Sofosbuvir-velpatasvir in children 3-17 years old with hepatitis C virus infection

BACKGROUND

The safety and efficacy of sofosbuvir-velpatasvir in children aged 3-17 years with chronic hepatitis C virus (HCV) infection of any genotype were evaluated.

METHODS

In this Phase 2, multicenter, open-label study, patients received once daily for 12 weeks either sofosbuvir-velpatasvir 400/100 mg tablet (12-17 years), 200/50 mg low dose tablet or oral granules (3-11 years and ≥17 kg), or 150/37.5 mg oral granules (3-5 years and <17 kg). The efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Dose appropriateness was confirmed by intensive pharmacokinetics in each age group.

FINDINGS

Among 216 patients treated, 76% had HCV genotype 1% and 12% had genotype 3. Rates of SVR12 were 83% (34/41) among 3-5-year-olds, 93% (68/73) among 6-11-year-olds, and 95% (97/102) among 12-17-year-olds. Only two patients experienced virologic failure. The most common adverse events were headache, fatigue, and nausea in 12-17-year-olds; vomiting, cough, and headache in 6-11-year-olds; and vomiting in 3-5-year-olds. Three patients discontinued treatment because of adverse events. Four patients had serious adverse events; all except auditory hallucination (n = 1) were considered unrelated to study drug. Exposures of sofosbuvir, its metabolite GS-331007, and velpatasvir were comparable to those in adults in prior Phase 2/3 studies. Population pharmacokinetic simulations supported weight-based dosing for children in this age range.

INTERPRETATION

The pangenotypic regimen of sofosbuvir-velpatasvir is highly effective and safe in treating children 3-17 years with chronic HCV infection.

Umbilical Cord Mesenchymal Stromal/Stem Cells and Their Interplay with Th-17 Cell Response Pathway

As a form of immunomodulatory therapeutics, mesenchymal stromal/stem cells (MSCs) from umbilical cord (UC) tissue were assessed for their dynamic interplay with the Th-17 immune response pathway. UC-MSCs were able to modulate lymphocyte response by promoting a Th-17-like profile. Such modulation depended on the cell ratio of the cocultures as well as the presence of an inflammatory setting underlying their plasticity. UC-MSCs significantly increased the expression of IL-17A and RORγt but differentially modulated T cell expression of IL-23R. In parallel, the secretion profile of the fifteen factors (IL1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-22, IL-21, IL-23, IL-25, IL-31, IL-33, INF-γ, sCD40, and TNF-α) involved in the Th-17 immune response pathway was substantially altered during these cocultures. The modulation of these factors demonstrates the capacity of UC-MSCs to sense and actively respond to tissue challenges. Protein network and functional enrichment analysis indicated that several biological processes, molecular functions, and cellular components linked to distinct Th-17 signaling interactions are involved in several trophic, inflammatory, and immune network responses. These immunological changes and interactions with the Th-17 pathway are likely critical to tissue healing and may help to identify molecular targets that will improve therapeutic strategies involving UC-MSCs.

Characterization, evolution and risk factors of diabetes and prediabetes in a pediatric cohort of renal and liver transplant recipients

BACKGROUND

Hyperglycemia (HG) and prediabetes are rarely sought in pediatric liver (LT) and renal (RT) transplantation, yet their presence indicates a high risk of diabetes and cardiovascular disease. The objectives of our DIABGRAFT study were to retrospectively (rDIABGRAFT) and longitudinally (pDIABGRAFT) characterize HG and (pre)diabetes in a cohort of children with LT or/and RT.

METHODS

We retrospectively analyzed risk factors of HG from 195 children with LT from 2012 to 2019 and twenty children with RT from 2005 to 2019 at Cliniques universitaires Saint-Luc. In addition, we prospectively followed four LT and four RT children to evaluate the evolution of their glucose metabolism.

RESULTS

Our rDIABGRAFT study showed that 25% and 35% of LT and RT children respectively presented transient HG and 20% of RT developed diabetes. The occurrence of HG was associated with the use of glucocorticoids and with acute events as graft rejection and infection. In our pDIABGRAFT cohort, biological markers of diabetes were in the normal range for HbA_1C, fasting glucose and insulin levels. However, oral glucose tolerance test and glucose sensors showed insulin resistance, impaired glucose tolerance and HG in the post-prandial afternoon period.

CONCLUSION

Our study shows that children with LT and RT were more at risk of developing HG when glucocorticoids were required and that HbA_1C and fasting glucose lack sensitivity for early detection of glucose intolerance. Also, measurement of glycemia immediately after the transplantation and in postprandial period is key to detect dysglycemia since insulin resistance prevailed in our cohort.

CLINICALTRIALSGOV ID

NCT05464043.

Everolimus is Safe as a Second-/Third-Line Therapy in Pediatric Autoimmune Hepatitis

Autoimmune hepatitis (AIH) can lead to progressive fibrosis in patients refractory to conventional therapy with prednisolone and azathioprine. The use of mammalian target of rapamycin (mTOR) inhibitors has recently emerged in refractory AIH, but no data have been published about everolimus in pediatric AIH to date. Our aim was to share our experience about everolimus as a second-/third-line therapy in pediatric AIH.

Methods

Pretransplant AIH patients aged 0-18 years who received everolimus therapy from 2014 to 2021 were retrospectively identified. All patients underwent regular plasma monitoring of everolimus trough levels to avoid toxicity and assess adherence. Special attention was paid to the clinical and biochemical occurrence of everolimus-related adverse events.

Results

We report six difficult-to-treat AIH patients who received everolimus therapy for 8-46 months (median 28 months). No side effects were reported when everolimus plasma trough levels were in the therapeutic range. Liver transaminases improved in 5 of 6 patients at everolimus introduction and significantly decreased at the last follow-up (FU) in our cohort (P < 0.05). None of our patients achieved complete biochemical remission at the last FU and 3 of 6 admitted to have suboptimal adherence to therapy.

Conclusions

Our data bring preliminary safety for the use of everolimus as a second-/third-line therapy in pediatric AIH. Although liver transaminases improved in our cohort, prospective studies are needed to determine if everolimus can induce long-term remission.

Exosomal microRNAs miR-30d-5p and miR-126a-5p Are Associated with Heart Failure with Preserved Ejection Fraction in STZ-Induced Type 1 Diabetic Rats

Exosomal microRNAs (EXO-miRNAs) are promising non-invasive diagnostic biomarkers for cardiovascular disease. Heart failure with preserved ejection fraction (HFpEF) is a poorly understood cardiovascular complication of diabetes mellitus (DM). Little is known about whether EXO-miRNAs can be used as biomarkers for HFpEF in DM. We aimed to investigate the relationship between EXO-miRNAs and HFpEF in STZ-induced diabetic rats. We prepared STZ-induced diabetic rats exhibiting a type 1 DM phenotype with low body weight, hyperglycemia, hyperlipidemia and hypoinsulinemia. Histological sections confirmed atrophy and fibrosis of the heart, with collagen accumulation representing diabetic cardiomyopathy. Significant decreases in end-diastolic volume, stroke volume, stroke work, end-systolic elastance and cardiac output indicated impaired cardiac contractility, as well as mRNA conversion of two isoforms of myosin heavy chain (α-MHC and β-MHC) and increased atrial natriuretic factor (ANF) mRNA indicating heart failure, were consistent with the features of HFpEF. In diabetic HFpEF rats, we examined a selected panel of 12 circulating miRNAs associated with HF (miR-1-3p, miR-21-5p, miR-29a-5p, miR-30d-5p, miR-34a-5p, miR-126a-5p, miR-143-3p, miR-145-5p, miR-195-5p, miR-206-3p, miR-320-3p and miR-378-3p). Although they were all expressed at significantly lower levels in the heart compared to non-diabetic controls, only six miRNAs (miR-21-5p, miR-30d-5p, miR-126a-5p, miR-206-3p, miR-320-3p and miR-378-3p) were also reduced in exosomal content, while one miRNA (miR-34a-5p) was upregulated. Similarly, although all miRNAs were correlated with reduced cardiac output as a measure of cardiovascular performance, only three miRNAs (miR-30d-5p, miR-126a-5p and miR-378-3p) were correlated in exosomal content. We found that miR-30d-5p and miR-126a-5p remained consistently correlated with significant reductions in exosomal expression, cardiac expression and cardiac output. Our findings support their release from the heart and association with diabetic HFpEF. We propose that these two EXO-miRNAs may be important for the development of diagnostic tools for diabetic HFpEF.

