Safety and efficacy profile of G-CSF therapy in patients with acute on chronic liver failure

Granulocyte colony-stimulating factor plus pentoxifylline increases short-term survival in patients with severe alcoholic hepatitis: a network meta-analysis

Background: Optimal treatments for severe alcoholic hepatitis (SAH) remain controversial. Previous network meta-analysis showed that corticosteroid (CS) combined with N-acetylcysteine (NAC) was superior in reducing short-term mortality of patients with SAH. Recently, granulocyte colony-stimulating factor (G-CSF) treatments for SAH yielded promising results.Objectives: To determine how currently available treatments affect the survival and complications of patients with SAH.Methods: The study was conducted following the guidelines of PRISMA. The data from PubMed, Embase, MEDLINE, Cochrane Library, and clinicaltrials.gov to October 2022 were searched, and patients with SAH with pharmacotherapy were included in our study. The primary outcome was short-term survival, and the other outcomes were medium- (3/6 months) or long-term (12 months) survival and complications after treatment. R software was used to establish network meta-analysis models and the result was expressed by the odd ratio (OR) value and 95% credible interval (Crls).Results: A total of 31 randomized controlled trials, including 19 treatment regimens, were enrolled in our study. As the primary outcome, G-CSF+ pentoxifylline (PTX) ranked first in one-month survival and showed significant superiority when compared with the placebo (OR 8.60, 95% Crls 1.92-45.10) and CS (OR 4.95, 95% Crls 1.11-25.53). Also, G-CSF+PTX ranked first in improving three-month survival and reducing the occurrence of infection. PTX+MTD ranked first in six-month survival, and G-CSF ranked first in twelve-month survival. CS+MTD ranked first in the occurrence of gastrointestinal bleeding and hepatorenal syndrome.Conclusions: The combination of G-CSF and PTX showed a significant benefit in improving the short-term survival of SAH patients.

Granulocyte-colony stimulating factor in acute-on-chronic liver failure: Systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

A dysfunctional immune response is key to the pathogenesis of acute-on-chronic liver failure (ACLF). It has been suggested that treatment with granulocyte colony-stimulating factor (G-CSF) increases survival in patients with ACLF by improving immune cell dysfunction and promoting liver regeneration. The aim of the study is to evaluate the survival benefit associated with G-CSF administration compared with standard medical therapy (SMT) in ACLF.

METHODS

Systematic review and meta-analysis of randomized controlled trials. The primary outcome was survival at 60-90 days. We searched Ovid Medline, EMBASE, and Cochrane Central Register of Controlled Trials from inception to August 2021. Manual searches of reference lists in relevant articles and conference proceedings were also included. The revised Cochrane risk-of-bias tool was used for quality and risk of bias assessment. Two independent investigators extracted the data, and disagreements were solved by a third collaborator.

RESULTS

The initial search identified 142 studies. Four randomized controlled trials were selected for quantitative analysis including 310 patients (154 G-CSF and 156 SMT). Significant heterogeneity was observed (I²=74%, Chi²=11.57, p=0.009). G-CSF administration did not improve survival in patients with ACLF (random-effects model, risk ratio=0.64 [95% CI 0.39, 1.07]). However, when considering only the results from the studies performed in Asia, a significant decrease on mortality was observed (risk ratio=0.53 [95% CI 0.35, 0.81]). Severity scores (MELD and Child) and CD34+ peripheral cells mobilization did not significantly improve with G-CSF.

CONCLUSION

In a systematic review and meta-analysis, G-CSF administration did not significantly improve overall survival compared to SMT in patients with ACLF. The beneficial effects observed in Asian studies, as opposed to the European region, suggest that specific populations may benefit from further research aiming to identify certain subgroups with favourable outcomes when using G-CSF.

Therapeutic targets in alcohol-associated liver disease: progress and challenges

Alcohol-associated liver disease (ALD) is a complex disease with rapidly increasing prevalence. Although there are promising therapeutic targets on the horizon, none of the newer targets is currently close to an Food and Drug Administration approval. Strategies are needed to overcome challenges in study designs and conducting clinical trials and provide impetus to the field of drug development in the landscape of ALD and alcoholic hepatitis. Management of ALD is complex and should include therapies to achieve and maintain alcohol abstinence, preferably delivered by a multidisciplinary team. Although associated with clear mortality benefit in select patients, the use of early liver transplantation still requires refinement to create uniformity in selection protocols across transplant centers. There is also a need for reliable noninvasive biomarkers for prognostication. Last but not the least, strategies are urgently needed to implement integrated multidisciplinary care models for treating the dual pathology of alcohol use disorder and of liver disease for improving the long-term outcomes of patients with ALD.

Granulocyte Colony-Stimulating Factor Accelerates the Recovery of Hepatitis B Virus-Related Acute-on-Chronic Liver Failure by Promoting M2-Like Transition of Monocytes

Background and Aim

Acute-on-chronic liver failure (ACLF) has a high mortality rate. The role of granulocyte colony-stimulating factor (G-CSF) in ACLF remains controversial. Monocytes/macrophages are core immune cells, which are involved in the initiation and progression of liver failure; however, the effect of G-CSF on monocytes/macrophages is unclear. The study aimed to verify the clinical efficacy of G-CSF and explore the effect of it on monocytes in hepatitis B virus (HBV)-related ACLF (HBV-ACLF) paitents.

Methods

We performed a large randomized controlled clinical trial for the treatment of HBV-ACLF using G-CSF. A total of 111 patients with HBV-ACLF were prospectively randomized into the G-CSF group (5 μg/kg G-CSF every day for 6 days, then every other day until day 18) or the control group (standard therapy). All participants were followed up for at least 180 days. The relationship between monocyte count and mortality risk was analyzed. The effect of G-CSF on the phenotype and function of monocytes from patients with HBV-ACLF was evaluated using flow cytometry in vivo and in vitro experiments.

Results

The survival probability of the G-CSF group at 180 days was higher than that of the control group (72.2% vs. 53.8%, P = 0.0142). In the G-CSF-treated group, the monocyte counts on days 0 and 7 were independently associated with an evaluated mortality risk in the fully adjusted model (Model 3) [at day 0: hazard ratio (HR) 95% confidence interval (CI): 15.48 (3.60, 66.66), P = 0.0002; at day 7: HR (95% CI): 1.10 (0.50, 2.43), P=0.8080]. Further analysis showed that after treatment with G-CSF in HBV-ACLF patients, the expression of M1-like markers (HLA-DR and CD86) in monocytes decreased (HLA-DR: P = 0.0148; CD86: P = 0.0764). The expression of MerTK (M2-like marker) increased (P = 0.0002). The secretion of TNF-α, IL-6, and IL-10 from monocytes decreased without lipopolysaccharide (LPS) stimulation (TNF-α: P < 0.0001; IL-6: P= 0.0025; IL-10: P = 0.0004) or with LPS stimulation (TNF-α: P = 0.0439; P = 0.0611; IL-10: P = 0.0099). Similar effects were observed in vitro experiments.

Conclusion

G-CSF therapy confers a survival benefit to patients with HBV-ACLF. G-CSF can promote the anti-inflammatory/pro-restorative phenotype (M2-like) transition of monocytes, which may contribute to the recovery of ACLF.

Effectiveness of granulocyte colony-stimulating factor for patients with acute-on-chronic liver failure: a meta-analysis

BACKGROUND

The safety and efficacy of granulocyte colony-stimulating factor (G-CSF) for the treatment of acute-on-chronic liver failure (ACLF) remain uncertain. Therefore, we conducted a meta-analysis to draw a firmer conclusion.

METHODS

We searched the Cochrane library, PubMed, Embase, and China Biology Medicine disc to identify relevant RCTs performed before January 2020. Risk ratios (RRs) and their 95% confidence intervals (95% CIs) were calculated using a random effects model.

