detrimental effects on islets and reduction of long-term graft function. Few studies investigate the direct effects of these drugs combined in parallel with single drug exposure. Human islets were treated with or without tacrolimus (30 μg/L), sirolimus (30 μg/L), or a combination thereof for 24 hrs. Islet function as well as apoptosis was assessed by glucose-stimulated insulin secretion (GSIS) and Cell Death ELISA. Proinflammatory cytokines were analysed by qRT-PCR and Bio-Plex. Islets exposed to the combination of sirolimus and tacrolimus were treated with or without methylprednisolone (1000 μg/L) and the expression of the proinflammatory cytokines was investigated. We found the following: (i) No additive reduction in function and viability in islets existed when tacrolimus and sirolimus were combined compared to the single drug. (ii) Increased expression of proinflammatory cytokines mRNA and protein levels in islets took place. (iii) Methylprednisolone significantly decreased the proinflammatory response in islets induced by the drug combination. Although human islets are prone to direct toxic effect of tacrolimus and sirolimus, we found no additive effects of the drug combination. Short-term exposure of glucocorticoids could effectively reduce the proinflammatory response in human islets induced by the combination of tacrolimus and sirolimus.

Comparing the effect of isotopically labeled or structural analog internal standards on the performance of a LC-MS/MS method to determine ciclosporin A, everolimus, sirolimus and tacrolimus in whole blood

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is routinely used for analysis of immunosuppressive drugs. This study investigated whether replacing analog internal standards (ANISs) with isotopically labeled internal standards (ILISs) has an impact on the performance of a LC-MS/MS method for the quantification of tacrolimus (TAC), sirolimus (SIR), ciclosporin A (CsA) and everolimus (EVE) in whole blood.

Following hemolysis, protein precipitation, and extraction with either ANISs (ascomycin, desmethoxy-rapamycin, CsD), or ILISs (TAC-

Within-day imprecision was <10%, between-day <8%, and trueness 91%–110% for all the analytes with both ISs. No carryover or matrix effects were observed. The median accuracy was −2.1% for CsA, 9.1% for EVE, 12.2% for SIR, and −1.2% for TAC with the ILISs; and −2% for CsA, 9.8% for EVE, 11.4% for SIR, and 0.2% for TAC with the ANISs. Results of patient and proficiency testing samples were not statistically different.

: Although ILISs are generally considered superior to ANISs, they may not be always essential. When optimizing a LC-MS/MS method other factors must be also considered.

Kidney transplantation, bioengineering and regeneration: an originally immunology-based discipline destined to transition towards ad hoc organ manufacturing and repair

Kidney transplantation (KT), as a modality of renal replacement therapy (RRT), has been shown to be both economically and functionally superior to dialysis for the treatment of end-stage renal disease (ESRD). Progress in KT is limited by two major barriers: a) a chronic and burgeoning shortage of transplantable organs and b) the need for chronic immunosuppression following transplantation. Although ground-breaking advances in transplant immunology have improved patient survival and graft durability, a new pathway of innovation is needed in order to overcome current obstacles. Regenerative medicine (RM) holds the potential to shift the paradigm in RRT, through organ bioengineering. Manufactured organs represent a potentially inexhaustible source of transplantable grafts that would bypass the need for immunosuppressive drugs by using autologous cells to repopulate extracellular matrix (ECM) scaffolds. This overview discusses the current status of renal transplantation while reviewing the most promising innovations in RM therapy as applied to RRT.

Early withdrawal of calcineurin inhibitor from a sirolimus-based immunosuppression stabilizes fibrosis and the transforming growth factor-β signalling pathway in kidney transplant

AIM

The focus in renal transplantation is to increase long-term allograft survival. One of the limiting factors is calcineurin inhibitor (CNI)-induced fibrosis. This study attempted to examine the histological aspect of interstitial fibrosis and the modulation of the transforming growth factor-β (TGF-β) canonical signalling pathway following early withdrawal of CNI from sirolimus-based immunosuppressive therapy.