Efficacy and safety of maralixibat treatment in patients with Alagille syndrome and cholestatic pruritus (ICONIC): a randomised phase 2 study

BACKGROUND

Alagille syndrome is a rare genetic disease that often presents with severe cholestasis and pruritus. There are no approved drugs for management. Maralixibat, an apical, sodium-dependent, bile acid transport inhibitor, prevents enterohepatic bile acid recirculation. We evaluated the safety and efficacy of maralixibat for children with cholestasis in Alagille syndrome.

METHODS

ICONIC was a placebo-controlled, randomised withdrawal period (RWD), phase 2b study with open-label extension in children (aged 1-18 years) with Alagille syndrome (NCT02160782). Eligible participants had more than three times the normal serum bile acid (sBA) levels and intractable pruritus. After 18 weeks of maralixibat 380 μg/kg once per day, participants were randomly assigned (1:1) to continue maralixibat or receive placebo for 4 weeks. Subsequently, all participants received open-label maralixibat until week 48. During the long-term extension (204 weeks reported), doses were increased up to 380 μg/kg twice per day. The primary endpoint was the mean sBA change during the RWD in participants with at least 50% sBA reduction by week 18. Cholestastic pruritus was assessed using observer-rated, patient-rated, and clinician-rated 0-4 scales. The safety population was defined as all participants who had received at least one dose of maralixibat. This trial was registered with ClinicalTrials.gov, NCT02160782, and is closed to recruitment.

FINDINGS

Between Oct 28, 2014, and Aug 14, 2015, 31 participants (mean age 5·4 years [SD 4·25]) were enrolled and 28 analysed at week 48. Of the 29 participants who entered the randomised drug withdrawal period, ten (34%) were female and 19 (66%) were male. In the RWD, participants switched to placebo had significant increases in sBA (94 μmol/L, 95% CI 23 to 164) and pruritus (1·7 points, 95% CI 1·2 to 2·2), whereas participants who continued maralixibat maintained treatment effect. This study met the primary endpoint (least square mean difference -117 μmol/L, 95% CI -232 to -2). From baseline to week 48, sBA (-96 μmol/L, -162 to -31) and pruritus (-1·6 pts, -2·1 to -1·1) improved. In participants who continued to week 204 (n=15) all improvements were maintained. Maralixibat was generally safe and well tolerated throughout. The most frequent adverse events were gastrointestinal related. Most adverse events were self-limiting in nature and mild-to-moderate in severity.

INTERPRETATION

In children with Alagille syndrome, maralixibat is, to our knowledge, the first agent to show durable and clinically meaningful improvements in cholestasis. Maralixibat might represent a new treatment paradigm for chronic cholestasis in Alagille syndrome.

FUNDING

Mirum Pharmaceuticals.

In Vitro Cellular and Molecular Interplay between Human Foreskin-Derived Mesenchymal Stromal/Stem Cells and the Th17 Cell Pathway

Foreskin, considered a biological waste material, has been shown to be a reservoir of therapeutic cells. The immunomodulatory properties of mesenchymal stromal/stem cells (MSCs) from the foreskin (FSK-MSCs) are being evaluated in cell-based therapy for degenerative, inflammatory and autoimmune disorders. Within the injured/inflamed tissue, proinflammatory lymphocytes such as IL-17-producing T helper cells (Th17) may interact with the stromal microenvironment, including MSCs. In this context, MSCs may encounter different levels of T cells as well as specific inflammatory signals. Uncovering the cellular and molecular changes during this interplay is central for developing an efficient and safe immunotherapeutic tool. To this end, an in vitro human model of cocultures of FSK-MSCs and T cells was established. These cocultures were performed at different cell ratios in the presence of an inflammatory setting. After confirming that FSK-MSCs respond to ISCT criteria by showing a typical phenotype and multilineage potential, we evaluated by flow cytometry the expression of Th17 cell markers IL-17A, IL23 receptor and RORγt within the lymphocyte population. We also measured 15 human Th17 pathway-related cytokines. Regardless of the T cell/MSC ratio, we observed a significant increase in IL-17A expression associated with an increase in IL-23 receptor expression. Furthermore, we observed substantial modulation of IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, INF-γ, sCD40, and TNF-α secretion. These findings suggest that FSK-MSCs are receptive to their environment and modulate the T cell response accordingly. The changes within the secretome of the stromal and immune environment are likely relevant for the therapeutic effect of MSCs. FSK-MSCs represent a valuable cellular product for immunotherapeutic purposes that needs to be further clarified and developed.

Is ABO-Incompatible Living Donor Liver Transplantation Really a Good Alternative for Pediatric Recipients?

BACKGROUND

ABO-incompatible (ABOi) living donor liver transplantation (LDLT) has been proposed to compensate for donor shortage. To date, few studies have reported detailed ABOi LDLT results in large series of pediatric patients. C4d complement deposition in graft capillaries has been reported to be associated with antibody-mediated rejection in solid organ transplantation.

METHODS

A retrospective case-control study was conducted, comparing clinical outcomes of each of 34 consecutive pediatric ABOi LDLT recipients with those of 2 non-ABOi pairs (n = 68), matched according to pre-transplant diagnostic criteria, age, and date of transplantation. In addition, we studied the C4d immunostaining pattern in 22 ABOi and in 36 non-ABOi recipients whose liver biopsy was performed within the first 4 post-transplant weeks for suspected acute rejection.

RESULTS

The incidence of biliary complications was higher in ABOi recipients (p < 0.05), as were the incidence of acute humoral rejection (p < 0.01) and the incidence of retransplantation (p < 0.05). All children who required retransplantation were older than 1 year at the time of ABOi LDLT. Positive C4d immunostaining was observed in 13/22 (59%) ABOi recipients versus 3/36 (8.3%) non-ABOi recipients (p < 0.0001).

CONCLUSIONS

ABOi LDLT is a feasible option for pediatric end-stage liver disease but carries increased risks for the recipient, especially for children older than 1 year, even with a specific preparation protocol. C4d immunostaining may be a hallmark of acute humoral rejection in ABOi liver transplantation.

A phase II study of human allogeneic liver-derived progenitor cell therapy for acute-on-chronic liver failure and acute decompensation

Background & Aims

Human allogeneic liver-derived progenitor cells (HALPC, HepaStem®; Promethera Biosciences, Mont-Saint-Guibert, Belgium) are an advanced therapy medicinal product that could potentially alleviate systemic inflammation and ameliorate liver function in patients with acute-on-chronic liver failure (ACLF) or acute decompensation of cirrhosis (AD).

Methods

This open-label phase II study was conducted in 9 centres in Belgium, Spain, and Bulgaria between 2016 and 2019. The primary objective was to assess the safety of HALPC therapy up to Day 28 and the secondary objectives were to assess its safety and preliminary efficacy up to Month 3.

Results

The 24 treated patients (mean age: 51 years) were mostly male with an alcoholic cirrhosis. On pre-infusion Day 1, 15 patients had ACLF and 9 patients had AD. Two of the 3 initial patients treated with high HALPC doses (∼5×10⁶ cells/kg body weight [BW]) had severe adverse bleeding events attributed to treatment. In 21 patients subsequently treated with lower HALPC doses (0.6 or 1.2×10⁶ cells/kg BW, 1 or 2 times 7 days apart), no serious adverse events were related to treatment, and the other adverse events were in line with those expected in patients with ACLF and AD. Overall, markers of systemic inflammation and altered liver function decreased gradually for the surviving patients. The Day-28 and Month-3 survival rates were 83% (20/24) and 71% (17/24), and at Month 3, no patient had ACLF.

Conclusions

The treatment of patients with ACLF or AD with up to 2 doses of 1.2×10⁶ HALPC/kg BW appeared safe. The results of this study support the initiation of a proof-of-concept study in a larger cohort of patients with ACLF to further confirm the safety and evaluate the efficacy of HALPC therapy.

Clinical Trials Registration

EudraCT 2016-001177-32.

Lay summary

Patients with liver cirrhosis may suffer from the rapid onset of organ failure or multiple organ failure associated with a high risk of death in the short term. This clinical study of 24 patients suggests that an advanced therapy based on the intravenous infusion of low doses of human allogeneic liver-derived progenitor cells is safe and supports the next phase of clinical development of this type of therapy.

