Transplantation 50 years later--progress, challenges, and promises

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.

Management of Antimicrobial Agents in Abdominal Organ Transplant Patients in Intensive Care Unit

PURPOSE OF REVIEW

Early diagnosis of infections and immediate initiation of appropriate antimicrobials are crucial in the management of patients before and after organ transplantation. We reviewed the most recent literature and guidelines in this field and organized the current recommendations for healthcare professionals caring for critically ill organ transplant recipients.

RECENT FINDINGS

The incidence of multidrug-resistant organisms is increasing. Multidrug-resistant Gram-negative bacteria comprise about 14% of organisms. Vancomycin-resistant enterococci bloodstream infections are also on the rise, as 20.5% of nosocomial enterococci are now vancomycin-resistant, changing empiric antibiotic selection. Fluconazole-resistant Candida species comprise up to 46% of cases of candidemia in hospitalized patients. Consequently, new guidelines recommend primary use of echinocandins in patients with candidemia who have moderate-to-severe disease. Finally, the incidence of emergence of ganciclovir-resistant cytomegalovirus infection in patients is 5-12%, requiring early recognition and change to alternative regimens in the case of poor response to therapy.

SUMMARY

Bloodstream infections are a major cause of mortality and morbidity in solid organ transplantation. Mortality as high as 24% and 50% have been reported with sepsis and septic shock respectively. As such, bloodstream infections should be diagnosed rapidly and intravenous antibiotics should be started immediately. Appropriate resuscitation should be initiated and the number and/or dose of immunosuppressive drugs should be reduced. Proper source control must also be achieved with radiologic drainage or surgical intervention as appropriate. Initial antibiotic treatment of these patients should cover both Gram-positive organisms, especially in the presence of intravascular catheters, and Gram-negative bacteria. Echinocandins like caspofungin should also be considered especially in critically ill patients, particularly if a patient has been on total parenteral nutrition or broad-spectrum antibiotics.

Enhanced Host Neovascularization of Prevascularized Engineered Muscle Following Transplantation into Immunocompetent versus Immunocompromised Mice

: Engineering of functional tissue, by combining either autologous or allogeneic cells with biomaterials, holds promise for the treatment of various diseases and injuries. Prevascularization of the engineered tissue was shown to enhance and improve graft integration and neovascularization post-implantation in immunocompromised mice. However, the neovascularization and integration processes of transplanted engineered tissues have not been widely studied in immunocompetent models. Here, we fabricated a three-dimensional (3D) vascularized murine muscle construct that was transplanted into immunocompetent and immunocompromised mice. Intravital imaging demonstrated enhanced neovascularization in immunocompetent mice compared to immunocompromised mice, 18 days post-implantation, indicating the advantageous effect of an intact immune system on neovascularization. Moreover, construct prevascularization enhanced neovascularization, integration, and myogenesis in both animal models. These findings demonstrate the superiority of implantation into immunocompetent over immunocompromised mice and, therefore, suggest that using autologous cells might be beneficial compared to allogeneic cells and subsequent immunosuppression. Taken together, these observations have the potential to advance the field of regenerative medicine and tissue engineering, ultimately reducing the need for donor organs and tissues.

[Renal transplantation: Procedure and early follow-up]

More than fifty years after the success of the two first renal transplantations in Boston and in Necker hospital in Paris, renal transplantation became the treatment of choice of end stage renal failure, because it improves not only the quality of life of the patients but also their long-term survival. In France, more than 3,700 kidney transplantations are performed every year and more than 40,000 patients are living with a functioning kidney allograft. This treatment of end stage renal disease requires a fine-tuned pre-transplant evaluation and a multidisciplinary post-transplant care in order to prevent, to detect and to treat comorbidities and complications of immunosuppression. The ambition of this manuscript is not to describe in an exhaustive way all the aspects of renal transplantation but starting from the experience of a team, recently published data, and national and international guidelines, to try to provide a synthetic and chronological view of the early post-transplant monitoring.

In Situ Tissue Regeneration of Renal Tissue Induced by Collagen Hydrogel Injection

Host stem/progenitor cells can be mobilized and recruited to a target location using biomaterials, and these cells may be used for in situ tissue regeneration. The objective of this study was to investigate whether host biologic resources could be used to regenerate renal tissue in situ. Collagen hydrogel was injected into the kidneys of normal mice, and rat kidneys that had sustained ischemia/reperfusion injury. After injection, the kidneys of both animal models were examined up to 4 weeks for host tissue response. The infiltrating host cells present within the injection regions expressed renal stem/progenitor cell markers, PAX‐2, CD24, and CD133, as well as mesenchymal stem cell marker, CD44. The regenerated renal structures were identified by immunohistochemistry for renal cell specific markers, including synaptopodin and CD31 for glomeruli and cytokeratin and neprilysin for tubules. Quantitatively, the number of glomeruli found in the injected regions was significantly higher when compared to normal regions of renal cortex. This phenomenon occurred in normal and ischemic injured kidneys. Furthermore, the renal function after ischemia/reperfusion injury was recovered after collagen hydrogel injection. These results demonstrate that introduction of biomaterials into the kidney is able to facilitate the regeneration of glomerular and tubular structures in normal and injured kidneys. Such an approach has the potential to become a simple and effective treatment for patients with renal failure. Stem Cells Translational Medicine2018;7:241–250

Immunosuppression and Graft Rejection in Living-related HLA-identical Renal Transplantation: The RADOVFULL Study

BACKGROUND

We aimed to describe the immunosuppressive regimens and graft rejection rates in living-related HLA-identical (LR HLAid) renal transplantation.

METHODS

We performed a retrospective multicenter analysis of the French national database for LR HLAid renal transplantations performed between 2002 and 2012. Univariate and multivariate analysis were performed to determine risk factors for graft rejection in LR HLAid recipients.