METHODS

Forty-five kidney transplant recipients with low-medium immunologic risk were randomized and underwent protocol biopsies obtained at the time of transplantation and at 3 and 12 months thereafter. The recipients were taking tacrolimus, sirolimus and prednisone. After the 3rd month, patients were randomized into two groups: sirolimus (SRL) (removed CNI and increased sirolimus) and tacrolimus (TAC) (maintained CNI). Renal biopsies were analyzed according to Banff's 2007 criteria. The sum of Banff's ct and ci constituted the chronicity index. Fibrosis was evaluated by the histomorphometrical analysis of the total collagen and myofibroblast deposition. Immunohistochemical characterization and quantification of TGF-β, TGF-β receptor 1 (TGF-β-R1), receptor 2 (TGF-β-R2) and phospho-Smad2/3 (p-Smad2/3) were performed.

RESULTS

Maintenance of CNI was associated with the increase of the surface density of collagen and α-smooth muscle actin (α-SMA), (P = 0.001). Furthermore, increased TGF-β (P = 0.02), TGF-β-R1 (P = 0.02), p-Smad2/3 (P = 0.03) and stabilized TGF-β-R2. On the other hand, the removal of CNI with increase in the dose of sirolimus limited the enhancement of the chronicity index at 12 m (SRL, 2.18 vs TAC, 3.12, P = 0.0007), diminished the deposition of fibrosis and promoted the stabilization of TGF-β, TGF-β-R2, p-Smad2/3 and myofibroblasts as well as the reduction of TGF-β-R1 (P = 0.01).

CONCLUSION

The early withdrawal of CNI limited the fibrosis progression through the stabilization of chronicity index and of the canonical TGF-β signalling pathway.

Impact of irradiation and immunosuppressive agents on immune system homeostasis in rhesus macaques

In this study we examined the effects of non-myeloablative total body irradiation (TBI) in combination with immunosuppressive chemotherapy on immune homeostasis in rhesus macaques. Our results show that the administration of cyclosporin A or tacrolimus without radiotherapy did not result in lymphopenia. The addition of TBI to the regimen resulted in lymphopenia as well as alterations in the memory/naive ratio following reconstitution of lymphocyte populations. Dendritic cell (DC) numbers in whole blood were largely unaffected, while the monocyte population was altered by immunosuppressive treatment. Irradiation also resulted in increased levels of circulating cytokines and chemokines that correlated with T cell proliferative bursts and with the shift towards memory T cells. We also report that anti-thymocyte globulin (ATG) treatment and CD3 immunotoxin administration resulted in a selective and rapid depletion of naive CD4 and CD8 T cells and increased frequency of memory T cells. We also examined the impact of these treatments on reactivation of latent simian varicella virus (SVV) infection as a model of varicella zoster virus (VZV) infection of humans. None of the treatments resulted in overt SVV reactivation; however, select animals had transient increases in SVV-specific T cell responses following immunosuppression, suggestive of subclinical reactivation. Overall, we provide detailed observations into immune modulation by TBI and chemotherapeutic agents in rhesus macaques, an important research model of human disease.

The need for minimization strategies: current problems of immunosuppression

New immunosuppressants and the better use of immunosuppressant combination therapy have led to significant improvements in renal allograft outcomes over the last decades. Yet, despite dramatic reduction in rejection rates and improvement in 1-year graft survival, long-term graft attrition rates remained rather constant. Current immunosuppressant combinations are frequently leading to overimmunosuppression and are increasing cardiovascular risk. Importantly, calcineurin inhibitors are nephrotoxic, contribute to cardiovascular risk and chronic allograft dysfunction. Furthermore, immunosuppressant-associated toxicities aggravate immune-mediated nephron injury and side effects lead to nonadherence, an identified important reason for late acute and chronic antibody-mediated rejections. The frequent development of a chronic humoral response indicates rather insufficient immunosuppression of current combinations than simple under-immunosuppression. While there is no evidence that increasing immunosuppressive doses will improve outcomes or reduce de novo HLA-antibody formation, there is clear evidence that adequate minimization strategies will reduce side effect burden. Because of low rejection risk, but frequent side effects, drug minimization is particularly relevant for the many maintenance patients. In summary, new therapeutic strategies need to be developed from adequately powered clinical trials for reduction of the many side effects of immunosuppressants. Such evidence-based and time-dependent immunosuppressive minimization strategies are needed to achieve better long-term outcomes in the future.