MAIN OUTCOME MEASURES

RRs (95% CI) for 1-, 2-, and 3-month survival rates.

SAMPLE SIZE

Six RCTs, including three open-label studies.

RESULTS

The six studies included 246 subjects (121 in a G-CSF group and 125 in a control group). G-CSF administration significantly improved the 1-, 2-, and 3-month survival rates in patients with ACLF. The pooled RRs (95% CI, P) were 0.43 (0.27-0.69, P=.0004), 0.44 (0.32-0.62, P<.00001), and 0.39 (0.22-0.68, P=.0009), respectively.

CONCLUSION

G-CSF may be beneficial and effective in the treatment of ACLF, but further studies are needed to verify this conclusion.

LIMITATIONS

The sample size was small, and studies were restricted to countries in Asia.

PROSPERO REGISTRATION NUMBER

CRD42021225681 CONFLICT OF INTEREST: None.

Longitudinal effects of modified creatinine index on all-cause mortality in individuals receiving hemodialysis treatment

BACKGROUND

The modified creatinine index (mCI), as a surrogate marker of muscle mass, has been associated with poor outcomes in patients undergoing hemodialysis. However, a single assessment may not reflect the clinical significance before an adverse clinical endpoint.

OBJECTIVE

Analyze mCI trajectories and their association with all-cause mortality in incident hemodialysis patients.

DESIGN

Retrospective observational cohort.

SETTING

Outpatient dialysis facility.

PATIENTS AND METHODS

We followed a cohort of patients who underwent maintenance hemodialysis treatment at least three times weekly for at least three months from 19 June 2010 to 29 December 2017. Clinical and laboratory features were measured at baseline. Longitudinal changes in the mCI were modeled using a joint longitudinal and survival model adjusted for baseline covariates and body mass index trajectories.

MAIN OUTCOME MEASURE

All-cause mortality.

SAMPLE SIZE

408 with 208 males (50.7%).

RESULTS

The mean (SD) age was 62.2 (12.3) years. The mCI changes were evaluated for a median (interquartile range) follow-up of 2.16 (1.13, 3.73) years. Forty-six percent (n=188) of patients reached the endpoint. A steeper slope (per 0.1 unit increase in the decrease rate) in modified creatinine index was associated with increased risk of all-cause mortality (HR, 1.04; 95% CI, 1.02-1.07; P=.011). In addition, an annual 1 mg/kg/day decrease in modified creatinine index level increased the hazard of all-cause mortality by 4% (HR, 1.04; 95% CI, 1.02-1.07; P=.001).

LIMITATIONS

Residual kidney function was not observed in the data. Setting was single center and thus results may not be generalizable to other populations.

CONCLUSION

All-cause death was significantly associated with loss of muscle mass over time. Longitudinal trajectories of nutritional markers may predict the clinical outcomes in patients undergoing hemodialysis. This may also be valuable for individual risk stratification. Furthermore, early management may provide an opportunity to improve patient survival.

CONFLICT OF INTEREST

None.

The Current Status of Granulocyte-Colony Stimulating Factor to Treat Acute-on-Chronic Liver Failure

Patients with acute-on-chronic liver failure (ACLF) have a devastating prognosis and therapeutic options are limited. Granulocyte-colony stimulating factor (G-CSF) mobilizes immune and stem cells and possess immune-modulatory and proregenerative capacities. In this review, we aim to define the current evidence for the treatment with G-CSF in end-stage liver disease. Several smaller clinical trials in patients with different severity grades of end-stage liver disease have shown that G-CSF improves survival and reduces the rate of complications. Adequately powered multicenter European trials could not confirm these beneficial effects. In mouse models of ACLF, G-CSF increased the toll-like receptor (TLR)-mediated inflammatory response which led to an increase in mortality. Adding a TLR4 signaling inhibitor allowed G-CSF to unfold its proregenerative properties in these ACLF models. These data suggest that G-CSF requires a noninflammatory environment to exert its protective properties.

Granulocyte-colony stimulating factor GCSF mobilizes hematopoietic stem cells in Kasai patients with biliary atresia in a phase 1 study and improves short term outcome

AIMS

In RCT of adults with decompensated cirrhosis, GCSF mobilizes hematopoietic stem cells HSC and improves short-term outcome. An FDA-IND for sequential Kasai-GCSF treatment in biliary atresia BA was approved. This phase 1 study examines GCSF safety in Kasai subjects. Preliminary short-term outcome was evaluated.

METHODS

GCSF (Neupogen) at 5 or 10 μg/kg (n = 3/group) was given in 3 daily doses starting on day 3 of Kasai surgery (NCT03395028). Serum CD34+ HSC cell counts, and 1-month of GCSF-related adverse events were monitored. The 6-months Phase 1 clinical outcome was compared against 10 subsequent post Phase 1 Kasai patients who did not receive GCSF.

RESULTS

With GCSF, WBC and platelet count transiently increased, LFT and serum creatinine remained stable. Reversible splenic enlargement (by 8.5-20%) occurred in 5/6 subjects. HSC count increased 12-fold and 17.5-fold for the 5 μg/kg and10 ug/kg dose respectively; with respective median total bilirubin levels for GCSF vs no-GCSF groups of 55 vs 91 μM at 1 month, p = 0.05; 15 vs 37 μM at 3 months, p = 0.24); and the 6-months cholangitis frequency of 40% vs 90%, p = 0.077.

CONCLUSIONS

GCSF safely mobilizes HSC in Kasai infants and may improve short-term biliary drainage and cholangitis. Phase 2 efficacy outcome of GCSF adjunct therapy for sequential Kasai and GCSF is pending.

Neuroprotection through G-CSF: recent advances and future viewpoints

Granulocyte-colony stimulating factor (G-CSF), a member of the cytokine family of hematopoietic growth factors, is 19.6 kDa glycoprotein which is responsible for the proliferation, maturation, differentiation, and survival of neutrophilic granulocyte lineage. Apart from its proven clinical application to treat chemotherapy-associated neutropenia, recent pre-clinical studies have highlighted the neuroprotective roles of G-CSF i.e., mobilization of haemopoietic stem cells, anti-apoptotic, neuronal differentiation, angiogenesis and anti-inflammatory in animal models of neurological disorders. G-CSF is expressed by numerous cell types including neuronal, immune and endothelial cells. G-CSF is released in autocrine manner and binds to its receptor G-CSF-R which further activates numerous signaling transduction pathways including PI3K/AKT, JAK/STAT and MAP kinase, and thereby promote neuronal survival, proliferation, differentiation, mobilization of hematopoietic stem and progenitor cells. The expression of G-CSF receptors (G-CSF-R) in the different brain regions and their upregulation in response to neuronal insult indicates the autocrine protective signaling mechanism of G-CSF by inhibition of apoptosis, inflammation, and stimulation of neurogenesis. These observed neuroprotective effects of G-CSF makes it an attractive target to mitigate neurodegeneration associated with neurological disorders. The objective of the review is to highlight and summarize recent updates on G-CSF as a therapeutically versatile neuroprotective agent along with mechanisms of action as well as possible clinical applications in neurodegenerative disorders including AD, PD and HD.

Abnormal Innate Immunity in Acute-on-Chronic Liver Failure: Immunotargets for Therapeutics

Acute-on-chronic liver failure (ACLF) is a severe life-threatening condition with high risk of multiorgan failure, sepsis, and mortality. ACLF activates a multifaceted interplay of both innate and adaptive immune response in the host which governs the overall outcome. Innate immune cells recognize the conserved elements of microbial and viral origin, both to extort instant defense by transforming into diverse modules of effector responses and to generate long-lasting immunity but can also trigger a massive intrahepatic immune inflammatory response. Acute insult results in the activation of innate immune cells which provokes cytokine and chemokine cascade and subsequently initiates aggressive systemic inflammatory response syndrome, hepatic damage, and high mortality in ACLF. Dysregulated innate immune response not only plays a critical role in disease progression but also potentially correlates with clinical disease severity indices including Child-Turcotte-Pugh, a model for end-stage liver disease, and sequential organ failure assessment score. A better understanding of the pathophysiological basis of the disease and precise immune mechanisms associated with liver injury offers a novel approach for the development of new and efficient therapies to treat this severely ill entity. Immunotherapies could be helpful in targeting immune-mediated organ damage which may constrain progression toward liver failure and eventually reduce the requirement for liver transplantation. Here, in this review we discuss the defects of different innate immune cells in ACLF which updates the current knowledge of innate immune response and provide potential targets for new therapeutic interventions.

