Mesenchymal stem cells (MSCs) are currently studied and used in numerous clinical trials. Nevertheless, some concerns have been raised regarding the safety of these infusions and the thrombogenic ...risk they induce. MSCs express procoagulant activity (PCA) linked to the expression of tissue factor (TF) that, when in contact with blood, initiates coagulation. Some even describe a dual activation of both the coagulation and the complement pathway, called Instant Blood-Mediated Inflammatory Reaction (IBMIR), explaining the disappointing results and low engraftment rates in clinical trials. However, nowadays, different approaches to modulate the PCA of MSCs and thus control the thrombogenic risk after cell infusion are being studied. This review summarizes both in vitro and in vivo studies on the PCA of MSC of various origins. It further emphasizes the crucial role of TF linked to the PCA of MSCs. Furthermore, optimization of MSC therapy protocols using different methods to control the PCA of MSCs are described.
Abstract
Post-operative bacterial infections are a leading cause of mortality and morbidity after ongoing liver transplantation. Bacteria causing these infections in the hospital setting can exhibit ...high degrees of resistance to multiple types of antibiotics, which leads to major therapeutic hurdles. Alternate ways of treating these antibiotic-resistant infections are thus urgently needed. Phage therapy is one of them and consists in using selected bacteriophage viruses – viruses who specifically prey on bacteria, naturally found in various environmental samples – as bactericidal agents in replacement or in combination with antibiotics. The use of phage therapy raises various research questions to further characterize what determines therapeutic success or failure. In this work, we report the story of a toddler who suffered from extensively drug-resistant
Pseudomonas aeruginosa
sepsis after liver transplantation. He was treated by a bacteriophage-antibiotic intravenous combination therapy for 86 days. This salvage therapy was well tolerated, without antibody-mediated phage neutralization. It was associated with objective clinical and microbiological improvement, eventually allowing for liver retransplantation and complete resolution of all infections. Clear in vitro phage-antibiotic synergies were observed. The occurrence of bacterial phage resistance did not result in therapeutic failure, possibly due to phage-induced virulence tradeoffs, which we investigated in different experimental models.
Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative,or at least as a bridge,to orthotopic liver transplantation.The success of such a ...therapeutic approach remains limited by the quality of the transplanted cells.Cryopreservation remains the best option for long-term storage of hepatocytes,providing a permanent and sufficient cell supply.However, isolated adult hepatocytes are poorly resistant to such a process,with a significant alteration both...
This case report describes a child born with both cystic fibrosis (CF) and alpha-1 antitrypsin deficiency (A1ATD). Both are autosomal recessive inherited diseases, mainly affecting the lungs and the ...liver. The combination of both diseases together is rare and may lead to a fulminant disease with limited life span. To the best of our knowledge, no case has been reported of a patient born with both diseases.
After an uneventful pregnancy, a male baby was born with meconium ileus. The suspected diagnosis of CF was confirmed based on the sweat test and genetic analysis. The child developed persisting cholestasis, too severe to be likely caused by CF alone and indicating an associated problem. The diagnosis of A1ATD was established based on clinical suspicion (persisting cholestasis), decreased serum alpha-1 antitrypsin and genetic analysis. Supportive therapy was started, however the boy evolved to rapidly progressive liver disease leading to liver failure which necessitated an infant liver transplantation.
This case illustrates the complexity of care in case of two severe inherited diseases as well as post solid organ transplant care.
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.
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).
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.
These results suggest the potential use of ADHLSCs in the treatment of hemophilia A.
Liver cell transplantation is an attractive technique to treat liver-based inborn errors of metabolism. The feasibility and efficacy of the procedure has been demonstrated, leading to medium term ...partial metabolic control of various diseases. Crigler-Najjar is the paradigm of such diseases in that the host liver is lacking one function with an otherwise normal parenchyma. The patient is at permanent risk for irreversible brain damage. The goal of liver cell transplantation is to reduce serum bilirubin levels within safe limits and to alleviate phototherapy requirements to improve quality of life. Preliminary data on Gunn rats, the rodent model of the disease, were encouraging and have led to successful clinical trials. Herein we report on two additional patients and describe the current limits of the technique in terms of durability of the response as compared to alternative therapeutic procedures. We discuss the future developments of the technique and new emerging perspectives.
Mesenchymal stem cell (MSC) transplantation is a fast-developing therapy in regenerative medicine. However, some concerns have been raised regarding their safety and the infusion-related ...pro-coagulant activity. The aim of this study is to analyze the induced thrombogenic risk and the safety of adding anticoagulants during intraportal infusions of liver-derived MSCs (HepaStem), in patients with Crigler-Najjar (CN) and urea cycle disorders (UCD).
Eleven patients (6 CN and 5 UCD patients) were included in this partially randomized phase 1/2 study. Three cell doses of HepaStem were investigated: low (12.5 × 10
cells/kg), intermediate (50 × 10
cells/kg), and high doses (200 × 10
cells/kg). A combination of anticoagulants, heparin (10 I.U./5 × 10
cells), and bivalirudin (1.75 mg/kg/h) were added during cell infusions. The infusion-related thrombogenic risk and anticoagulation were evaluated by clinical monitoring, blood sampling (platelet and D-dimer levels, activated clotting time, etc.) and liver Doppler ultrasound. Mixed effects linear regression models were used to assess statistically significant differences.
One patient presented a thrombogenic event such as a partial portal vein thrombus after 6 infusions. Minor adverse effects such as petechiae, epistaxis, and cutaneous hemorrhage at the site of catheter placement were observed in four patients. A significant decrease in platelet and increase in D-dimer levels were observed at the end of the infusion cycle, normalizing spontaneously after 7 days. No significant and clinically relevant increase in portal vein pressure could be observed once the infusion cycle was completed.
The safety- and the infusion-related pro-coagulant activity remains a concern in MSC transplantation. In our study, a combination of heparin and bivalirudin was added to prevent the thrombogenic risk induced by HepaStem infusions in 11 patients. A significant decrease in platelet and increase in D-dimer levels were observed, suggesting the activation of coagulation in these patients; however, this was spontaneously reversible in time. We can conclude that adding this combination of anticoagulants is safe and limits infusion-related thrombogenesis to subclinical signs in most of the patients.
ClinicalTrials.gov identifier: NCT01765283-January 10, 2013.
AIM: To investigate the activity and expression of EAAT2 glutamate transporter in both in vitro and in vivo models of cholestasis. METHODS: This study was conducted on human hepatoblastoma HepG2 cell ...cultures, the liver of bile duct ligated rats and human specimens from cholestatic patients. EAAT2 glutamate transporter activity and expression were analyzed using a substrate uptake assay, immunofluorescence, reverse transcription-polymerase chain reaction, and immunohistochemistry, respectively. RESULTS: In HepG2 cells, cholestasis was mimicked by treating cells with the protein kinase C activator, phorbol 12-myristate 13-acetate. Under such conditions, EAAT2 transporter activity was decreased both at the level of substrate affinity and maximal transport velocity. The decreased uptake was correlated with intracellular translocation of EAAT2 molecules as demonstrated using immunofluorescence. In the liver of bile duct ligated rats, an increase in EAAT2 transporter protein expression in hepatocytes was demonstrated using immunohistochemistry. The same findings were observed in human liver specimens of cholestasis in which high levels of γ-glutamyl transpeptidase were documented in patients with biliary atresia and progressive familial intrahepatic cholestasis type 3. CONCLUSION: This study demonstrates the alteration in glutamate handling by hepatocytes in liver cholestasis and suggests a potential cross-talk between glutamatergic and bile systems.
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.
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