Donor ABCB1 genetic polymorphisms influence epithelial-to-mesenchyme transition in tacrolimus-treated kidney recipients

Aim: The contribution of epithelial–mesenchymal transition (EMT) has been suggested in renal transplant recipients receiving calcineurin inhibitors and developing nephrotoxicity. Materials & methods: We assessed whether interindividual variability in tacrolimus pharmacokinetics is associated with the occurrence in tubular cells of two EMT markers (vimentin, β-catenin) detected at 3‐month in 140 allograft biopsies. We investigated whether genetic polymorphisms affecting CYP3A5 and ABCB1 influence EMT and kidney fibrosis. Results: In univariate analysis, the donor CYP3A5*1 allele was significantly associated with a lower vimentin expression. In multivariate analysis, grafts carrying ABCB1 3435T allele(s) developed significantly less EMT and less interstitial fibrosis. Conclusion: Donor SNPs significantly influence the epithelial program in the context of kidney transplantation, and the epithelial metabolism of tacrolimus is one key to understand graft fibrogenesis.

In vivo intratumoral Epstein-Barr virus replication is associated with XBP1 activation and early-onset post-transplant lymphoproliferative disorders with prognostic implications

Post-transplant lymphoproliferative disorders are life-threatening complications following hematopoietic or solid organ transplantation. They represent a spectrum of mostly EBV-driven lymphoplasmacytic proliferations. While the oncogenic effect of EBV is related to latent infection, lytic infection also has a role in lymphomagenesis. In vitro, EBV replication is linked to plasma cell differentiation and XBP1 activation, although this phenomenon has never been addressed in vivo. We analyzed for the first time latent and lytic intratumoral EBV infection in a series of 35 adult patients with a diagnosis of post-transplant lymphoproliferative disorder (26M/9F, median age 54 years). A complete EBV study was performed including the analysis of the latent EBER, latent membrane protein-11, and EBV nuclear antigens as well as the immediate-early BZLF1/ZEBRA and early BMRF1/EADE31 lytic genes. XBP1 activation was assessed by nuclear protein expression. EBV infection was observed in 28 (80%) cases being latency II and III the most frequently observed 22 (79%). Intratumoral EBV replication was detected in 17 (60%) cases. Among these, XBP1 activation was observed in 11/12 evaluable cases associated with strong cytoplasmic immunoglobulin expression consistent with plasma cell differentiation. Intriguingly, the combination of latency III infection and EBV replication identified a high-risk subgroup of patients with significantly shorter survival (overall survival at 1 year 18% vs 48%) and early-onset (median of 7 vs 26 months) post-transplant lymphoproliferative disorder. Moreover, these patients appear to be more heavily immunosuppressed, so they exhibit lower rates of rejection and graft vs host disease but higher rates of cytomegalovirus reactivation. In conclusion, EBV replication is associated with plasma cell differentiation and XBP1 activation with prognostic implications. Both latency III and lytic EBV infection are related to aggressive and early-onset post-transplant lymphoproliferative disorder. These results suggest that immunohistochemical study of latent and lytic EBV genes in the clinical practice may help to select higher-risk patients to new therapies including antiviral treatments.

Effect of low-dose tacrolimus with mycophenolate mofetil on renal function following liver transplantation

AIM: To determine whether low-dose tacrolimus (TAC) combined with mycophenolate mofetil (MMF) is a safe approach to decrease the incidence of chronic kidney disease (CKD) in liver transplantation (LT) recipients.

