Post-Liver Transplant Acute Kidney Injury.

Acute kidney injury (AKI) is a common condition following liver transplantation (LT). It negatively impacts patient outcomes by increasing the chances of developing chronic kidney disease and reducing graft and patient survival rates. Multiple definitions of AKI have been proposed and used throughout the years, with the International Club of Ascites definition being the most widely now used for patients with cirrhosis. Multiple factors are associated with the development of post-LT AKI and can be categorized into pre-LT comorbidities, donor and recipient characteristics, operative factors, and post-LT factors. Many of these factors can be optimized in an attempt to minimize the risk of AKI occurring and to improve renal function if AKI is already present. A special consideration during the post-LT phase is needed for immunosuppression as certain immunosuppressive medications can be nephrotoxic. The calcineurin inhibitor tacrolimus (TAC) is the mainstay of immunosuppression but can result in AKI. Several strategies including use of the monoclonoal antibody basilixamab to allow for delayed initiation of tacrolimus therapy and minimization through combination and minimization or elimination of TAC through combination with mycophenolate mofetil or mammalian target of rapamycin inhibitors have been implemented to reverse and avoid AKI in the post-LT setting. Renal replacement therapy may ultimately be required to support patients until recovery of AKI after LT. Overall, by improving renal function in post-LT patients with AKI, outcomes can be improved.

Identifying Modifiable Predictors of Long-Term Survival in Liver Transplant Recipients With Diabetes Mellitus Using Machine Learning.

Diabetes mellitus (DM) significantly impacts long-term survival after liver transplantation (LT). We identified survival factors for LT recipients who had DM to inform preventive care using machine-learning analysis. We analyzed risk factors for mortality in patients from across the United States using the Scientific Registry of Transplant Recipients (SRTR). Patients had undergone LT from 1987 to 2019, with a follow-up of 6.47 years (standard deviation [SD] 5.95). Findings were validated on a cohort from the University Health Network (UHN) from 1989 to 2014 (follow-up 8.15 years [SD 5.67]). Analysis was conducted with Cox proportional hazards and gradient boosting survival. The training set included 84.67% SRTR data (n = 15,289 patients), and the test set included 15.33% SRTR patients (n = 2769) and data from UHN patients (n = 1290). We included 18,058 adults (12,108 [67.05%] men, average age 54.21 years [SD 9.98]) from the SRTR who had undergone LT and had complete data for investigated features. A total of 4634 patients had preexisting DM, and 3158 had post-LT DM. The UHN data consisted of 1290 LT recipients (910 [70.5%] men, average age 54.0 years [SD 10.4]). Increased serum creatinine and hypertension significantly impacted mortality with preexisting DM 1.36 (95% confidence interval [CI], 1.21-1.54) and 1.20 (95% CI, 1.06-1.35) times, respectively. Sirolimus use increased mortality 1.36 times (95% CI, 1.18-1.58) in nondiabetics and 1.33 times (95% CI, 1.09-1.63) in patients with preexisting DM. A similar effect was found in post-LT DM, although it was not statistically significant (1.38 times; 95% CI, 1.07-1.77; P = 0.07). Survival predictors generally achieved a 0.60 to 0.70 area under the receiver operating characteristic for 5-year mortality. LT recipients who have DM have a higher mortality risk than those without DM. Hypertension, decreased renal function, and sirolimus for maintenance immunosuppression compound this mortality risk. These predisposing factors must be intensively treated and modified to optimize long-term survival after transplant.

Using technology to assess nutritional status and optimize nutrition therapy in critically ill patients.

