Showing 3 ideas for tag "rejection"

Goal 2: Reduce Human Disease

Heart transplant surveillance

It is essential to develop clinically viable, non-invasive, less expensive technologies for the surveillance of allograft rejection in heart transplant patients. Critical challenges that exist in the near term or long term surveillance after transplant is the unavailability of molecular and cellular level markers that can be non-invasively imaged and quantified detect rejection and thus improve patient survival. Development... more »

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Development of methods for near term or long term surveillance after transplant can help detect the rejection and thus improve patient survival

Feasibility and challenges of addressing this CQ or CC

The fast growth in the imaging technologies and molecular and cellular imaging technologies are gaining foot in cardiovascular sciences and should be feasible within a decade
The current surveillance to detect transplant rejection requires repeated testing with endo myocardial biopsy and catheter angiography. Both technologies are highly invasive and very expensive. Post-transplant surveillance is focused on the cellular rejection in the near term after transplant and cardiac allograft vasculopathy in the long term.

Name of idea submitter and other team members who worked on this idea NHLBI Staff

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Goal 2: Reduce Human Disease

Stem Cell Immunology

We now can create critical cell types like cardiomyocytes etc. from stem cells. Additionally, we are learning the rules of using these cells to rebuild tissues. A major gap in our knowledge relates to the immunobiology of these cells. Lessons from transplantation medicine are only partially applicable, because solid organs are more complex and likely more immunogenic than defined cell populations.

How does the immune... more »

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We now can generate large quantities of critical cell types whose deficiencies underlie many chronic diseases like heart failure. This breakthrough brings us to the next-level impediment: the immune system. While induced pluripotent stem cells have the potential to obviate rejection, in practical terms this is cost-prohibitive: It will cost huge amounts of money to produce and qualify a single patient's cell dose. Moreover, human cardiomyocytes are potent when given to infarcted hearts in the acute or sub-acute phase of infarction, but they have no benefit with chronic heart failure. The 6 months required to produce iPSC-cardiomyocytes precludes their autologous use for myocardial infarction.

We need an off the shelf cell therapy product for myocardial infarction that can be mass produced and qualified for large numbers of patients. This means an allogeneic product is necessary. Identifying the immune response to cardiomyocytes or other cell products will teach us how to precisely immunosuppress the patient, thereby minimizing complications, or alternatively, how to engineer the cells so as to avoid immunogenicity in the first place.

Lessons from the study of cardiomyocyte transplantation could extend to dopamine neurons, pancreatic beta-cells, retinal cells, myelinating cells and many other areas that cause common chronic disease.

Feasibility and challenges of addressing this CQ or CC

We know a great deal of transplant immunology from hematopoietic stem cell transplantation (graft versus host) and from solid organ transplantation (host versus graft). There are good mouse and large animal (including non-human primate) models of stem cell differentiation and organ transplantation. This offers low hanging fruit where, in perhaps 5 years, we could discern the critical similarities and differences between transplanting stem cell derivatives and organ or marrow transplantation. These studies will inform clinical trials of allogeneic human stem cell derivatives that will be underway by then.

Success in this area will require bringing together researchers interested in stem cell biology and transplant immunology. A properly resourced RFA from NIH could be just the thing needed to promote this interaction.

Name of idea submitter and other team members who worked on this idea Charles Murry, MD, PhD

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Goal 2: Reduce Human Disease

The role of Extracorporeal Photopheresis (ECP) in the prevention and treatment of rejection of heart and lung transplants

According to the ISHLT, more than 4,000 patients undergo a heart transplant each year, and almost 4,000 receive single or double lung transplants. Their prognosis depends heavily on the avoidance of rejection, which claims the majority of their lives. For heart transplant recipients, the median survival is 11 years, while for lung transplant recipients, it is approximately 5 years. The current most common anti-rejection... more »

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Patients who are fortunate to receive a matched heart or one or two lungs transplants are at high risk of dying from rejection early and even years after the operation. Thus, they are given cocktails of highly toxic anti-rejection drugs for the rest of their lives. Unfortunately, despite compliance with their drug regimens, many patients still suffer repeated episodes of rejection that may be fatal. In addition, they develop serious side-effects such as diabetes, infections, malignancies, renal failure, etc. ECP has been shown efficacy in preventing and treating cardiac transplant rejection, but the data are limited. ECP appears to benefit such patients by causing an increase in the number of circulating T regulatory (“T regs”) cells. T regs are known to mediate immune tolerance, the ultimate goal of a long-term successful transplant. The role of ECP in lung transplantation is mostly unknown. Very preliminary data have been gathered from retrospective studies. We suspect that patients with early bronchiolitis obliterans syndrome (“BOS”) will benefit from ECP prior to developing irreversible pulmonary damage. In both types of transplants, however, it is unknown when should ECP be started, how often it should be employed (treatment schedule), and for how long. Finally, the most compelling argument to use ECP in heart and lung transplantation is its excellent side-effect profile. Furthermore, ECP may allow a decrease in the number of drugs needed to prevent rejection.

Feasibility and challenges of addressing this CQ or CC

Many patients with heart and lung transplants develop severe and often fatal rejection despite the current drug options to prevent rejection. ECP could be added to their treatment regimens and decrease side-effects, improving long-term survival.

ECP is generally well tolerated and complications are extremely infrequent.

There is a great potential for multi-disciplinary collaboration between Apheresis Medicine, Cardiology, and Pulmonary specialists.

It is conceivable that manufacturers of ECP instruments will be interested in contributing to the design and support of these studies.

Such studies could shed light in the mechanism of action of ECP in heart and lung transplantation.

There is a need to develop standardized treatment regimens based on well designed clinical trials to further optimize the use of ECP. Development and standardization of measurable outcomes is critical for the success of clinical studies in apheresis in general, and ECP in particular.

Challenges:

  1. Limited number of institutions providing ECP treatment.
  2. Cost of ECP procedures.
  3. Small number of animal models available for apheresis research. Thus, limited studies of ECP mechanism(s) of action. However, understanding pathological mechanisms and their relationship to response to apheresis is critical for optimization and advancement of patient care in heart and lung transplantation.
  4. Lack of infra-structure for apheresis research.

Name of idea submitter and other team members who worked on this idea Marisa Marques on behalf of ASFA

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