Cell transplantation process

Acute rejection is a cell-mediated process that generally occurs within 5 to 90 days of the transplant procedure however, it can occur at any time after transplantation. This reaction is mediated through alloreactive T cells, as outlined previously. Organ-specific signs and symptoms of acute rejection are listed in Table 52-2. 

Allogeneic hematopoietic stem cell transplantation (HSCT) has been used in the treatment of pediatric AML in first complete remission. In most clinical trials, the availability of HLA-matched sibling donors determined whether patients underwent HSCT as postremission treatment. To facilitate this process, it is important to obtain HLA typing on all younger patients with AML and siblings shortly after diagnosis. Patients who do not have an HLA-matched sibling will proceed to postremission therapy. 

The culture module greatly facilitated homogeneous distribution of seeded cells and cultivation of a large number of cells under identical conditions. In addition, the module required a smaller volume of medium than standard cell culture systems. Importantly, this modular system provides the great advantages of scalability and safety because cell processing can be performed in a closed system. Thus, the modules facilitate the production of cells that are safe for use in cell transplantation therapies. 

In accordance with the conference s main topics, the book is divided into five chapters - Haematopoietic stem cells and haematopoiesis , Biology of non-haematopoietic stem cells , Stem cells and malignancy , Cell processing expansion and genetic modification and Clinical haematopoietic stem cell transplantation . 

Hematopoietic stem cells are used to treat people whose own blood-forming cells fail because of a rare condition called aplastic anemia, or to help people who have been accidentally exposed to very high doses of irradiation. Hematopoietic stem cells are most often used as part of the treatment for certain forms of cancer. Sometimes cancer patients are given very high doses of irradiation and/or chemotherapy drugs that destroy the blood-forming stem cells in the bone marrow. Transplants with the patient s own blood stem cells that were removed before the treatment, or stem cells from a healthy donor, allow the patient to recover. The transplant process is very simple The cells in a salt solution are slowly injected into a vein just like a blood transfusion. If the blood stem cells come from a donor, then the donor and the patient must share certain inherited proteins to make sure that the donor s immune system cells will not attack the treated patient. 

In the process of regeneration, irreversibly damaged or surgically removed liver tissue is replaced as far as possible by new growth. The regeneration of the liver (s. p. 5 ) is a most important process in (7.) overcoming necrosis, (2.) determining the course of a liver disease, (i.) liver resection, (4.) partial liver transplantation, and (5.) liver cell transplantation. (29)... 

Egress of more mature cells from the bone marrow occurs through the endothelial cell barrier. Release of cells such as neutrophils may be stimulated by complement, steroids, or endotoxin. Immature (progenitor) cells that may ultimately become any one of the blood cellular components can be mobilized from the bone marrow into peripheral blood by the administration of a cytotoxic chemotherapy drug (e.g., cyclophosphamide) or a colony-stimulating factor (G-CSE or GM-CSE). This process is commonly referred to as priming the bone marrow for peripheral blood progenitor or stem cell transplantation (see Chap. 134). 

Hematopoietic stem cell transplantation (HSCT) is a process that involves intravenous infusion of hematopoietic stem cells from a donor into a recipient, following the administration of chemotherapy with or without radiation. The rationale is to increase tumor cell kill by increasing the dose of chemotherapy. Immune-mediated effects may also contribute to the tumor cell kill observed after allogeneic HSCT. 

Several criteria define the ideal material for a cell transplantation matrix, (i) The material should be biocompatible, in the sense that it does not provoke a connective tissue response which will impair the function of the new tissue (ii) it should be resorbable, to leave a completely natural tissue replacement (this is important, because it could avoid some of the problems that occur in long-lasting polymers such as those used in breast implants) (iii) it should be processable into a variety of shapes and structures which retain their shape once implanted and (iv) the surface should interact with transplanted cells in a way which allows retention of differentiated cell function and which promotes cell growth if such growth is desired. 

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