Single-cell RNA sequencing of human liver reveals hepatic stellate cell heterogeneity

Background & Aims

The multiple vital functions of the human liver are performed by highly specialised parenchymal and non-parenchymal cells organised in complex collaborative sinusoidal units. Although crucial for homeostasis, the cellular make-up of the human liver remains to be fully elucidated. Here, single-cell RNA-sequencing was used to unravel the heterogeneity of human liver cells, in particular of hepatocytes (HEPs) and hepatic stellate cells (HSCs).

Method

The transcriptome of ~25,000 freshly isolated human liver cells was profiled using droplet-based RNA-sequencing. Recently published data sets and RNA in situ hybridisation were integrated to validate and locate newly identified cell populations.

Results

In total, 22 cell populations were annotated that reflected the heterogeneity of human parenchymal and non-parenchymal liver cells. More than 20,000 HEPs were ordered along the portocentral axis to confirm known, and reveal previously undescribed, zonated liver functions. The existence of 2 subpopulations of human HSCs with unique gene expression signatures and distinct intralobular localisation was revealed (i.e. portal and central vein-concentrated GPC3⁺ HSCs and perisinusoidally located DBH⁺ HSCs). In particular, these data suggest that, although both subpopulations collaborate in the production and organisation of extracellular matrix, GPC3⁺ HSCs specifically express genes involved in the metabolism of glycosaminoglycans, whereas DBH⁺ HSCs display a gene signature that is reminiscent of antigen-presenting cells.

Conclusions

This study highlights metabolic zonation as a key determinant of HEP transcriptomic heterogeneity and, for the first time, outlines the existence of heterogeneous HSC subpopulations in the human liver. These findings call for further research on the functional implications of liver cell heterogeneity in health and disease.

Lay summary

This study resolves the cellular landscape of the human liver in an unbiased manner and at high resolution to provide new insights into human liver cell biology. The results highlight the physiological heterogeneity of human hepatic stellate cells.

•

A cell atlas from the near-native transcriptome of >25,000 human liver cells is presented.

•

Hepatocytes were ordered along the portocentral axis to reveal previously undescribed gene expression patterns and zonated liver functions.

•

Two subpopulations of human hepatic stellate cells (HSCs) are reported, characterised by different spatial distribution in the native tissue.

•

Characteristic gene signatures of HSC subpopulations are suggestive of far-reaching functional differences.

Sequential Treatment of Biliary Atresia With Kasai Hepatoportoenterostomy and Liver Transplantation: Benefits, Risks, and Outcome in 393 Children

Introduction: Surgical treatment of biliary atresia (BA) is still based on sequential strategy with Kasai hepatoportoenterostomy (KP) followed by liver transplantation (LT), in case of complicated secondary biliary cirrhosis. Concerns have been expressed regarding the risks of LT related to previous KP, suggesting primary LT as an exclusive treatment of BA. Methods: Single-center retrospective analysis including 393 pediatric patients who underwent LT for BA from 1993 to 2018, categorized into two groups: with (KP) or without (NoKP) previous KP. Pre-LT clinical condition was estimated considering age at LT, time on waiting list, pediatric end-stage liver disease score (PELD), and presence of portal vein hypoplasia. Post-LT outcome was evaluated considering patient and graft survival rates, and need for early reoperation due to abdominal or graft-related complications (<45 days after LT). Results: Two-hundred ninety-six patients (75.3%) were categorized in the KP group, and 97 (24.7%) in the NoKP group. Median age at LT was 1.14 years in the KP group and 0.85 years in the NoKP group (p < 0.0001). PELD score was significantly less severe in KP patients (p < 0.05). One-year patient survival rates were 96.9 and 96.8% in the KP and NoKP groups, respectively (p = 0.43), and the corresponding graft survival was 92.5 and 94.8% (p = 0.97). The need for early reoperation was more frequent in the KP group (29.8%) vs. NoKP group (12.4%, p = 0.01). The rate of bowel perforation was non-significantly higher in the KP group (8.1%) vs. NoKP group (3.1%, p = 0.11). Conclusions: The sequential strategy including KP and LT allowed performing LT in patients with significant older age and better clinical conditions, when compared to those transplanted without previous KP. Patient and graft survivals were not impacted by previous KP. Although previous KP was associated with an increased rate of post-LT surgical complications, bowel perforation and bleeding did not occur significantly more frequently. Such results support the current strategy based on sequential treatment.

High Dose Versus Low Dose Syngeneic Hepatocyte Transplantation in Pex1-G844D NMRI Mouse Model is Safe but Does Not Achieve Long Term Engraftment

Genetic alterations in PEX genes lead to peroxisome biogenesis disorder. In humans, they are associated with Zellweger spectrum disorders (ZSD). No validated treatment has been shown to modify the dismal natural history of ZSD. Liver transplantation (LT) improved clinical and biochemical outcomes in mild ZSD patients. Hepatocyte transplantation (HT), developed to overcome LT limitations, was performed in a mild ZSD 4-year-old child with encouraging short-term results. Here, we evaluated low dose (12.5 million hepatocytes/kg) and high dose (50 million hepatocytes/kg) syngeneic male HT via intrasplenic infusion in the Pex1-G844D NMRI mouse model which recapitulates a mild ZSD phenotype. HT was feasible and safe in growth retarded ZSD mice. Clinical (weight and food intake) and biochemical parameters (very long-chain fatty acids, abnormal bile acids, etc.) were in accordance with ZSD phenotype but they were not robustly modified by HT. As expected, one third of the infused cells were detected in the liver 24 h post-HT. No liver nor spleen microchimerism was detected after 7, 14 and 30 days. Future optimizations are required to improve hepatocyte engraftment in Pex1-G844D NMRI mouse liver. The mouse model exhibited the robustness required for ZSD liver-targeted therapies evaluation.

Longitudinal study of Pex1-G844D NMRI mouse model: A robust pre-clinical model for mild Zellweger spectrum disorder

Zellweger spectrum disorders (ZSD) are inborn errors of metabolism caused by mutations in PEX genes that lead to peroxisomal biogenesis disorder (PBD). No validated treatment is able to modify the dismal progression of the disease. ZSD mouse models used to develop therapeutic approaches are limited by poor survival and breeding restrictions. To overcome these limitations, we backcrossed the hypomorphic Pex1 p.G844D allele to NMRI background. NMRI mouse breeding restored an autosomal recessive Mendelian inheritance pattern and delivered twice larger litters. Mice were longitudinally phenotyped up to 6 months of age to make this model suitable for therapeutic interventions. ZSD mice exhibited growth retardation and relative hepatomegaly associated to progressive hepatocyte hypertrophy. Biochemical studies associated with RNA sequencing deciphered ZSD liver glycogen metabolism alterations. Affected fibroblasts displayed classical immunofluorescence pattern and biochemical alterations associated with PBD. Plasma and liver showed very long-chain fatty acids, specific oxysterols and C₂₇ bile acids intermediates elevation in ZSD mice along with a specific urine organic acid profile. With ageing, C₂₆ fatty acid and phytanic acid levels tended to normalize in ZSD mice, as described in patients reaching adulthood. In conclusion, our mouse model recapitulates a mild ZSD phenotype and is suitable for liver-targeted therapies evaluation.

Inflammation Differentially Modulates the Biological Features of Adult Derived Human Liver Stem/Progenitor Cells

The progression of mesenchymal stem cell-based therapy from concept to cure closely depends on the optimization of conditions that allow a better survival and favor the cells to achieve efficient liver regeneration. We have previously demonstrated that adult-derived human liver stem/progenitor cells (ADHLSC) display significant features that support their clinical development. The current work aims at studying the impact of a sustained pro-inflammatory environment on the principal biological features of ADHLSC in vitro. METHODS: ADHLSC from passages 4–7 were exposed to a cocktail of inflammatory cytokines for 24 h and 9 days and subsequently analyzed for their viability, expression, and secretion profiles by using flow cytometry, RT-qPCR, and antibody array assay. The impact of inflammation on the hepatocytic differentiation potential of ADHLSC was also evaluated. RESULTS: ADHLSC treated with a pro-inflammatory cocktail displayed significant decrease of cell yield at both times of treatment while cell mortality was observed at 9 days post-priming. After 24 h, no significant changes in the immuno-phenotype of ADHLSC expression profile could be noticed while after 9 days, the expression profile of relevant markers has changed both in the basal conditions and after inflammation treatment. Inflammation cocktail enhanced the release of IL-6, IL-8, CCL5, monocyte-chemo-attractant protein-2 and 3, CXCL1/GRO, and CXCL5/ENA78. Furthermore, while IP-10 secretion was increased after 24 h priming, granulocyte macrophage colony-stimulating factor enhanced secretion was noticed after 9 days treatment. Finally, priming of ADHLSC did not affect their potential to differentiate into hepatocyte-like cells. CONCLUSION: These results indicate that ADHLSCs are highly sensitive to inflammation and respond to such signals by adjusting their gene and protein expression. Accordingly, monitoring the inflammatory status of patients at the time of cell transplantation, will certainly help in enhancing ADHLSC safety and efficiency.