PURPOSE OF REVIEW: Malnutrition is prevalent in critically ill patients and is linked to worse outcomes such as prolonged mechanical ventilation, length of intensive care unit (ICU) stay, and increased mortality. Therefore, nutritional therapy is important. However, it is often difficult to accurately identify those at high malnutrition risk and to optimize nutritional support. Different technological modalities have therefore been developed to identify patients at high nutritional risk and to guide nutritional support in an attempt to optimize outcomes. RECENT FINDINGS: Computed tomography (CT), ultrasound (US), and bioelectrical impedance analysis are tools that allow assessment of lean body mass and detection of sarcopenia, which is a significant marker of poor nutrition. The use of indirect calorimetry allows the determination of resting energy expenditure to serve as a guide to providing optimal nutrition intake in ICU patients. SUMMARY: By using CT, US, or bioelectrical impedance analysis, detection of sarcopenia can be undertaken in patients admitted to the ICU. This allows for an accurate picture of underlying nutritional status to help clinicians focus on nutritional support for these patients. Subsequently, indirect calorimetry can be used to guide optimal nutrition therapy and caloric intake in critically ill patients. However, whether these methods result in improved outcomes in critically ill patients remains to be validated.

Significant lung injury and its prognostic significance in acute liver failure: A cohort analysis.

BACKGROUND AND AIMS: Respiratory failure complicating acute liver failure (ALF) may preclude liver transplantation (LT). We evaluated the association between significant lung injury (SLI) and important clinical outcomes. METHODS: Retrospective cohort study of 947 ALF patients with chest radiograph (CXR) and arterial blood gas (ABG) data enrolled in the US Acute Liver Failure Study Group (US-ALFSG) from January 1998 to December 2016. SLI was defined by moderate hypoxaemia (Berlin classification; PaO2 /FiO2  < 200 mm Hg) and abnormalities on CXR. Primary outcomes were 21-day transplant-free survival (TFS) and overall survival. RESULTS: Of 947 ALF patients, 370 (39%) had evidence of SLI. ALF patients with SLI (ALF-SLI) had significantly worse oxygenation than controls on admission (median PF ratio 120 vs 300 mm Hg, P < .0001) and higher lactate (6.1 vs 4.6 mmol/l, P = .0008). ALF-SLI patients had higher rates of tracheal (19% vs 14%) and bloodstream (17% vs 11%, P < .005 for both) infections and were more likely to receive transfusions (red cells 55% vs 43%; FFP 74% vs 66%; P < .009 for both). ALF-SLI patients were less likely to receive LT (18% vs 25%, P = .02) and had significantly decreased 21-day TFS (34% vs 42%) and overall survival (49% vs 64%, P < .007 for both). After adjusting for significant covariates (INR, bilirubin, acetaminophen aetiology), the development of SLI was independently associated with decreased 21-day TFS (OR 0.71, P = .03) in ALF patients (C-index 0.78). The incorporation of SLI improved discriminatory ability of the King's College Criteria (P = .0061) but not the ALFSG prognostic index (P = .34). CONCLUSION: Significant lung injury is a common complication in ALF patients that adversely affects patient outcomes.

The impact of delayed source control and antimicrobial therapy in 196 patients with cholecystitis-associated septic shock: a cohort analysis

Background: Cholecystitis-associated septic shock carries a significant mortality. Our aim was to determine whether timing of source control affects survival in cholecystitis patients with septic shock. Methods: We conducted a nested cohort study of all patients with cholecystitis-associated septic shock from an international, multicentre database (1996­2015). Multivariable logistic regression was performed to determine associations between clinical factors and in-hospital mortality. The results were used to inform a classification and regression tree (CART) analysis that modelled the association between disease severity (APACHE II), time to source control and survival. Results: Among 196 patients with cholecystitis-associated septic shock, overall mortality was 37%. Compared with nonsurvivors (n = 72), survivors (n = 124) had lower mean admission APACHE II scores (21 v. 27, p < 0.001) and lower median admission serum lactate (2.4 v. 6.8 µmol/L, p < 0.001). Survivors were more likely to receive appropriate antimicrobial therapy earlier (median 2.8 v. 6.1 h from shock, p = 0.012). Survivors were also more likely to undergo successful source control earlier (median 9.8 v. 24.7 h from shock, p < 0.001). Adjusting for covariates, APACHE II (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.06­1.21 per increment) and delayed source control > 16 h (OR 4.45, 95% CI 1.88­10.70) were independently associated with increased mortality (all p < 0.001). The CART analysis showed that patients with APACHE II scores of 15­26 benefitted most from source control within 16 h (p < 0.0001). Conclusion: In patients with cholecystitis-associated septic shock, admission APACHE II score and delay in source control (cholecystectomy or percutaneous cholecystostomy drainage) significantly affected hospital outcomes.

