Time since liver transplant and immunosuppression withdrawal outcomes: Systematic review and individual patient data meta-analysis.

BACKGROUND & AIMS: Successful immunosuppression withdrawal (ISW) is possible for a subfraction of liver transplant (LT) recipients but the factors that define the risk of ISW failure are largely unknown. One candidate prognostic factor for ISW success or operational tolerance (OT) is longer time between LT and ISW which we term "pre-withdrawal time". To clarify the impact of pre-withdrawal time span on subsequent ISW success or failure, we conducted a systematic review with meta-analysis. METHODS: We systematically interrogated the literature for LT recipient ISW studies reporting pre-withdrawal time. Eligible articles from Embase, Medline, and the Cochrane Central Register of Controlled Trials were used for backward and forward citation searching. Pre-withdrawal time individual patient data (IPD) was requested from authors. Pooled mean differences and time-response curves were calculated using random-effects meta-analyses. RESULTS: We included 17 studies with 691 patients, 15 of which (620 patients) with IPD. Study-level risk of bias was heterogeneous. Mean pre-withdrawal time was greater by 427 days [95% confidence interval (CI) 67-788] in OT compared to non-OT patients. This increase was potentiated to 799 days (95% CI 369-1229) or 1074 days (95% CI 685-1463) when restricting analysis to adult or European study participants. In time-response meta-analysis for adult or European ISW candidates, likelihood of OT increased by 7% (95% CI 4-10%) per year after LT (GRADE low- and moderate-certainty of evidence, respectively). CONCLUSIONS: Our data support the impact of pre-withdrawal time in ISW decision-making for adult and European LT recipients. PROSPERO REGISTRATION: CRD42021272995.

Magnetic Dynamo Caused by Axions in Neutron Stars.

The coupling between axions and photons modifies Maxwell's equations, introducing a dynamo term in the magnetic induction equation. In neutron stars, for critical values of the axion decay constant and axion mass, the magnetic dynamo mechanism increases the total magnetic energy of the star. We show that this generates substantial internal heating due to enhanced dissipation of crustal electric currents. These mechanisms would lead magnetized neutron stars to increase their magnetic energy and thermal luminosity by several orders of magnitude, in contrast to observations of thermally emitting neutron stars. To prevent the activation of the dynamo, bounds on the allowed axion parameter space can be derived.

Effects of everolimus plus minimized tacrolimus on kidney function in liver transplantation: REDUCE, a prospective, randomized controlled study.

BACKGROUND AND AIM: reduction in calcineurin inhibitor levels is considered crucial to decrease the incidence of kidney dysfunction in liver transplant (LT) recipients. The aim of this study was to evaluate the safety and impact of everolimus plus reduced tacrolimus (EVR + rTAC) vs. mycophenolate mofetil plus tacrolimus (MMF + TAC) on kidney function in LT recipients from Spain. METHODS: the REDUCE study was a 52-week, multicenter, randomized, controlled, open-label, phase 3b study in de novo LT recipients. Eligible patients were randomized (1:1) 28 days post-transplantation to receive EVR + rTAC (TAC levels ≤ 5 ng/mL) or to continue with MMF + TAC (TAC levels = 6-10 ng/mL). Mean estimated glomerular filtration rate (eGFR), clinical benefit in renal function, and safety were evaluated. RESULTS: in the EVR + rTAC group (n = 105), eGFR increased from randomization to week 52 (82.2 [28.5] mL/min/1.73 m2 to 86.1 [27.9] mL/min/1.73 m2) whereas it decreased in the MMF + TAC (n = 106) group (88.4 [34.3] mL/min/1.73 m2 to 83.2 [25.2] mL/min/1.73 m2), with significant (p < 0.05) differences in eGFR throughout the study. However, both groups had a similar clinical benefit regarding renal function (improvement in 18.6 % vs. 19.1 %, and stabilization in 81.4 % vs. 80.9 % of patients in the EVR + rTAC vs. MMF + TAC groups, respectively). There were no significant differences in the incidence of acute rejection (5.7 % vs. 3.8 %), deaths (5.7 % vs. 2.8 %), and serious adverse events (51.9 % vs. 44.0 %) between the 2 groups. CONCLUSION: EVR + rTAC allows a safe reduction in tacrolimus exposure in de novo liver transplant recipients, with a significant improvement in eGFR but without significant differences in renal clinical benefit 1 year after liver transplantation.

