Liver Regeneration Following Thermal Ablation Using Nanocarrier Mediated Targeted Mesenchymal Stem Cell Therapy.

Purpose: To test the efficacy of nanocarrier (NC) mediated mesenchymal stem cell (MSC) therapy for liver regeneration following thermal ablation of porcine livers.

Materials And Methods: Liver radiofrequency ablation was performed in 18 swines divided into MSC, MSC + NC and control groups. The test groups received infusion of MSC or MSC + NC labeled with enhanced green fluorescent protein (eGFP) via hepatic artery.

Nuances in the interpretation and utility of donor-derived cell-free DNA in lung transplantation following allogeneic hematopoietic stem cell transplantation - Case report.

Respiratory complications following allogeneic HSCT can lead to severe morbidity and mortality. Lung transplantation (LT) is a potential treatment for select patients with late-onset non-infectious pulmonary complications post-HSCT. Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive biomarker for monitoring the health of allografts following LT.

Morphologic and immunophenotypic evaluation of liver allograft biopsies with contemporaneous serum DSA measurements.

Background: Acute antibody mediated rejection is increasingly identified in liver allografts as a unique form of alloimmune injury associated with donor specific antibodies (DSA). This manifests pathologically as microvascular injury and C4d uptake. Despite the liver allograft's relative resistance to alloimmune injury, liver allografts are not impervious to cellular and antibody-mediated rejection.

Pharmacological Disruption of the Notch1 Transcriptional Complex Inhibits Tumor Growth by Selectively Targeting Cancer Stem Cells.

In many human cancers, deregulation of the Notch pathway has been shown to play a role in the initiation and maintenance of the neoplastic phenotype. Aberrant Notch activity also plays a central role in the maintenance and survival of cancer stem cells (CSC), which underlie metastasis and resistance to therapy. For these reasons, inhibition of Notch signaling has become an exceedingly attractive target for cancer therapeutic development.

Prevalence and Clinical Impact of Donor-Specific Alloantibody Among Intestinal Transplant Recipients.

Background: Rejection remains the leading cause of allograft loss, and a major barrier to improving long-term outcomes after intestinal transplantation. Our aim is to define the prevalence and investigate the role of donor-specific antibody (DSA) on intestinal graft outcomes.

Methods: The study includes 109 transplants performed in 95 recipients at a single center.

Acute liver allograft antibody-mediated rejection: an inter-institutional study of significant histopathological features.

Acute antibody-mediated rejection (AMR) occurs in a small minority of sensitized liver transplant recipients. Although histopathological characteristics have been described, specific features that could be used (1) to make a generalizable scoring system and (2) to trigger a more in-depth analysis are needed to screen for this rare but important finding. Toward this goal, we created training and validation cohorts of putative acute AMR and control cases from 3 high-volume liver transplant programs; these cases were evaluated blindly by 4 independent transplant pathologists.

Donor-specific human leukocyte antigen antibodies in intestinal transplantation.

Purpose Of Review: Early outcomes following intestinal transplantation (ITx) have markedly improved in recent years. However, there has been a lack of improvement in long-term outcomes. Increasing amounts of data suggest the humoral immune system is a major contributor to rejection and late allograft loss.

Donor-specific alloantibodies are associated with fibrosis progression after liver transplantation in hepatitis C virus-infected patients.

Hepatitis C virus (HCV) fibrosis progression after liver transplantation (LT) is accelerated in comparison with fibrosis progression before transplantation. The vast majority of the risk factors for fibrosis progression after LT are not modifiable. With the goal of identifying modifiable risk factors for fibrosis progression, we evaluated the impact of preformed and de novo donor-specific human leukocyte antigen alloantibodies (DSAs) on fibrosis progression after LT in HCV-viremic patients.

Antibody-mediated rejection as a contributor to previously unexplained early liver allograft loss.

