Mobilization of Mesenchymal Stem Cells During Liver Transplantation
Condition: Liver Failure; Liver Neoplasm
MeSH terms: Liver Neoplasms; Liver Failure
Study type: Observational

Summary: 
      To study if the administration of corticoid hinder or enhance the mobilization of Mesenchymal
      Stem Cells (MSCs) in the peripheral blood during liver transplantation and whether this
      affects the outcome with respect to graft versus host response.
    

Detailed description: 
      Mesenchymal stem cells (MSCs) are a known immune modulator with significant immunosuppressive
      effects. MSCs have emerged as a promising frontier in human clinical trials. MSCs have been
      shown to be non-immunogenic making them capable of transplantation across allogeneic barrier.
      These qualities make MSCs an ideal candidate to study if they are involved in reducing the
      rejection of the graft, in this case, liver transplant. If so, the information would be
      highly significant as it would lead to significant reduction in use of immunosuppressants
      with the replacement of MSCs. This will serve dual purposes: reduced clinical problems
      associated with pharmacological immunosuppression (discussed in the next paragraph);
      additional help in the protection of the transplanted liver by the MSCs.

      The use of immunosuppressants in particular is vital in organ transplantation including liver
      transplant patients. However, their use is accompanied by numerous drawbacks such as
      reactivation of viral hepatitis, opportunistic infections and other complications. If MSCs
      can be used to decrease the use of immunosuppressive agents in liver transplant patients it
      can lead to a significant decrease in morbidity and mortality as a consequence of liver
      transplantation.

      Hepatic macrophages, ie Kupffer cells, have a known function of recruiting monocytes into the
      liver. They have been shown to have a proinflammatory effect by attracting monocytes into the
      liver. They also interact with hepatic stellate cells (HSCs) which have pro-fibrogenic
      functions. However, they have been shown to have anti-inflammatory effects as well,
      implicating a role in fibrosis regression. Hepatic macrophages are an interesting new target
      for therapeutic intervention and the effect of steroids on kupffer cells as well as their
      interaction with MSCs have not been fully explored.

      Patient will be attached to standard American Society of Anesthesiologists (ASA) monitors
      including pulse oximetry, electrocardiogram, noninvasive blood pressure monitoring
      temperature and capnometry. Patients will be placed under general anesthesia with
      endotracheal intubation and controlled ventilation. As is customary for all liver surgeries,
      an arterial line will be inserted for blood pressure monitoring and for repeat blood samples.
      If indicated, a pulmonary artery catheter will be inserted.

      Anesthesia will be maintained using a volatile agent. Paralysis will be provided using a
      non-depolarizing neuromuscular blocking agent of the anesthesiologist's choice.

      As is standard practice hourly blood samples will be taken from the arterial line to analyze
      Protime(PT)/International Normalized Ratio (INR)/Complete Blood Count/electrolytes. Red Blood
      Cells, Fresh Frozen Plasma and platelets will be transfused as necessary.

      As is customary liver transplant recipients will be given the customary dose of
      methylprednisolone for immune suppression in the anhepatic phase.

      Intraoperatively, patients undergoing transplant will have three blood samples collected from
      the arterial line for study purposes. Each sample will contain 3cc of blood.

      The time points for blood samples are as follows:

        -  Immediately after arterial line placement as a baseline

        -  In the anhepatic stage prior to steroid injection

        -  Two hours after administration of steroids Post-operatively, two additional 3 mL blood
           samples will be taken by a member of the study team. The first will be on postoperative
           day 1 prior to the administration of immunosuppressive drugs and the second sample on
           postoperative day five. Thus for liver transplant patients a total of 15 milliliters
           (mL) of blood over a period of 5 days will be collected for the study.

      The administration of immunosuppression drugs and or dosage will not be altered as a
      component of the research study.

      A tissue sample of the liver donor organ will also be taken to culture MCSs (exempt informed
      consent).

      Control group patients will undergo liver resection. They will not receive the dose of
      methylprednisolone. Intra-operatively blood samples will be collected at these time points:

        -  immediately after arterial line placement

        -  two hours after liver resection. Postoperatively two additional 3-mL blood samples will
           be taken. The first will be taken on postoperative day one and the second on
           postoperative day five or on the day of discharge whichever comes sooner. These samples
           will be collected by a study team member. A total of 12mL of blood over a period of 5
           days will be collected from the liver resection patients for study purposes.

      All blood samples will be immediately delivered to Dr. Rameswhar's lab, located in MSB, E579.
      The relative frequency of MSCs present in the blood of the two groups will be assessed by
      flow cytometry. The data will be presented as the percentage of MSCs/106 mononuclear cells.
      Statistical analyses will be performed to determine if there are differences between the two
      groups of subjects.

      In addition to the above studies with the donor liver, we will also treat liver cells with
      glucocorticoids and then examine the liver for changes in aquaporin. The reason for this
      modification is to determine if aquaporin increases the ability to accumulate water. This
      additional study will not change the samples since only a small (<1mg) of tissue will be
      sufficient.
    

Intervention name(s): blood samples; blood samples
Intervention type(s): Procedure; Procedure
Intervention description(s): liver transplant patients will have (5) 3cc blood samples drawn at specific time points.; liver resection patients will have (3) 3cc. blood samples drawn at specific time points
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients undergoing liver transplant or liver resection