RESULTS

A total of 27 218 renal transplantations were performed, of whom 163 had a LR HLAid donor. About immunosuppressive treatment, <60% of the cohort had induction therapy with polyclonal or monoclonal antibodies, 28% did not receive calcineurin inhibitors, and 36% did not receive steroids in maintenance. Biopsy-proven acute rejection was diagnosed in 21 patients (12.9%). Rejection occurred on an average of 24 months after transplantation, in 28.5% of the cases after minimization of immunosuppression. Factors associated with rejection were age of recipient (OR, 0.91 [0.84-0.96]; P = 0.003), the body mass index of donors (odds ratio [OR], 1.22 [1.04-1.46]; P = 0.01), and minimization of immunosuppression (OR, 26.2 [5.48-166.6]; P < 0.001). Overall and graft survival rates were not statistically different according to rejection at 1, 5, and 10 years posttransplantation.

CONCLUSIONS

Minimization of immunosuppression should be done with caution in LR HLAid renal transplantations.

Targeting metabolism to regulate immune responses in autoimmunity and cancer

Metabolic programming is emerging as a critical mechanism to alter immune cell activation, differentiation and function. Targeting metabolism does not completely suppress or activate the immune system but selectively regulates immune responses. The different metabolic requirements of the diverse cells that constitute an immune response provide a unique opportunity to separate effector functions from regulatory functions. Likewise, cells can be metabolically reprogrammed to promote either their short-term effector functions or long-term memory capacity. Studies in the growing field of immunometabolism support a paradigm of 'cellular selectivity based on demand', in which generic inhibitors of ubiquitous metabolic processes selectively affect cells with the greatest metabolic demand and have few effects on other cells of the body. Targeting metabolism, rather than particular cell types or cytokines, in metabolically demanding processes such as autoimmunity, graft rejection, cancer and uncontrolled inflammation could lead to successful strategies in controlling the pathogenesis of these complex disorders.

Organ Preservation into the 2020s: The Era of Dynamic Intervention

Organ preservation has been of major importance ever since transplantation developed into a global clinical activity. The relatively simple procedures were developed on a basic comprehension of low-temperature biology as related to organs outside the body. In the past decade, there has been a significant increase in knowledge of the sequelae of effects in preserved organs, and how dynamic intervention by perfusion can be used to mitigate injury and improve the quality of the donated organs. The present review focuses on (1) new information about the cell and molecular events impacting on ischemia/reperfusion injury during organ preservation, (2) strategies which use varied compositions and additives in organ preservation solutions to deal with these, (3) clear definitions of the developing protocols for dynamic organ perfusion preservation, (4) information on how the choice of perfusion solutions can impact on desired attributes of dynamic organ perfusion, and (5) summary and future horizons.

Vasculogenically conditioned peripheral blood mononuclear cells inhibit mouse immune response to induced pluripotent stem cell-derived allogeneic cardiac grafts

Allogeneic transplantation of induced pluripotent stem cell (iPSC)-derived cardiomyocytes is apromising treatment for cardiac diseases, although immune rejection by the recipient poses a concern. In this study, we aimed to investigate whether concomitant transplantation of vasculogenically conditioned peripheral blood mononuclear cells, which are otherwise immunosuppressive, may enhance graft survival. Luciferase-transduced, iPSC-derived cardiomyocytes from C57BL/6 mice were transplanted to the dorsal subcutaneous space of syngeneic C57BL/6 mice (n = 19), allogeneic Balb/c mice treated with (n = 20) or without (n = 20) immunosuppressants, and those injected with vasculogenically conditioned peripheral blood mononuclear cells (n = 20). Although graft survival, assessed by bioluminescence, was comparable among the groups initially, it improved significantly at days 7 and 10 in allogeneic transplanted mice treated with vasculogenically conditioned peripheral blood mononuclear cells than in others (P < 0.01). Our results proved that cell-based immunosuppression may boost clinical outcomes from allogeneic cell therapy.

The development of an extended normothermic ex vivo reperfusion model of the sheep uterus to evaluate organ quality after cold ischemia in relation to uterus transplantation

INTRODUCTION

Uterus transplantation has recently proved that infertility in women with uterine factor infertility can be cured. It is still an experimental procedure with numerous critical details remaining to be established, including tolerance to warm and cold ischemic insults. In preparation for human uterus transplantation trials, most teams use the sheep as a model system for research and team training, since the vasculature and the uterus is of similar size as in the human. We, therefore, aimed to develop an ex vivo sheep uterus reperfusion platform that mimics the reperfusion situation so that initial assessments and comparisons can be performed without the need for costly and labor-intensive in vivo transplantation experiments.

MATERIAL AND METHODS

Isolated sheep uteri were perfused with the preservation solution IGL-1 and were then exposed to cold ischemia for either 4 (n = 6) or 48 hours (n = 7). Uteri were then reperfused for 48 hours under normothermic conditions with an oxygenated recirculating perfusate containing growth factors and synthetic oxygen carriers. Histological and biochemical analysis of the perfusate was conducted to assess reperfusion injury.

RESULTS

Quantification of cell density indicated no significant edema in the myometrium or in the endometrium of uteri exposed to 4 hours cold ischemia and then a normothermic ex vivo reperfusion for 48 hours. Only the outer serosa layer and the inner columnar luminal epithelial cells were affected by the reperfusion. However, a much faster and severe reperfusion damage of all uterine layers were evident during the reperfusion experiment following 48 hours of cold ischemia. This was indicated by major accumulation of extracellular fluid, presence of apoptotic-labeled glandular epithelial layer and vascular endothelium. A significant accumulation of lactate was measured in the perfusate with a subsequent decrease in pH.

CONCLUSIONS

We developed a novel ex vivo sheep uterus model for prolonged perfusion. This model proved to be able to distinguish reperfusion injury-related differences associated to organ preservation. The experimental setup is a platform that can be used to conduct further studies on uterine ischemia- and reperfusion injury that may lead to improved human uterus transplantation protocols.