Contexte: Le choc septique associé à une cholécystite s'accompagne d'une mortalité significative. Notre but était de déterminer si le moment du contrôle de la source affecte la survie chez les patients atteints de cholécystite qui se trouvent en choc septique. Méthodes: Nous avons procédé à une étude de cohorte nichée regroupant tous les patients ayant présenté un choc septique associé à une cholécystite à partir d'une base de données multicentrique internationale (1996­2015). La régression logistique multivariée a été utilisée pour déterminer les liens entre les facteurs cliniques et la mortalité perhospitalière. Les résultats ont été utilisés pour éclairer une analyse par arbre de classification (CART) qui modélisait le lien entre la gravité de la maladie (APACHE II), le temps nécessaire au contrôle de la source et la survie. Résultats: Parmi 196 patients souffrant d'un choc septique associé à une cholécystite, la mortalité globale a été de 37 %. Comparativement aux patients décédés (n = 72), les survivants (n = 124) présentaient à l'admission des scores APACHE II moyens plus bas (21 c. 27, p < 0,001) et un taux de lactate sérique médian plus bas (2,4 c. 6,8 µmol/L, p < 0,001). Les survivants étaient plus susceptibles de recevoir une antibiothérapie adéquate plus hâtive (médiane 2,8 c. 6,1 h suivant le choc, p = 0,012). Les survivants étaient aussi plus susceptibles de bénéficier plus hâtivement d'un contrôle réussi de la source (médiane 9,8 c. 24,7 h suivant le choc, p < 0,001). L'ajustement pour tenir compte des covariables du score APACHE II (rapport des cotes [RC] 1,13, intervalle de confiance [IC] de 95 % 1,06­1,21 par palier) et le retard du contrôle de la source > 16 h (RC 4,45, IC de 95 % 1,88­10,70) ont été associés indépendamment à une mortalité plus élevée (tous deux p < 0,001). L'analyse CART a révélé que les patients ayant des scores APACHE II de 15­26 ont le plus bénéficié d'un contrôle de la source dans les 16 h (p < 0,0001). Conclusion: Chez les patients présentant un choc septique associé à une cholécystite, le score APACHE II à l'admission et le retard de contrôle de la source (cholécystectomie ou drainage par cholécystotomie percutanée) ont significativement influé sur les résultats hospitaliers.

Detection, Monitoring, and Mitigation of Drug-Induced Nephrotoxicity: A Pragmatic Approach.

The kidneys play a pivotal role in elimination of most drugs; therefore, a comprehensive understanding of renal physiology and pathology is important for those involved in drug development. High filtration capacity and metabolic activity make the kidneys vulnerable to drug-induced nephrotoxicity (DIN). Acute DIN may manifest on a background of renal impairment that has resulted from underlying disease, previously administered nephrotoxic medications, congenital renal abnormalities, or the natural aging process. The ability of the kidneys to compensate for DIN depends on the degree of pre-insult renal function. Therefore, it can be difficult to identify. The discovery and development of novel biomarkers that can diagnose kidney damage earlier and more accurately than current clinical measures and may be effective in detecting DIN. The goal of this manuscript is to provide a pragmatic and evidence-based supportive guidance for the early identification and management of DIN during the drug development process for clinical trial participants of all ages. The overall objective is to minimize the impact of DIN on kidney function and to collect renal safety data enabling risk analysis and mitigation.

Continuous renal replacement therapy and survival in acute liver failure: A systematic review and meta-analysis.