The Mexican consensus on alcoholic hepatitis

Alcoholic hepatitis is a frequent condition in the Mexican population. It is characterized by acute-on-chronic liver failure, important systemic inflammatory response, and multiple organ failure. The severe variant of the disease implies elevated mortality. Therefore, the Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Hepatología brought together a multidisciplinary team of health professionals to formulate the first Mexican consensus on alcoholic hepatitis, carried out utilizing the Delphi method and resulting in 37 recommendations. Alcohol-related liver disease covers a broad spectrum of pathologies that includes steatosis, steatohepatitis, different grades of fibrosis, and cirrhosis and its complications. Severe alcoholic hepatitis is defined by a modified Maddrey's discriminant function score ≥ 32 or by a Model for End-Stage Liver Disease (MELD) score equal to or above 21. There is currently no specific biomarker for its diagnosis. Leukocytosis with neutrophilia, hyperbilirubinemia (> 3 mg/dL), AST > 50 U/l (< 400 U/l), and an AST/ALT ratio > 1.5-2 can guide the diagnosis. Abstinence from alcohol, together with nutritional support, is the cornerstone of treatment. Steroids are indicated for severe disease and have been effective in reducing the 28-day mortality rate. At present, liver transplantation is the only life-saving option for patients that are nonresponders to steroids. Certain drugs, such as N-acetylcysteine, granulocyte-colony stimulating factor, and metadoxine, can be adjuvant therapies with a positive impact on patient survival.

Granulocyte colony-stimulating factor for alcoholic hepatitis: A systematic review and meta-analysis of randomised controlled trials

Background & Aims

Granulocyte colony-stimulating factor (G-CSF) treatment has been proposed as a therapeutic option for patients with severe alcoholic hepatitis (AH). The aim of this study was to synthesise available evidence on the efficacy of G-CSF in AH.

Methods

This is a meta-analysis of randomised controlled trials evaluating the risk of death at 90 days and the risk of infection.

Results

Seven studies were included. Of a total of 396 patients, 336 had AH, 197 patients were treated with G-CSF, and 199 received placebo or pentoxifylline. In overall meta-analysis, G-CSF therapy was associated with a reduced risk of death at 90 days (odds ratio [OR] 0.28; 95% CI 0.09–0.88; p = 0.03). There was high heterogeneity between studies (p <0.001; I² = 80%). Five studies were performed in Asia and 2 in Europe. In the subgroup analysis of studies performed in Asia, G-CSF was associated with a reduced risk of death (OR 0.15; 95% CI 0.08–0.28; p <0.001; heterogeneity: p = 0.5, I² = 0%). In European studies, G-CSF tended to increase mortality compared with controls, although the difference was not significant (OR 1.89; 95% CI 0.90–3.98; p = 0.09; heterogeneity: p = 0.8, I² = 0%). In Asian studies, occurrence of infection was less frequent in G-CSF patients than in controls (OR 0.12; 95% CI 0.06–0.23; p <0.001; heterogeneity: p = 0.7, I² = 0%), whilst in European studies, this occurrence was not statistically different (OR 0.92; 95% CI 0.50–1.68; p = 0.78; heterogeneity: p = 0.5, I² = 0%). In sensitivity analyses, excluding studies that included patients with acute-on-chronic liver failure (ACLF) other than AH, patients with less severe AH, or patients with non-response to corticosteroids, results were similar to those of overall analyses, both for mortality and occurrence of infection.

Conclusions

Granulocyte colony-stimulating factor therapy may improve the prognosis of patients with severe AH. However, owing to the high heterogeneity observed in the overall analysis caused by conflicting results between the Asian and European studies, G-CSF cannot currently be recommended for AH, particularly in Europe. Whether these differences can be explained by ethnic differences or disparities in patient selection and disease severity remains unclear.

Lay summary

The main finding of this meta-analysis is that the use of granulocyte colony-stimulating factor (G-CSF) is associated with a mortality reduction of more than 70% at 3 months amongst patients with alcoholic hepatitis (AH) compared with controls who did not receive this therapy. However, owing to the high heterogeneity observed in the overall analysis caused by conflicting results between the Asian and European studies, G-CSF cannot currently be recommended for patients with AH, particularly in Europe. Whether these differences can be explained by ethnic differences or disparities in patient selection and disease severity remains unclear.

•

This meta-analysis reports pooled data from 7 studies on the use of G-CSF in patients with alcoholic hepatitis.

•

The favourable effect of G-CSF was only encountered in Asian not European studies.

•

Additional data are needed to clarify the usefulness of G-CSF in severe alcoholic hepatitis, particularly in Europe.

Evaluating the best empirical antibiotic therapy in patients with acute-on-chronic liver failure and spontaneous bacterial peritonitis

BACKGROUND/AIMS

Spontaneous bacterial peritonitis (SBP) is a life-threatening complication of advanced cirrhosis. By studying the susceptibility of isolated organisms and analyzing empirical antibiotic therapy combined with clinical outcomes, we aimed to find an improved empirical antibiotic therapy by considering the individual acute-on-chronic liver failure (ACLF) grade for patients with or without sepsis.

METHODS

Clinical outcomes of 182 patients were assessed retrospectively with multivariable regression analysis. Each of the 223 isolates was individually evaluated regarding susceptibility results and intrinsic resistances.

RESULTS

Piperacillin/tazobactam had the highest antimicrobial susceptibility among monotherapies/fixed combinations, which was significantly lower than combination therapies such as meropenem-linezolid (75.3% vs. 98.5%, P < 0.001). The sensitivity of pathogens to empirical antibiotic therapy correlated with significantly lower inpatient mortality (18.9% vs. 37.0%, P = 0.018), shorter inpatient stay (16.3 ± 10.2 vs. 26.4 ± 21.0 days, P = 0.053) and shorter intensive care treatment (2.1 ± 4.5 vs. 7.9 ± 15.4 days, P = 0.016). The largest difference of mortality was observed in patients with ACLF grade 3 (54.5% vs. 73.1% [sensitive vs. non-sensitive]).

CONCLUSION

All SBP patients benefited from efficient empirical antibiotic therapy, regarding the reduced inpatient mortality and complications. For SBP patients with ACLF grade 3 without sepsis, the combination therapy with meropenem-linezolid may be suitable considering the susceptibility results and the concentration in the peritoneal cavity.

Acute-on-chronic liver failure: consensus recommendations of the Asian Pacific association for the study of the liver (APASL): an update

The first consensus report of the working party of the Asian Pacific Association for the Study of the Liver (APASL) set up in 2004 on acute-on-chronic liver failure (ACLF) was published in 2009. With international groups volunteering to join, the "APASL ACLF Research Consortium (AARC)" was formed in 2012, which continued to collect prospective ACLF patient data. Based on the prospective data analysis of nearly 1400 patients, the AARC consensus was published in 2014. In the past nearly four-and-a-half years, the AARC database has been enriched to about 5200 cases by major hepatology centers across Asia. The data published during the interim period were carefully analyzed and areas of contention and new developments in the field of ACLF were prioritized in a systematic manner. The AARC database was also approached for answering some of the issues where published data were limited, such as liver failure grading, its impact on the 'Golden Therapeutic Window', extrahepatic organ dysfunction and failure, development of sepsis, distinctive features of acute decompensation from ACLF and pediatric ACLF and the issues were analyzed. These initiatives concluded in a two-day meeting in October 2018 at New Delhi with finalization of the new AARC consensus. Only those statements, which were based on evidence using the Grade System and were unanimously recommended, were accepted. Finalized statements were again circulated to all the experts and subsequently presented at the AARC investigators meeting at the AASLD in November 2018. The suggestions from the experts were used to revise and finalize the consensus. After detailed deliberations and data analysis, the original definition of ACLF was found to withstand the test of time and be able to identify a homogenous group of patients presenting with liver failure. New management options including the algorithms for the management of coagulation disorders, renal replacement therapy, sepsis, variceal bleed, antivirals and criteria for liver transplantation for ACLF patients were proposed. The final consensus statements along with the relevant background information and areas requiring future studies are presented here.

