Acute liver failure.

Acute liver failure (ALF) is a life-threatening disorder characterised by rapid deterioration of liver function, coagulopathy, and hepatic encephalopathy in the absence of pre-existing liver disease. The cause of ALF varies across the world. Common causes of ALF in adults include drug toxicity, hepatotropic and non-hepatotropic viruses, herbal and dietary supplements, antituberculosis drugs, and autoimmune hepatitis. The cause of liver failure affects the management and prognosis, and therefore extensive investigation for cause is strongly suggested. Sepsis with multiorgan failure and cerebral oedema remain the leading causes of death in patients with ALF and early identification and appropriate management can alter the course of ALF. Liver transplantation is the best current therapy, although the role of artificial liver support systems, particularly therapeutic plasma exchange, can be useful for patients with ALF, especially in non-transplant centres. In this Seminar, we discuss the cause, prognostic models, and management of ALF.

Large-Scale Formation and Long-Term Culture of Hepatocyte Organoids From Streamlined In Vivo Genome-Edited GGTA1-/- Pigs for Bioartificial Liver Applications.

Hepatocyte transplantation and bioartificial liver (BAL) systems hold significant promise as less invasive alternatives to traditional transplantation, providing crucial temporary support for patients with acute and chronic liver failure. Although human hepatocytes are ideal, their use is limited by ethical concerns and donor availability, leading to the use of porcine hepatocytes in BAL systems due to their functional similarities. Recent advancements in gene-editing technology have improved porcine organ xenotransplantation clinical trials by addressing immune rejection issues. Gene-edited pigs, such as alpha-1,3-galactosyltransferase (GGTA1) knockout pigs, offer a secure source of primary cells for BAL systems. Our research focuses on optimizing the safety and functionality of porcine primary hepatocytes during large-scale cultivation. We achieved this by creating GGTA1 knockout pigs through one-step delivery of CRISPR/Cas9 to pig zygotes via oviduct injection of rAAV, and enhancing hepatocyte viability and function by co-culturing hepatocytes with Roof plate-specific spondin 1 overexpressing HUVECs (R-HUVECs). Using a Rocker culture system, approximately 1010 primary porcine hepatocytes and R-HUVECs rapidly formed organoids with a diameter of 92.1 ± 28.1 µm within 24 h. These organoids not only maintained excellent functionality but also supported partial hepatocyte self-renewal during long-term culture over 28 days. Gene-edited primary porcine hepatocyte organoids will significantly advance the applications of hepatocyte transplantation and BAL systems.

Bioartificial liver system approved for clinical trials in China.

Bioartificial organ systems are becoming more attractive options for end-stage organ disease. Currently, end-stage liver disease has several palliative options but relies on transplantation for curative management. A new bioartificial liver has been approved for clinical trials in China and helps support the failed liver via stem cells.

[Mass transfer of bilirubin and bovine serum albumin in hollow fiber membrane module of artificial liver].

Understanding the mass transfer behaviors in hollow fiber membrane module of artificial liver is important for improving toxin removal efficiency. A three-dimensional numerical model was established to study the mass transfer of small molecule bilirubin and macromolecule bovine serum albumin (BSA) in the hollow fiber membrane module. Effects of tube-side flow rate, shell-side flow rate, and hollow fiber length on the mass transfer of bilirubin and BSA were discussed. The simulation results showed that the clearance of bilirubin was significantly affected by both convective and diffusive solute transport, while the clearance of macromolecule BSA was dominated by convective solute transport. The clearance rates of bilirubin and BSA increasd with the increase of tube-side flow rate and hollow fiber length. With the increase of shell-side flow rate, the clearance rate of bilirubin first rose rapidly, then slowly rose to an asymptotic value, while the clearance rate of BSA gradually decreased. The results can provide help for designing structures of hollow fiber membrane module and operation parameters of clinical treatment.

Characteristics of circulating immune cells in HBV-related acute-on-chronic liver failure following artificial liver treatment.