Changes in humoral immune response after SARS-CoV-2 infection in liver transplant recipients compared to immunocompetent patients.

The protective capacity and duration of humoral immunity after SARS-CoV-2 infection are not yet understood in solid organ transplant recipients. A prospective multicenter study was performed to evaluate the persistence of anti-nucleocapsid IgG antibodies in liver transplant recipients 6 months after coronavirus disease 2019 (COVID-19) resolution. A total of 71 liver transplant recipients were matched with 71 immunocompetent controls by a propensity score including variables with a well-known prognostic impact in COVID-19. Paired case-control serological data were also available in 62 liver transplant patients and 62 controls at month 3 after COVID-19. Liver transplant recipients showed a lower incidence of anti-nucleocapsid IgG antibodies at 3 months (77.4% vs. 100%, p < .001) and at 6 months (63.4% vs. 90.1%, p < .001). Lower levels of antibodies were also observed in liver transplant patients at 3 (p = .001) and 6 months (p < .001) after COVID-19. In transplant patients, female gender (OR = 13.49, 95% CI: 2.17-83.8), a longer interval since transplantation (OR = 1.19, 95% CI: 1.03-1.36), and therapy with renin-angiotensin-aldosterone system inhibitors (OR = 7.11, 95% CI: 1.47-34.50) were independently associated with persistence of antibodies beyond 6 months after COVID-19. Therefore, as compared with immunocompetent patients, liver transplant recipients show a lower prevalence of anti-SARS-CoV-2 antibodies and more pronounced antibody levels decline.

Controlled donation after circulatory death up to 80 years for liver transplantation: Pushing the limit again.

Our main objective was to compare liver transplant (LT) results between donation after circulatory death (DCD) and donation after brainstem death (DBD) in our hospital and to analyze, within the DCD group, the influence of age on the results obtained with DCD donors aged >70 years and up to 80 years. All DCD-LTs performed were analyzed prospectively. The results of the DCD group were compared with those of a control group who received a DBD-LT immediately after each DCD-LT. Later, the results obtained within the DCD group were analyzed according to the age of the donors, considering 2 subgroups with a cut-off point at 70 years. Survival results for LT with DCD and super rapid recovery were not inferior to those obtained in a similar group of patients transplanted with DBD livers. However, the cost of DCD was a higher rate of biliary complications, including ischemic cholangiopathy. Donor age was not a negative factor.

Extracellular adenosine reversibly inhibits the activation of human regulatory T cells and negatively influences the achievement of the operational tolerance in liver transplantation.

The artificial induction of tolerance in transplantation is gaining strength. In mice, a differential role of extracellular adenosine (eADO) for regulatory and effector T cells (Tregs and Teffs, respectively) has been proposed: inhibiting Teffs and inducing Tregs. The aim of this study was to analyze the action of extracellular nucleotides in human T cells and, moreover, to examine the influence of CD39 and CD73 ectonucleotidases and subsequent adenosine signaling through adenosine 2 receptor (A2 R) in the induction of clinical tolerance after liver transplant. The action of extracellular nucleotides in human T cells was analyzed by in vitro experiments with isolated T cells. Additionally, 17 liver transplant patients were enrolled in an immunosuppression withdrawal trial, and the differences in the CD39-CD73-A2 R axis were compared between tolerant and nontolerant patients. In contrast to the mice, the activation of human Tregs was inhibited similarly to Teffs in the presence of eADO. Moreover, the expression of the enzyme responsible for the degradation of ADO, adenosine deaminase, was higher in tolerant patients with respect to the nontolerant group along the immunosuppression withdrawal. Our data support the idea that eADO signaling and its degradation may play a role in the complex system of regulation of liver transplant tolerance.