A late B lymphocyte action in dysfunctional tissue repair following kidney injury and transplantation

The mechanisms initiating late immune responses to an allograft are poorly understood. Here we show, via transcriptome analysis of serial protocol biopsies from kidney transplants, that the initial responses to kidney injury correlate with a late B lymphocyte signature relating to renal dysfunction and fibrosis. With a potential link between dysfunctional repair and immunoreactivity, we investigate the immunological consequences of dysfunctional repair examining chronic disease in mouse kidneys 18 months after a bilateral ischemia/reperfusion injury event. In the absence of foreign antigens, a sustained immune response involving both innate and adaptive immune systems accompanies a transition to chronic kidney damage. At late stages, B lymphocytes exhibite an antigen-driven proliferation, selection and maturation into broadly-reacting antibody-secreting cells. These findings reveal a previously unappreciated role for dysfunctional tissue repair in local immunomodulation that may have particular relevance to transplant-associated immunobiology.

New approaches for the detection of invasive fungal diseases in patients following liver transplantation-results of an observational clinical pilot study

PURPOSE

Despite antifungal prophylaxis following liver transplantation (LTX), patients are at risk for the development of subsequent opportunistic infections, such as an invasive fungal disease (IFD). However, culture-based diagnostic procedures are associated with relevant weaknesses.

METHODS

Culture and next-generation sequencing (NGS)-based fungal findings as well as corresponding plasma levels of ß-D-glucan (BDG), galactomannan (GM), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-2, -4, -6, -10, -17A and mid-regional proadrenomedullin (MR-proADM) were evaluated in 93 patients at 6 consecutive time points within 28 days following LTX.

RESULTS

A NGS-based diagnostic approach was shown to be suitable for the early identification of fungal pathogens in patients following LTX. Moreover, MR-proADM and IL-17A in plasma proved suitable for the identification of patients with an IFD.

CONCLUSION

Plasma measurements of MR-proADM and IL-17A as well as a NGS-based diagnostic approach were shown to be attractive methodologies to attenuate the weaknesses of routinely used culture-based diagnostic procedures for the determination of an IFD in patients following LTX. However, an additional confirmation within a larger multicenter trial needs to be recommended.

TRIAL REGISTRATION

German Clinical Trials Register: DRKS00005480 .

[Gut microbiota in renal transplant recipients, patients with chronic kidney disease and healthy subjects]

OBJECTIVE

Recent studies have shown that gut microbiota is associated with immunomodulation in transplant recipients, but the composition and function of gut microbiota in renal transplant recipients have not been understood.

METHODS

We analyzed the composition and function of gut microbiota in the fecal samples from 16 renal transplant (RT) recipients by deep sequencing of the 16S rRNA V3 variable region. The gut microbiota of RT recipients was compared to that of 84 patients with chronic kidney disease (CKD) and 53 healthy subjects.

RESULTS

The overall microbial structure of RT recipients was similar to that of CKD. The abundance of Firmicutes, Lachnospiraceae, Ruminococcaceae and Faecalibacterium was decreased and that of Bacteroidetes, Proteobacteria, Clostridiales, and Enterobacteriaceae was increased significantly in RT recipients and CKD patients compared with the healthy control subjects. Functional comparison revealed significantly enhanced carbohydrate metabolism and decreased metabolism of cofactors, vitamins, cell motility and genetic information processing in RT recipients and CKD patients. RT recipients and CKD patients also showed slight differences in that the abundance of Proteobacteria and Enterobacteriaceae and the pathways involving transport system members and carbohydrate metabolism were much greater in the former. We found that several beneficial genera in the Lachnospiraceae and Veillonellaceae were negatively correlated with such clinical markers as serum creatinine and blood urea nitrogen.

CONCLUSIONS

Our results suggested that alterations in the composition and function of gut microbiota are significantly correlated with the clinical conditions of in RT recipients, and future prospective studies of these correlations may provide evidence for predicting the clinical outcomes of RT recipients.

Residual Activatability of Circulating Tfh17 Predicts Humoral Response to Thymodependent Antigens in Patients on Therapeutic Immunosuppression

The generation of antibodies against protein antigens (such as donor-specific HLA molecules) requires that T follicular helper cells (Tfh) provide help to B cells. Immunosuppressive (IS) armamentarium prevents T cell activation, yet a significant proportion of renal transplant patients develop donor-specific antibodies (DSA), which suggests that IS drugs do not efficiently block T follicular helper cells. To test this hypothesis, the number of circulating Tfh, their polarization profile, and ability to up-regulate (i) the co-stimulatory molecules CD40L and ICOS, and (ii) the activation marker CD25, following in vitro stimulation in presence of IS drugs, were compared between 36 renal transplant patients (6–72 months post transplantation) and nine healthy controls. IS drugs reduced the number of Tfh1 and 2 but had little impact on Tfh17, which was the dominant subset in transplant patients. Although, IS drugs decreased activation-induced expression of co-stimulatory molecules by Tfh, the impact was highly variable between individuals. Furthermore, 20% of transplant patients displayed normal expression of CD25 on Tfh following in vitro stimulation (i.e., “residual activatability”). To test whether residual activatability of Tfh correlates with antibody response against thymo-dependent antigens we took advantage of the 2015 influenza vaccination campaign, which provided a normalized setting for antigenic stimulation. In line with our hypothesis, responders to influenza vaccine exhibited significantly higher percentage of CD25-expressing Tfh17 after in vitro stimulation. A results that was confirmed retrospectively in nine transplanted patients at the time of first DSA detection. We concluded that “residual activatability” of Tfh17 might be used as a non-invasive biomarker to identify transplant patients at higher risk to develop DSA under immunosuppression. If validated in larger studies, this assay might help optimizing the prevention of DSA through personalized adaptation of immunosuppressive regimen.