OBJECTIVE: Acute liver failure (ALF) is a rare syndrome leading to significant morbidity and mortality. An important cause of mortality is cerebral edema due to hyperammonemia. Different therapies for hyperammonemia have been assessed including continuous renal replacement therapy (CRRT). We conducted a systematic review and meta-analysis to determine the efficacy of CRRT in ALF patients. MATERIALS AND METHODS: We searched MEDLINE, EMBASE, Cochrane Library, and Web of Science. Inclusion criteria included adult patients admitted to an ICU with ALF. Intervention was the use of CRRT for one or more indications with the comparator being standard care without the use of CRRT. Outcomes of interest were overall survival, transplant-free survival (TFS), mortality and changes in serum ammonia levels. RESULTS: In total, 305 patients underwent CRRT while 1137 patients did not receive CRRT. CRRT was associated with improved overall survival [risk ratio (RR) 0.83, 95% confidence interval (CI) 0.70-0.99, p-value 0.04, I2 = 50%] and improved TFS (RR 0.65, 95% CI 0.49-0.85, p-value 0.002, I2 = 25%). There was a trend towards higher mortality with no CRRT (RR 1.24, 95% CI 0.84-1.81, p-value 0.28, I2 = 37%). Ammonia clearance data was unable to be pooled and was not analyzable. CONCLUSION: Use of CRRT in ALF patients is associated with improved overall and transplant-free survival compared to no CRRT.

Safety of Secukinumab from 1 Million Patient-Years of Exposure: Experience from Post-Marketing Setting and Clinical Trials.

INTRODUCTION: Secukinumab is an anti-interleukin (IL)-17A monoclonal antibody indicated for multiple immunological disorders. Here, we aim to summarize secukinumab safety in clinical trials (CTs) and post-marketing setting (PMS) until 25 June 2022. METHODS: Adverse events (AEs) were summarized with crude reporting rate (RR) per 100 patient-years (PY) in PMS for all reported indications and with exposure-adjusted incident rates (EAIR) per 100 PY in pooled 47 CTs for approved indications. RESULTS: Secukinumab exposure totaled 1,159,260 PY in PMS and 27,765 PY in CTs. AEs were mostly (> 80%) non-serious in PMS. EAIR for serious AEs was 7.0/100 PY. Nasopharyngitis (RR 0.59/100 PY, EAIR 16.08/100 PY) and pneumonia (RR 0.14/100 PY, EAIR 0.17/100 PY) were the most common infection and serious infection, respectively. Candida infections (RR 0.20/100 PY, EAIR 2.16/100 PY) were the most common fungal infections. Inflammatory bowel disease (IBD) was observed in PMS (0.14/100 PY) and CTs (0.26/100 PY). Most (76%) patients with prior IBD did not report IBD flare during CTs. PMS monitoring identified paradoxical skin reactions including dyshidrotic eczema (RR 0.006/100 PY) and pyoderma gangrenosum (RR 0.003/100 PY). CONCLUSION: Secukinumab safety profile with increased patient exposure remained favorable. Paradoxical skin reactions were identified in post-marketing monitoring.

Iron chelation with deferasirox in adult and pediatric patients with thalassemia major: efficacy and safety during 5 years' follow-up.

Patients with ß-thalassemia require lifelong iron chelation therapy from early childhood to prevent complications associated with transfusional iron overload. To evaluate long-term efficacy and safety of once-daily oral iron chelation with deferasirox, patients aged ≥ 2 years who completed a 1-year, phase 3, randomized trial entered a 4-year extension study, either continuing on deferasirox (deferasirox cohort) or switching from deferoxamine to deferasirox (crossover cohort). Of 555 patients who received ≥ 1 deferasirox dose, 66.8% completed the study; 43 patients (7.7%) discontinued because of adverse events. In patients with ≥ 4 years' deferasirox exposure who had liver biopsy, mean liver iron concentration significantly decreased by 7.8 ± 11.2 mg Fe/g dry weight (dw; n = 103; P < .001) and 3.1 ± 7.9 mg Fe/g dw (n = 68; P < .001) in the deferasirox and crossover cohorts, respectively. Median serum ferritin significantly decreased by 706 ng/mL (n = 196; P < .001) and 371 ng/mL (n = 147; P < .001), respectively, after ≥ 4 years' exposure. Investigator-assessed, drug-related adverse events, including increased blood creatinine (11.2%), abdominal pain (9.0%), and nausea (7.4%), were generally mild to moderate, transient, and reduced in frequency over time. No adverse effect was observed on pediatric growth or adolescent sexual development. This first prospective study of long-term deferasirox use in pediatric and adult patients with ß-thalassemia suggests treatment for ≤ 5 years is generally well tolerated and effectively reduces iron burden. This trial was registered at www.clinicaltrials.gov as #NCT00171210.

