A case of granulocyte-colony stimulating factor/plasmapheresis-induced activation of granulocyte-colony stimulating factor-positive hepatic progenitors in acute-on-chronic liver failure

Challenges in Diagnosis and Therapeutic Approach of Acute on Chronic Liver Failure-A Review of Current Evidence

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by acute and severe decompensation of chronic liver disease (CLD) correlated with multiple organ failure, poor prognosis, and increased mortality. In 40-50% of ACLF cases, the trigger is not recognized; for many of these patients, bacterial translocation associated with systemic inflammation is thought to be the determining factor; in the other 50% of patients, sepsis, alcohol consumption, and reactivation of chronic viral hepatitis are the most frequently described trigger factors. Other conditions considered precipitating factors are less common, including acute alcoholic hepatitis, major surgery, TIPS insertion, or inadequate paracentesis without albumin substitution. Host response is likely the primary factor predicting ACLF severity and prognosis, the host immune response having a particular significance in this syndrome, together with the inflammatory cascade. The management of ACLF includes both the prevention of the precipitating factors that lead to acute liver decompensation and the support of vital functions, the prevention and management of complications, the estimation of prognosis, and the opportunity for liver transplantation.

Plasma Exchange in Acute and Acute on Chronic Liver Failure

Liver failure in the context of acute (ALF) and acute on chronic liver failure (ACLF) is associated with high mortality in the absence of a liver transplant. For decades, therapeutic plasma exchange (TPE) is performed for the management of immune-mediated diseases. TPE has emerged as an attractive extracorporeal blood purification technique in patients with ALF and ACLF. The basic premise of using TPE is to remove the toxic substances which would allow recovery of native liver functions by facilitating liver regeneration. In recent years, encouraging data have emerged, suggesting the benefits of TPE in patients with liver failure. TPE has emerged as an attractive liver support device for the failing liver until liver transplantation or clinical recovery. The data in patients with ALF suggest routine use of high-volume TPE, while the data for such a strategy are less robust for patients with ACLF.

Long-term Outcomes of Autologous Peripheral Blood Stem Cell Transplantation in Patients With Cirrhosis

BACKGROUND & AIMS

Peripheral blood stem cells (PBSCs) mobilized with colony-stimulating factor can promote liver regeneration and increase liver function in patients with liver diseases. However, the long-term effects of stem cell treatments on survival and risk of hepatocellular carcinoma (HCC) in patients with cirrhosis have not been determined. We investigated the long-term effects of autologous stem cell transplantation and risk of HCC in patients with cirrhosis.

METHODS

We performed a retrospective analysis of 2 cohorts of patients with decompensated cirrhosis who received transplantations of autologous PBSCs (n = 282) or standard medical treatment (SMT, n = 286) in China from January 1, 2006, through December 31, 2016. Patients were followed up until death or liver transplantation. Mortality data were obtained by case records and confirmed by telephone calls. Survival time was calculated and HCC was confirmed by computed tomography or ultrasound. We used propensity score matching to adjust the differences between the 2 groups. Survival and incidence of HCC were analyzed and Cox proportional hazard regression was used to determine the prognostic factors.

RESULTS

After propensity score matching, time of survival was significantly higher in the PBSC group than the SMT group (P = .001). The adjusted rate of 5-year survival was 71.2% in the PBSC group and 52.1% in the SMT group. The overall incidence of HCC did not differ significantly between the PBSC and SMT groups (21.1% vs 20.4%; P = .999). Significant improvement of liver functions was observed at 1 year, 2 years, 3 years, and 5 years after PBSC transplantation compared with the SMT group.

CONCLUSIONS

In a long-term analysis of patients with decompensated cirrhosis, autologous transplants of PBSCs significantly improved long-term survival compared with a control group. PBSC transplant did not appear to increase the risk of HCC.