Acute Alcoholic Hepatitis

Alcoholic hepatitis is a unique type of alcohol-associated liver disease characterized by acute liver inflammation caused by prolonged heavy alcohol use. Treatment is mostly supportive. The short-term prognosis of acute alcoholic hepatitis depends on liver recovery, and ranges widely from rapid improvement to grim multiorgan failure despite treatment. Refinement of scoring systems have enhanced prognostication to guide clinical decision making in alcoholic hepatitis. Recent advances in the treatment of alcoholic hepatitis have solidified corticosteroids as the cornerstone of treatment to enhance short-term survival, but not intermediate or long-term survival.

Efficacy of Granulocyte Colony-Stimulating Factor and N-Acetylcysteine Therapies in Patients With Severe Alcoholic Hepatitis

BACKGROUND & AIMS

Patients with alcoholic hepatitis (AH) have high mortality, so new therapies are needed. Administration of granulocyte colony stimulating factor (G-CSF) increases survival times of patients with AH. It is not known whether addition of N-acetyl cysteine (NAC) to G-CSF could further increase survival time. We performed a randomized controlled pilot study to compare the efficacy of standard medical therapy with pentoxifylline to treatment with a combination of G-CSF and standard medical therapy as well as to the combination of NAC, G-CSF, and standard medical therapy in patients with severe AH.

METHODS

We performed an open-label, single-center study of 57 patients with severe AH admitted to a Liver Intensive Care unit in India from October 2014 through March 2017. Patients were randomly assigned to groups that received standard medical therapy (with pentoxifylline) plus G-CSF for 5 days (G-CSF group; n = 18), standard medical therapy plus G-CSF and intravenous NAC for 5 days (combination group; n = 19), or standard medical therapy alone (n = 20). Clinical data and blood samples were collected at baseline; on day 6; and 1, 2, and 3 months after the study began. CD34+ cells were measured in blood samples collected on days 0 and 6. The primary outcome was proportion of patients surviving for 90 days. Secondary outcomes were mobilization of CD34+ cells at day 6, as well as Child Turcotte Pugh, model for end-stage liver disease, and modified discriminant function scores until day 90.

RESULTS

Significantly higher proportions of patients in the G-CSF group (16/18) and the combination group (13/19) survived for 90 days than in the standard medical therapy group (6/20) (P = .0001 for G-CSF group and P = .037 and combination group). The GGSF and combination groups each had increased numbers of CD34+ cells from baseline until day 6, compared with the standard medical therapy group. The G-CSF group (but not the combination group) had significantly larger median reductions in modified discriminant function scores at study months 1 (reduction of 60.36%), 2 (reduction of 75.36%), and 3 (reduction of 88.73%) vs the standard medical therapy group (P = .02; P = .05; and P = .00, respectively). The G-CSF group had a significantly larger median reduction in model for end-stage liver disease score at 3 months (reduction of 55.77%; P = .01), but not in Child Turcotte Pugh score, compared with the standard medical therapy group. All groups had similar numbers of complications.

CONCLUSION

In a pilot randomized controlled trial, we found administration of G-CSF to improve liver function and increase survival times in patients with severe AH, compared with standard therapy. We found no evidence for benefit of adding NAC to G-CSF. These findings require confirmation in larger trials. ClincialTrials.gov, number: NCT02971306.

Molecular and functional characterization of CD133+ stem/progenitor cells infused in patients with end-stage liver disease reveals their interplay with stromal liver cells

BACKGROUND AIMS

Growing evidence supports the therapeutic potential of bone marrow (BM)-derived stem/progenitor cells for end-stage liver disease (ESLD). We recently demonstrated that CD133⁺ stem/progenitor cell (SPC) reinfusion in patients with ESLD is feasible and safe and improve, albeit transiently, liver function. However, the mechanism(s) through which BM-derived SPCs may improve liver function are not fully elucidated.

METHODS

Here, we characterized the circulating SPCs compartment of patients with ESLD undergoing CD133⁺ cell therapy. Next, we set up an in vitro model mimicking SPCs/liver microenvironment interaction by culturing granulocyte colony-stimulating factor (G-CSF)-mobilized CD133⁺and LX-2 hepatic stellate cells.

RESULTS

We found that patients with ESLD show normal basal levels of circulating hematopoietic and endothelial progenitors with impaired clonogenic ability. After G-CSF treatment, patients with ESLD were capable to mobilize significant numbers of functional multipotent SPCs, and interestingly, this was associated with increased levels of selected cytokines potentially facilitating SPC function. Co-culture experiments showed, at the molecular and functional levels, the bi-directional cross-talk between CD133⁺ SPCs and human hepatic stellate cells LX-2. Human hepatic stellate cells LX-2 showed reduced activation and fibrotic potential. In turn, hepatic stellate cells enhanced the proliferation and survival of CD133⁺ SPCs as well as their endothelial and hematopoietic function while promoting an anti-inflammatory profile.

DISCUSSION

We demonstrated that the interaction between CD133⁺ SPCs from patients with ESLD and hepatic stellate cells induces significant functional changes in both cellular types that may be instrumental for the improvement of liver function in cirrhotic patients undergoing cell therapy.

Granulocyte colony-stimulating factor improves survival of patients with decompensated cirrhosis: a randomized-controlled trial

BACKGROUND

Liver transplantation is the only curative option for patients with decompensated cirrhosis; however, many patients die while awaiting transplantation. Granulocyte colony-stimulating factor (GCSF) has shown promising results in improving outcomes in patients with advanced liver disease. We evaluated the efficacy of GCSF in patients with decompensated cirrhosis in an open-labeled randomized-controlled trial.

METHODS

Consecutive patients with decompensated cirrhosis were randomized to receive either GCSF 300 μg twice daily for 5 days plus standard medical therapy (SMT) (GCSF+SMT group) or SMT alone (SMT alone group). Outcomes were assessed at 6 months from randomization.

RESULTS

A total of 126 patients [median age: 53 (range: 31-76) years, 85% men] received GCSF+SMT and 127 patients received SMT alone. Baseline characteristics were similar in both the groups. The 5-day GCSF therapy did not lead to any significant adverse effects. At 6 months, in the GCSF+SMT group, 17 patients had died and nine were lost to follow-up, whereas in the SMT-alone group, 30 patients had died and 11 were lost to follow-up. By intention-to-treat analysis, cumulative survival was significantly higher in the GCSF+SMT group (79 vs. 68%; P=0.025). Also, significantly more patients (66%) showed improvement or stability in the Child-Turcotte-Pugh score at 6 months in the GCSF+SMT group compared with the SMT-alone group (51%, P=0.021).

CONCLUSION

GCSF therapy improves survival and clinical outcome in patients with decompensated cirrhosis. It may be useful in patients awaiting transplantation to prevent worsening during the waiting period. Further studies are needed to explore whether repeated periodic GCSF courses can further increase the survival and decrease the need for liver transplantation.Clinical trial registered at https://clinicaltrials.gov vide NCT02642003.