Technical, Immunological, and Ethical Similarities and Differences Between Vascularized Composite Allotransplantation and Solid Organ Transplantation in Current Practice

Solid organ transplantation (SOT) is a surgical method used as the gold standard in end-term organ failure. Following SOT, successful results have also been achieved in vascularized composite tissue transplantation, which improves the quality of life with the success of solid organ transplants and the development of modern immunosuppressive regimens. This review discusses the preoperative, operative, postoperative, and immunological differences between vascularized tissue transplantation and SOT.

miR-199b-5p Regulates Immune-Mediated Allograft Rejection after Lung Transplantation Through the GSK3β and NF-κB Pathways

Emerging evidence indicates that acute rejection mainly associated with the inflammatory response is an independent risk factor for chronic rejection after lung transplantation. Monocytes are the main pro-inflammatory leukocytes infiltrating around the lesions and play vital roles in triggering the acute rejection. In the rat lung transplantation model, lipopolysaccharide (LPS)-induced severe acute rejection was strongly associated with advanced chronic rejection. The exact regulatory mechanism of pro-inflammation in monocytes is not yet clear. In this study, we identified a novel anti-inflammatory effect of miR-199b-5p (miR-199b) through the GSK3β and NF-κB pathways. THP-1 monocytes treated with LPS showed a significant decrease in miR-199b that is inversely correlated to GSK3β expression and NF-κB activation. Furthermore, the NF-κB-associated inflammatory response was reduced due to the overexpression of miR-199b targeting GSK3β, which was rescued by the inhibition of miR-199b. These results indicated that miR-199b attenuated the inflammatory response at least partly through the GSK3β/NF-κB signaling pathways in monocytes. Our data point toward a potentially important role for miR-199b in the inhibition of rejection after lung transplantation.

PI3Kγ promotes vascular smooth muscle cell phenotypic modulation and transplant arteriosclerosis via a SOX9-dependent mechanism

Background

Transplant arteriosclerosis (TA) remains the major cause of chronic graft failure in solid organ transplantation. The phenotypic modulation of vascular smooth muscle cells (VSMCs) is a key event for the initiation and progression of neointimal formation and TA. This study aims to explore the role and underlying mechanism of phosphoinositide 3-kinases γ (PI3Kγ) in VSMC phenotypic modulation and TA.

Methods

The rat model of aortic transplantation was established to detect PI3Kγ expression and its role in neointimal formation and vascular remodeling in vivo. PI3Kγ shRNA transfection was employed to knockdown PI3Kγ gene. Aortic VSMCs was cultured and treated with TNF-α to explore the role and molecular mechanism of PI3Kγ in VSMC phenotypic modulation.

Findings

Activated PI3Kγ/p-Akt signaling was observed in aortic allografts and in TNF-α-treated VSMCs. Lentivirus-mediated shRNA transfection effectively inhibited PI3Kγ expression in medial VSMCs while restoring the expression of VSMC contractile genes, associated with impaired neointimal formation in aortic allografts. In cultured VSMCs, PI3Kγ blockade with pharmacological inhibitor or genetic knockdown markedly abrogated TNF-α-induced downregulation of VSMC contractile genes and increase in cellular proliferation and migration. Moreover, SOX9 located in nucleus competitively inhibited the interaction of Myocardin and SRF, while PI3Kγ inhibition robustly reduced SOX9 expression and its nuclear translocation and repaired the Myocardin/SRF association.

Interpretation

These results suggest that PI3Kγ plays a critical role in VSMC phenotypic modulation via a SOX9-dependent mechanism. Therefore, PI3Kγ in VSMCs may represent a promising therapeutic target for the treatment of TA.

Fund

National Natural Science Foundation of China.

Optimal immunosuppressor induces stable gut microbiota after liver transplantation

AIM

To study the influence of different doses of tacrolimus (FK506) on gut microbiota after liver transplantation (LT) in rats.

METHODS

Specific pathogen-free Brown Norway (BN) rats and Lewis rats were separated into five groups: (1) Tolerance group (BN-BN LT, n = 8); (2) rejection group (Lewis-BN LT, n = 8); (3) high dosage FK506 (FK506-H) group (Lewis-BN LT, n = 8); (4) middle dosage FK506 (FK506-M) group (Lewis-BN LT, n = 8); and (5) low dosage FK506 (FK506-L) group (Lewis-BN LT, n = 8). FK506 was administered to recipients at a dose of 1.0 mg/kg, 0.5 mg/kg, and 0.1 mg/kg body weight for 29 d after LT to the FK506-H, FK506-M, and FK506-L groups, respectively. On the 30^th day after LT, all rats were sampled and euthanized. Blood samples were harvested for liver function and plasma endotoxin testing. Hepatic graft and ileocecal tissues were collected for histopathology observation. Ileocecal contents were used for DNA extraction, Real-time quantitative polymerase chain reaction (RT-PCR) and digital processing of denaturing gradient gel electrophoresis (DGGE) profiles and analysis.

RESULTS

Compared to the FK506-H and FK506-L groups, FK506-M was optimal for maintaining immunosuppression and inducing normal graft function; the FK506-M maintained gut barrier integrity and low plasma endotoxin levels; furthermore, DGGE results showed that FK506-M induced stable gut microbiota. Diversity analysis indicated that FK506-M increased species richness and rare species abundance, and cluster analysis confirmed the stable gut microbiota induced by FK506-M. Phylogenetic tree analysis identified crucial bacteria associated with FK506-M; seven of the nine bacteria that were decreased corresponded to Bacteroidetes, while increased bacteria were of the Bifidobacterium species. FK506-M increased Faecalibacterium prausnitzii and Bifidobacterium spp. and decreased Bacteroides-Prevotella and Enterobacteriaceae, as assessed by RT-PCR, which confirmed the crucial bacterial alterations identified through DGGE.

CONCLUSION

Compared to the low or high dosage of FK506, an optimal dosage of FK506 induced immunosuppression, normal graft function and stable gut microbiota following LT in rats. The stable gut microbiota presented increased probiotics and decreased potential pathogenic endotoxin-producing bacteria. These findings provide a novel strategy based on gut microbiota for immunosuppressive dosage assessment for recipients following LT.