An Optimized Protocol for Histochemical Detection of Senescence-associated Beta-galactosidase Activity in Cryopreserved Liver Tissue

Senescence-associated beta-galactosidase (SA-β-gal) activity assay is commonly used to evaluate the increased beta-galactosidase (β-gal) activity in senescent cells related to enhanced lysosomal activity. Although the optimal pH for β-gal is 4.0, this enzymatic activity has been most commonly investigated at a suboptimal pH by using histochemical reaction on fresh tissue material. In the current study, we optimized a SA-β-gal activity histochemistry protocol that can also be applied on cryopreserved hepatic tissue. This protocol was developed on livers obtained from control rats and after bile duct resection (BDR). A significant increase in β-gal liver activity was observed in BDR rats vs controls after 2 hr of staining at physiological pH 4.0 (6.98 ± 1.19% of stained/total area vs 0.38 ± 0.22; p<0.01) and after overnight staining at pH 5.8 (24.09 ± 6.88 vs 0.12 ± 0.08; p<0.01). Although we noticed that β-gal activity staining decreased with cryopreservation time (from 4 to 12 months of storage at -80C; p<0.05), the enhanced staining observed in BDR compared with controls remained detectable up to 12 months after cryopreservation (p<0.01). In conclusion, we provide an optimized protocol for SA-β-gal activity histochemical detection at physiological pH 4.0 on long-term cryopreserved liver tissue.

Accurate and live peroxisome biogenesis evaluation achieved by lentiviral expression of a green fluorescent protein fused to a peroxisome targeting signal 1

Peroxisomes are ubiquitous organelles formed by peroxisome biogenesis (PB). During PB, peroxisomal matrix proteins harboring a peroxisome targeting signal (PTS) are imported inside peroxisomes by peroxins, encoded by PEX genes. Genetic alterations in PEX genes lead to a spectrum of incurable diseases called Zellweger spectrum disorders (ZSD). In vitro drug screening is part of the quest for a cure in ZSD by restoring PB in ZSD cell models. In vitro PB evaluation is commonly achieved by immunofluorescent staining or transient peroxisome fluorescent reporter expression. Both techniques have several drawbacks (cost, time-consuming technique, etc.) which we overcame by developing a third-generation lentiviral transfer plasmid expressing an enhanced green fluorescent protein fused to PTS1 (eGFP-PTS1). By eGFP-PTS1 lentiviral transduction, we quantified PB and peroxisome motility in ZSD and control mouse and human fibroblasts. We confirmed the stable eGFP-PTS1 expression along cell passages. eGFP signal analysis distinguished ZSD from control eGFP-PTS1-transduced cells. Live eGFP-PTS1 transduced cells imaging quantified peroxisomes motility. In conclusion, we developed a lentiviral transfer plasmid allowing stable eGFP-PTS1 expression to study PB (deposited on Addgene: #133282). This tool meets the needs for in vitro PB evaluation and ZSD drug discovery.

Sofosbuvir and Ribavirin Therapy for Children Aged 3 to <12 Years With Hepatitis C Virus Genotype 2 or 3 Infection

Currently, the only approved hepatitis C virus (HCV) treatment for children aged <12 years is pegylated interferon plus ribavirin. In an open-label study, we evaluated the safety and efficacy of sofosbuvir plus ribavirin for 12 weeks in children aged 3 to <12 years chronically infected with genotype 2 or for 24 weeks in patients with genotype 3. Patients aged 3 to <6 years weighing <17 kg received sofosbuvir 150 mg, and patients aged 3 to <6 years weighing ≥17 kg and all patients aged 6 to <12 years received sofosbuvir 200 mg once daily. Intensive pharmacokinetic sampling conducted in each age group confirmed the appropriateness of sofosbuvir doses. For all patients, ribavirin dosing was determined by baseline weight (up to 1,400 mg/day, two divided doses). The primary efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Fifty-four patients were enrolled (41 aged 6 to <12 years and 13 aged 3 to <6 years). Most were treatment naïve (98%) and infected perinatally (94%). All but one patient achieved SVR12 (53/54, 98%; 95% confidence interval, 90%-100%). The patient who did not achieve SVR12 was a 4-year-old who discontinued treatment after 3 days because of "abnormal drug taste." The most commonly reported adverse events in patients aged 6 to <12 years were vomiting (32%) and headache (29%), and those in patients aged 3 to <6 years were vomiting (46%) and diarrhea (39%). One 3-year-old patient had a serious adverse event of accidental ribavirin overdose requiring hospitalization for monitoring; this patient completed treatment and achieved SVR12. Conclusion: Sofosbuvir plus ribavirin was well tolerated and highly effective in children aged 3 to <12 years with chronic HCV genotype 2 or 3 infection.

Th17 immune response to adipose tissue-derived mesenchymal stromal cells

Adipose tissue-derived mesenchymal stromal cells (ASCs) hold the promise of achieving successful immunotherapeutic results due to their ability to regulate different T-cell fate. ASCs also show significant adaptability to environmental stresses by modulating their immunologic profile. Cell-based therapy for inflammatory diseases requires a detailed understanding of the molecular relation between ASCs and Th17 lymphocytes taking into account the influence of inflammation and cell ratio on such interaction. Accordingly, a dose-dependent increase in Th17 generation was only observed in high MSC:T-cell ratio with no significant impact of inflammatory priming. IL-23 receptor (IL-23R) expression by T cells was not modulated by ASCs when compared to levels in activated T cells, while ROR-γt expression was significantly increased reaching a maximum in high (1:5) unprimed ASC:T-cell ratio. Finally, multiplex immunoassay showed substantial changes in the secretory profile of 15 cytokines involved in the Th17 immune response (IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-22, IL-21, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40, and TNF-α), which was modulated by both cell ratio and inflammatory priming. These findings suggest that Th17 lymphocyte pathway is significantly modulated by ASCs that may lead to immunological changes. Therefore, future ASC-based immunotherapy should take into account the complex and detailed molecular interactions that depend on several factors including inflammatory priming and cell ratio.

Childhood Fructoholism and Fructoholic Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is an emerging entity, becoming the most prevalent pediatric chronic liver disease. Its broad spectrum of histological findings, comorbidities, and complications, including cirrhosis and liver failure, can occur in childhood, emphasizing the severity of pediatric NAFLD. Current lifestyle and diet modifications have been linked to the increasing prevalence of NAFLD, including the rise of fructose consumption, a monosaccharide present in foods that contain added sugar, such as sugar‐sweetened beverages. Excessive fructose consumption is believed to cause addiction like alcohol and other drugs. As such, the new term “fructoholism” refers to the consumption of a substance (fructose) that can cause psychological and physical damage and become a major public health concern, highlighting the seriousness of the excessive consumption of fructose in the pediatric age. Hepatic fructose metabolization leads to hepatic steatosis and progression to fibrosis through mechanisms comparable to alcoholic liver disease, hence the term “fructoholic liver disease.” Conclusion: The importance of implementing reliable global strategies, such as education campaigns to promote healthy diet, increasing taxes on foods that contain added sugars, subsidies to promote accessibility to fruit and vegetables, and strict food industry regulation to reduce sugar intake in children and adolescents, cannot be overemphasized.

Immunological modulation following bone marrow-derived mesenchymal stromal cells and Th17 lymphocyte co-cultures

OBJECTIVE AND DESIGN

The objective of the study is to uncover the influence of human bone marrow-derived mesenchymal stem cells (BM-MSCs) on the generation of Th17 lymphocytes in co-cultures of both BM-MSCs and T cells.