Ultrasound-guided percutaneous portal transplantation of peripheral blood monocytes in patients with liver cirrhosis

BACKGROUND/AIMS

Liver transplantation offers the only definite cure for cirrhosis but lacking donors is problem. Stem cell therapy is attractive in this setting. In this study, we aimed to explore the safety and efficacy of ultrasound-guided percutaneous portal transplantation of peripheral blood monocyte cell (PBMC) in cirrhotic patients.

METHODS

A total of nine decompensated cirrhotic patients were randomized into three groups: group 1 (n = 3) was control group, group 2 (n = 3) received granulocyte-colony stimulating factor (G-CSF) mobilization for 3 days, and group 3 (n = 3) received G-CSF mobilized PBMCs by leukapheresis and PBMC transplantation through ultrasound-guided percutaneous portal vein puncture. Liver function and clinical features were evaluated.

RESULTS

At baseline, the Child-Turcotte-Pugh and the model for end-stage liver disease scores were comparable in study groups. Compared with group 1, there was a tendency to improve liver function in group 3 at 6 months after treatment. Treatment was tolerable and no complications were encountered related to the G-CSF mobilization or percutaneous portal administration of PBMCs. Imaging studies showed patent portal veins at the end of the study period.

CONCLUSIONS

Autologous PBMC transplantation through ultrasound-guided percutaneous portal vein puncture could be considered as a safe alternative treatment for decompensated cirrhotic patients.

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.

Overview on acute-on-chronic liver failure

Liver failure (LF) is defined as severe dysfunction in hepatic synthesis, detoxification, and metabolism induced by various etiologies. Clinical presentation of LF typically includes severe jaundice, coagulation disorder, hepatic encephalopathy, and ascites. LF can be classified into acute LF, acute-on-chronic LF (ACLF), and chronic LF. ACLF has been demonstrated as a distinct syndrome with unique clinical presentation and outcomes. The severity, curability, and reversibility of ACLF have attracted considerable attention. Remarkable developments in ACLF-related conception, diagnostic criteria, pathogenesis, and therapy have been achieved. However, this disease, especially its diagnostic criteria, remains controversial. In this paper, we systemically reviewed the current understanding of ACLF from its definition, etiology, pathophysiology, pathology, and clinical presentation to management by thoroughly comparing important findings between east and west countries, as well as those from other regions. We also discussed the controversies, challenges, and needs for future studies to promote the standardization and optimization of the diagnosis and treatment for ACLF.

Acute-on-chronic liver failure: terminology, mechanisms and management

Acute-on-chronic liver failure (ACLF) is a distinct clinical entity and differs from acute liver failure and decompensated cirrhosis in timing, presence of acute precipitant, course of disease and potential for unaided recovery. The definition involves outlining the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific timeframe. The pathophysiology of ACLF relates to persistent inflammation, immune dysregulation with initial wide-spread immune activation, a state of systematic inflammatory response syndrome and subsequent sepsis due to immune paresis. The disease severity and outcome can be predicted by both hepatic and extrahepatic organ failure(s). Clinical recovery is expected with the use of nucleoside analogues for hepatitis B, and steroids for severe alcoholic hepatitis and, possibly, severe autoimmune hepatitis. Artificial liver support systems help remove toxins and metabolites and serve as a bridge therapy before liver transplantation. Hepatic regeneration during ongoing liver failure, although challenging, is possible through the use of growth factors. Liver transplantation remains the definitive treatment with a good outcome. Pre-emptive antiviral agents for hepatitis B before chemotherapy to prevent viral reactivation and caution in using potentially hepatotoxic drugs can prevent the development of ACLF.

Potent antiviral therapy improves survival in acute on chronic liver failure due to hepatitis B virus reactivation

Acute on chronic liver failure (ACLF) is a disease entity with a high mortality rate. The acute event arises from drugs and toxins, viral infections, bacterial sepsis, interventions (both surgical and non-surgical) and vascular events on top of a known or occult chronic liver disease. ACLF secondary to reactivation of chronic hepatitis B virus is a distinct condition; the high mortality of which can be managed in the wake of new potent antiviral therapy. For example, lamivudine and entecavir use has shown definite short-term survival benefits, even though drug resistance is a concern in the former. The renoprotective effects of telbivudine have been shown in a few studies to be useful in the presence of renal dysfunction. Monotherapy with newer agents such as tenofovir and a combination of nucleos(t)ides is promising for improving survival in this special group of liver disease patients. This review describes the current status of potent antiviral therapy in patient with acute on chronic liver failure due to reactivation of chronic hepatitis B, thereby providing an algorithm in management of such patients.

Concise review: bone marrow autotransplants for liver disease?

There are increasing reports of using bone marrow-derived stem cells to treat advanced liver disease. We consider several critical issues that underlie this approach. For example, are there multipotent stem cell populations in human adult bone marrow? Can they develop into liver cells or supporting cell types? What are stromal stem/progenitor cells, and can they promote tissue repair without replacing hepatocytes? Does reversal of end-stage liver disease require new hepatocytes, a new liver microenvironment, both, neither or something else? Although many of these questions are unanswered, we consider the conceptual and experimental bases underlying these issues and critically analyze results of clinical trials of stem cell therapy of end-stage liver disease.

Granulocyte colony-stimulating factor in severe alcoholic hepatitis: a randomized pilot study

OBJECTIVES

Severe alcoholic hepatitis has high short-term mortality. The aim of this study was to test the hypothesis that treatment of patients with alcoholic hepatitis with granulocyte colony-stimulating factor (G-CSF) might mobilize bone marrow-derived stem cells and promote hepatic regeneration and thus improve survival.

METHODS

Forty-six patients with severe alcoholic hepatitis were prospectively randomized in an open study to standard medical therapy (SMT) plus G-CSF (group A; n=23) at a dose of 5 μg/kg subcutaneously every 12 h for 5 consecutive days or to SMT alone (group B; n=23) at a tertiary care center. We assessed the mobilization of CD34(+) cells on day 6, Child-Turcotte-Pugh (CTP), model for end-stage liver disease (MELD), and modified Maddrey's discriminant function (mDF) scores, and survival until day 90.

RESULTS

There was a statistically significant increase in the number of CD34(+) cells in peripheral blood in group A as compared with group B (P=0.019) after 5 days of G-GSF therapy. There was a significant reduction in median Δ change% in CTP, MELD, and mDF at 1, 2, and 3 months in group A as compared with group B (P<0.05). There was marked improvement in survival in group A as compared with group B (78.3% vs. 30.4%; P=0.001) at 90 days.

CONCLUSIONS

G-CSF is safe and effective in the mobilization of hematopoietic stem cells and improves liver function as well as survival in patients with severe alcoholic hepatitis.

Altered frequencies of dendritic cells and IFN-gamma-secreting T cells with granulocyte colony-stimulating factor (G-CSF) therapy in acute-on- chronic liver failure

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) is a serious hepatic ailment with impaired immunity and poor treatment options resulting high mortality. Treatment with granulocyte colony-stimulating factor(G-CSF) mobilizes CD34(+) cells in ACLF patients; however its effect on impaired immune responses remains to be elucidated. To analyse the effect of G-CSF in immune modulation in ACLF.

METHODS

We have analysed the frequencies of circulating and intrahepatic myeloid (mDCs) and plasmacytoid(pDCs) dendritic cells (DCs) and T cells in ACLF patients treated with G-CSF (Group A; n = 23) and placebo (Group B; n = 24) using flow cytometry. IFN-c production was compared in both groups following stimulation of PBMCs with phorbol myristate acetate (PMA).

RESULTS

In Group A, circulating and intrahepatic mDCs, pDCs (P < 0.04, P < 0.02) and T cells(CD3, CD4 and CD8) increased significantly post-G-CSF treatment in comparison to placebo group. Importantly in Group A, IFN-c-producing CD8 T cells were significantly decreased (P > 0.05) along with decreased serum bilirubin and international normalized ratio (INR). Intrahepatic DCs and IFN-clevel were compared in survivor and non-survivor. Non-survivors from both groups, showed decreased DCs, high IFN-c level and no improvement in clinical parameters including s-bilirubin and INR.