Identification of a Novel Bone Marrow Cell-Derived Accelerator of Fibrotic Liver Regeneration Through Mobilization of Hepatic Progenitor Cells in Mice

Granulocyte colony stimulating factor (G-CSF) has been reported to ameliorate impaired liver function in patients with advanced liver diseases through mobilization and proliferation of hepatic progenitor cells (HPCs). However, the underlying mechanisms remain unknown. We previously showed that G-CSF treatment increased the number of bone marrow (BM)-derived cells migrating to the fibrotic liver following repeated carbon tetrachloride (CCl₄ ) injections into mice. In this study, we identified opioid growth factor receptor-like 1 (OGFRL1) as a novel BM cell-derived accelerator of fibrotic liver regeneration in response to G-CSF treatment. Endogenous Ogfrl1 was highly expressed in the hematopoietic organs such as the BM and spleen, whereas the liver contained a relatively small amount of Ogfrl1 mRNA. Among the peripheral blood cells, monocytes were the major sources of OGFRL1. Endogenous Ogfrl1 expression in both the peripheral blood monocytes and the liver was decreased following repeated CCl₄ injections. An intrasplenic injection of cells overexpressing OGFRL1 into CCl₄ -treated fibrotic mice increased the number of HPC and stimulated proliferation of hepatic parenchymal cells after partial resection of the fibrotic liver. Furthermore, overexpression of OGFRL1 in cultured HPC accelerated their differentiation as estimated by increased expression of liver-specific genes such as hepatocyte nuclear factor 4α, cytochrome P450, and fatty acid binding protein 1, although it did not affect the colony forming ability of HPC. These results indicate a critical role of OGFRL1 in the mobilization and differentiation of HPC in the fibrotic liver, and administration of OGFRL1-expressing cells may serve as a potential regenerative therapy for advanced liver fibrosis. Stem Cells 2019;37:89-101.

Management of acute-on-chronic liver failure: an algorithmic approach

Acute-on-chronic liver failure (ACLF) is a distinct syndrome of liver failure in a patient with chronic liver disease presenting with jaundice, coagulopathy and ascites and/or hepatic encephalopathy, developing following an acute hepatic insult and associated with high 28-day mortality. The definition though lacks global consensus, excludes patients with known distinct entities such as acute liver failure and those with end-stage liver disease. The initial Systemic Inflammatory Response Syndrome (SIRS) because of cytokine storm in relation to acute insult and/or subsequent development of sepsis due to immunoparalysis leads to extrahepatic organ failure. These cascades of events progress through a 'Golden Window' period of about 7 days, subsequent to which majority of the patients develop complications, such as sepsis and extrahepatic organ failure. Prevention of sepsis, support of organs and management of organ failure (commonly hepatic, renal, cerebral, coagulation) and early referral for transplant is crucial. The APASL ACLF research consortium (AARC) liver failure score is a dynamic prognostic model for management decisions and is superior to existing models. Aggressive multidisciplinary approach can lead to a transplant-free survival in nearly half of the cases. The present review provides an algorithmic approach to management of organ failure, sepsis prevention, use of dynamic prognostic models for management decision and is aimed to improve the skills for managing and improving the outcomes of such critically ill patients.

Progress in stem cell-based therapy for liver disease

Liver transplantation has been accepted as a useful therapeutic approach for patients with end-stage liver disease. However, the mismatch between the great demand for liver transplants and the number of available donor organs underscores the urgent need for alternative therapeutic strategies for patients with acute and chronic liver failure. The rapidly growing knowledge on stem cell biology has opened new avenues toward stem cell-based therapy for liver disease. As stem cells have capacity for high proliferation and multipotent differentiation, the characteristics of stem cells fit the cell therapy. Several types of cells have been investigated as possible sources of liver regeneration: mesenchymal stem cells, hematopoietic stem cells, liver progenitor cells, induced pluripotent stem cells, and bone marrow mononuclear cells. In vitro and in vivo experiments revealed that these cells have great potential as candidates of stem cell therapy. We reviewed the reports on clinical trials of cell therapy for liver disease that have been recently undertaken using mesenchymal stem cells, hematopoietic stem cells, bone marrow mononuclear cells, and liver progenitor cells. These reports have heterogeneity of description of trial design, types of infused cells, patient population, and efficacy of therapies. We addressed these reports from these viewpoints and clarified their significance. We hope that this review article will provide a perspective on the available approaches based on stem cell-based therapy for liver disease.