MATERIALS AND METHODS

BM-MSCs, characterized according to the international society for cellular therapy (ISCT) criteria, were co-cultured with T cells isolated from peripheral blood. The expression levels of IL-17 receptor, RORγt and IL-23 receptor were evaluated using flow cytometry. The levels of cytokines involved in Th17 immunomodulation were measured using multiplex assay.

TREATMENT

Inflammatory primed and non-primed BM-MSCs were co-cultured with either activated or non-activated T cells either at (1/80) and (1/5) ratio respectively.

RESULTS

MSC/T-cell ratio and inflammation significantly influenced the effect of BM-MSCs on the generation of Th17 lymphocytes. Cocultures of either primed or non-primed BM-MSCs with activated T cells significantly induced IL-17A-expressing lymphocytes. Interestingly, the expression of the transcription factor RORγt was significantly increased when compared to levels in activated T cells. Finally, both cell ratio and priming of BM-MSCs with cytokines substantially influenced the cytokine profile of BM-MSCs and T cells.

CONCLUSION

Our findings suggest that BM-MSCs significantly modulate the Th17 lymphocyte pathway in a complex manner.

Cytokinome of adult-derived human liver stem/progenitor cells: immunological and inflammatory features

Background

Being non-immunogenic and capable of achieving major metabolic liver functions, adult-derived human liver stem/progenitor cells (ADHLSCs) are of special interest in the field of liver cell therapy. The cytokine repertoire of engrafted cells may have critical impacts on the immune response balance, particularly during cell transplantation.

Methods

In this work, we analyzed the cytokinome of ADHLSCs during hepatogenic differentiation (HD) following stimulation with a mixture of inflammatory cytokines (I) in vitro and compared it to that of mature hepatocytes.

Results

Independent of their hepatic state, ADHLSCs showed no constitutive expression of pro-inflammatory cytokines, which were significantly induced by inflammation (IL-1β, IL-6, IL-8, TNFα, CCL5, IL-12a, IL-12b, IL-23p19, IL-27p28 and EBI-3). IL1-RA and IDO-1, as immunoregulatory cytokines, were highly induced in undifferentiated ADHLSCs, whereas TGF-β was downregulated by both hepatic and inflammatory events. Interestingly, TDO-1 was exclusively expressed in ADHLSCs after hepatic differentiation and enhanced by inflammatory cytokines. Compared to mature hepatocytes, hepatic-differentiated ADHLSCs showed significantly different cytokine expression patterns.

Conclusions

By establishing the cytokinome of ADHLSCs and highlighting their immunological and inflammatory features, we can enhance our knowledge about the safety and efficiency of the transplantation strategy.

Biodistribution of Liver-Derived Mesenchymal Stem Cells After Peripheral Injection in a Hemophilia A Patient

BACKGROUND

With the exception of liver transplantation, there is no cure for hemophilia, which is currently managed by preemptive replacement therapy. Liver-derived stem cells are in clinical development for inborn and acquired liver diseases and could represent a curative treatment for hemophilia A. The liver is a major factor VIII (FVIII) synthesis site, and mesenchymal stem cells have been shown to control joint bleeding in animal models of hemophilia. Adult-derived human liver stem cells (ADHLSCs) have mesenchymal characteristics and have been shown able to engraft in and repopulate both animal and human livers. Thus, the objectives were to evaluate the potency of ADHLSCs to control bleeding in a hemophilia A patient and assess the biodistribution of the cells after intravenous injection.

METHODS

A patient suffering from hemophilia A was injected with repeated doses of ADHLSCs via a peripheral vein (35 million In-oxine-labeled cells, followed by 125 million cells the next day, and 3 infusions of 250 million cells every 2 weeks thereafter; total infusion period, 50 days).

RESULTS

After cell therapy, we found a temporary (15 weeks) decrease in the patient's FVIII requirements and severe bleeding complications, despite a lack of increase in circulating FVIII. The cells were safely administered to the patient via a peripheral vein. Biodistribution analysis revealed an initial temporary entrapment of the cells in the lungs, followed by homing to the liver and to a joint afflicted with hemarthrosis.

CONCLUSION

These results suggest the potential use of ADHLSCs in the treatment of hemophilia A.

Long-Term In Vivo Monitoring of Adult-Derived Human Liver Stem/Progenitor Cells by Bioluminescence Imaging, Positron Emission Tomography, and Contrast-Enhanced Computed Tomography

Adult-derived human liver stem/progenitor cells (ADHLSCs) have the potential to alleviate liver injury. However, the optimal delivery route and long-term biodistribution of ADHLSCs remain unclear. In this article, we used a triple fusion reporter system to determine the kinetic differences in the biodistribution of ADHLSCs following intrasplenic (IS) and intrahepatic (IH) administration in severe combined immunodeficiency/beige mice. ADHLSCs were transduced with a lentiviral vector expressing a triple fusion reporter comprising renilla luciferase, monomeric red fluorescent protein, and truncated HSV-1 thymidine kinase. The stability and duration of the transgenes, and the effects of transduction on the cell properties were evaluated in vitro. The acute retention and long-term engraftment in vivo were revealed by positron emission tomography and bioluminescence imaging (BLI), respectively, followed by histochemical analysis. We showed that ADHLSCs can be safely transduced with the triple fusion reporter. Radiolabeled ADHLSCs showed acute cell retention at the sites of injection. The IH group showed a confined BLI signal at the injection site, while the IS group displayed a dispersed distribution at the upper abdominal liver area, and a more intense signal. In conclusion, ADHLSCs could be monitored by BLI for up to 4 weeks with a spread out biodistribution following IS injection.

Hepatitis B: changing epidemiology and interventions

Hepatitis B virus infection is still a major public health problem worldwide, since more than 350 million people have chronic, lifelong infection and nearly 1 million deaths occur each year owing to complications. Most infections are acquired at birth or during early childhood. Nowadays, low- and middle-income countries bear the majority of the burden of hepatitis B-related liver cancer deaths despite the availability of an effective vaccine and antiviral treatments. In this review the epidemiology, strategies of prevention and the recent advances in therapy, genotype diversity and resistance are discussed.

The histological quantification of alpha-smooth muscle actin predicts future graft fibrosis in pediatric liver transplant recipients

Activated hepatic stellate cells express cytoplasmic ASMA prior to secreting collagen and consequent liver fibrosis. We hypothesized that quantifying ASMA could predict severity of future fibrosis after LT. For this, 32 pairs of protocol biopsies, that is, "baseline" and "follow-up" biopsies taken at 1- to 2-year intervals from 18 stable pediatric LT recipients, transplanted between 2006 and 2012 were selected. Morphometric quantification of "ASMA-positive area percentage" was performed on the baseline biopsy. Histological and fibrosis assessment using Metavir and LAFSc was performed on all biopsies. The difference of fibrosis severity between the "baseline" and "follow-up" was termed "prospective change in fibrosis." Significant association was seen between extent of ASMA positivity on baseline biopsy and "prospective change in fibrosis" using Metavir (P=.02), cumulative LAFSc (P=.02), and portal LAFSc (P=.01) values. ASMA-positive area percentage >1.05 predicted increased fibrosis on next biopsy with 90.0% specificity. Additionally, an association was observed between extent of ASMA positivity and concomitant ductular reaction (P=.06), but not with histological inflammation in the portal tract or lobular area. Hence, ASMA quantification can predict the future course of fibrosis.

Cyclosporine A disposition, hepatic and renal tolerance in Wistar rat

Cyclosporine A, a potent calcineurin inhibitor, has been widely used in organ transplantation and in the treatment of autoimmune diseases. It has, however, been shown to induce serious renal and hepatic side effects. The drug is also used in preclinical studies, but with little published information on the optimal dose and route of administration in rodents. Objectives of this study were to identify efficient and safe doses of cyclosporine A in rodent and to assess its effects on hepatic and renal functions. For this purpose, we tested the effects of different doses and administration routes of cyclosporine A (5, 2.5 and 1 mg/kg) administered during 28 days intraperitoneally, or by gastric feeding on Wistar rats. Our data indicate that rats injected intraperitoneally with 5 mg/kg/2d (every two days) exhibited trough cyclosporine A levels within known therapeutic range in human, but were subject to blood cyclosporine A accumulation, whereas the 5 mg/kg/d gavage resulted in only a small cyclosporine A accumulation over time. In both cases this accumulation was not deleterious to renal and hepatic functions, as shown by transaminase, urea, creatinine and bilirubin measurements.