CONCLUSIONS

G-CSF therapy increased the frequencies of dendritic cells and reduced IFN-c secreting CD8 T cells with improved clinical severity indices. Decreased IFN- c production may contribute to reduced hepatocellular damage in ACLF patients.Our observations support the basis for further use of G-CSF therapy as immune modulator in these patients.

Liver bioengineering: Current status and future perspectives

The present review aims to illustrate the strategies that are being implemented to regenerate or bioengineer livers for clinical purposes. There are two general pathways to liver bioengineering and regeneration. The first consists of creating a supporting scaffold, either synthetically or by decellularization of human or animal organs, and seeding cells on the scaffold, where they will mature either in bioreactors or in vivo. This strategy seems to offer the quickest route to clinical translation, as demonstrated by the development of liver organoids from rodent livers which were repopulated with organ specific cells of animal and/or human origin. Liver bioengineering has potential for transplantation and for toxicity testing during preclinical drug development. The second possibility is to induce liver regeneration of dead or resected tissue by manipulating cell pathways. In fact, it is well known that the liver has peculiar regenerative potential which allows hepatocyte hyperplasia after amputation of liver volume. Infusion of autologous bone marrow cells, which aids in liver regeneration, into patients was shown to be safe and to improve their clinical condition, but the specific cells responsible for liver regeneration have not yet been determined and the underlying mechanisms remain largely unknown. A complete understanding of the cell pathways and dynamics and of the functioning of liver stem cell niche is necessary for the clinical translation of regenerative medicine strategies. As well, it will be crucial to elucidate the mechanisms through which cells interact with the extracellular matrix, and how this latter supports and drives cell fate.

Regeneration and bioengineering of transplantable abdominal organs: current status and future challenges

INTRODUCTION

The most critical issue to organ transplantation is the identification of new sources of organs. The present manuscript illustrates the state-of-the-art regenerative medicine (RM) investigations aiming to manufacturing abdominal organs for transplant purposes.

AREAS COVERED

This manuscript focuses on research in the bioengineering and regeneration of kidneys, insulin-producing cells, livers and small bowel. The main technology currently under development exploits the seeding of cells on supporting scaffolding material. Despite favorable preliminary results obtained with relatively simple, hollow organs, when more complex organs are considered, the scenario changes dramatically. Investigations are still in early stages, and clinical translation is not yet foreseeable based on current knowledge and information. Obstacles are numerous but we believe the critical factor hampering success is lack of in-depth understanding of the extracellular matrix (ECM) and cell-ECM interactions, as well as the mechanisms with which organs develop in utero.

EXPERT OPINION

The success of RM to generate transplantable abdominal organs relies heavily on progress in (stem) cell therapies, developmental and ECM biology, and in the thorough understanding of the intricate relationship and interplay between cells and the ECM. This will require enormous investments in financial and medical resources, which ideally should be embarked upon by governments, the private sector and academia.

Influence of allogeneic bone marrow mesenchymal stem cell transplantation on serum levels of HMGB1 in mice with acute live failure

AIM: To explore the influence of allogeneic bone marrow mesenchymal stem cell (BMSC) transpantion on serum levels of high group box protein B1 (HMGB1) in an animal model of acute live failure (ALF).

METHODS: Balb/c mice were given D-galactosamine (D-GaIN) and lipopolysaccharide (LPS) to induce acute liver failure. BMSCs were cultured and purified. Ninety healthy Balb/c mice were randomly assigned to three groups: normal control group, ALF group, and BMSC treatment group. ALT/AST levels were tested 12, 24, and 48 h after treatment, and liver tissue pathological examination was performed after 48 h. The expression of HMGB1 in serum was detected by Western blot.

RESULTS: The survival rate was significantly higher in the BMSC treatment group than in the ALF group (83.3% vs 16.7%, P < 0.05). AST/ALT levels in the ALF group and BMSC treatment group rose significantly at 12 h, peaked at 24 h, and began to fall at 48 h. ALT/AST levels at 12, 24 and 48 h were significantly higher in the ALF group and BMSC treatment group than in the normal group (all P < 0.01), and in the ALF group than in the BMSC treatment group (all P < 0.01). The degeneration and necrosis in liver tissue were less obvious in the BMSC treatment group than in the ALF group. HMGB1 was almost not detectable in normal mouse serum. Serum levels of HMGB1 were significantly higher in the ALF group than in the BMSC treatment group (P < 0.01).

CONCLUSION: BMSC transplantation inhibits HMGB1 expression, reduces liver inflammation, and thereby lowers mortality in mice with ALF.

Regenerative Cells for Transplantation in Hepatic Failure

Human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells have an enormous potential; however, their potential clinical application is being arrested due to various limitations such as teratoma formation followed by tumorigenesis, emergent usage, and the quality control of cells, as well as safety issues regarding long-term culture are also delaying their clinical application. In addition, human ES cells have two crucial issues: immunogenicity and ethical issues associated with their clinical application. The efficient generation of human iPS cells requires gene transfer, yet the mechanism underlying pluripotent stem cell induction has not yet been fully elucidated. Otherwise, although human adult regenerative cells including mesenchymal stem cells have a limited capacity for differentiation, they are nevertheless promising candidates for tissue regeneration in a clinical setting. This review highlights the use of regenerative cells for transplantation in hepatic failure.

Granulocyte colony-stimulating factor mobilizes CD34(+) cells and improves survival of patients with acute-on-chronic liver failure

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) develops in patients with chronic liver disease and has high mortality. Mobilization of bone marrow-derived stem cells with granulocyte colony-stimulating factor (G-CSF) could promote hepatic regeneration.

METHODS

Consecutive patients with ACLF were randomly assigned to groups given 5 μg/kg G-CSF subcutaneously (12 doses; group A, n = 23) or placebo (group B, n = 24) plus standard medical therapy. We assessed survival until day 60; Child-Turcotte-Pugh (CTP), Model for End-Stage Liver Disease (MELD), and Sequential Organ Failure Assessment (SOFA) scores; and the development of other related complications.

RESULTS

After 1 week of treatment, group A had higher median leukocyte and neutrophil counts than group B (P < .001). Sixteen patients in group A (69.6%) and 7 in group B (29%) survived; the actuarial probability of survival at day 60 was 66% versus 26%, respectively (P = .001). Treatment with G-CSF also reduced CTP scores in group A by a median of 33.3% compared with an increase of 7.1% in group B (P = .001), along with MELD (median reduction of 15.3% compared with an increase of 11.7% in group B; P = .008) and SOFA scores (median reduction of 50% compared with an increase of 50% in group B; P = .001). The percentages of patients who developed hepatorenal syndrome, hepatic encephalopathy, or sepsis were lower in group A than in group B (19% vs 71% [P = .0002], 19% vs 66% [P = .001], and 14% vs 41% [P = .04], respectively). After 1 month of treatment, G-CSF increased the number of CD34(+) cells in the liver (by 45% compared with 27.5% in group B; P = .01).

CONCLUSIONS

G-CSF therapy more than doubles the percentage of patients with ACLF who survive for 2 months; it also significantly reduces CTP, MELD, and SOFA scores and prevents the development of sepsis, hepatorenal syndrome, and hepatic encephalopathy.

Stem cells in liver failure

Orthotopic liver transplantation (OLT) represents the only reliable therapeutic approach for acute liver failure (ALF), liver failure associated to end-stage chronic liver diseases (CLD) and non-metastatic liver cancer. The clinical impact of liver failure is relevant because of the still high ALF mortality and the increasing worldwide prevalence of cirrhosis that, in turn, is the main predisposing cause for hepatocellular carcinoma (HCC). Moreover, in the next decade because an increased number of patients reaching end-stage disease and requiring OLT may face a shortage of donor livers. This clinical scenario led several laboratories to explore the feasibility and efficiency of alternative approaches, involving cellular therapy, to counteract liver failure. The present chapter overviews results and concepts emerged from recent experimental and clinical studies in which adult or embryonic hepatocytes, hepatic stem/progenitor cells, induced pluripotent stem (iPS) cells as well as extrahepatic stem cells have been used as putative transplantable cell sources.