Post liver transplantation delirium assessment using the CAM-ICU-7 scale: A cohort analysis.

Background: We applied the Confusion Assessment Method (CAM)-Intensive Care Unit (ICU)-7 delirium scale to patients who underwent liver transplant (LT). Methods: Retrospective cohort including patients who underwent LT for cirrhosis admitted to the ICU from June 2013 to June 2016 at the University of Alberta Hospital, Canada. Delirium was assessed using the CAM-ICU-7 scale (0-7 points) twice daily on days one and 3 post LT, with the highest score being considered. Primary endpoint was hospital mortality. Results: Among all patients, 101/150 (67.3%) were men and mean age was 52.4 (SD 11.8) years. On days 1 and 3 post LT, mean CAM-ICU-7 scores were 1.8 (SD 1.3) and 1.6 (SD 1.8), respectively. Therefore, on days 1 and 3 post LT, 38/150 (25.3%) and 26/95 (27.4%) patients had delirium. While delirium on day 3 post LT was associated with higher hospital mortality (11.5% versus 0%; p = 0.019), it was not associated with length-of-hospital stay (29.2 versus 34.4 days; p = 0.36). Following adjustment for APACHEII score, delirium on day 3 post LT was associated with higher odds of hospital mortality (adjusted odds ratio [aOR] 1.89 [95% CI 1.02-3.50]). Following adjustment for Glasgow Coma Scale and mechanical ventilation, serum creatinine was associated with higher odds of delirium on day 3 post LT (aOR 2.02 [95% CI 1.08-3.77]). Conclusions: Using the CAM-ICU-7 scale, delirium was diagnosed in a fourth of patients who underwent LT. Delirium on day 3 post LT was associated with higher odds of hospital mortality.

Development and validation of an ensemble machine learning framework for detection of all-cause advanced hepatic fibrosis: a retrospective cohort study.

BACKGROUND: Cirrhosis is the result of advanced scarring (or fibrosis) of the liver, and is often diagnosed once decompensation with associated complications has occurred. Current non-invasive tests to detect advanced liver fibrosis have limited performance, with many indeterminate classifications. We aimed to identify patients with advanced liver fibrosis of all-causes using machine learning algorithms (MLAs). METHODS: In this retrospective study of routinely collected laboratory, clinical, and demographic data, we trained six MLAs (support vector machine, random forest classifier, gradient boosting classifier, logistic regression, artificial neural network, and an ensemble of all these algorithms) to detect advanced fibrosis using 1703 liver biopsies from patients seen at the Toronto Liver Clinic (TLC) between Jan 1, 2000, and Dec 20, 2014. Performance was validated using five datasets derived from patient data provided by the TLC (n=104 patients with a biopsy sample taken between March 24, 2014, and Dec 31, 2017) and McGill University Health Centre (MUHC; n=404). Patients with decompensated cirrhosis were excluded. Performance was benchmarked against aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis-4 index (FIB-4), non-alcoholic fatty liver disease fibrosis score (NFS), transient elastography, and an independent panel of five hepatology experts (MB, GS, HK, KP, and RSK). MLA performance was evaluated using the area under the receiver operating characteristic curve (AUROC) and the percentage of determinate classifications. FINDINGS: The best MLA was an ensemble algorithm of support vector machine, random forest classifier, gradient boosting classifier, logistic regression, and neural network algorithms, which achieved 100% determinate classifications (95% CI 100·0-100·0), an AUROC score of 0·870 (95% CI 0·797-0·931) on the TLC validation set (fibrosis stages F0 and F1 vs F4), and an AUROC of 0·716 (95% CI 0·664-0·766) on the MUHC validation set (fibrosis stages F0, F1, and F2 vs F3 and F4). The ensemble MLA outperformed all routinely used biomarkers and achieved comparable performance to hepatologists as measured by AUROC and percentage of indeterminate classifications in both the TLC validation dataset (APRI AUROC score 0·719 [95% CI 0·611-0·820], 83·7% determinate [95% CI 76·0-90·4]; FIB-4 AUROC score 0·825 [95% CI 0·730-0·912], 72·1% determinate [95% CI 63·5-80·8]) and the MUHC validation dataset (APRI AUROC score 0·618 [95% CI 0·548-0·691], 75·5% determinate [95% CI 71·5-79·2]; FIB-4 AUROC score 0·717 (95% CI 0·652-0·776), 75·5% determinate [95% CI 0·713-0·797]), and achieving only slightly lower AUROC than transient elastography (0·773 [95% CI 0·699-0·834] vs 0·826 [95% CI 0·758-0·889]). INTERPRETATION: We have shown that an ensemble MLA outperforms non-imaging-based methods in detecting advanced fibrosis across different causes of liver disease. Our MLA was superior to APRI, FIB-4, and NFS with no indeterminate classifications, while achieving performance comparable to an independent panel of experts. MLAs using routinely collected data could identify patients at high-risk of advanced hepatic fibrosis and cirrhosis among patients with chronic liver disease, allowing intervention before onset of decompensation. FUNDING: Toronto General Hospital Foundation.