We analyzed 60 patients with idiopathic early allograft loss (defined as death or retransplantation at <90 days) to determine the relative contribution of preformed donor-specific human leukocyte antigen alloantibodies (DSAs) to this endpoint, and we defined strict criteria for the diagnosis of antibody-mediated rejection (AMR) in liver allografts. The inclusion criteria encompassed the availability of a pretransplant serum sample and both postreperfusion and follow-up tissue specimens for a blinded, retrospective re-review of histology and complement component 4d (C4d) staining. AMR was diagnosed on the basis of the presence of all 4 of the following strict criteria: (1) DSAs in serum, (2) histopathological evidence of diffuse microvascular injury/microvasculitis consistent with antibody-mediated injury, (3) diffuse C4d staining in the portal microvasculature with or without staining in the sinusoids or central veins in at least 1 sample, and (4) the exclusion of other causes of a similar type of injury.

The Role of Donor-Specific Antibodies in Intestinal Transplantation: Experience at the University of California Los Angeles and Literature Review.

Intestinal transplantation is a viable treatment strategy for patients with irreversible intestinal failure for whom parenteral nutrition is no longer an option. Although improvements have been made in short-term post-transplant survival outcomes, long-term allograft loss, mainly to acute or chronic rejection, remains a major obstacle to successful transplantation. In all types of solid organ transplants, there is increasing evidence that antibodies directed against human leukocyte antigens, and in particular donor-specific antibodies (DSA), contribute to acute and chronic rejection as well as allograft loss.

Preformed class II donor-specific antibodies are associated with an increased risk of early rejection after liver transplantation.

Preformed donor-specific human leukocyte antigen antibodies (DSAs) are considered a contraindication to the transplantation of most solid organs other than the liver. Conflicting data currently exist on the importance of preformed DSAs in rejection and patient survival after liver transplantation (LT). To evaluate preformed DSAs in LT, we retrospectively analyzed prospectively collected samples from all adult recipients of primary LT without another organ from January 1, 2000 to May 31, 2009 with a pre-LT sample available (95.

2013 annual literature review of donor-specific HLA antibodies after organ transplantation.

1. There is still a need to better differentiate clinically relevant from irrelevant DSA in all organs. Modified bead assay testing for different immunoglobulin (Ig) G characteristics (Clq-fixing DSA, C4d-fixing DSA, IgG subclasses, or IgM) often improve the predictive value for rejection and failure compared to standard IgG DSA.

Fatal peri-operative hyperacute graft rejection during heart transplantation related to infusion of red blood cell concentrate.

With the use of sensitive new technology, hyperacute graft rejection is currently reported as an extremely rare event due to prospective lymphocyte crossmatches and/or virtual crossmatches. In this case study we describe a case of fatal early graft failure after a cardiac transplant in a male recipient who had no anti-HLA antibodies detected before transplantation, but who received, during heart transplant surgery, a red blood cell concentrate containing high levels of graft-specific alloantibodies. In addition, we analyze the relationship between these alloantibodies and the occurrence of hyperacute allograft rejection.

Using donor-specific antibodies to monitor the need for immunosuppression.

Background: Experience with tolerance protocols has shown that none is perfect and that each escape from tolerance must be identified early to prevent graft failure. In addition, some test is needed for patients who are weaned off immunosuppression (IS) to forewarn of weaning failure. The usual measures of function--such as serum creatinine levels--are not sensitive enough to detect rejection in a timely manner.

Donor-specific human leukocyte antigen antibodies of the immunoglobulin G3 subclass are associated with chronic rejection and graft loss after liver transplantation.

In a previous study, we found that 92% of patients with chronic rejection had donor-specific human leukocyte antigen antibodies (DSAs), but surprisingly, 61% of comparator patients without rejection also had DSAs. We hypothesized that immunoglobulin G (IgG) subclasses were differentially distributed between the 2 groups. A modified single-antigen bead assay was used to detect the presence of individual IgG subclasses against human leukocyte antigen in 39 chronic rejection patients and 66 comparator patients.

2012 annual literature review of donor-specific HLA antibodies after organ transplantation.