Safety evaluation of stem cells used for clinical cell therapy in chronic liver diseases; with emphasize on biochemical markers

There are several issues to be considered to reduce the risk of rejection and minimize side effects associated with liver cell transplantation in chronic liver diseases. The source and the condition of stem cell proliferation and differentiation ex vivo and the transplantation protocols are important safety considerations for cell based therapy. The biochemical and molecular markers are important tools for safety evaluation of different processes of cell expansion and transplantation. Studies show that hepatocytes differentiated from adult and embryonic stem cells exhibit biochemical and metabolic properties resembling mature hepatocytes. Therefore these assays can help to assess the biological and metabolic performance of hepatocytes and progenitor stem cells. The assays also help in testing the contribution of transplanted hepatocytes in improving the repair and function of damaged liver in the recipient. Here we review the biochemical and metabolic markers, which are implicated in evaluation of safety issues of stem cells used for therapeutic purposes in chronic liver diseases and regeneration of damaged liver. We also highlight application of biochemical tests for assessment of liver cell transplantation.

Therapeutic application of stem cells in gastroenterology: An up-date

Adult stem cells represent the self-renewing progenitors of numerous body tissues, and they are currently classified according to their origin and differentiation ability. In recent years, the research on stem cells has expanded enormously and holds therapeutic promises for many patients suffering from currently disabling diseases. This paper focuses on the possible use of stem cells in the two main clinical settings in gastroenterology, i.e., hepatic and intestinal diseases, which have a strong impact on public health worldwide. Despite encouraging results obtained in both regenerative medicine and immune-mediated conditions, further studies are needed to fully understand the biology of stem cells and carefully assess their putative oncogenic properties. Moreover, the research on stem cells arouses fervent ethical, social and political debate. The Italian Society of Gastroenterology sponsored a workshop on stem cells held in Verona during the XVI Congress of the Federation of Italian Societies of Digestive Diseases (March 6-9, 2010). Here, we report on the issues discussed, including liver and intestinal diseases that may benefit from stem cell therapy, the biology of hepatic and intestinal tissue repair, and stem cell usage in clinical trials.

Stem and progenitor cells in liver regeneration and repair

Mammalian liver has a unique capacity to regenerate following resection or injury, and recovery of liver mass is mainly through proliferation of remaining adult hepatocytes. However, in pathologic conditions, especially during acute liver failure (ALF) and advanced stages of chronic liver disease (CLD), regeneration eventually fails and orthothopic liver transplantation (OLT) represents the only curative approach. The clinical scenario of a world-wide increasing incidence of end-stage CLD and an associated lack of organ availability has led several laboratories to explore the feasibility and efficiency of experimental alternatives to OLT involving cellular therapy. This review presents experimental and clinical studies performed in the last 10-15 years where adult and embryonic hepatocytes, hepatic stem/progenitor cells and extrahepatic stem cells have been used as transplantable cell sources.

Management of Liver Failure: From Transplantation to Cell-Based Therapy

The severe shortage of deceased donor organs has driven a search for alternative methods of treating liver failure. In this context, cell-based regenerative medicine is emerging as a promising interdisciplinary field of tissue repair and restoration, able to contribute to improving health in a minimally invasive fashion. Several cell types have allowed long-term survival in experimental models of liver injury, but their therapeutic potential in humans should be regarded with deep caution, because few clinical trials are currently available and the number of patients enrolled so far is too small to assess benefits versus risks. This review summarizes the current literature on the physiological role of endogenous stem cells in liver regeneration and on the therapeutic benefits of exogenous stem cell administration with specific emphasis on the potential clinical uses of mesenchymal stem cells. Moreover, critical points that still need clarification, such as the exact identity of the stem-like cell population exerting the beneficial effects, as well as the limitations of stem cell-based therapies, are discussed.

Granulocyte colony-stimulating factor treatment ameliorates liver injury and improves survival in rats with D-galactosamine-induced acute liver failure

Only liver transplantation is currently available therapy for the patients with acute liver failure (ALF). This study was designed to determine whether administration of granulocyte colony-stimulating factor (G-CSF) has therapeutic efficacy in animals with ALF. Female Sprague-Dawley (SD) rats were intraperitoneally injected with a single dose of d-galactosamine (d-GalN, 1.4g/kg) to induce ALF. After 2h, the rats were randomized to receive G-CSF (50μg/kg/day), or saline vehicle injection for 5 days. Rats were observed for survival and assessed for liver injury by serum alanine transaminase (ALT) measurement and histological analysis. CD34+ cells in bone marrow were assessed by flow cytometry. CD34+ cells and Ki-67+ hepatocytes in liver tissue were evaluated by immunohistochemistry. In the ALF model, 5-day survival after d-GalN injection was 33.3% (10/30), while G-CSF administration following d-GalN resulted in 53.3% (16/30) survival (p=0.027). G-CSF treated rats had lower ALT level and less hepatic injury compared with saline vehicle rats. The increases of CD34+ cells in bone marrow and liver tissue and Ki-67+ cells in liver tissue in G-CSF treated rats were higher than those in saline rats. No correlation was observed between CD34+ cells and Ki-67+ hepatocytes in liver tissue in both G-CSF and vehicle rats. It is suggested that G-CSF increases survival rate, decreases liver injury and enhances hepatocyte proliferation in rats with d-GalN-induced ALF possibly through actions including but not limiting to CD34+ cell mobilization, and that G-CSF may be of potential value in treating ALF.

Stem cells in acute liver failure

Patients with acute liver failure are a particularly challenging group, with unique difficulties faced in treatment decisions. Life-saving therapy is available, but organ shortage, delays in transplantation, and complications in management result in a high mortality in this group of patients even after transplant. Any pharmacologic intervention that improved outcomes in this population of critically ill patients would be of great benefit. Based on available evidence, different scenarios of participation of HSCs in liver recovery are conceivable. Encouraging HSCs to differentiate into hepatocytes or supply paracrine and cellular level support to accelerate ongoing local repair mechanisms and assist a failing liver with inadequate mass and functional capacity might be directed to occur effectively in humans. Evidence within small animal models of liver injury and observations within the human population suggest that this might also be encouraged. The use of pharmacologic agents to mobilize hematopoietic stem cells is well established and effectively used in a different population of patients. As such, extending the use of these drugs, such as plerixafor, to the human population has a sound basis. However, there is a need for clarification of the mechanisms by which these cells exert their effect as well as which specific population of cells is involved in the regenerative process. To be clinically relevant in scenarios of acute liver failure, stem cell mobilizing strategies would have to impact survival when administered well after injury. Applications in other settings may also prove useful. Limits to liver resection exist where the size of the future liver remnant governs the extent of resection possible. Preexisting functional impairment may be restrictive, and strategies involving stem cells may assist the future liver remnant in both normal and functionally impaired livers. Benefit has already been reported from treatment with G-CSF in other injured tissues, including the injured myocardium and acutely injured kidney. However, as yet no clinical trial exists to assess the effects of stem cell mobilization in humans with acute liver failure. The familiarity in the use of and success demonstrated in the clinical and experimental use of plerixafor and G-CSF make exploration of hematopoietic stem cells as therapy in patients with acute liver failure appealing.

Stem cell mobilization is life saving in an animal model of acute liver failure

OBJECTIVE

No therapy except liver transplantation currently exists for patients with acute liver failure (ALF). The aim of this study was to determine whether pharmacologic mobilization of endogenous hematopoietic stem cells (HSCs) can aid in liver repair and improve survival in an animal model of ALF.