Influence of donor liver CYP3A4*20 loss-of-function genotype on tacrolimus pharmacokinetics in transplanted patients.

OBJECTIVE: Cytochrome P450 3A4 (CYP3A4) metabolizes about half of all drugs on the market; however, the impact of CYP3A4 loss-of-function variants on drug exposures remains poorly characterized. Here, we report the effect of the CYP3A4*20 frameshift allele in two Spanish liver transplant patients treated with tacrolimus. PATIENTS AND METHODS: A series of 90 transplanted patients (with DNA available for 89 of the recipients and 76 of the liver donors) treated with tacrolimus were included in the study. The genotypes of liver donors and of the recipients for CYP3A4*20 (rs67666821), CYP3A4*22 (rs35599367) and CYP3A5*3 (rs776746) were compared with weight-adjusted tacrolimus dose (D), tacrolimus trough concentration (C0), and dose-adjusted tacrolimus trough concentrations (C0/D) using the Mann-Whitney U-nonparametric test. RESULTS: The CYP3A4*20 allele was detected in two of the liver donors. This genotype yielded at all times higher C0/D (2.6-fold, average) than intermediate CYP3A metabolizers (CYP3A4*1/*1 and CYP3A5*3/*3) (P=0.045, 90 days after transplantation). CYP3A4*22 carriers showed a 1.9-fold average increase in C0/D (P=0.047, 0.025, and 0.053; at days 7, 14, and 30 after transplantation, respectively) compared with intermediate metabolizers. In terms of recipients' genotype, CYP3A5*1 had reduced (P=0.025) and CYP3A4*22 increased C0/D (P=0.056) 7 days after transplantation. The incidence of biopsy-proven acute rejection was 0, 12, and 20% for livers with poor, intermediate, and extensive CYP3A-metabolizing capacity, respectively (P=0.0995). CONCLUSION: This first description of CYP3A4*20 null genotype in liver-transplanted patients, supports the relevance of CYP3A genotyping in tacrolimus therapy.

Acute cellular rejection versus recurrent hepatitis C after liver transplantation: Clinical and pathological features driving a rational diagnostic approach.

AIM: The aim of our study was develop and validate an algorithm system based on morphological features for finding the differences between recurrent hepatitis C virus (HCV) and acute cellular rejection (ACR) in liver biopsies of HCV-transplanted patients. METHODS: Two hundred and eighty-eight liver biopsies were analyzed from 121 patients transplanted for HCV. A diagnostic consensus was reached between clinicians and pathologists in 214 biopsies for the diagnosis of recurrent HCV or ACR. A random sample of 114 liver biopsies (derivation cohort) was taken to generate the diagnostic tree and was subsequently evaluated using the validation cohort in 100 liver biopsies by recursive partitioning analysis of morphological variables and time since transplantation. RESULTS: The presence of endotheliitis together with a time of less than 6 weeks since LT definitely excluded recurrent HCV. After obtaining the regression tree, diagnostic accuracy was 96% and 93% in the derivation and validation cohort, respectively. Both cases surpassed the pathologist's original diagnosis, which had a diagnostic accuracy of 91% (P < 0.05, for both comparisons). CONCLUSION: A recursive partitioning analysis of the morphological features in liver biopsies from HCV-transplanted patients may be useful for easily distinguishing between recurrent HCV and ACR.

PNPLA3 rs738409 causes steatosis according to viral & IL28B genotypes in hepatitis C.