BACKGROUND AND AIM: Liver failure, which is predominantly caused by hepatitis B (HBV) can be improved by an artificial liver support system (ALSS). This study investigated the phenotypic heterogeneity of immunocytes in patients with HBV-related acute-on-chronic liver failure (HBV-ACLF) before and after ALSS therapy. METHODS: A total of 22 patients with HBV-ACLF who received ALSS therapy were included in the study. Patients with Grade I according to the ACLF Research Consortium score were considered to have improved. Demographic and laboratory data were collected and analyzed during hospitalization. Immunological features of peripheral blood in the patients before and after ALSS were detected by mass cytometry analyses. RESULTS: In total, 12 patients improved and 10 patients did not. According to the immunological features data after ALSS, the proportion of circulating monocytes was significantly higher in non-improved patients, but there were fewer γδT cells compared with those in improved patients. Characterization of 37 cell clusters revealed that the frequency of effector CD8+ T (P = 0.003), CD4+ TCM (P = 0.033), CD4+ TEM (P = 0.039), and inhibitory natural killer (NK) cells (P = 0.029) decreased in HBV-ACLF patients after ALSS therapy. Sub group analyses after treatment showed that the improved patients had higher proportions of CD4+ TCM (P = 0.010), CD4+ TEM (P = 0.021), and γδT cells (P = 0.003) and a lower proportion of monocytes (P = 0.012) compared with the non-improved patients. CONCLUSIONS: Changes in effector CD8+ T cells, effector and memory CD4+ T cells, and inhibitory NK cells are associated with ALSS treatment of HBV-ACLF. Moreover, monocytes and γδT cells exhibited the main differences when patients obtained different prognoses. The phenotypic heterogeneity of lymphocytes and monocytes may contribute to the prognosis of ALSS and future immunotherapy strategies.

Artificial liver support systems for hepatitis B virus-associated acute-on-chronic liver failure: A meta-analysis of the clinical literature.

To evaluate the short-term and long-term survival efficacy of an artificial liver support system (ALSS) in patients with acute-on-chronic liver failure (ACLF). A systematic search was performed for relevant published data in PubMed, Web of Science and Cochrane Library databases. Studies that evaluated the efficacy of ALSS in patients with ACLF and provided the short-term or long-term survival rate were included. A total of 10 studies involving 3685 patients were included in this analysis. The pooled 28-day survival rate and 90-day survival rate were 68.7% (95% CI: 64.5%-72.9%) and 53.4% (95% CI: 45.5%-61.4%), respectively. The pooled estimates of the OR for the 28-day and 90-day survival rates between the ALSS group and the control group were 1.91 (95% CI: 1.21-3.04) and 1.41 (95% CI: 1.17-1.70), respectively. Subgroup analysis showed that patients treated with lower levels of TBIL and MELD scores had a higher 28-day survival rate (χ2  = 15.75, p < 0.01; χ2  = 13.80, p < 0.01). The present meta-analysis suggests that ALSS treatment could remarkably improve short-term survival rates in HBV-ACLF patients, which implies that treatment with ALSS may help to reduce high mortality. Further prospective randomized trials are needed to validate these findings.

In vitro recovery of FIX clotting activity as a marker of highly functional hepatocytes in a hemophilia B iPSC model.

BACKGROUND AND AIMS: Pluripotent stem cell-derived hepatocytes differentiated in monolayer culture are known to have more fetal than adult hepatocyte characteristics. If numerous studies tend to show that this immature phenotype might not necessarily be an obstacle to their use in transplantation, other applications such as drug screening, toxicological studies, or bioartificial livers are reliant on hepatocyte functionality and require full differentiation of hepatocytes. New technologies have been used to improve the differentiation process in recent years, usually evaluated by measuring the albumin production and CYP450 activity. Here we used the complex production and most importantly the activity of the coagulation factor IX (FIX) produced by mature hepatocytes to assess the differentiation of hemophilia B (HB) patient's induced pluripotent stem cells (iPSCs) in both monolayer culture and organoids. APPROACH AND RESULTS: Indeed, HB is an X-linked monogenic disease due to an impaired activity of FIX synthesized by hepatocytes in the liver. We have developed an in vitro model of HB hepatocytes using iPSCs generated from fibroblasts of a severe HB patient. We used CRISPR/Cas9 technology to target the genomic insertion of a coagulation factor 9 minigene bearing the Padua mutation to enhance FIX activity. Noncorrected and corrected iPSCs were differentiated into hepatocytes under both two-dimensional and three-dimensional differentiation protocols and deciphered the production of active FIX in vitro. Finally, we assessed the therapeutic efficacy of this approach in vivo using a mouse model of HB. CONCLUSIONS: Functional FIX, whose post-translational modifications only occur in fully mature hepatocytes, was only produced in corrected iPSCs differentiated in organoids. Immunohistochemistry analyses of mouse livers indicated a good cell engraftment, and the FIX activity detected in the plasma of transplanted animals confirmed rescue of the bleeding phenotype.