Acute-on-chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a distinct entity that differs from acute liver failure and decompensated cirrhosis in timing, presence of treatable acute precipitant, and course of disease, with a potential for self-recovery. The core concept is acute deterioration of existing liver function in a patient of chronic liver disease with or without cirrhosis in response to an acute insult. The insult should be a hepatic one and presentation in the form of liver failure (jaundice, encephalopathy, coagulopathy, ascites) with or without extrahepatic organ failure in a defined time frame. ACLF is characterized by a state of deregulated inflammation. Initial cytokine burst presenting as SIRS, progression to CARS and associated immunoparalysis leads to sepsis and multi-organ failure. Early identification of the acute insult and mitigation of the same, use of nucleoside analogue in HBV-ACLF, steroid in severe alcoholic hepatitis, steroid in severe autoimmune hepatitis and/or bridging therapy lead to recovery, with a 90-day transplant-free survival rate of up to 50 %. First-week presentation is crucial concerning SIRS/sepsis, development, multiorgan failure and consideration of transplant. A protocol-based multi-disciplinary approach including critical care hepatology, early liver transplant before multi-organ involvement, or priority for organ allocation may improve the outcome. Presentation with extrahepatic organ involvement or inclusion of sepsis as an acute insult in definition restricts the therapy, i.e., liver transplant or bridging therapy, and needs serious consideration. Augmentation of regeneration, cell-based therapy, immunotherapy, and gut microbiota modulation are the emerging areas and need further research.

Effects of Granulocyte Colony-Stimulating Factor on Patients with Liver Failure: a Meta-Analysis

BACKGROUND AND AIMS

It remains controversial whether granulocyte colony-stimulating factor (G-CSF) prolongs survival in liver failure (LF) patients. This meta-analysis was performed to evaluate the effect of G-CSF on patients with LF.

METHODS

PubMed, EMBASE, and Web of Science databases were searched to identify English language randomized controlled trials comparing G-CSF with control therapy published before14 February 2015. A meta-analysis was performed to examine changes in liver function and patient survival. The association was tested using odds ratio (OR) or risk ratio (RR) with 95% confidence intervals (CI).

RESULTS

Five randomized controlled trials were eligible for the meta-analysis. Significant amelioration of prothrombin time and total bilirubin in LF patients was attributed to G-CSF therapy (OR, -0.064; 95% CI,-0.481 to 0.353; p< 0.001; and OR, -0.803; 95% CI, -1.177 to -0.430; p = 0.000, respectively). Treatment with G-CSF resulted in improved Model for End-Stage Liver Disease and Child-Turcotte-Pugh scores (OR, -1.741; 95% CI, -2.234 to -1.250; p = 0.000; and OR, -0.830, 95% CI, -1.194 to -0.465; p = 0.000, respectively). A lower incidence of sepsis was found in patients treated with G-CSF (RR, 0.367; 95% CI, 0.158 to 0.854; p = 0.020). G-CSF therapy significantly increased survival rate in LF patients (RR, 2.25; 95% CI, 1.517 to 3.338; p = 0.000).

CONCLUSIONS

The results of this meta-analysis indicate that G-CSF treatment in patients with LF significantly improved liver function, reduced the incidence of sepsis, and prolonged short-term survival.