BACKGROUND: Hepatitis C virus (HCV) is associated with a higher prevalence of steatosis compared to the general population. AIM: Our aim was to assess the impact of PNPLA3 rs738409 G-allele on steatosis in HCV patients. MATERIAL AND METHODS: We included 474 HCV patients treated with peginterferon plus ribavirin. PNPLA3 rs738409 was genotyped and patients were classified according to alleles and genotypes. Steatosis was detected in 46.4% (220/474). Fibrosis was assessed by Scheuer score. Gene expression was analyzed in Huh7.5 and Huh7 cells using Real Time-PCR. RESULTS: PNPLA3 allele-G was associated with steatosis [54.1% (126/233) vs. 39% (94/241)] (p = 0.0001). In HCV-1, allele-G was related to steatosis [50.6% (82/162) vs. 32.3% (53/164)] (p = 0.001), but did not in HCV-3 [61.9% (26/42) vs. 62% (31/50)] (p = 0.993). PNPLA3 allele-G was associated with steatosis in patients with IL28B-CT/TT [57.7% (82/142) vs. 37.1% (56/151)] (p = 0.0001), but did not in IL28B-CC [47.8% (43/90) vs. 42% (37/88)] (p = 0.442). Independent variables associated with steatosis were: PNPLA3 G-allele [O.R. 1.84 (CI95%: 1.06-3.21); p = 0.007], age [O.R. 1.04 (CI95%: 1.01-1.07); p = 0.017], HCV-genotype 3 [O.R. 2.46 (CI95%: 1.30-4.65); p = 0.006], HOMA > 4 [O.R. 2.72 (CI95%: 1.27-5.82); p = 0.010]. Since PNPLA3 RNA could not be detected on PBMC from HCV patients, an in vitro analysis was performed. Huh7.5 cells infected with JFH1 had a decreased PNPLA3 gene expression (fold inhibition = 3.2 ± 0.2), while Huh7 cells presented increased PNPLA3 gene expression (fold induction = 1.5 ± 0.2). CONCLUSION: PNPLA3 allele-G modulated the development of steatosis, particularly in patients with HCV-1 and IL28B-CT/TT genotype, but was not associated with SVR. Metabolic but not viral steatosis seems to be PNPLA3 regulated. Gene interaction may result in differential PNPLA3 gene expression levels in HCV infection.

Detection of inflammasome activation in liver tissue during the donation process as potential biomarker for liver transplantation.

Deceased donor liver transplantation (LT) is a crucial lifesaving option for patients with end-stage liver diseases. Although donation after brain death (DBD) remains the main source of donated organs, exploration of donation after circulatory death (DCD) addresses donor scarcity but introduces challenges due to warm ischemia. While technical advances have improved outcomes, challenges persist, with a 13% mortality rate within the first year. Delving into liver transplantation complexities reveals the profound impact of molecular signaling on organ fate. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation play a pivotal role, influencing inflammatory responses. The NLRP3 inflammasome, found in hepatocytes, contributes to inflammation, fibrosis, and liver cell death. This study explores these dynamics, shedding light on potential biomarkers and therapeutic targets. Samples from 36 liver transplant patients were analyzed for ASC specks detection and inflammasome-related gene expression. Liver biopsies, obtained before and after cold ischemia storage, were processed for immunofluorescence, qRT-PCR, and Western blot. One year post-LT clinical follow-up included diagnostic procedures for complications, and global survival was assessed. Immunofluorescence detected activated inflammasome complexes in fixed liver tissues. ASC specks were identified in hepatocytes, showing a trend toward more specks in DCD livers. Likewise, inflammasome-related gene expression analysis indicated higher expression in DCD livers, decreasing after cold ischemia. Similar results were found at protein level. Patients with increased ASC specks staining exhibited lower overall survival rates, correlating with IL1B expression after cold ischemia. Although preliminary, these findings offer novel insights into utilizing direct detection of inflammasome activation in liver tissue as a biomarker. They suggest its potential impact on post-transplant outcomes, potentially paving the way for improved diagnostic approaches and personalized treatment strategies in LT.

Endothelial cell activation mediated by cold ischemia-released mitochondria is partially inhibited by defibrotide and impacts on early allograft function following liver transplantation.