Screening and Validation Potential Therapeutic Marker of Early to Middle Stage ACLF Patients Treated by ALSSs.

BACKGROUND: Artificial liver support systems (ALSSs) are important approaches for treating acute-on-chronic liver failure (ACLF) patients. Few studies have investigated potential serum therapeutic markers of ACLF patients treated by ALSSs. METHODS: Serum samples were obtained from 57 early to middle stage ACLF patients before and after ALSSs treatment and analyzed by metabonomics. The diagnostic values were evaluated by the area under receiver-operating characteristic curve (AUROC). A retrospective cohort analysis was further employed. RESULTS: Metabonomic study showed that serum ratios of lactate: creatinine in ACLF patients is significantly altered and then restored to normal levels after ALSSs treatment. A retrospective cohort analysis (n = 47) validated that the lactate: creatinine ratio of ACLF patients in the one-month death group remained unchanged after ALSSs treatment, but fell markedly in the survival group with AUROC of 0.682 for diagnosis of survival group from death group, which is a more sensitive measure than measures of prothrombin time activity (PTA) to evaluate the therapeutic effect of ALSSs treatment. CONCLUSIONS: Our results demonstrated the greater the decline in the serum lactate: creatinine ratio with better effective treatments of ALSSs in the ACLF patients with early to middle stage, which presents a potential therapeutic biomarker of ALSSs treatment.

A bioartificial transgenic porcine whole liver expressing human proteins alleviates acute liver failure in pigs.

BACKGROUND: Preventing heterologous protein influx in patients is important when using xenogeneic bioartificial livers (BALs) to treat liver failure. The development of transgenic porcine livers synthesizing human proteins is a promising approach in this regard. Here, we evaluated the safety and efficacy of a transgenic porcine liver synthesizing human albumin (hALB) and coagulation factor VII (hFVII) within a bioartificial system. METHODS: Tibetan miniature pigs were randomly subjected to different interventions after surgery-induced partially ischemic liver failure. Group A (n = 4) was subjected to basic treatment; group B (n = 4) was to standard medical treatment and wild-type porcine BAL perfusion, and group C (n = 2) was to standard medical treatment and transgenic BAL perfusion. Biochemical parameters, coagulation status, survival time, and pathological changes were determined. Expressions of hALB and hFVII were detected using immunohistochemistry and enzyme-linked immunosorbent assays. RESULTS: The survival time in group A was 9.75 ± 1.26 days; this was shorter than that in both perfused groups, in which all animals reached an endpoint of 12 days (P = 0.006). Ammonia, bilirubin, and lactate levels were significantly decreased, whereas albumin and fibrinogen levels were increased after perfusion (all P < 0.05). hALB and hFVII were detected in transgenic BAL-perfused pig serum and ex vivo in the liver tissues. CONCLUSIONS: The humanized transgenic pig livers could synthesize and secrete hALB and hFVII ex vivo in a whole organ-based bioartificial system, while maintaining their metabolism, detoxification, transformation, and excretion functions, which were comparable to those observed in wild-type porcine livers. Therefore, the use of transgenic bioartificial whole livers is expected to become a new approach in treating acute liver failure.

[Research progress of non-biological artificial liver support system therapy for paitents with liver failure].

Liver failure progresses quickly with high mortality. Non-biological artificial liver support system therapy is one of the important treatments for patients with liver failure. The basic techniques of non-biological artificial liver support system therapy include plasma exchange, plasma adsorption and continuous renal replacement therapy. In this paper, the effect and choice of these basic techniques, the treatment timing, the possible patients who may benefit, and the existing problems are summarized and discussed. We hope to provide a reference for the rational use of non-biological artificial liver support system therapy in clinical practice.

Hollow Fiber and Nanofiber Membranes in Bioartificial Liver and Neuronal Tissue Engineering.