METHODS: We analyzed the medical records of 689 patients who underwent LT between March 1999 and December 2012 in a single Chinese center. Immunosuppression was initiated with a calcineurin inhibitor (TAC or CSA) and prednisone with or without MMF. CKD is defined by the glomerular filtration rate (GFR), estimated by an abbreviated Modification of Diet in Renal Disease formula, < 60 mL/min per 1.73 m² for at least 3 consecutive months after LT. Individuals with TAC trough concentrations ≤ 8 ng/mL at 3 mo after LT were defined as the low-dose group. The incidence of CKD within 5 years was compared between the TAC group and the CSA group, as well as between four subgroups (low-dose and high-dose TAC groups with or without MMF).

RESULTS: No difference regarding the occurrence of pre-LT renal dysfunction or that of post-LT rejection was found between the TAC and CSA groups or between the four subgroups. With a definition of GFR < 60 mL/min per 1.73 m², the overall incidence of CKD was significantly higher in the CSA group than in the TAC group. The incidence of CKD in the low-dose TAC + MMF group (7.7%) was significantly lower than that observed in the low-dose TAC group (15.9%), high-dose TAC group (24.6%) and high-dose TAC + MMF group (18.5%). The cumulative 1-, 3- and 5-year incidence rates of CKD were 12.7%, 14.5% and 16.7%, respectively. The cumulative 5-year survival rates were 61.7% and 82.2% in patients with or without CKD, respectively.

CONCLUSION: In LT patients, the choice of immunosuppressive therapy appears to affect renal function and patient survival.

Calcineurin inhibitor sparing strategies in renal transplantation, part one: Late sparing strategies

Kidney transplantation improves quality of life and reduces the risk of mortality. A majority of the success of kidney transplantation is attributable to the calcineurin inhibitors (CNIs), cyclosporine and tacrolimus, and their ability to reduce acute rejection rates. However, long-term graft survival rates have not improved over time, and although controversial, evidence does suggest a role of chronic CNI toxicity in this failure to improve outcomes. Consequently, there is interest in reducing or removing CNIs from immunosuppressive regimens in an attempt to improve outcomes. Several strategies exist to spare calcineurin inhibitors, including use of agents such as mycophenolate mofetil (MMF), mycophenolate sodium (MPS), sirolimus, everolimus or belatacept to facilitate late calcineurin inhibitor withdrawal, beyond 6 mo post-transplant; or using these agents to plan early withdrawal within 6 mo; or to avoid the CNIs all together using CNI-free regimens. Although numerous reviews have been written on this topic, practice varies significantly between centers. This review organizes the data based on patient characteristics (i.e., the baseline immunosuppressive regimen) as a means to aid the practicing clinician in caring for their patients, by matching up their situation with the relevant literature. The current review, the first in a series of two, examines the potential of immunosuppressive agents to facilitate late CNI withdrawal beyond 6 mo post-transplant, and has demonstrated that the strongest evidence resides with MMF/MPS. MMF or MPS can be successfully introduced/maintained to facilitate late CNI withdrawal and improve renal function in the setting of graft deterioration, albeit with an increased risk of acute rejection and infection. Additional benefits may include improved blood pressure, lipid profile and serum glucose. Sirolimus has less data directly comparing CNI withdrawal to an active CNI-containing regimen, but modest improvement in short-term renal function is possible, with an increased risk of proteinuria, especially in the setting of baseline renal dysfunction and/or proteinuria. Renal outcomes may be improved when sirolimus is used in combination with MMF. Although data with everolimus is less robust, results appear similar to those observed with sirolimus.

Immunomodulatory drugs: oral and systemic adverse effects

OBJECTIVE

The main objectives are to present the different adverse effects of the immunomodulatory drugs that can impair the quality of life of the immunosuppressed patients and study the impact of immunomodulation on oral diseases. Immunomodulatory drugs have changed the treatment protocols of many diseases where immune functions play a central role, such as rheumatic diseases. Their effect on oral health has not been systematically investigated, however.

STUDY DESIGN

We review current data on the new immunomodulatory drugs from the oral health perspective based on open literature search of the topic.