DAMPs (danger-associated molecular patterns) are self-molecules of the organism that appear after damage. The endothelium plays several roles in organ rejection, such as presenting alloantigens to T cells and contributing to the development of inflammation and thrombosis. This study aimed to assess whether DAMPs present in the organ preservation solution (OPS) after cold ischemic storage (CIS) contribute to exacerbating the endothelial response to an inflammatory challenge and whether defibrotide treatment could counteract this effect. The activation of cultured human umbilical vein endothelial cells (HUVECs) was analyzed after challenging with end-ischemic OPS (eiOPS) obtained after CIS. Additionally, transwell assays were performed to study the ability of eiOPS to attract lymphocytes across the endothelium. The study revealed that eiOPS upregulated the expression of MCP-1 and IL-6 in HUVECs. Moreover, eiOPS increased the membrane expression of ICAM-1and HLA-DR, which facilitated leukocyte migration toward a chemokine gradient. Furthermore, eiOPS demonstrated its chemoattractant ability. This activation was mediated by free mitochondria. Defibrotide was found to partially inhibit the eiOPS-mediated activation. Moreover, the eiOPS-mediated activation of endothelial cells (ECs) correlated with early allograft dysfunction in liver transplant patients. Our finding provide support for the hypothesis that mitochondria released during cold ischemia could trigger EC activation, leading to complications in graft outcomes. Therefore, the analysis and quantification of free mitochondria in the eiOPS samples obtained after CIS could provide a predictive value for monitoring the progression of transplantation. Moreover, defibrotide emerges as a promising therapeutic agent to mitigate the damage induced by ischemia in donated organs.

Danger signals released during cold ischemia storage activate NLRP3 inflammasome in myeloid cells and influence early allograft function in liver transplantation.

BACKGROUND: Innate immunity plays a fundamental role in solid organ transplantation. Myeloid cells can sense danger signals or DAMPs released after tissue or cell damage, such as during ischemia processes. This study aimed to identify DAMPs released during cold ischemia storage of human liver and analyze their ability to activate the inflammasome in myeloid cells and the possible implications in terms of short-term outcomes of liver transplantation. METHODS: 79 samples of organ preservation solution (OPS) from 79 deceased donors were collected after cold static storage. We used different analytical methods to measure DAMPs in these end-ischemic OPS (eiOPS) samples. We also used eiOPS in the human macrophage THP-1 cell line and primary monocyte cultures to study inflammasome activation. FINDINGS: Different DAMPs were identified in eiOPS, several of which induced both priming and activation of the NLRP3 inflammasome in human myeloid cells. Cold ischemia time and donation after circulatory death negatively influenced the DAMP signature. Moreover, the presence of oligomeric inflammasomes and interleukin-18 in eiOPS correlated with early allograft dysfunction in liver transplant patients. INTERPRETATION: DAMPs released during cold ischemia storage prime and activate the NLRP3 inflammasome in liver macrophages after transplantation, inducing a pro-inflammatory environment that will complicate the outcome of the graft. The use of pharmacological blockers targeting DAMPs or the NLRP3 inflammasome in liver ischemia during static cold storage or through extracorporeal organ support could be a suitable strategy to increase the success of liver transplantation. FUNDING: Fundación Mutua Madrileña and Instituto de Salud Carlos III, Madrid, Spain.

Attitudinal study of organ xenotransplantation in patients on the kidney and liver transplant waiting list in a country with a high rate of deceased donation.

BACKGROUND: The organ transplant deficit is leading to an increase in the importance of solid organ xenotransplantation. However, the use of animals for human transplantation causes a certain amount of opposition in patients and the general public. The objective of this study was to analyze the attitude of patients on the kidney and liver waiting list toward xenotransplantation and the variables affecting this attitude. METHODS: Patients on the kidney and liver waiting list (January 2003 - December 2005) were surveyed. Attitude toward xenotransplantation was assessed using a psychosocial questionnaire about the donation of organs of animal origin administered by a healthcare professional from the Transplant Unit. RESULTS: A total of 373 patients were interviewed (kidney [n=214] and liver patients [n=158]). In the case of kidney patients, if the results of xenotransplantation were as effective as those attained using human organs, 76% (n=162) would be in favor. If the results were worse, only 8% (n=17) would be in favor. Two factors affected this attitude: a high level of education (P=0.007) and a positive attitude toward organ donation upon death (P< 0.001). In the case of liver patients, 67% (n=106) would be in favor if the results of xenotransplantation were as effective as those attained using human organs, decreasing to 16% (n=25) if the results were worse. Attitude toward deceased organ donation also affected the attitude of these patients (P<0.043). CONCLUSIONS: The attitude toward xenotransplantation of patients on the kidney and liver transplant waiting list was favorable and associated with a positive attitude toward human organ donation.