To date, the creation of biomimetic devices for the regeneration and repair of injured or diseased tissues and organs remains a crucial challenge in tissue engineering. Membrane technology offers advanced approaches to realize multifunctional tools with permissive environments well-controlled at molecular level for the development of functional tissues and organs. Membranes in fiber configuration with precisely controlled, tunable topography, and physical, biochemical, and mechanical cues, can direct and control the function of different kinds of cells toward the recovery from disorders and injuries. At the same time, fiber tools also provide the potential to model diseases in vitro for investigating specific biological phenomena as well as for drug testing. The purpose of this review is to present an overview of the literature concerning the development of hollow fibers and electrospun fiber membranes used in bioartificial organs, tissue engineered constructs, and in vitro bioreactors. With the aim to highlight the main biomedical applications of fiber-based systems, the first part reviews the fibers for bioartificial liver and liver tissue engineering with special attention to their multifunctional role in the long-term maintenance of specific liver functions and in driving hepatocyte differentiation. The second part reports the fiber-based systems used for neuronal tissue applications including advanced approaches for the creation of novel nerve conduits and in vitro models of brain tissue. Besides presenting recent advances and achievements, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field.

Acute liver failure.

PURPOSE OF REVIEW: Present an outline of acute liver failure, from its definition to its management in critical care, updated with findings of selected newer research. RECENT FINDINGS: Survival of patients with acute liver failure has progressively improved. Intracranial hypertension complicating hepatic encephalopathy is now much less frequent than in the past and invasive ICP monitoring is now rarely used. Early renal replacement therapy and possibly therapeutic plasma exchange have consolidated their role in the treatment. Further evidence confirms the low incidence of bleeding in these patients despite striking abnormalities in standard tests of coagulation and new findings of abnormalities on thromboelastographic testing. Specific coagulopathy profiles including an abnormal vWF/ADAMTS13 ratio may be associated with poor outcome and increased bleeding risk. Use of N-acetylcysteine in nonparacetamol-related cases remains unsupported by robust clinical evidence. New microRNA-based prognostic markers to select patients for transplantation are described but are still far from widespread clinical applicability; imaging-based prognostication tools are also promising. The use of extracorporeal artificial liver devices in clinical practice is yet to be supported by evidence. SUMMARY: Medical treatment of patients with acute liver failure is now associated with significantly improved survival. Better prognostication and selection for emergency liver transplant may further improve care for these patients.

Dimethyl sulfoxide for cryopreservation of alginate encapsulated liver cell spheroids in bioartificial liver support; assessments of cryoprotectant toxicity tolerance and dilution strategies.

The Bioartificial Liver (BAL) is an extra-corporeal liver support designed to support the function of the Liver in patients with impaired liver function. The BAL biomass consists of alginate encapsulated liver spheroids (AELS). To facilitate rapid delivery of a BAL to patients the AELS are cryopreserved using a DMSO-containing cryoprotectant solution. This study assesses toxicity of DMSO in AELS at concentrations and temperatures relevant to the cryopreservation and recovery process of a cellular biomass. Additionally, it develops a process to remove DMSO from AELS before delivery of cell product to patients. Exposure of AELS to DMSO, at a concentration of 12% (v/v) for 10 min did not have a negative effect on the viability of the AELS up to 24 h after exposure, irrespective of the exposure temperature between 37 C and 0 C. Evidence of toxicity was only seen with exposure to 40% (v/v) DMSO, which was more notable at warm temperatures. Post-Thaw removal of DMSO was measured by determining the DMSO concentration of the post-thaw washes using refractometry. Washing AELS 3 times in tapering concentrations of Glucose supplemented DMEM at an AELS:wash ratio of 1:2 was sufficient to reduce DMSO to undetectable levels (<1%). The study demonstrated that the thawing method minimised DMSO toxicity to the BAL biomass, and the post-thaw washing protocol successfully removed all the DMSO present in the cryopreserved BAL. Thereby enabling effective cryopreservation of the BAL for future clinical translation.

Lower level of IL-28A as a predictive index of the artificial liver support system in effective treatment of patients with HBV-ACLF.