Adult-Derived Human Liver Stem/Progenitor Cells Infused 3 Days Postsurgery Improve Liver Regeneration in a Mouse Model of Extended Hepatectomy

There is growing evidence that cell therapy constitutes a promising strategy for liver regenerative medicine. In the setting of hepatic cancer treatments, cell therapy could prove a useful therapeutic approach for managing the acute liver failure that occurs following extended hepatectomy. In this study, we examined the influence of delivering adult-derived human liver stem/progenitor cells (ADHLSCs) at two different early time points in an immunodeficient mouse model (Rag2-/-IL2Rγ-/-) that had undergone a 70% hepatectomy procedure. The hepatic mesenchymal cells were intrasplenically infused either immediately after surgery (n = 26) or following a critical 3-day period (n = 26). We evaluated the cells' capacity to engraft at day 1 and day 7 following transplantation by means of human Alu qPCR quantification, along with histological assessment of human albumin and α-smooth muscle actin. In addition, cell proliferation (anti-mouse and human Ki-67 staining) and murine liver weight were measured in order to evaluate liver regeneration. At day 1 posttransplantation, the ratio of human to mouse cells was similar in both groups, whereas 1 week posttransplantation this ratio was significantly improved (p < 0.016) in mice receiving ADHLSC injection at day 3 posthepatectomy (1.7%), compared to those injected at the time of surgery (1%). On the basis of liver weight, mouse liver regeneration was more extensive 1 week posttransplantation in mice transplanted with ADHLSCs (+65.3%) compared to that of mice from the sham vehicle group (+42.7%). In conclusion, infusing ADHLSCs 3 days after extensive hepatectomy improves the cell engraftment and murine hepatic tissue regeneration, thereby confirming that ADHLSCs could be a promising cell source for liver cell therapy and hepatic tissue repair.

β-cell replacement sources for type 1 diabetes: a focus on pancreatic ductal cells

Thorough research on the capacity of human islet transplantation to cure type 1 diabetes led to the achievement of 3- to 5-year-long insulin independence in nearly half of transplanted patients. Yet, translation of this technique to clinical routine is limited by organ shortage and the need for long-term immunosuppression, restricting its use to adults with unstable disease. The production of new bona fide β cells in vitro was thus investigated and finally achieved with human pluripotent stem cells (PSCs). Besides ethical concerns about the use of human embryos, studies are now evaluating the possibility of circumventing the spontaneous tumor formation associated with transplantation of PSCs. These issues fueled the search for cell candidates for β-cell engineering with safe profiles for clinical translation. In vivo studies revealed the regeneration capacity of the exocrine pancreas after injury that depends at least partially on facultative progenitors in the ductal compartment. These stimulated subpopulations of pancreatic ductal cells (PDCs) underwent β-cell transdifferentiation through reactivation of embryonic signaling pathways. In vitro models for expansion and differentiation of purified PDCs toward insulin-producing cells were described using cocktails of growth factors, extracellular-matrix proteins and transcription factor overexpression. In this review, we will describe the latest findings in pancreatic β-cell mass regeneration due to adult ductal progenitor cells. We will further describe recent advances in human PDC transdifferentiation to insulin-producing cells with potential for clinical translational studies.

Progressive Fibrosis Is Driven by Genetic Predisposition, Allo-immunity, and Inflammation in Pediatric Liver Transplant Recipients

Aim

To determine predisposing factors of idiopathic allograft fibrosis among pediatric liver transplant recipients.

Background

Protocol biopsies (PB) from stable liver transplant (LT) recipient children frequently exhibit idiopathic fibrosis. The relation between allograft inflammation, humoral immune response and fibrosis is uncertain. Also the role of HLA-DRB1 genotype has not been evaluated, though it's associated with fibrosis in autoimmune hepatitis.

Patients and Methods

This observational study, included 89 stable LT recipient transplanted between 2004–2012 with mean follow-up of 4.3 years, 281 serial PBs (3.1 biopsy/child) and human leukocyte antigen (HLA) antibody data. PBs were taken 1–2, 2–3, 3–5, 5–7, and 7–10 years post-LT, and evaluated for inflammation and fibrosis using liver allograft fibrosis score (LAFSc). The evolution of fibrosis, inflammation and related predisposing factors were analysed.

Findings

HLA-DRB1*03/04 allele and Class II DSA were significantly associated with portal fibrosis (p = 0.03; p = 0.03, respectively). Portal inflammation was predisposed by Class II DSA (p = 0.02) and non-HLA antibody presence (p = 0.01). Non-portal fibrosis wasn't predisposed by inflammation. Lobular inflammation was associated with non-HLA antibodies.

Interpretation

We conclusively demonstrated that allograft inflammation results in fibrosis and is associated with post-LT Class II DSA and non-HLA antibodies. The HLA-DRB1*03/04 allele caused genetic predisposition for fibrosis.

Funding

None.

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There is a link between genetic predisposition, alloimmune antibodies, allograft inflammation and fibrosis

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Description of allograft natural history by assessing evolution of inflammation, fibrosis in different histological zones

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Allograft inflammation results in allograft fibrosis and is associated with post-LT Class II DSA and non-HLA antibodies

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The HLA-DRB1*03/04 allele causes genetic predisposition for fibrosis

Among pediatric liver transplant recipients, the graft longevity is expected to parallel the life expectancy of the recipient. A major impediment in this is progressive allograft fibrosis, the cause of which is not well understood. If this pathogenesis could be found, then interventions to arrest the progressive fibrosis could be explored. In our 89 patients for whom we did periodic surveillance liver biopsies, inflammation was found to precede the fibrosis and associated with presence of specific antibodies. Certain genetic predisposition for higher fibrogenesis was also found, thus establishing a link between genetic predisposition, alloimmune response, inflammation, and allograft fibrosis.

Concise Review: Updated Advances and Current Challenges in Cell Therapy for Inborn Liver Metabolic Defects

: The development of liver cell transplantation (LCT), considered a major biotechnological breakthrough, was intended to provide more accessible treatments for liver disease patients. By preserving the native recipient liver and decreasing hospitalization time, this innovative approach has progressively gained interest among clinicians. LCT initially targets inborn errors of liver metabolism, enabling the compensation of deficient metabolic functions for up to 18 months post-transplantation, supporting its use at least as a bridge to transplantation. The rigorous clinical development and widespread use of LCT depends strongly on controlled and consistent clinical trial data, which may help improve several critical factors, including the standardization of raw biological material and immunosuppression regimens. Substantial effort has also been made in defining and optimizing the most efficient cell population to be transplanted in the liver setting. Although isolated hepatocytes remain the best cell type, showing positive clinical results, their widespread use is hampered by their poor resistance to both cryopreservation and in vitro culture, as well as ever-more-significant donor shortages. Hence, there is considerable interest in developing more standardized and widely accessible cell medicinal products to improve engraftment permanency and post-cell transplantation metabolic effects.

SIGNIFICANCE

In this therapeutic approach to liver disease, new solutions are being designed and evaluated to bypass the documented limitations and move forward toward wide clinical use. Future developments also require a deep knowledge of regulatory framework to launch specific clinical trials that will allow clear assessment of cell therapy and help patients with significant unmet medical needs.

New Insights into Diabetes Cell Therapy

Since insulin discovery, islet transplantation was the first protocol to show the possibility to cure patients with type 1 diabetes using low-risk procedures. The scarcity of pancreas donors triggered a burst of studies focused on the production of new β cells in vitro. These were rapidly dominated by pluripotent stem cells (PSCs) demonstrating diabetes-reversal potential in diabetic mice. Subsequent enthusiasm fostered a clinical trial with immunoisolated embryonic-derived pancreatic progenitors. Yet safety is the Achilles' heel of PSCs, and a whole branch of β cell engineering medicine focuses on transdifferentiation of adult pancreatic cells. New data showed the possibility to chemically stimulate acinar or α cells to undergo β cell neogenesis and provide opportunities to intervene in situ without the need for a transplant, at least after weighing benefits against systemic adverse effects. The current studies suggested the pancreas as a reservoir of facultative progenitors (e.g., in the duct lining) could be exploited ex vivo for expansion and β cell differentiation in timely fashion and without the hurdles of PSC use. Diabetes cell therapy is thus a growing field not only with great potential but also with many pitfalls to overcome for becoming fully envisioned as a competitor to the current treatment standards.

Reassessing the boundaries of liver transplantation for hepatocellular carcinoma: Where do we stand with tumor down-staging?