Dual effects of the alloresponse by Th1 and Th2 cells on acute and chronic rejection of allotransplants.

The contribution of direct and indirect alloresponses by CD4(+) Th1 and Th2 cells in acute and chronic rejection of allogeneic transplants remains unclear. In the present study, we addressed this question using a transplant model in a single MHC class I-disparate donor-recipient mouse combination. BALB/c-dm2 (dm2) mutant mice do not express MHC class I L(d) molecules and reject acutely L(d+) skin grafts from BALB/c mice. In contrast, BALB/c hearts placed in dm2 mice are permanently accepted in the absence of chronic allograft vasculopathy. In this model, CD4(+) T cells are activated following recognition of a donor MHC class I determinant, L(d) 61-80, presented by MHC Class II A(d) molecules on donor and recipient APC. Pre-transplantation of recipients with L(d) 61-80 peptide emulsified in complete Freund's adjuvant induced a Th1 response, which accelerated the rejection of skin allografts, but it had no effect on cardiac transplants. In contrast, induction of a Th2 response to the same peptide abrogated the CD8(+) cytotoxic T cells response and markedly delayed the rejection of skin allografts while it induced de novo chronic rejection of heart transplants. This shows that Th2 cells activated via indirect allorecognition can exert dual effects on acute and chronic rejection of allogeneic transplants.

Pathophysiology of Acute Liver Failure.

Acute liver failure (ALF) is a rare syndrome resulting from an acute insult to the liver in patients without known underlying chronic liver disease. It is characterized by loss of synthetic function in the form of jaundice and coagulopathy and development of hepatic encephalopathy. Multiorgan failure (MOF) eventually develops, leading to death. Many different etiologies have been identified, with acetaminophen (APAP) overdose and viral hepatitis being the most common causes worldwide. The pathophysiology of ALF can be divided into cause-specific liver injury pathophysiologies and pathophysiology related to occurrence of secondary MOF. In terms of liver injury pathophysiology, APAP toxicity is the most well known. Secondary MOF is often a result of the initial massive proinflammatory response generating a systemic inflammatory response syndrome followed by a compensatory anti-inflammatory response leading to immune cell dysfunction and sepsis. As the liver is a tremendously important metabolic organ involved in energy metabolism, protein synthesis, fat metabolism, and glycemic control, multiple aspects of nutrition also need to be considered as part of the overall pathophysiology of ALF.

Trimethoprim-induced drug reaction with eosinophilia and systemic symptoms (DRESS) associated with reactivation of human herpes virus-6 (HHV-6) leading to acute liver failure.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome can have insidious symptoms which may lead to acute liver failure and death. Prompt recognition, stopping offending drug, and initiating corticosteroid are the mainstay of treatment. Early involvement of a specialist liver unit is vital.

Acute-on-chronic liver failure: Objective admission and support criteria in the intensive care unit.