BACKGROUND: HBV-related acute-on-chronic liver failure (HBV-ACLF) is the most common type of liver failure with high mortality. Artificial liver support system (ALSS) is an important mean to reduce the mortality of HBV-ACLF but lacking index to assess its effectiveness. The cytokines are closely related to the prognosis of HBV-ACLF patients with ALSS treatment, however, which is not fully understood. METHODS: One hundred forty-two patients with HBV-ACLF and 25 healthy donors were enrolled. The cytokine profile of peripheral blood was determined in the patients before and after ALSS treatment, and their relationship with effectiveness of ALSS treatment in HBV-ACLF was analyzed. RESULTS: Serum IL-28A levels were markedly lower in ALSS-effective patients than those in non-effective patients pre-ALSS treatment. Similarly, serum IL-6 was significantly lower in ALSS-effective patients. Furthermore, for patients with effective treatment, serum IL-28A levels were positively related with IL-6 levels post-ALSS (r = 0.2413, p = 0.0383). The ROC curve analysis showed that serum levels of IL-28A (AUC = 0.6959 when alone or 0.8795 when combined with total bilirubin, platelet count and INR, both p < 0.0001) and IL-6 (AUC = 0.6704, p = 0.0005) were useful indices for separating effective from non-effective ALSS treatment of HBV-ACLF patients. Multivariate logistic regression analysis demonstrated that lower level of IL-28A was independently associated with higher effective rate of ALSS treatments. CONCLUSIONS: Lower level of IL-28A is a predictive biomarker for ALSS in effective treatment of HBV-ACLF patients and IL-28A may be potential target for the treatment of HBV-ACLF.

[Effect of artificial liver with double plasma molecular absorb system model on patients' platelets and corresponding treatment strategy].

OBJECTIVE: To compare the effects of artificial liver treatment with double plasma molecular adsorption system(DPMAS) mode and traditional plasma exchange (PE) mode on platelets in patients, and to evaluate the clinical efficacy of recombinent human thrombopoietin (rhTPO) in the treatment of thrombocytopenia. METHODS: A total of fifteen patients undergoing artificial liver with DPMAS model admitted to the Fifth Affiliated Hospital of Guangzhou Medical University from January 2018 to November 2020 were selected and included in the DPMAS group, and another 15 patients receiving PE were selected and included in the PE group. The improvement of clinical symptoms, such as fatigue, jaundice, oliguria, edema, etc. before and after artificial liver treatment was compared between the two groups, and the trend of blood routine (especially platelet), coagulation function and other indexes before and after treatment were compared between the two groups. The use of rhTPO and the number of platelets were recorded during treatment. RESULTS: The improvement rate of clinical symptoms in DPMAS group was 86.67%, which was higher than that in PE group, but the difference was not statistically significant (P>0.05). There was no statistical significance in the outcome of the two groups within 90 days (P>0.05). There was no significant difference in white blood cell (WBC) and hemoglobin (HB) between the two groups after treatment (P>0.05). However, the level of platelet(PLT) in DPMAS group was significantly lower than that before treatment (P < 0.05), and was significantly lower than that in PE group (P < 0.05). After treatment, the international normalized ratio (INR) level in PE group was significantly improved (P < 0.05), but there was no significant difference in the INR level in DPMAS group (P>0.05). The patients in the DPMAS group received an average of (8.2±3.1) doses of rhTPO and (1.5±0.3) IU of platelet transfusions during hospitalization. In DMPAS group, platelets increased significantly after infusion of terbium. CONCLUSION: Compared with PE mode, the artificial liver with DPMAS mode can reduce platelet levels in patients, but the application of rhTPO can stimulate platelet regeneration and increase platelet levels in the patients, thereby reducing the risk of bleeding due to platelet hypoplasia.

[Model selection and curative effect judgment criteria for artificial liver in the treatment of liver failure].

Artificial liver is one of the effective methods to treat liver failure. Patients with liver failure are critically ill and have great individualized differences. Therefore, the specific program for the treatment of liver failure with artificial liver should be individualized. The commonly used non-biological artificial liver models include simple plasmapheresis, double filtration plasmapheresis, plasma filtration with dialysis, double plasma molecular adsorption system, molecular absorbent recirculating system, hemodiafiltration, continuous venovenous hemodiafiltration, hybrid, etc. The curative effect should be properly judged from patient's symptoms, laboratory test indicators, survival rate and other aspects after artificial liver therapy.

[A study on treatment timing selection and short-term efficacy prediction with changes in cytokine levels before and after non-biological artificial liver treatment in acute-on-chronic liver failure].