Differential effects of donor-specific HLA antibodies in living versus deceased donor transplant

The presence of donor-specific anti-HLA antibodies (DSAs) is associated with increased risk of graft failure after kidney transplant. We hypothesized that DSAs against HLA class I, class II, or both classes indicate a different risk for graft loss between deceased and living donor transplant. In this study, we investigated the impact of pretransplant DSAs, by using single antigen bead assays, on long-term graft survival in 3237 deceased and 1487 living donor kidney transplants with a negative complement-dependent crossmatch. In living donor transplants, we found a limited effect on graft survival of DSAs against class I or II antigens after transplant. Class I and II DSAs combined resulted in decreased 10-year graft survival (84% to 75%). In contrast, after deceased donor transplant, patients with class I or class II DSAs had a 10-year graft survival of 59% and 60%, respectively, both significantly lower than the survival for patients without DSAs (76%). The combination of class I and II DSAs resulted in a 10-year survival of 54% in deceased donor transplants. In conclusion, class I and II DSAs are a clear risk factor for graft loss in deceased donor transplants, while in living donor transplants, class I and II DSAs seem to be associated with an increased risk for graft failure, but this could not be assessed due to their low prevalence.

March1-dependent modulation of donor MHC II on CD103+ dendritic cells mitigates alloimmunity

In transplantation, donor dendritic cells (do-DCs) initiate the alloimmune response either by direct interaction with host T cells or by transferring intact donor MHC to host DCs. However, how do-DCs can be targeted for improving allograft survival is still unclear. Here we show CD103+ DCs are the major do-DC subset involved in the acute rejection of murine skin transplants. In the absence of CD103+ do-DCs, less donor MHC-II is carried to host lymph nodes, fewer allogenic T cells are primed and allograft survival is prolonged. Incubation of skin grafts with the anti-inflammatory mycobacterial protein DnaK reduces donor MHC-II on CD103+DCs and prolongs graft survival. This effect is mediated through IL-10-induced March1, which ubiquitinates and decreases MHC-II levels. Importantly, in vitro pre-treatment of human DCs with DnaK reduces their ability to prime alloreactive T cells. Our findings demonstrate a novel therapeutic approach to dampen alloimmunity by targeting donor MHC-II on CD103+DCs.

Analyses of the short- and long-term graft survival after kidney transplantation in Europe between 1986 and 2015

The evolution of kidney allograft survival remains insufficiently studied in the context of the changing donor and recipient demographics. Since European data are lacking we performed a cohort study (1986-2015) that, based on the Collaborative Transplant Study, included 108 787 recipients of brain-death kidney donors in 135 hospitals across 21 European countries. We analyzed the hazard rate of kidney failure after transplantation. Between 1986 and 1999, improvement in graft survival was more pronounced in the short term than in the long term: one-, five- and ten-year hazard rates after transplantation declined 64% (95% confidence interval, 61%-66%), 53% (49%-57%) and 45% (39%-50%), respectively. Between 2000 and 2015, hazard rates at one, five and ten years post-transplant declined respectively 22% (12-30%), 47% (36-56%) and 64% (45-76%). Improvement in graft survival in the first five years post-transplant was significantly less since 2000, while improvement after five years was comparable to before. During the 2000-2015 period improvement of graft survival was greater in the long than in the short term. These changes were independent of changing donor and recipient characteristics, and reflect the evolution in global kidney transplant management over the past decades. Unfortunately, after accounting for the evolution of donor and recipient characteristics, we found that short-term improvement in graft survival decreased since 2000, while long-term improvement remained unchanged in Europe. Thus, deceleration of short-term graft survival improvement in more recent years illustrates an unmet need for innovation.

Peptide Tk-PQ induces immunosuppression in skin allogeneic transplantation via increasing Foxp3+ Treg and impeding nuclear translocation of NF-κB

Solid organ transplantation is used as the last resort for patients with end-stage disease, but allograft rejection is an unsolved problem. Here, we showed that Tk-PQ, a peptide derived from trichosanthin, had an immune-suppressive effect without obvious cytotoxicity in vitro and in a mouse skin allo-transplantation model. In vitro, treatment of Tk-PQ administrated type 2 T helper cell (Th2)/regulatory T-cell (Treg) cytokines, and increased the ratio of CD4⁺CD25⁺Foxp3⁺ Treg by repressing the PI3K/mTOR pathway. In addition, Tk-PQ decreased NF-κB activation to downregulate pro-inflammatory cytokines. Tk-PQ treatment in the mouse skin transplantation model also caused the similar molecular and cellular phenotypes. Furthermore, Tk-PQ enhanced the suppressive function of Treg by increasing Foxp3 expression, and substantially improved allograft survival. These finding demonstrate that Tk-PQ has the potential to be used in clinical allogeneic transplantation.

Quality Metrics in Solid Organ Transplantation: A Systematic Review

BACKGROUND

The best approach for determining whether a transplant program is delivering high-quality care is unknown. This review aims to identify and characterize quality metrics in solid organ transplantation.

METHODS

Medline, Embase, and Cochrane Central Register of Controlled Trials were searched from inception until February 1, 2017. Relevant full text reports and conference abstracts that examined quality metrics in organ transplantation were included. Two reviewers independently extracted study characteristics and quality metrics from 52 full text reports and 24 abstracts. PROSPERO registration: CRD42016035353.

RESULTS

Three hundred seventeen quality metrics were identified and condensed into 114 unique indicators with sufficient detail to be measured in practice; however, many lacked details on development and selection, were poorly defined, or had inconsistent definitions. The process for selecting quality indicators was described in only 5 publications and patient involvement was noted in only 1. Twenty-four reports used the indicators in clinical care, including 12 quality improvement studies. Only 14 quality metrics were assessed against patient and graft survivals.

CONCLUSIONS

More than 300 quality metrics have been reported in transplantation but many lacked details on development and selection, were poorly defined, or had inconsistent definitions. Measures have focused on safety and effectiveness with very few addressing other quality domains, such as equity and patient-centeredness. Future research will need to focus on transparent and objective metric development with proper testing, evaluation, and implementation in practice. Patients will need to be involved to ensure that transplantation quality metrics measure what is important to them.