Cirrhosis is a leading cause of morbidity and mortality throughout the world. Significant complications include variceal bleeding, hepatic encephalopathy, hepatorenal syndrome, and infection. When these complications are severe, admission to the intensive care unit (ICU) is often required for organ support and management. Intensive care therapy can also serve as a bridge to liver transplantation. Along with decompensation of cirrhosis, the concept of acute-on-chronic liver failure (ACLF) has emerged. This involves an acute precipitating event, such as the development of infection in a patient with cirrhosis, which leads to acute deterioration of hepatic function and extrahepatic organ failure. Extrahepatic complications often include renal, cardiovascular, and respiratory failures. Patients with significant extrahepatic and hepatic failures need ICU admission for organ support. Again, in patients who are deemed suitable liver transplant candidates, intensive care management may allow bridging to liver transplantation. However, patients with a Chronic Liver Failure Consortium ACLF score greater than 70 at 48 to 72 hours post-ICU admission do not seem to benefit from ongoing intensive support and a palliative approach may be more appropriate.

Graft Dysfunction and Management in Liver Transplantation.

Graft dysfunction of the liver allograft manifests across a spectrum in both timing posttransplantation and clinical presentation. This can range from mild transient abnormalities of liver tests to acute liver failure potentially leading to graft failure. The causes of graft dysfunction can be divided into those resulting in early and late graft dysfunction. Although nonspecific, liver biochemistry abnormalities are still the mainstay investigation used in monitoring for dysfunction. This article provides a summary of the main causes and management strategies for liver graft dysfunction in the early through late posttransplant stages.

Progressive multifocal leukoencephalopathy after fingolimod treatment.

OBJECTIVE: We describe the characteristics of the 15 patients with fingolimod-associated progressive multifocal leukoencephalopathy (PML) identified from the Novartis data safety base and provide risk estimates for the disorder. METHODS: The Novartis safety database was searched for PML cases with a data lock point of August 31, 2017. PML classification was based on previously published criteria. The risk and incidence were estimated using the 15 patients with confirmed PML and the overall population of patients treated with fingolimod. RESULTS: As of August 31, 2017, 15 fingolimod-treated patients had developed PML in the absence of natalizumab treatment in the preceding 6 months. Eleven (73%) were women and the mean age was 53 years (median: 53 years). Fourteen of the 15 patients were treated with fingolimod for >2 years. Two patients had confounding medical conditions. Two patients had natalizumab treatment. This included one patient whose last dose of natalizumab was 3 years and 9 months before the diagnosis of PML. The second patient was receiving fingolimod for 4 years and 6 months, which was discontinued to start natalizumab and was diagnosed with PML 3 months after starting natalizumab. Absolute lymphocyte counts were available for 14 of the 15 patients and none exhibited a sustained grade 4 lymphopenia (≤200 cells/µL). CONCLUSIONS: The risk of PML with fingolimod in the absence of prior natalizumab treatment is low. The estimated risk was 0.069 per 1,000 patients (95% confidence interval: 0.039-0.114), and the estimated incidence rate was 3.12 per 100,000 patient-years (95% confidence interval: 1.75-5.15). Neither clinical manifestations nor radiographic features suggested any unique features of fingolimod-associated PML.

Mechanisms of targeting CD28 by a signaling monoclonal antibody in acute and chronic allograft rejection.

There is increasing evidence that ongoing T-cell recognition of alloantigen and activation are key mediators of chronic allograft rejection. The CD28-B7 pathway is unique among costimulatory pathways in that two alternate ligands for B7 exist: CD28 and CTLA4. Recently, it has been suggested that CTLA4 negative signaling may be required for induction of acquired tolerance in vivo. A strategy by which the T cell is targeted at the CD28 receptor rather than its ligands would theoretically allow the inhibitory functions of the CTLA4-B7-1/2 axis to remain intact. Using a rat-specific monoclonal antibody, we investigated the effect of targeting CD28 in a model of chronic rejection without the confounding variable of immunosuppression. We also used an acute cardiac allograft rejection model to investigate CD28 stimulation-based strategies to induce donor-specific tolerance. We demonstrated that anti-CD28 monoclonal antibody was as effective as CTLA4 immunoglobulin in protecting against chronic allograft vasculopathy. In addition, a short course of cyclosporine therapy synergized with either anti-CD28 monoclonal antibody or CTLA4 immunoglobulin, suggesting that it may be clinically relevant to combine low-dose calcineurin inhibitors with CTLA4 immunoglobulin or anti-B7 antibodies. Finally, we report on the potential mechanisms of action of targeting CD28 in vivo.