Down-staging of hepatocellular carcinoma prior to liver transplantation (LT) has generated a lot of interest in recent years and has been identified in two recent national conferences on hepatocellular carcinoma as one of the priorities for research. Down-staging is defined as reduction in the tumor burden using local regional therapy specifically to meet acceptable criteria for LT. The rationale behind down-staging of tumors initially exceeding conventional criteria for LT is to select a subgroup of tumors with favorable biology and prognosis for LT as assessed by their response to local regional therapy. The expectation is to achieve comparable posttransplant survival between patients who achieve successful tumor down-staging before LT and those whose tumors meet LT criteria at the outset without needing down-staging. The application of tumor down-staging requires a highly structured approach using a treatment protocol that includes five essential components: eligibility criteria, down-staging endpoints, selection of the type of local regional therapy, minimal observation period from successful tumor down-staging to LT, and criteria for treatment failure and exclusion from LT. This review article summarizes published data on down-staging and addresses key questions related to each of the components of the down-staging protocol as well as treatment efficacy.

CONCLUSION

Based on a review of published data and recommendations from recent national and international conferences on hepatocellular carcinoma and LT, a standardized down-staging protocol is proposed to further evaluate the feasibility and efficacy of applying tumor down-staging on a broader scale.

Homozygous familial hypercholesterolemia in childhood: Genotype-phenotype description, established therapies and perspectives

Familial hypercholesterolemia (FH) is a co-dominantly inherited disorder of plasma lipoprotein metabolism. The prevalence of heterozygous FH (HeFH) is between 1/500 and 1/200 whereas that of homozygous form (HoFH) is about 1/1,000,000. Diagnosis is based on cutaneous xanthomas and untreated levels of LDL-cholesterol over 500 mg/dl before 10 years of age. Life expectancy, without treatment, does not exceed 20 years of age. The aim of this study is to characterise in details a cohort of 8 HoFH paediatric patients in order to illustrate all the current therapeutic options and to add some clinical and genetic information about this rare disease. We collected demographic, clinical, biological, imaging and genotype details. Furthermore, clinical and biochemical response to different treatment methods was retrospectively evaluated. All patients had genetically proven HoFH. All patients were subject to a lipid-lowering diet and medical treatment (except one), three patients underwent a liver transplant and one an hepatocytes infusion. Medical treatment was well tolerated with a median reduction of 44% and 47% in LDL-Cholesterol and Total Cholesterol respectively. The hepatocytes transplant produced a further, though slight, decrease in cholesterol levels as opposed to medical therapy alone. Transplanted patients normalized their cholesterol levels. Since the very high cardiovascular risk, HoFH requires immediate diagnosis, treatment and monitoring. Nowadays, the use of statins remains the cornerstone of medical therapy and liver transplantation is the possibly curative therapy. Besides, high hopes are pinned in new drugs (antibody targeting PCSK9, Mipomersen and Lomitapide) and stem cells.

Hepatitis C Virus in Children: Deferring Treatment in Expectation of Direct-Acting Antiviral Agents

The major route of hepatitis C virus (HCV) infection in the pediatric age group is vertical, with infection occurring in up to 5% of infants born to mothers positive for HCV-RNA. The natural course of pediatric HCV infection is characterized by a high rate of spontaneous clearance, an asymptomatic clinical course, and normal or mild histologic changes. Cirrhosis is reported in 1-2% of children, and progression to severe chronic liver disease and HCC occurs 20-30 years after infection. Treatment with pegylated interferon (Peg-IFN) + ribavirin results in a sustained viral response (SVR) reaching 100% in children with HCV genotypes 2 or 3 but only 45-55% in those infected with genotypes 1 or 4. Treatment is associated with adverse effects ranging from flu-like symptoms, myalgia, anemia and thrombocytopenia, to less commonly observed thyroid-related symptoms, alopecia, neuropsychiatric manifestations and possible long-term effects on growth. Ongoing trials with direct-acting antiviral agents in adults show promising results with treatment regimens of shorter duration and high tolerance. The next few years will likely see these advances introduced to the pediatric population as well. In the meantime, in children with HCV an expectant approach is advocated and treatment should be offered only to those at high risk for more severe, progressive disease.

Human Progenitor Cell Quantification after Xenotransplantation in Rat and Mouse Models by a Sensitive qPCR Assay

Xenotransplantation of human cells in animal models is an essential tool for evaluation of safety and efficacy of cell-based products for therapeutic use. Sensitive and reproducible methods are needed to detect and quantify human cells engrafted into the host tissue either in the targeted organ or in undesired locations. We developed a robust quantitative polymerase chain reaction (qPCR) assay based on amplification of human AluYb8 repeats, to assess the number of human cells present in rat or mouse tissues after transplantation. Standard curves of mixed human/rodent DNA and mixed human/rodent cells have been performed to determine the limit of detection and linear range of the assay. Standard curves from DNA mixing differed significantly from standard curves from cell mixing. We show here that the AluYb8 qPCR assay is highly reproducible and is able to quantify human cells in a rodent cell matrix over a large linear range that extends from 50% to 0.01% human cells. Short-term in vivo studies showed that human cells could be quantified in mouse liver up to 7 days after intrasplenic transplantation and in rat liver 4 h after intrahepatic transplantation.

Clinical Parameters vs Cytokine Profiles as Predictive Markers of IgE-Mediated Allergy in Young Children

Background

Allergy afflicts one third of children, negatively impacting their quality of life and generating a significant socio-economic burden. To this day, this disorder remains difficult to diagnose early in young patients, with no predictive test available.

Objective

This study was designed to correlate cytokine profiles with clinical phenotypes of allergy development.

Methods

Three hundred patients were recruited and followed from birth to 18 months of age. They were given a clinical exam at birth and at 2, 6, 12, and 18 months of age, with skin prick tests at 6, and 18 months, in order to have a record of their medical history and determine their allergic status. In addition, mononuclear cells from 131 patients were isolated from cord blood and from peripheral blood samples at 2, 6 and 18 months of age, to analyse their cytokine and chemokine production.

Results

Cord blood mononuclear cells (CBMCs) from future Immunoglobulin (Ig) E-mediated allergic children produced significantly less Interleukin (IL)-12p70 and IL-15 than cells from the rest of the cohort. Multivariate analyses revealed that the best predictive model of allergy was built on cytokine data, whereas the best predictive model of IgE-mediated allergy was built on clinical parameters.

Conclusions and clinical relevance

Although univariate analyses can yield interesting information regarding the immune responses of allergic children, finding predictive markers of the disorder will likely rely on monitoring multiple parameters. Nonetheless these analyses suggest a potential key role for IL-15 in the development of atopic disease. In addition, the study highlights the importance of clinical parameters in predicting the development of IgE-mediated allergy.

β-Cell differentiation of human pancreatic duct-derived cells after in vitro expansion

β-Cell replacement therapy is a promising field of research that is currently evaluating new sources of cells for clinical use. Pancreatic epithelial cells are potent candidates for β-cell engineering, but their large-scale expansion has not been evidenced yet. Here we describe the efficient expansion and β-cell differentiation of purified human pancreatic duct cells (DCs). When cultured in endothelial growth-promoting media, purified CA19-9(+) cells proliferated extensively and achieved up to 22 population doublings over nine passages. While proliferating, human pancreatic duct-derived cells (HDDCs) downregulated most DC markers, but they retained low CK19 and SOX9 gene expression. HDDCs acquired mesenchymal features but differed from fibroblasts or pancreatic stromal cells. Coexpression of duct and mesenchymal markers suggested that HDDCs were derived from DCs via a partial epithelial-to-mesenchymal transition (EMT). This was supported by the blockade of HDDC appearance in CA19-9(+) cell cultures after incubation with the EMT inhibitor A83-01. After a differentiation protocol mimicking pancreatic development, HDDC populations contained about 2% of immature insulin-producing cells and showed glucose-unresponsive insulin secretion. Downregulation of the mesenchymal phenotype improved β-cell gene expression profile of differentiated HDDCs without affecting insulin protein expression and secretion. We show that pancreatic ducts represent a new source for engineering large amounts of β-like-cells with potential for treating diabetes.

