front 1 what are the different types of grafts? | back 1 autograft isograft allograft xenograft |
front 2 autograft | back 2 self-tissue grafted to another self area (skin grafts, blood vessels) |
front 3 isograft | back 3 transplant between genetically identical individuals |
front 4 allograft | back 4 tissue transferred between genetically different numbers of the same species |
front 5 allotypic determinant | back 5 an antigenic determinant that varies among members of a species or between different inbread strains of animals (also referred to as an alloantigen); antibodies made against alloantigens are called alloanitbodies |
front 6 xenograft | back 6 tissue transferred between different species |
front 7 what is histocompatibility? | back 7 the degree of recognition and response to donor tissue by the recipient's immune system the degree of antigenic similarity between donor and recipient |
front 8 what role do MHC haplotypes play in organ transplantation? | back 8 the antigens involved are encoded by up to 40 different loci, but those most responsible loci are found in the major histocompatibility complex other loci are also involved |
front 9 what are the reasons that blood transplantation is so simple? | back 9 it can be donated with "minimal" impact on the donor simple, inexpensive, and involves relatively few medical personnel usually, blood only needs to function in the recipient for a short amount of time; the recipient will eventually make more erythrocytes DO NOT express MHC |
front 10 what is the relationship between A/B/O blood types and carbohydrates of commensal bacteria? | back 10 antigens A and B, but not O are structurally similar to carbohydrates on the surface of commensal bacteria people that like "A" or "B" make antibodies against the carbohydrates of the bacteria |
front 11 what is the Rh factor? | back 11 the Rh factor adds another level of complexity A/B/O/Rh incompatibility stimulates a type II hypersensitivity response, similar to penicillin, but... there are actually 30+ polymorphisms known |
front 12 what is hyperacute rejection? | back 12 antibody mediated rejection |
front 13 how is hyperacute rejection characterized? | back 13 antibodies for A/B RBC antigens are thought to come from cross-reactive oligosaccharides antibodies against alloantigens may come from past blood transfusions, from past pregnancies, infectious disease anti-HLA class I antibodies |
front 14 what is the relevance of major histocompatibility complex? | back 14 dendritic cells in the kidney graft are of donor origin dendritic cells travel in the blood to the spleen where they activate recipient's alloreactive T cells effector alloreactive T cells leave the spleen and travel in the blood to the grafted allogenic kidney effector T cells damage and kill the epithelial cells of the kidney, stopping all kidney function |
front 15 what is the relevance of MHC matching in bone marrow transplantation? | back 15 minimize the risk of graft rejection |
front 16 what is the difference between allogenic transplantation and autologous transplantation? | back 16 an autologous transplant uses the patient's own stem cells, while an allogenic transplant uses stem cells from a donor |
front 17 what kinds of diseases are treated by BMT? | back 17 wiskott-aldrich syndrome franconi's anemia osteopetrosis sickle-cell anemia |
front 18 what is myoablative therapy? | back 18 the destruction of previous bone marrow to (1) give new bone marrow the space and opportunity to thrive (2) ensure that the grafted bone marrow won't be rejection (called conditioning) |
front 19 what is engraftment? | back 19 the point at which hemapoietic stem cells have successfully established themselves in the bone marrow and are making new blood cells |
front 20 what is a chimera? | back 20 the HSCs have the donor phenotype and everything else has the recipient phenotype |
front 21 what is graft vvs. host disease? | back 21 because conditioning is so intense, there are very few (in any recipient) T cells to attack donor tissue however donor T cells can respond to recipient HLA allotypes, the graft rejects the host GVHD can attack all tissues, but concentrates in the skin, intestines, and liver |
front 22 how is HLA compatibility related to engraftment? | back 22 the best option is an identical twin the next-best is an HLA-matched sibling national and international registries likelihood of a match is still low umbicial cord blood can be obtained ; rich in HSCs and relatively few alloreactive T cells engraftment is slower, but less GVHD |
front 23 what are minor histocompatibility antigens? | back 23 in brothers who receive transplant from an HLA-identical sister, the donor's T cells may recognize proteins coded on the Y chromosomes as foreign, termed H-Y antigens polymorphisms in various autosomal genes can cause minor differences in expressed proteins that can cause reactivity from donor T cells |
front 24 why is GVHD "good"? | back 24 alloreactive T cells are known to make contributions they subdue the recipient's immune system which facilitates engraftment they eliminate malignant cells missed by conditioning |
front 25 what happens if there are no mature T cells in the transplanted bone marrow? | back 25 a decrease in alloreactivity leads to increases in relapse alloreactivity from minor histocompatibility alleles improves outcomes; an HLA-matched sister is considered a better donor than an HLA-matched brother because of H-Y antigens elimination of tumor cells by alloreactive T cells is called GVL or GVT |
front 26 what is the relationship between HSC transplant and a solid organ transplant? | back 26 approximately 10 % of fraternal twins share blood during gestation as a result, their HSCs are a chimera (combination) of both genotypes and are therefore tolerant of the other twin's cells |
front 27 what is the purpose of immunosuppressive durgs? | back 27 to reduce the body's immune response |
front 28 what are general immunotherapies? | back 28 lymphoid irradiation: common in bone marrow transplants azathioprine: methotrexate prednisone/dexamethasone rapamycin/cyclosporine |
front 29 what are specific immunotherapies? | back 29 basiliximab (monoclonal antibody for CD25(IL-2R) on T cells) rituximab (monoclonal antibody for CD20 on B cells) belatacept (CTLA-4Ig) |
front 30 what is immune privilege? | back 30 characterized by lack of vasculature, both lymphatic vessels and blood vessels T cells are significantly less likely to become sensitized to various alloantigens |
front 31 what are some areas of immune privilege? | back 31 cartilage heart valves eye cornea uterus testes the brain the thymus |