Proteomics in Liver Transplantation: A Systematic Review.

Background: Although proteomics has been employed in the study of several models of liver injury, proteomic methods have only recently been applied not only to biomarker discovery and validation but also to improve understanding of the molecular mechanisms involved in transplantation. Methods: The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and the guidelines for performing systematic literature reviews in bioinformatics (BiSLR). The PubMed, ScienceDirect, and Scopus databases were searched for publications through April 2020. Proteomics studies designed to understand liver transplant outcomes, including ischemia-reperfusion injury (IRI), rejection, or operational tolerance in human or rat samples that applied methodologies for differential expression analysis were considered. Results: The analysis included 22 studies after application of the inclusion and exclusion criteria. Among the 497 proteins annotated, 68 were shared between species and 10 were shared between sample sources. Among the types of studies analyzed, IRI and rejection shared a higher number of proteins. The most enriched pathway for liver biopsy samples, IRI, and rejection was metabolism, compared to cytokine-cytokine receptor interactions for tolerance. Conclusions: Proteomics is a promising technique to detect large numbers of proteins. However, our study shows that several technical issues such as the identification of proteoforms or the dynamic range of protein concentration in clinical samples hinder the successful identification of biomarkers in liver transplantation. In addition, there is a need to minimize the experimental variability between studies, increase the sample size and remove high-abundance plasma proteins.

A high concentration of TGF-ß correlates with opportunistic infection in liver and kidney transplantation.

Transforming growth factor-ß (TGF-ß) has been associated with numerous human infections, but its role in the occurrence of opportunistic infection (OI) after solid organ transplantation remains unexplored. This study aimed to assess the utility of the TGF-ß following in vitro stimulation of whole peripheral blood (WPB) as a surrogate biomarker of post-transplant OI in a cohort of liver and kidney recipients. Thirty liver and thirty-one kidney transplant recipients were recruited to be prospectively monitored for one-year post-transplantation. Enzyme-linked immunosorbent assay (ELISA) was performed to calculate IFN-γ, IL-17, IL-10 and TGF-ß concentration in the supernatant from the activated WPB. Recipients showed higher TGF-ß concentrations compared to IFN-γ, IL-17, IL-10 at baseline, although these differences were not significant between INF and NoINF. However, recipients who developed an OI within the first sixth months had a higher concentration of TGF-ß than those without OI. A concentration of TGF-ß > 363.25 pg/ml in liver and TGF-ß > 808.51 pg/ml in kidney recipients were able to stratify patients at high risk of OI with a sensitivity and specificity above 70% in both types of solid organ transplantations. TGF-ß could provide valuable information for the management of liver and kidney recipients at risk of post-transplant infection.

Severe COVID-19 after liver transplantation, surviving the pitfalls of learning on-the-go: Three case reports.

BACKGROUND: The novel coronavirus 2019 (COVID-19) pandemic has dramatically transformed the care of the liver transplant patient. In patients who are immunosuppressed and with multiple comorbidities, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with increased severity and mortality. The main objective of this report is to communicate our experience in the therapeutic management of SARS-CoV-2 infection in 3 liver transplant patients. Secondly, we stress the management and investigation of the contagious spreading into a liver transplant ward. CASE SUMMARY: The patients were two women (aged 61 years and 62 years) and one man (aged 68 years), all of them having recently received a liver transplant. All three patients required intensive care unit admission and invasive mechanical ventilation. Two of them progressed severely until death. The other one, who received tocilizumab, had a good recovery. In the outbreak, the wife of one of the patients and four healthcare professionals involved in their care were also infected. CONCLUSION: We illustrate in detail the evolution of a nosocomial COVID-19 outbreak in a liver transplant ward. We believe that these findings will contribute to a better understanding of the natural history of the disease and will improve the treatment of the liver transplant patient with COVID-19.

Influence of Preformed Antibodies in Liver Transplantation.