Objective: To investigate the efficacy and diagnostic accuracy of changes in cytokine levels before and after non-biological artificial liver (referred to as ABL) treatment in patients with acute-on-chronic liver failure (ACLF) in order to establish a basis for treatment timing selection and short-term (28d) prognosis. Methods: 90 cases diagnosed with ACLF were selected and divided into a group receiving artificial liver treatment (45 cases) and a group not receiving artificial liver treatment (45 cases). Age, gender, first routine blood test after admission, liver and kidney function, and procalcitonin (PCT) of the two groups were collected. The 28-day survival of the two groups was followed-up for survival analysis. The 45 cases who received artificial liver therapy were further divided into an improvement group and a deterioration group according to the clinical manifestations before discharge and the last laboratory examination results as the efficacy evaluation indicators. Routine blood test, coagulation function, liver and kidney function, PCT, alpha fetoprotein (AFP), ß-defensin-1 (HBD-1), 12 cytokines and other indicators were analyzed and compared. A receiver operating characteristic curve (ROC curve) was used to analyze the diagnostic efficacy of the short-term (28 d) prognosis and an independent risk factors affecting the prognosis of ACLF patients. According to different data, Kaplan-Meier method, log-rant test, t-test, Mann-Whitney U test, Wilcoxon rank-sum test, χ2 test, Spearman rank correlation analysis and logistic regression analysis were used for statistical analysis. Results: The 28-day survival rate was significantly higher in ACLF patients who received artificial liver therapy than that of those who did not receive artificial liver therapy (82.2% vs. 61.0%, P<0.05). The levels of serum HBD-1, alpha interferon (IFN-α) and interleukin-5 (IL-5) after artificial liver treatment were significantly lower in ACLF patients than those before treatment (P<0.05), while liver and coagulation function were significantly improved compared with those before treatment (P<0.05), and there was no statistically significant difference in other serological indexes before and after treatment (P＞0.05). Before artificial liver treatment, serum HBD-1 and INF-α levels were significantly lower in the ACLF improvement group than in the deterioration group (P<0.05) and were positively correlated with the patients' prognosis (deteriorating) (r=0.591, 0.427, P<0.001, 0.008). The level of AFP was significantly higher in the improved ACLF group than that in the deterioration group (P<0.05), and was negatively correlated with the prognosis (deteriorating) of the patients (r=-0.557, P<0.001). Univariate logistic regression analysis showed that HBD-1, IFN-α and AFP were independent risk factors for the prognosis of ACLF patients (P=0.001, 0.043, and 0.036, respectively), and that higher HBD-1 and IFN-α levels were associated with lower AFP level and a deteriorating prognosis. The area under the curve (AUC) of HBD-1, IFN-α, and AFP for short-term (28d) prognostic and diagnostic efficacy of ACLF patients was 0.883, 0.763, and 0.843, respectively, and the sensitivity and specificty was 0.75, 0.75, and 0.72, and 0.84, 0.80, and 0.83, respectively. The combination of HBD-1 and AFP had further improved the diagnostic efficiency of short-term prognosis of ACLF patients (AUC=0.960, sensitivity and specificity: 0.909 and 0.880 respectively). The combination of HBD-1+IFN-α+AFP had the highest diagnostic performance, with an AUC of 0.989, sensitivity of 0.900, and specificity of 0.947. Conclusion: Artificial liver therapy can effectively improve the clinical symptoms and liver and coagulation function of patients with ACLF; remove cytokines such as HBD-1, IFN-α, and IL-5 in patients with liver failure; delay or reverse the progression of the disease; and improve the survival rate of patients. HBD-1, IFN-α, and AFP are independent risk factors affecting the prognosis of ACLF patients, which can be used as biological indicators for evaluating the short-term prognosis of ACLF patients. The higher the level of HBD-1 and/or IFN-α, the higher the risk of disease deterioration. Therefore, artificial liver therapy should be started as soon as possible after the exclusion of infection. In diagnosing the prognosis of ACLF, HBD-1 has higher sensitivity and specificity than IFN-α and AFP, and its diagnostic efficiency is greatest when combined with IFN-α and AFP.

[Assessment Value of Short-Term Prognosis of Six Predictive Models for Patients with Acute-on-Chronic Liver Failure Treated with Artificial Liver Support System].