CD47 blockade reduces ischemia/reperfusion injury in donation after cardiac death rat kidney transplantation

Modulation of nitric oxide activity through blockade of CD47 signaling has been shown to reduce ischemia-reperfusion injury (IRI) in various models of tissue ischemia. Here, we evaluate the potential effect of an antibody-mediated CD47 blockade in a syngeneic and an allogeneic DCD rat kidney transplant model. The donor organ was subjected to 1 hour of warm ischemia time after circulatory cessation, then flushed with a CD47 monoclonal antibody (CD47mAb) in the treatment group, or an isotype-matched immunoglobulin in the control group. We found that CD47mAb treatment improved survival rates in both models. Serum markers of renal injury were significantly decreased in the CD47mAb-treated group compared with the control group. Histologically the CD47mAb-treated group had significantly reduced scores of acute tubular injury and acute tubular necrosis. The expression of biomarkers related to mitochondrial stress and apoptosis also were significantly lower in the CD47mAb-treated groups. Overall, the protective effects of CD47 blockade were greater in the syngeneic model. Our data show that CD47mAb blockade decreased the IRI of DCD kidneys in rat transplant models. This therapy has the potential to improve DCD kidney transplant outcomes in the human setting.

Persistent hyperparathyroidism as a risk factor for long-term graft failure: the need to discuss indication for parathyroidectomy

BACKGROUND

Although a successful kidney transplant (KTx) improves most of the mineral and bone disorders (MBD) produced by chronic kidney disease (CKD), hyperparathyroidism may persist (pHPT). Current guidelines recommend parathyroidectomy if serum parathormone is persistently elevated 1 year after KTx, because pHPT has been recently associated with poor graft outcomes. However, whether patients with pHPT and adequate renal function are at risk for long-term graft failure is unknown.

METHODS

Longitudinal follow-up of 911 adults submitted to KTx between January 2005 and December 2014, with estimated glomerular filtration rate (eGFR) ≥ 30 mL/min 1 year after surgery. Clinical and laboratory data were collected from electronic database. Graft failure was defined as return to dialysis.

RESULTS

Overall, 62% of the patients were classified as having pHPT 1 year after KTx. After a mean follow-up time of 47 months, there were 59 graft failures (49 in pHPT and 10 in non-pHPT group, P = .003). At last follow-up, death-censored graft survival was lower in the pHPT group (P = .009), even after adjustment for age at KTx, donor age, donor type, acute rejection, parathyroidectomy, and eGFR at 1 year after transplantation (odds ratio [OR] 1.99; 1.004-3.971; P = .049). A PTH of 150 pg/mL at 6 months was the best cutoff to predict pHPT at 1 year (specificity = 92.1%).

CONCLUSION

Having pHPT after a successful KTx increases the long-term risk of death-censored graft failure. This result highlights the need for better recognition and management of CKD-MBD before and during the first year after KTx, and opens a discussion on the more appropriate timing to perform parathyroidectomy.

Gut microbial balance and liver transplantation: alteration, management, and prediction

Liver transplantation is a conventional treatment for terminal stage liver diseases. However, several complications still hinder the survival rate. Intestinal barrier destruction is widely observed among patients receiving liver transplant and suffering from ischemia-reperfusion or rejection injuries because of the relationship between the intestine and the liver, both in anatomy and function. Importantly, the resulting alteration of gut microbiota aggravates graft dysfunctions during the process. This article reviews the research progress for gut microbial alterations and liver transplantation. Especially, this work also evaluates research on the management of gut microbial alteration and the prediction of possible injuries utilizing microbial alteration during liver transplantation. In addition, we propose possible directions for research on gut microbial alteration during liver transplantation and offer a hypothesis on the utilization of microbial alteration in liver transplantation. The aim is not only to predict perioperative injuries but also to function as a method of treatment or even inhibit the rejection of liver transplantation.

Prevention of chronic rejection after lung transplantation

Long-term survival after lung transplantation (LTx) is limited by chronic rejection (CR). Therapeutic strategies for CR have been largely unsuccessful, making prevention of CR an important and challenging therapeutic approach. In the current review, we will discuss current clinical evidence regarding prevention of CR after LTx.

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.

The activity of nintedanib in an animal model of allogenic left lung transplantation resembling aspects of allograft rejection

AIM OF THE STUDY

The prevention and treatment of chronic lung allograft dysfunction (CLAD) after lung transplantation (LTx) remain unsatisfactory. Growth factors may play an important role in the development of CLAD. This study evaluated the effects of nintedanib, a receptor tyrosine kinase inhibitor, in the treatment of CLAD after experimental LTx.

MATERIALS AND METHODS

A rat model of left lung allo-transplantation (Fisher 344 to Wistar Kyoto) was used to evaluate the effect of nintedanib (50 mg/kg per day) on the development of CLAD. Therapy with nintedanib began 2 days before LTx and ended on postoperative day (POD) 20 (n = 6) or 60 (n = 6). Nontreated animals who underwent LTx (n = 12) were used as controls, whereas naïve lungs (n = 24) served as reference for physiological healthy organs without transplantation damage or medical effects. Acute and chronic rejection were evaluated on POD 20 and 60, respectively.

RESULTS

Immunohistologic analysis showed a decrease in growth factors/receptors on POD 60 (nintedanib-treated vs. nontreated controls: platelet-derived growth factor (PDGF) A: [P ≤ 0.001]; PDGF receptor-α: [P ≤ 0.001]; vascular endothelial growth factor (VEGF) A: [P ≤ 0.001]; VEGF receptor-2: [P ≤ 0.001]). However, no reductions in fibrotic changes were observed in nintedanib-treated allografts compared with nontreated allografts. Although nintedanib treatment started before LTx none of the animals showed impaired wound healing. No dehiscence of the sutures of the bronchus, vessels or skin, or stenosis of the bronchus was found.