The significance of human leukocyte antigen (HLA) matching and preformed donor-specific antibodies (DSAs) in liver transplantation remains unclear. The aim of this study was to analyze the presence of DSAs in a large cohort of 810 liver recipients undergoing liver transplant to determine the influence on acute (AR) or chronic liver rejection (CR), graft loss and allograft survival. DSAs were identified using complement dependent cytotoxicity crossmatch (CDC-CM) and multiplexed solid-phase-based flow cytometry assay (Luminex). CDC-CM showed that a 3.2% of liver transplants were positive (+CDC-CM) with an AR frequency of 19.2% which was not different from that observed in negative patients (-CDC-CM, 22.3%). Only two patients transplanted with +CDC-CM (7.6%) developed CR and suffered re-transplant. +CDC-CM patients showed a significantly lower survival rate compared to -CDC-CM patients (23.1% vs. 59.1%, p = 0.0003), developing allograft failure within the first three months (p < 0.00001). In conclusion, we have demonstrated a relationship between the presence of preformed DSAs and the low graft liver survival, indicating the important role and the potential interest of performing this analysis before liver transplantation. Our results could help to detect patients with an increased risk of graft loss, a better choice of liver receptors as well as the establishment of individualized immunosuppressive regimens.

Immunosuppression withdrawal improves long-term metabolic parameters, cardiovascular risk factors and renal function in liver transplant patients.

After liver transplantation, long-term immunosuppression (IS) administration is commonly complicated by renal dysfunction and cardiovascular complications. Twenty liver transplant patients on cyclosporine (CyA)-based IS were followed up prospectively after IS withdrawal. They consisted of 10 electively weaned patients and 10 either forcibly or incidentally weaned patients. Liver biochemical tests, blood pressure, serum creatinine, serum urea, serum uric acid, triglycerides, cholesterol and glucose were monitored after the start of weaning. Eight of the 20 patients (40%) were IS therapy free for a mean period of 61 +/- 39 months (range: 10-132 months). Of the remaining 12 patients, mild or moderate acute rejection occurred in six patients (30%), and mixed inflammatory portal tract infiltrate was seen in another six patients (30%). At the end of the study, mean (SD) serum creatinine had fallen by 0.28 (0.10) mg/dL (p < 0.001) in operationally tolerant (T) patients whereas the serum creatinine level increased in IS-dependent patients [+0.35 (0.35) mg/dL] (p = 0.005). In T patients, serum cholesterol, serum uric acid, fasting glucose and diastolic arterial pressure values significantly decreased. IS withdrawal can be achieved in selected liver transplant patients, and can improve not only kidney function, but also other CyA-associated side effects, such as hypercholesterolemia, hyperuricemia, hypertension and diabetes.

Tolerance Biomarkers in Liver Transplantation: Independent External Validation of the Predictive Strength of SENP6 and FEM1C Gene Expression.

BACKGROUND: Numerous studies have emphasized the genetic and phenotypic profiles of tolerant transplant patients. Moreover, different groups have defined several biomarkers, trying to distinguish patients who are going to be tolerant from those who are going to reject. However, most of these biomarkers have not been validated by other groups or even established for clinical practice. METHODS: We reanalyzed and stratified the predictive capacity of 20 previously described biomarkers for liver transplantation tolerance in a cohort of 17 liver transplant patients subjected to an independent, nonrandomized, prospective study of immunosuppression drug withdrawal. RESULTS: Only 4 of the 20 studied biomarkers (expression of SENP6, FEM1C, miR31, and miR95) showed a strong predictive capacity in the present study. miR31 and FEM1C presented an area under the ROC curve of 96.7%, followed by SENP1 with 93.3%. Finally, miR95 had an area under the ROC curve value <86.7%. CONCLUSIONS: Even though this independent analysis seems to confirm the predictive strength of SENP6 and FEM1C in liver transplantation tolerance, there are also risks in establishing biomarkers for clinical phenotypes without an understanding of how they are biologically relevant. Future collaborations between groups should be promoted so that the most promising biomarkers can be validated and implemented in daily clinical practice.