RESULTS

These target specific drugs appear to have less drug interactions than earlier immunomodulating medicines but have nevertheless potential side effects such as activating latent infections. There are some data showing that the new immunomodulatory drugs may also have a role in the treatment of certain oral diseases such as lichen planus or ameliorating symptoms in Sjögren's syndrome, but the results have not been overly promising.

CONCLUSION

In general, data are sparse of the effect of these new drugs vs. oral diseases and there are no properly powered randomized controlled trials published on this topic.

Time-dependent variability in tacrolimus trough blood levels is a risk factor for late kidney transplant failure

Wide variations in tacrolimus levels have been identified as a risk factor for inferior kidney allograft survival but past studies have not properly accounted for the dynamic nature of drug exposure over time. Here we evaluated whether time-varying exposure to tacrolimus increases the risk of long-term adverse outcomes in a retrospective cohort study in adult kidney transplant recipients on tacrolimus-based immunosuppression. Time-dependent Cox proportional hazards models were used to examine the association between the standard deviation of tacrolimus levels (TacSD) starting at 1-year post-transplant and the composite end point of late allograft rejection, transplant glomerulopathy, or total graft loss (including death). Among 356 patients, there was a significant 27% increase in the adjusted hazard of the composite end point for every 1-unit increase in TacSD (hazard ratio 1.27 (95% confidence interval 1.03, 1.56)). There was also a graded increase in the relative hazard for the composite end point by TacSD threshold (hazard ratios 1.33, 1.50, 1.84, and 2.56 for TacSD 1.5, 2, 2.5, and 3, respectively). The results were similar for total graft loss and the composite end point excluding death. Thus, increased time-dependent TacSD may be an independent risk factor for adverse kidney transplant outcomes. TacSD may serve as a monitoring tool to identify high-risk patients. Whether interventions to decrease TacSD will improve outcomes requires further study.

Safety of human neural stem cell transplantation in chronic spinal cord injury

The spinal cord injury (SCI) microenvironment undergoes dynamic changes over time, which could potentially affect survival or differentiation of cells in early versus delayed transplantation study designs. Accordingly, assessment of safety parameters, including cell survival, migration, fate, sensory fiber sprouting, and behavioral measures of pain sensitivity in animals receiving transplants during the chronic postinjury period is required for establishing a potential therapeutic window. The goal of the study was assessment of safety parameters for delayed transplantation of human central nervous system-derived neural stem cells (hCNS-SCns) by comparing hCNS-SCns transplantation in the subacute period, 9 days postinjury (DPI), versus the chronic period, 60 DPI, in contusion-injured athymic nude rats. Although the number of surviving human cells after chronic transplantation was lower, no changes in cell migration were detected between the 9 and 60 DPI cohorts; however, the data suggest chronic transplantation may have enhanced the generation of mature oligodendrocytes. The timing of transplantation did not induce changes in allodynia or hyperalgesia measures. Together, these data support the safety of hCNS-SCns transplantation in the chronic period post-SCI.

Ultrasound prevents renal ischemia-reperfusion injury by stimulating the splenic cholinergic anti-inflammatory pathway

AKI affects both quality of life and health care costs and is an independent risk factor for mortality. At present, there are few effective treatment options for AKI. Here, we describe a nonpharmacologic, noninvasive, ultrasound-based method to prevent renal ischemia-reperfusion injury in mice, which is a model for human AKI. We exposed anesthetized mice to an ultrasound protocol 24 hours before renal ischemia. After 24 hours of reperfusion, ultrasound-treated mice exhibited preserved kidney morphology and function compared with sham-treated mice. Ultrasound exposure before renal ischemia reduced the accumulation of CD11b(+)Ly6G(high) neutrophils and CD11b(+)F4/80(high) myeloid cells in kidney tissue. Furthermore, splenectomy and adoptive transfer studies revealed that the spleen and CD4(+) T cells mediated the protective effects of ultrasound. Last, blockade or genetic deficiency of the α7 nicotinic acetylcholine receptor abrogated the protective effect of ultrasound, suggesting the involvement of the cholinergic anti-inflammatory pathway. Taken together, these results suggest that an ultrasound-based treatment could have therapeutic potential for the prevention of AKI, possibly by stimulating a splenic anti-inflammatory pathway.