CONCLUSION

In conclusion, while nintedanib reduced the expression of growth factors/receptors in a rat LTx model, a reduction in fibrotic alterations was not observed at POD 60.

Pretransplant Numbers of CD16+ Monocytes as a Novel Biomarker to Predict Acute Rejection After Kidney Transplantation: A Pilot Study

Acute rejection is one of the major immunological determinants of kidney graft function and survival. Early biomarkers to predict rejection are lacking. Emerging evidence reveals a crucial role for the monocyte/macrophage lineage cells in the pathogenesis of rejection. We hypothesized that higher pretransplant numbers of proinflammatory CD16+ monocytes can predict rejection. The study cohort consisted of 104 kidney transplant recipients (58 with no rejection and 46 with biopsy-proven rejection) and 33 healthy persons. Posttransplant median follow-up time was 14.7 mo (interquartile range 0.3-34 mo). Pretransplantation blood samples were analyzed by flow cytometry for monocyte immunophenotypes. Groups were compared by Cox regression models for the occurrence of acute rejection. We documented a significantly increased absolute number of pretransplant CD16+ monocytes in patients who developed biopsy-proven rejection after transplantation compared with those with no rejection (hazard ratio [HR] 1.60, 95% CI 1.28-2.00, p < 0.001) and healthy persons (HR 1.47, 95% CI 1.18-1.82, p < 0.001). In parallel, significantly fewer absolute numbers of CD16- monocytes were observed at pretransplant time points in rejectors versus nonrejectors (HR 0.74, 95% CI 0.58-0.94, p < 0,014). A higher pretransplant number of CD16+ monocytes is significantly associated with a higher risk of acute rejection after kidney transplantation.

Chronic Rejection of Cardiac Allografts Is Associated With Increased Lymphatic Flow and Cellular Trafficking

BACKGROUND

Cardiac transplantation is an excellent treatment for end-stage heart disease. However, rejection of the donor graft, in particular, by chronic rejection leading to cardiac allograft vasculopathy, remains a major cause of graft loss. The lymphatic system plays a crucial role in the alloimmune response, facilitating trafficking of antigen-presenting cells to draining lymph nodes. The encounter of antigen-presenting cells with T lymphocytes in secondary lymphoid organs is essential for the initiation of alloimmunity. Donor lymphatic vessels are not anastomosed to that of the recipient during transplantation. The pathophysiology of lymphatic disruption is unknown, and whether this disruption enhances or hinders the alloimmune responses is unclear. Although histological analysis of lymphatic vessels in donor grafts can yield information on the structure of the lymphatics, the function following cardiac transplantation is poorly understood.

METHODS

Using single-photon emission computed tomography/computed tomography lymphoscintigraphy, we quantified the lymphatic flow index following heterotrophic cardiac transplantation in a murine model of chronic rejection.

RESULTS

Ten weeks following transplantation of a minor antigen (HY) sex-mismatched heart graft, the lymphatic flow index was significantly increased in comparison with sex-matched controls. Furthermore, the enhanced lymphatic flow index correlated with an increase in donor cells in the mediastinal draining lymph nodes; increased lymphatic vessel area; and graft infiltration of CD4⁺, CD8⁺ T cells, and CD68⁺ macrophages.

CONCLUSIONS

Chronic rejection results in increased lymphatic flow from the donor graft to draining lymph nodes, which may be a factor in promoting cellular trafficking, alloimmunity, and cardiac allograft vasculopathy.

Ethylene carbodiimide-fixed donor splenocytes combined with α-1 antitrypsin induce indefinite donor-specific protection to mice cardiac allografts

Peritransplant infusion of ethylene carbodiimide-fixed donor splenocytes (ECDI-SPs) induces protection of islet and cardiac allografts. However, pro-inflammatory cytokine production during the peritransplantation period may negate the effect of ECDI-SPs. Therefore, we hypothesized that blocking pro-inflammatory cytokine secretion while increasing levels of anti-inflammatory cytokines would enhance the tolerance-induced efficacy of ECDI-SPs. The objective of this study was to determine the effectiveness of using ECDI-SPs combined with a short course of α1-antitrypsin (AAT) for induction of tolerance. Using a mice cardiac transplant model, we demonstrated that ECDI-SPs + AAT effectively induced indefinite mice cardiac allograft protection in a donor-specific fashion. This effect was accompanied by modulation of cytokines through decreasing levels of pro-inflammatory cytokines (including IFN-γ, TNF-α, IL-1β, IL-6, IL-17, and IL-23) and increasing levels of anti-inflammatory cytokines (including IL-10, IL-13, and TGF-β), and by inhibition of effector T cells (Teff) and expansion of regulatory T cells (Tregs). Therefore, we concluded that combined ECDI-SPs and AAT appeared to modulate the expression of cytokines and regulate the Teff:Treg balance to create a support milieu for graft protection. Our strategy of combining ECDI-SPs and AAT provides a promising approach for inducing donor-specific transplant tolerance.

Ushering in the era of penile transplantation

Penile transplantation is a novel approach to management of penile loss in the developing field of composite tissue allotransplantation (CTA). Prior management for significant penile loss has been free flap phalloplasty with issues related to function, cosmesis, and functional loss from the location of flap harvest. Transplantation has been an evolving field with advancement in CTA over the past several decades leading to the option of penile transplant. Management of penile injury with replantation provided some preliminary groundwork on the technical aspects for penile transplantation. Additionally, penile transplantation raises many ethical, emotional, and psychological considerations with need for patience amidst ongoing advancement within the field.

The unsuitability of implantable Doppler probes for the early detection of renal vascular complications - a porcine model for prevention of renal transplant loss

BACKGROUND

Vascular occlusion is a rare, but serious complication after kidney transplantation often resulting in graft loss. We therefore aimed to develop an experimental porcine model for stepwise reduction of the renal venous blood flow and to compare an implantable Doppler probe and microdialysis for fast detection of vascular occlusion.