From the articles reviewed in the present chapter, we observed: 1. The frequency of de novo donor-specific human leukocyte antigen (HLA) antibodies (DSA) detection in different organs is very similar: ranging between 15% and 23% in kidney, 23% in pancreas, and 18% in intestinal transplant patients. Apparently, all organs can elicit humoral responses after transplantation at comparable rates.

Annual literature review of donor-specific HLA antibodies after organ transplantation.

The literature review of post-transplant DSA published in 2011 shows: Observations after kidney and lung transplant in non-sensitized transplant recipients show that monitoring post-transplant HLA antibodies offers limited benefit in predicting acute rejection episodes. It remains to be seen if a different monitoring schedule and/ or studying other organs may show otherwise. Nevertheless, others have shown that monitoring post-transplant antibodies does identify patients at higher risk for chronic rejection.

Anti-HLA-E mAb 3D12 mimics MEM-E/02 in binding to HLA-B and HLA-C alleles: Web-tools validate the immunogenic epitopes of HLA-E recognized by the antibodies.

HLA-E shares several peptide sequences with HLA-class Ia molecules. Therefore, anti-HLA-E antibodies that recognize the shared sequences may bind to HLA-class Ia alleles. This hypothesis was validated with a murine anti-HLA-E monoclonal antibody (mAb) MEM-E/02, which reacted with microbeads coated with several HLA-B and HLA-C antigens.

Protective immunity remains intact after antibody removal by means of proteasome inhibition.

Background: Proteasome inhibition abrogates donor-specific anti-human leukocyte antigen (HLA) antibody (DSA) in patients posttransplant. However, its effects on protective humoral immunity to vaccine antigens remain unknown. Herein, we report on bortezomib's safety regarding protective immunity in patients who have experienced HLA antibody reduction/removal.

Antibodies to HLA-E in nonalloimmunized males: pattern of HLA-Ia reactivity of anti-HLA-E-positive sera.

Natural anti-HLA Abs found in sera of healthy nonalloimmunized males recognize HLA-Ia alleles parallel to those recognized by anti-HLA-E mAbs (MEM-E/02/06/07). Therefore, some of the HLA-Ia Abs seen in healthy males could be due to anti-HLA-E Abs cross-reacting with HLA-Ia. If anti-HLA-E Abs occur in healthy nonalloimmunized males, it can be assessed whether they evoke HLA-Ia reactivity as do mouse HLA-E mAbs.

A "new" road to tolerance: clonal deletion and drugs added when needed (DAWN).

We propose clonal deletion--immunization followed by deletion--as a "new" way to achieve tolerance. Immunization of a donor results in specific stimulation of a clone of cells, which can then be killed by various agents, leaving the patient otherwise immunologically normal. The theory of clonal deletion is supported by experimental evidence as well as earlier experiences with kidney transplants and donor-specific transfusions.

Impact of donor-specific HLA antibodies in transplantation, a review of the literature published in the last three years.

This chapter summarizes some of the recent findings published on the role in organ transplantation of HLA antibodies, and--more important--donor-specific HLA antibodies. The negative impact of both, preformed and de novo DSA is now better recognized in recipients of kidney, heart, lung, liver, pancreas, islet cells and bone marrow transplants. An appropriate design of a schedule to monitor HLA antibodies may identify patients at higher risk for immunological events earlier and allow interventions to avoid later graft loss.

HLA-E monoclonal antibodies recognize shared peptide sequences on classical HLA class Ia: relevance to human natural HLA antibodies.

The non-classical HLA-Ib molecule, HLA-E share several peptide sequence similarities with the heavy chains of classical HLA class Ia (-B and -C) molecules. Therefore, the antibodies to HLA-E, that recognize shared sequences, may bind to HLA-Ia alleles. This hypothesis is tested by examining the affinity of HLA-E monoclonal antibodies (HLA-E-MAbs) to HLA-Ia molecules and by inhibiting the antibody binding to both HLA-E and HLA-Ia with the shared peptide sequence(s).

Abrogation of anti-HLA antibodies via proteasome inhibition.

Background: Current treatments for autoantibody-mediated diseases (i.e., systemic lupus erythematosus) and alloantibodies (in transplant) are minimally effective.