METHODS

Rodents were treated with a single near-lethal intraperitoneal injection of carbon tetrachloride (CCl4). After 12 hours, animals were randomized to receive plerixafor and granulocyte colony-stimulating factor (G-CSF), agents known to mobilize marrow-derived stem cells, or saline vehicle injection. Mice were observed for survival, and serial assessment of liver injury by serum transaminase measurements, and histologic analysis was performed.

RESULTS

In our ALF model, 7-day survival after injection of CCl4 was 25%. Administration of plerixafor and G-CSF following CCl4 resulted in 87% survival (n = 8, P < 0.05). On serial histopathologic analysis, animals treated with plerixafor and G-CSF demonstrated less hepatic injury compared with control animals. Evaluation of peripheral blood demonstrated an increase in circulating HSCs in response to plerixafor and G-CSF, and immunostaining suggested the infiltration of HSCs into the hepatic parenchyma after stem cell mobilization.

CONCLUSIONS

Our results suggest a possible new treatment strategy for patients with ALF, a group for whom either liver transplantation or death is frequently the outcome. Pharmacologic agents that mobilize HSCs may lead to an infiltration of the injured liver with cells that may participate in or expedite liver regeneration. This therapy has the potential to avert liver transplantation in some patients with ALF and may be of benefit in a wide variety of medical and surgical patients with liver injury.

Stem cell-based therapies for liver diseases: state of the art and new perspectives

Millions of patients worldwide suffer from end-stage liver pathologies, whose only curative therapy is liver transplantation (OLT). Given the donor organ shortage, alternatives to OLT have been evaluated, including cell therapies. Hepatocyte transplantation has been attempted to cure metabolic liver disorders and end-stage liver diseases. The evaluation of its efficacy is complicated by the shortage of human hepatocytes and their difficult expansion and cryopreservation. Recent advances in cell biology have led to the concept of "regenerative medicine", based on the therapeutic potential of stem cells (SCs). Different types of SCs are theoretically eligible for liver cell replacement. These include embryonic and fetal SCs, induced pluripotent cells, annex SCs, endogenous liver SCs, and extrahepatic adult SCs. Aim of this paper is to critically analyze the possible sources of SCs suitable for liver repopulation and the results of the clinical trials that have been published until now.

Autologous hematopoietic stem cell transplantation in 48 patients with end-stage chronic liver diseases

The only presently viable treatment for end-stage liver disease is whole organ transplantation. However, there are insufficient livers available. The aim of the present study is to provide autologous bone marrow-derived stem cells as a potential therapeutic for patients with end-stage cirrhosis. This is a retrospective chart review of autologous stem cell treatment in 48 patients, 36 with chronic end-stage hepatitis C-induced liver disease and 12 with end-stage autoimmune liver disease. For all patients, granulocyte colony-stimulating factor was administered to mobilize their hematopoietic stem cells. Following leukapheresis, CD34(+) stem cells were isolated, amplified, and partially differentiated in culture, then reinjected into each subject via their hepatic artery or portal vein. Treatment was generally well tolerated with the expected moderate but transient bone pain from G-CSF in less than half of the patients. Three patients had serious treatment-related complications, and only 20.8% of these end-stage liver disease patients died during 12 months of follow up. For all patients there was a statistically significant decrease in ascites. There was clinical and biochemical improvement in a large percentage of patients who received the transplantation. In the viral group, there were marked changes in albumin (p = 0.0003), bilirubin (p = 0.04), INR (p = 0.0003), and ALT levels (p = 0.02). In the autoimmune group, values also improved significantly for albumin (p = 0.001), bilirubin (p = 0.002), INR (p = .0005), and ALT levels (p = 0.003). These results suggest that autologous CD34(+) stem cell transplantation may be safely administered and appears to offer some therapeutic benefit to patients with both viral and autoimmune-induced end-stage liver disease.

Nutraceutical augmentation of circulating endothelial progenitor cells and hematopoietic stem cells in human subjects

The medical significance of circulating endothelial or hematopoietic progenitors is becoming increasing recognized. While therapeutic augmentation of circulating progenitor cells using G-CSF has resulted in promising preclinical and early clinical data for several degenerative conditions, this approach is limited by cost and inability to perform chronic administration. Stem-Kine is a food supplement that was previously reported to augment circulating EPC in a pilot study. Here we report a trial in 18 healthy volunteers administered Stem-Kine twice daily for a 2 week period. Significant increases in circulating CD133 and CD34 cells were observed at days 1, 2, 7, and 14 subsequent to initiation of administration, which correlated with increased hematopoietic progenitors as detected by the HALO assay. Augmentation of EPC numbers in circulation was detected by KDR-1/CD34 staining and colony forming assays. These data suggest Stem-Kine supplementation may be useful as a stimulator of reparative processes associated with mobilization of hematopoietic and endothelial progenitors.

G-CSF enhanced SDF-1 gradient between bone marrow and liver associated with mobilization of peripheral blood CD34+ cells in rats with acute liver failure

The role of stromal cell-derived factor-1 (SDF-1) in modulating massive liver damage is not well known. In this study, expression of SDF-1 in bone marrow and liver was investigated in rats with acute liver failure (ALF) when mobilized using granulocyte colony-stimulating factor (G-CSF). ALF was induced in rats by D-galactosamine (D-GalN). Starting after 2 hours following D-GalN induction, the animals were injected with G-CSF 50 microg/kg daily or saline as placebo for 5 days. The percentages of CD34+ cells in peripheral blood and the expression of SDF-1 in bone marrow and liver were then determined. The percentages of peripheral CD34+ cells demonstrated a transient increase in placebo rats following D-GalN induction and a significant increase in rats after G-CSF administration. SDF-1 expression showed a transient decrease in bone marrow and a transient increase in liver tissue from placebo rats. However, a significant decrease of SDF-1 expression in bone marrow and a remarkable increase in liver tissue were observed in animals from the G-CSF group. It was concluded that G-CSF can enhance the reduced expression of SDF-1 in bone marrow and increased expression in liver in ALF rats, forming a greater SDF-1 gradient, and chemoattracting CD34+ cells' migration from bone marrow to an injured liver.

IFATS collection: in vivo therapeutic potential of human adipose tissue mesenchymal stem cells after transplantation into mice with liver injury

Mesenchymal stem cells (MSCs), largely present in the adult human body, represent an attractive tool for the establishment of a stem cell-based therapy for liver diseases. Recently, the therapeutic potential and immunomodulatory activity of MSCs have been revealed. Adipose tissue-derived mesenchymal stem cells (AT-MSCs), so-called adipose-derived stem cells or adipose stromal cells, because of their high accessibility with minimal invasiveness, are especially attractive in the context of future clinical applications. The goal of the present study was to evaluate the therapeutic potential of AT-MSCs by their transplantation into nude mice with CCl(4)-caused liver injury. We observed that after transplantation, AT-MSCs can improve liver functions, which we verified by changes in the levels of biochemical parameters. Ammonia, uric acid, glutamic-pyruvic transaminase, and glutamic-oxaloacetic transaminase concentrations returned to a nearly normal level after AT-MSC transplantation. These results raised the question of how AT-MSCs can achieve this. To discover the possible mechanisms involved in this therapeutic ability of AT-MSCs, in vitro production of cytokines and growth factors was analyzed and compared with MSCs from bone marrow (BM-MSCs) and normal human dermal fibroblasts (NHDFs). As a result we observed that AT-MSCs secrete interleukin 1 receptor alpha (IL-1Ralpha), IL-6, IL-8, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), monocyte chemotactic protein 1, nerve growth factor, and hepatocyte growth factor in a volume higher than both BM-MSCs and NHDFs. Thus, our findings suggest that AT-MSCs may account for their broad therapeutic efficacy in animal models of liver diseases and in the clinical settings for liver disease treatment. Disclosure of potential conflicts of interest is found at the end of this article.