Depleting anti-CD4 monoclonal antibody cures new-onset diabetes, prevents recurrent autoimmune diabetes, and delays allograft rejection in nonobese diabetic mice.

BACKGROUND: The prevention of recurrent autoimmunity is a prerequisite for successful islet transplantation in patients with type I diabetes. Therapies effective in preserving pancreatic beta-cell mass in patients with newly diagnosed diabetes are good candidates for achieving this goal. Anti-CD3 monoclonal antibody (mAb) and antilymphocyte antisera are the only therapies to date that have cured early diabetic disease in the nonobese diabetic (NOD) mouse. We investigated whether other immunosuppressive therapies, including short-term depleting anti-CD4 mAb or costimulation blockade, would affect the disease progression in recently diabetic NOD mice. We also evaluated the effect of the anti-CD4 mAb on syngeneic and allogeneic graft survival in diabetic NOD recipients. METHODS AND RESULTS: We demonstrate that a short course of anti-CD4 mAb early after hyperglycemia onset cured diabetes. Normal islets and islets with CD4+ and CD8+ T-cell peri-insulitic infiltrate were found in the pancreata of cured NOD mice. A similar regimen prevented the recurrence of autoimmune diabetes in NOD/severe combined immunodeficient disease (SCID) islet isografts and delayed the rejection of allogeneic C57BL/6 islet allografts in diabetic female NOD mice. The co-transfer of diabetogenic splenocytes with splenocytes from anti-CD4 mAb-treated and cured NOD mice into 7-week-old, irradiated, NOD male mice was not able to protect from diabetes occurrence. This indicates that an anti-CD4-mediated cure of diabetes is independent of the induction of immunoregulatory T cells. Anti-CD154 mAb and cytotoxic T-lymphocyte antigen 4 immunoglobulin were ineffective in early-onset diabetes. CONCLUSION: Our results provide the first evidence that newly established autoimmune islet destruction in NOD mice responds to a short course of anti-CD4 mAb. In contrast, costimulation blockade is ineffective in this clinically relevant model.

T-cell response to cardiac myosin persists in the absence of an alloimmune response in recipients with chronic cardiac allograft rejection.

BACKGROUND: Immune-mediated injury to the graft has been implicated in the pathogenesis of chronic rejection. However, little is known regarding the nature of the antigen(s) involved in this immune process. We demonstrated that cardiac transplantation in mice induces an autoimmune T-cell response to a heart tissue-specific protein, cardiac myosin (CM). This response contributes to transplant rejection in that its modulation affects cardiac graft survival. This study investigates whether anti-CM T cells undergo activation and expansion in mice with chronic cardiac allograft rejection. METHODS: The frequency of CM- and donor major histocompatibility complex (MHC)-specific interferon (IFN)-gamma-producing T cells were assessed by ELISPOT in BALB/c mice, which were injected with anti-CD40L (MR1) mAb (chronic rejection group) or CTLA4Ig fusion protein (tolerant group) and transplanted with C57BL/6 cardiac allografts. RESULTS AND CONCLUSIONS: MR1-treated BALB/c recipients of C57BL/6 hearts with chronic rejection displayed a high frequency of activated CM-specific T cells, whereas the frequency of activated alloreactive T cells were similar to naïve, nontransplanted mice. In contrast, no activation of CM-reactive T cells was detected in tolerant recipients after CTLA4Ig treatment. Therefore, in the absence of alloimmunity, chronic rejection is associated with persistence of a T-cell response against CM. Our data indicate that anti-CM autoimmunity may be involved in the immune mechanisms of chronic rejection and suggest that tolerance strategies should target both allo- and autoimmune responses to prevent this process.