Retargeting of bile salt export pump and favorable outcome in children with progressive familial intrahepatic cholestasis type 2

We investigated predictors of clinical evolution in progressive familial intrahepatic cholestasis type 2 patients and how they relate to bile salt export pump (BSEP) expression and its (re)targeting. Our retrospective study included 22 children with progressive familial intrahepatic cholestasis type 2. Clinical, biochemical, and histological characteristics were reviewed on admittance and following treatment with either ursodeoxycholic acid alone (10 mg/kg thrice daily, n = 19) or partial biliary diversion (n = 3). Immunostaining of BSEP was performed in 20 patients. Response to treatment was defined as normalization of pruritus, disappearance of jaundice, and alanine aminotransferase (ALT) levels <1.5 times the upper limit of normal. Ten of 22 patients were responders, and paired biopsies were available in six. De novo or retargeted canalicular expression of BSEP occurred in four of these six, two of whom exhibited baseline intracellular expression. Twelve of 22 were nonresponders and exhibited earlier onset of jaundice (<9 months), neonatal cholestasis, and higher ALT levels. An ALT >165 IU/L produced 72% sensitivity and 55% specificity in predicting nonresponse. Seven patients were still responding at last follow-up (median = 20 months, range 5-67 months). Three responders relapsed after 56, 72, and 82 months, respectively. Of nine surviving responders, median relapse-free survival time was 72 months (95% confidence interval 48-96 months) and 5-year relapse-free survival was 75% (95% confidence interval 33-100%). Intracellular BSEP at baseline was seen in six, of whom five were responders. Genetic analysis was performed in 17 of 22, confirming diagnosis in 13 (76%) and in four (24%) in whom only heterozygous mutation was identified.

CONCLUSION

De novo or retargeted canalicular expression of BSEP occurs in treatment responders; children with late-onset presentation, lower ALT, and intracellular BSEP expression are likely to respond, at least transiently, to nontransplant treatment.

Mesenchymal stem cell treatment for hemophilia: a review of current knowledge

Hemophilia remains a non-curative disease, and patients are constrained to undergo repeated injections of clotting factors. In contrast, the sustained production of endogenous factors VIII (FVIII) or IX (FIX) by the patient's own cells could represent a curative treatment. Gene therapy has thus provided new hope for these patients. However, the issues surrounding the durability of expression and immune responses against gene transfer vectors remain. Cell therapy, involving stem cells expanded in vitro, can provide de novo protein synthesis and, if implanted successfully, could induce a steady-state production of low quantities of factors, which may keep the patient above the level required to prevent spontaneous bleeding. Liver-derived stem cells are already being assessed in clinical trials for inborn errors of metabolism and, in view of their capacity to produce FVIII and FIX in cell culture, they are now also being considered for clinical application in hemophilia patients.

Adult human hepatocytes promote CD4(+) T-cell hyporesponsiveness via interleukin-10-producing allogeneic dendritic cells

The success of liver cell therapy remains closely dependent on how well the infused cells can be accepted after transplantation and is directly related to their degree of immunogenicity. In this study, we investigated the in vitro immunogenic properties of isolated human hepatocytes (hHeps) and adult-derived human liver progenitor cells (ADHLPCs), an alternative cell candidate for liver cell transplantation (LCT). The constitutive expression of immune markers was first analyzed on these liver-derived cells by flow cytometry. Human liver-derived cells were then cocultured with allogeneic human adult peripheral blood mononuclear cells (PBMCs), and the resulting activation and proliferation of PBMCs was evaluated, as well as the cytokine levels in the coculture supernatant. The effect of liver-derived cells on monocyte-derived dendritic cell (MoDC) properties was further analyzed in a secondary coculture with naive CD4(+) T-cells. We report that hHeps and ADHLPCs expressed human leukocyte antigen (HLA) class I and Fas but did not express HLA-DR, Fas ligand, and costimulatory molecules. hHeps and ADHLPCs did not induce T-cell activation or proliferation. Moreover, hHeps induced a cell contact-dependent production of interleukin (IL)-10 that was not observed with ADHLPCs. The IL-10 was produced by a myeloid DC subset characterized by an incomplete mature state. Furthermore, hHep-primed MoDCs induced an antigen-independent hyporesponsiveness of naive CD4(+) T lymphocytes that was partially reversed by blocking IL-10, whereas nonprimed MoDCs (i.e., those cultured alone) did not. hHeps and ADHLPCs present a low immunogenic phenotype in vitro. Allogeneic hHeps, but not ADHLPCs, promote a cell contact-dependent production of IL-10 by myeloid DCs, which induces naive CD4(+) T-cells antigen-independent hyporesponsiveness.

Biodistribution of adult derived human liver stem cells following intraportal infusion in a 17-year-old patient with glycogenosis type 1A

INTRODUCTION

Current treatment of inherited liver inborn errors of metabolism in children consists in appropriate diet and drugs and, for unstable patients, final orthotopic liver transplantation. Unfortunately, liver transplantation remains not easily available because of organ shortage and imposes inherent risks and lifelong immunosuppressive therapy. Therefore alternative treatments are required. Hepatocytes transplantation and its limitations led to consider innovative alternative such as transplantation of adult derived human liver stem cells (ADLHSC). These cells present high proliferative capacity, good resistance to cryopreservation and ability to differentiate into hepatocyte-like cells displaying mature hepatocyte functions.

AIM

Biodistribution of ADHLSC had never been assessed after infusion through the portal vein in patients. This information is required to determine the safety of the method.

METHODS

ADHLSC were efficiently labelled with 111-Indium DTPA radiotracer and SPECT imaging was used for the acquisition of whole body imaging to document short term biodistribution of ADHLSC.

RESULTS

Following infusion through the portal vein, ADHLSC diffused homogenously throughout the liver and remained strictly within the targeted organ. Images were acquired until 5 days after infusion. At that time, no signal was observed in any other organs except the liver. Urinary excretion of 111-Indium DTPA was also monitored.

CONCLUSION

For the first time, we documented the short term biodistribution of ADHLSC within the liver after infusion through the portal vein.

Prevention and treatment for Epstein-Barr virus infection and related cancers

Epstein-Barr virus (EBV) was the first herpes virus described as being oncogenic in humans. EBV infection is implicated in post-transplant lymphoproliferative diseases (PTLD) and several other cancers in non-immunocompromised patients, with more than 200,000 new cases per year. While prevention of PTLD is improving, mainly based on EBV monitoring and preemptive tapering of immunosuppression, early diagnosis remains the best current option for the other malignancies. Significant progress has been achieved in treatment, with decreased mortality and morbidity, but some challenges are still to face, especially for the more aggressive diseases. Possible prevention by EBV vaccination would be a more global approach of this public health problem, but further active research is needed before this goal could be reached.

A small-molecule inducer of PDX1 expression identified by high-throughput screening

Pancreatic and duodenal homeobox 1 (PDX1), a member of the homeodomain-containing transcription factor family, is a key transcription factor important for both pancreas development and mature β cell function. The ectopic overexpression of Pdx1, Neurog3, and MafA in mice reprograms acinar cells to insulin-producing cells. We developed a quantitative PCR-based gene expression assay to screen more than 60,000 compounds for expression of each of these genes in the human PANC-1 ductal carcinoma cell line. We identified BRD7552, which upregulated PDX1 expression in both primary human islets and ductal cells, and induced epigenetic changes in the PDX1 promoter consistent with transcriptional activation. Prolonged compound treatment induced both insulin mRNA and protein and also enhanced insulin expression induced by the three-gene combination. These results provide a proof of principle for identifying small molecules that induce expression of transcription factors to control cellular reprogramming.

Human Liver Progenitor Cells for Liver Repair

Because of their high proliferative capacity, resistance to cryopreservation, and ability to differentiate into hepatocyte-like cells, stem and progenitor cells have recently emerged as attractive cell sources for liver cell therapy, a technique used as an alternative to orthotopic liver transplantation in the treatment of various hepatic ailments ranging from metabolic disorders to end-stage liver disease. Although stem and progenitor cells have been isolated from various tissues, obtaining them from the liver could be an advantage for the treatment of hepatic disorders. However, the techniques available to isolate these stem/progenitor cells are numerous and give rise to cell populations with different morphological and functional characteristics. In addition, there is currently no established consensus on the tests that need to be performed to ensure the quality and safety of these cells when used clinically. The purpose of this review is to describe the different types of liver stem/progenitor cells currently reported in the literature, discuss their suitability and limitations in terms of clinical applications, and examine how the culture and transplantation techniques can potentially be improved to achieve a better clinical outcome.