METHODS

In 20 pigs, implantable Doppler probes were placed on the renal artery and vein and a microdialysis catheter was placed in the renal cortex. An arterial flowprobe served as gold standard. Following two-hour baseline measurements, the pigs were randomised to stepwise venous occlusion, complete venous occlusion, complete arterial occlusion or controls.

RESULTS

All parameters were stable through baseline measurements. Glutamate and lactate measured by microdialysis increased significantly (p = 0.02 and p = 0.03 respectively) 30 minutes after a 2/3 (66%) reduction in renal blood flow. The implantable Doppler probe was not able to detect flow changes until there was total venous occlusion. Microdialysis detected changes in local metabolism after both arterial and venous occlusion; the implantable Doppler probe could only detect vascular occlusions on the vessel it was placed.

CONCLUSIONS

We developed a new model for stepwise renal venous blood flow occlusion. Furthermore, the first comparison of the implantable Doppler probe and microdialysis for detection of renal vascular occlusions was made. The implantable Doppler probe could only detect flow changes after a complete occlusion, whereas microdialysis detected changes earlier, and could detect both arterial and venous occlusion. Based on these results, the implantable Doppler probe for early detection of vascular occlusions cannot be recommended.

Evaluation of TH17 and TH1 Immune Response Profile in Patients After Renal Transplant

BACKGROUND

Renal transplantation (RT) is the best treatment option for patients with end-stage renal disease (ESRD) because it improves both quality of life and survival. However, allograft rejection remains the most important barrier to successful transplantation. Underlying immunologic mechanisms should be understood to develop appropriate treatment strategies.

METHODS

In this prospective study, we followed renal transplant recipients for 6 months. The study population comprised 50 recipients of renal transplants, and these were divided into 2 groups: 44 patients with stable graft function (SGF) and 6 patients with rejection (RX). Peripheral blood samples were drawn from patients on the pre-RT day, at post-RT day 7, month 1, and month 6, and on the day of rejection for analysis of the percentages of cytokines interleukin (IL) 17 and interferon (IFN) γ with the use of flow cytometry and enzyme-linked immunosorbent assay.

RESULTS

The percentages of intracellular IFN-γ were not significant in the group with RX compared with SGF. Levels of intracellular IL-17 obtained at the 6th month after RT were significantly higher in the RX group than in the SGF group. Plasma levels of pre-RT IL-17 were also higher in the RX group; therefore, it may be a predictive biomarker of acute rejection of renal transplants.

CONCLUSIONS

The present study provides information about pre-RT and post-RT cytokine profiles of Turkish patients with ESRD. We consider cytokine analysis to be a valuable biomarker panel in the prevention of rejection and in assisting with new treatment strategies for patients undergoing renal transplant.

The Presence of Anti-Angiotensin II Type-1 Receptor Antibodies Adversely Affect Kidney Graft Outcomes

The aim of this study was to determine whether anti-angiotensin type 1 receptor antibodies (AT1R-Abs) are related to acute rejection (AR) and kidney graft failure in renal transplantation. We searched electronic databases including MEDLINE, EMBASE, and the ISI Web of Science databases for all studies on the association between anti-angiotensin type 1 receptor antibodies and kidney allograft outcomes updated to November 2016. Reference lists from included articles were also reviewed. The pooled relative risks (RRs) with 95% confidence intervals (CIs) were extracted or calculated using a random-effects model. The potential sources of heterogeneity and publication bias were estimated. Nine studies enrolling 1771 subjects were retrieved in the meta-analysis. AT1R-Abs showed significant associations with increased risk of AR (RR = 1.66; 95% CI, 1.23–2.09). In addition, a significant relationship was found between AT1R-Abs and kidney graft failure compared with AR (RR = 3.02; 95% CI, 1.77–4.26). The results were essentially consistent among subgroups stratified by participant characteristics. These results demonstrated that the AT1R-Abs were associated with an elevated risk of kidney allograft outcomes, especially with kidney graft failure. Large-scale studies are still required to further verify these findings.

Modification of immunosuppressive therapy as risk factor for complications after liver transplantation

Management of complications post-liver transplantation (LT) includes immunosuppressive manipulations with the aim to reduce the overall burden of immunologic suppression and compensate for renal, cardiovascular, metabolic toxicities, and for the increased oncologic risk. Two approaches can be implemented to reduce immunosuppression-related adverse events: upfront schedules tailored to the pretransplant individual patient's risk profile versus downstream modifications in the event of immunosuppression-related complications. Upfront strategies are supported by evidence originating from prospective randomized trials and consist of triple/quadruple schedules whereby calcineurin inhibitors (CNI)-exposure is reduced with combination of anti-CD25 monoclonal antibodies, antimetabolites and corticosteroids. Quadruple regimens allow for staggering of CNI introduction and higher renal function in the early term, but their superiority in the long term has not yet been established. A more recent upfront schedule contemplates early (4 weeks) introduction of mammalian target of rapamycin inhibitor (mTORi) everolimus and allows for reduction of CNI up to 4 years posttransplantation. Incorporation of mTORi has the potential to prolong time to recurrence for patients with hepatocellular carcinoma. However, as suggested by the available evidence, downstream immunosuppressive manipulations are more frequently adopted in clinical practice. These encompass CNI replacement and immunosuppression withdrawal. Switching CNI to mTORi monotherapy is the option most commonly adopted to relieve renal function and compensate for posttransplant malignancies. Its impact is dependent on interval from transplantation and underlying severity of renal impairment. Introduction of mTORi is associated with longer overall survival for patients with extrahepatic posttransplant malignancies, but results are awaited for recurrences of hepatocellular carcinoma. Immunosuppression withdrawal seems feasible (70%) in very long term survivors (>10 years), but is not associated with reversal of immunosuppression-related complications. Awaiting novel immunosuppressive drug categories, integration of upfront strategies with the aim to reduce CNI-exposure and a low threshold for adjustment in the posttransplant course are both advisable to improve long-term outcomes of LT.