Objective: To apply 6 predictive models on acute-on-chronic liver failure (ACLF) patients treated with artificial liver support system (ALSS), and to compare their assessment values for the short-term prognosis of patients. Methods: A total of 258 ACLF patients who underwent ALSS therapy between January 2018 and December 2019 were selected from the ALSS clinical database established by West China Hospital, Sichuan University, and their clinical data and 90-day prognosis information were collected. Cox proportional hazards model was used to estimate the association between the six predictive models, including Chinese Group on the Study of Severe Hepatitis B-ACLF (COSSH ACLF), European Association for the Study of the Liver--Chronic Liver Failure-Consortium (CLIF-C) ACLF, CLIF-C Organ Failure (OF), Asian Pacific Association for the Study of the Liver (APASL) ACLF Research Consortium (AARC) ACLF, Model for End-Stage Liver Disease (MELD) and Simplified MELD (sMELD), and 90-day mortality, which included death or receiving liver transplantation. The area under the receiver operating characteristic (ROC) curve ( AUC), Harrell's C-index and Brier scores were calculated and compared to evaluate the predictive power. Results: A total of 258 ACLF patients were enrolled. Of these patients, who had a mean age of (46.2±11.7) years old, 37 (14.3%) patients were female, 202 (78.3%) patients had a diagnosis of liver cirrhosis, and 107 (41.5%) patients died during the 90-day follow-up period. The six predictive models all yielded higher scores for patients who died than those for patients who survived (all P<0.001). The six predictive models were all independent risk factors for the short-term prognosis of ACLF patients treated with ALSS (all adjusted hazard ratio [HR]>1, all P<0.001). The AUC (0.806, 95% confidence interval [CI]: 0.753-0.853) and Harrell's C-index (0.772, 95% CI: 0.727-0.816) of COSSH ACLF were much higher than those of the five other predictive models (all AUCs<0.750, P<0.01; all Harrell's C-indices<0.750, P<0.001). The Brier score of COSSH ACLF was 0.18 (95% CI: 0.15-0.20). The 90-day mortality of patients defined as having low risk, moderate risk, and high risk according to the risk stratification of COSSH ACLF were 22.2%, 56.3%, and 90.2%, respectively. Conclusion: The COSSH ACLF could more accurately predict short-term prognosis in ACLF patients who received ALSS therapy, and could facilitate clinical decision-making.

Decisional tool for cost of goods analysis of bioartificial liver devices for routine clinical use.

BACKGROUND AIMS: Bioartificial liver devices (BALs) are categorized as advanced therapy medicinal products (ATMPs) with the potential to provide temporary liver support for liver failure patients. However, to meet commercial demands, next-generation BAL manufacturing processes need to be designed that are scalable and financially feasible. The authors describe the development and application of a process economics decisional tool to determine the cost of goods (COG) of alternative BAL process flowsheets across a range of industrial scales. METHODS: The decisional tool comprised an information database linked to a process economics engine, with equipment sizing, resource consumption, capital investment and COG calculations for the whole bioprocess, from cell expansion and encapsulation to fluidized bed bioreactor (FBB) culture to cryopreservation and cryorecovery. Four different flowsheet configurations were evaluated across demands, with cell factories or microcarriers in suspension culture for the cell expansion step and single-use or stainless steel technology for the FBB culture step. RESULTS: The tool outputs demonstrated that the lowest COG was achieved with microcarriers and stainless steel technology independent of the annual demand (1500-30 000 BALs/year). The analysis identified the key cost drivers were parameters impacting the medium volume and cost. CONCLUSIONS: The tool outputs can be used to identify cost-effective and scalable bioprocesses early in the development process and minimize the risk of failing to meet commercial demands due to technology choices. The tool predictions serve as a useful benchmark for manufacturing ATMPs.

Preclinical characterization of alginate-poly-L-lysine encapsulated HepaRG for extracorporeal liver supply.

We recently demonstrated that HepaRG cells encapsulated into 1.5% alginate beads are capable of self-assembling into spheroids. They adequately differentiate into hepatocyte-like cells, with hepatic features observed at Day 14 post-encapsulation required for external bioartificial liver applications. Preliminary investigations performed within a bioreactor under shear stress conditions and using a culture medium mimicking acute liver failure (ALF) highlighted the need to reinforce beads with a polymer coating. We demonstrated in a first step that a poly-l-lysine coating improved the mechanical stability, without altering the metabolic activities necessary for bioartificial liver applications (such as ammonia and lactate elimination). In a second step, we tested the optimized biomass in a newly designed perfused dynamic bioreactor, in the presence of the medium model for pathological plasma for 6 h. Performances of the biomass were enhanced as compared to the steady configuration, demonstrating its efficacy in decreasing the typical toxins of ALF. This type of bioreactor is easy to scale up as it relies on the number of micro-encapsulated cells, and could provide an adequate hepatic biomass for liver supply. Its design allows it to be integrated into a hybrid artificial/bioartificial liver setup for further clinical studies regarding its impact on ALF animal models.