Inhibitors of C5 complement enhance vaccinia virus oncolysis

Genetically engineered tumor-selective vaccinia virus (VV) has been demonstrated to be a highly effective oncolytic agent, but immune clearance may limit its therapeutic potential. As previously demonstrated, immunosuppression can lead to significant enhancement of viral recovery and therapeutic effect, but the magnitude of complement-mediated viral inactivation has not been fully elucidated and warrants further investigation. Using fluorescent microscopy and quantitative plaque assays, we have determined complement's key role in viral clearance and its multi-faceted means to pathogen destruction. Complement can lead to direct viral destruction and inhibition of viral uptake into cells, even in the absence of anti-vaccinia antibodies. Our data demonstrate C5 to be integral to the clearance pathway, and its inhibition by Staphylococcal superantigen-like protein leads to a 90-fold and 150-fold enhancement of VV infectivity in both the presence and absence of anti-VV antibodies, respectively. This study suggests that complement inhibition may reduce vaccinia viral neutralization and may be critical to future in vivo work.

Subclinical inflammation and chronic renal allograft injury in a randomized trial on steroid avoidance in pediatric kidney transplantation

Steroid avoidance is safe and effective in children receiving kidney transplants in terms of graft function and survival, but the effects on allograft histology are unknown. In this multicenter trial, 130 pediatric renal transplant recipients were randomized to steroid-free (SF; n = 60) or steroid-based (SB; n = 70) immunosuppression, and underwent renal allograft biopsies at the time of graft dysfunction and per protocol at implantation and 6, 12 and 24 months after transplantation. Clinical follow-up was 3 years posttransplant. Subclinical acute rejection was present in 10.6% SF versus 11.3% SB biopsies at 6 months (p = 0.91), 0% SF versus 4.3% SB biopsies at 1 year (p = 0.21) and 0% versus 4.8% at 2 years (p = 0.20). Clinical acute rejection was present in 13.3% SF and 11.4% SB patients by 1 year (p = 0.74) and in 16.7% SF and 17.1% SB patients by 3 years (p = 0.94) after transplantation. The cumulative incidence of antibody-mediated rejection was 6.7% in SF and 2.9% in SB by 3 years after transplantation (p = 0.30). There was a significant increase in chronic histological damage over time (p < 0.001), without difference between SF and SB patients. Smaller recipient size and higher donor age were the main risk factors for chronic histological injury in posttransplant biopsies.

Complete steroid avoidance is effective and safe in children with renal transplants: a multicenter randomized trial with three-year follow-up

To determine whether steroid avoidance in pediatric kidney transplantation is safe and efficacious, a randomized, multicenter trial was performed in 12 pediatric kidney transplant centers. One hundred thirty children receiving primary kidney transplants were randomized to steroid-free (SF) or steroid-based (SB) immunosuppression, with concomitant tacrolimus, mycophenolate and standard dose daclizumab (SB group) or extended dose daclizumab (SF group). Follow-up was 3 years posttransplant. Standardized height Z-score change after 3 years follow-up was -0.99 ± 2.20 in SF versus -0.93 ± 1.11 in SB; p = 0.825. In subgroup analysis, recipients under 5 years of age showed improved linear growth with SF compared to SB treatment (change in standardized height Z-score at 3 years -0.43 ± 1.15 vs. -1.07 ± 1.14; p = 0.019). There were no differences in the rates of biopsy-proven acute rejection at 3 years after transplantation (16.7% in SF vs. 17.1% in SB; p = 0.94). Patient survival was 100% in both arms; graft survival was 95% in the SF and 90% in the SB arms (p = 0.30) at 3 years follow-up. Over the 3 year follow-up period, the SF group showed lower systolic BP (p = 0.017) and lower cholesterol levels (p = 0.034). In conclusion, complete steroid avoidance is safe and effective in unsensitized children receiving primary kidney transplants.