Podoplanin discriminates distinct stromal cell populations and a novel progenitor subset in the liver

Podoplanin/gp38(+) stromal cells present in lymphoid organs play a central role in the formation and reorganization of the extracellular matrix and in the functional regulation of immune responses. Gp38(+) cells are present during embryogenesis and in human livers of primary biliary cirrhosis. Since little is known about their function, we studied gp38(+) cells during chronic liver inflammation in models of biliary and parenchymal liver fibrosis and steatohepatitis. Gp38(+) cells were analyzed using flow cytometry and confocal microscopy, and the expression of their steady state and inflammation-associated genes was evaluated from healthy and inflamed livers. Gp38(+) cells significantly expanded in all three models of liver injury and returned to baseline levels during regression of inflammation. Based on CD133 and gp38 expression in the CD45(-)CD31(-)Asgpr1(-) liver cell fraction, numerous subsets could be identified that were negative for CD133 (gp38(hi)CD133(-), gp38(low)CD133(-), and gp38(-)CD133(-)). Moreover, among the CD133(+) cells, previously identified as progenitor population in injured liver, two subpopulations could be distinguished based on their gp38 expression (gp38(-)CD133(+) and CD133(+)gp38(+)). Importantly, the distribution of the identified subsets in inflammation illustrated injury-specific changes. Moreover, the gp38(+)CD133(+) cells exhibited liver progenitor cell characteristics similar to the gp38(-)CD133(+) population, thus representing a novel subset within the classical progenitor cell niche. Additionally, these cells expressed distinct sets of inflammatory genes during liver injury. Our study illuminates a novel classification of the stromal/progenitor cell compartment in the liver and pinpoints a hitherto unrecognized injury-related alteration in progenitor subset composition in chronic liver inflammation and fibrosis.

Stem cell-based regenerative opportunities for the liver: State of the art and beyond

The existing mismatch between the great demand for liver transplants and the number of available donor organs highlights the urgent need for alternative therapeutic strategies in patients with acute or chronic liver failure. The rapidly growing knowledge on stem cell biology and the intrinsic repair processes of the liver has opened new avenues for using stem cells as a cell therapy platform in regenerative medicine for hepatic diseases. An impressive number of cell types have been investigated as sources of liver regeneration: adult and fetal liver hepatocytes, intrahepatic stem cell populations, annex stem cells, adult bone marrow-derived hematopoietic stem cells, endothelial progenitor cells, mesenchymal stromal cells, embryonic stem cells, and induced pluripotent stem cells. All these highly different cell types, used either as cell suspensions or, in combination with biomaterials as implantable liver tissue constructs, have generated great promise for liver regeneration. However, fundamental questions still need to be addressed and critical hurdles to be overcome before liver cell therapy emerges. In this review, we summarize the state-of-the-art in the field of stem cell-based therapies for the liver along with existing challenges and future perspectives towards a successful liver cell therapy that will ultimately deliver its demanding goals.

Acute-on-chronic liver failure: Pathogenesis, prognostic factors and management

Acute-on-chronic liver failure (ACLF) is increasingly recognized as a complex syndrome that is reversible in many cases. It is characterized by an acute deterioration of liver function in the background of a pre-existing chronic liver disease often associated with a high short-term mortality rate. Organ failure (OF) is always associated, and plays a key role in determining the course, and the outcome of the disease. The definition of ACLF remains controversial due to its overall ambiguity, with several disparate criteria among various associations dedicated to the study of liver diseases. Although the precise pathogenesis needs to be clarified, it appears that an altered host response to injury might be a contributing factor caused by immune dysfunction, ultimately leading to a pro-inflammatory status, and eventually to OF. The PIRO concept (Predisposition, Insult, Response and Organ Failure) has been proposed to better approach the underlying mechanisms. It is accepted that ACLF is a different and specific form of liver failure, where a precipitating event is always involved, even though it cannot always be ascertained. According to several studies, infections and active alcoholism often trigger ACLF. Viral hepatitis, gastrointestinal haemorrhage, or drug induced liver injury, which can also provoke the syndrome. This review mainly focuses on the physiopathology and prognostic aspects. We believe these features are essential to further understanding and providing the rationale for improveddisease management strategies.