The beneficial effect of donor-specific transfusions: a review of existing explanations and a new hypothesis based on a relatively unapplied theory of T cell immunoregulation. A regulatory hypothesis in progress

Shared alloimmune responses against blood and transplant donors result in adverse clinical outcomes following blood transfusion post-renal transplantation

De novo HLA donor-specific antibodies (DSA) following transplantation are associated with alloimmune injury and allograft failure. Blood transfusions are allogeneic, and when given posttransplant (PTBT) they may independently increase the risk of HLA antibody development. This study aims to analyze the development of HLA transfusion-specific antibodies (TSA) to blood donors of transfusions given posttransplant and examine the impact on clinical outcomes. A total of 244 blood donors of transfusions received by 86 transplant patients (46 who developed a DSA post transfusion and 40 who remained DSA negative) were HLA typed. De novo TSA developed against 150/244 (61.5%) blood donors. In 70/150 (46.7%) cases the TSA was of shared HLA antibody specificity with a DSA response in the recipient (DSA+ = TSA+). This occurred when there was a greater overall HLA match between the blood and transplant donor. DSA+ = TSA+ patients had increased risk of allograft failure (P = .0025) and AMR (P = .02) compared with the DSA+ ≠ TSA+ patients. To conclude, PTBT may elicit de novo HLA antibodies. Enhanced HLA matching between the blood and transplant donor is more likely to result in a DSA and TSA of shared antibody specificities. Transfusion avoidance or the use of HLA matched or selected blood may reduce this risk and improve outcomes.

Effect of donor-specific transfusions on the outcome of renal allografts in the cyclosporine era

Despite the introduction of new immunosuppressive agents, a steady decline of functioning renal allografts after living donation is observed. Thus nonpharmacological strategies to prevent graft loss have to be reconsidered, including donor-specific transfusions (DST). We introduced a cyclosporine-based DST protocol for renal allograft recipients from living-related/unrelated donation. From 1993 to 2003, 200 ml of whole blood, or the respective mononuclear cells from the potential living donor were administered twice to all of our 61 recipient candidates. The transplanted subjects were compared with three groups of patients without DST from the Collaborative Transplant Study (Heidelberg, Germany) during a 6-year period. Six patients were sensitized without delay for a subsequent cadaveric kidney. DST patients had less often treatment for rejection and graft survival was superior compared with subjects from the other Swiss transplant centers (n = 513) or from Western Europe (n = 7024). To diminish the probability that superior results reflect patient selection rather than effects of DST, a 'matched-pair' analysis controlling for relevant factors of transplant outcome was performed. Again, this analysis indicated that recipients with DST had better outcome. Thus, our observation suggests that DST improve the outcome of living kidney transplants even when modern immunosuppressive drugs are prescribed.

Immunoengineering: a credible mechanism for CAMPATH-1H action in bone marrow and organ transplantation and the implications for treatment of the immune dysfunction AIDS

Immunoengineering is a term coined to represent the mostly future ability to use or target the immune system's natural components, with emphasis on the regulatory components, to up or down regulate the immune system's attack against specific proteins associated with an unwanted pathology or immune occurrence. It will constitute manipulating parts of the immune system, mostly those specific for the disease associated antigen(s) and generally of a regulatory nature, in various immunological locale or the whole body compartment, to achieve a disease free state for the patient. The number of practical applications awaiting the mastery of immune components as regulatory therapeutics is enormous and immunoengineering should provide treatments in a wide range of disease categories. HIV is a disease where this discipline could provide a quick cure, even eradication of the virus. A potential cheap solution to HIV infection, based on using immunoengineering and adaptable to the infrastructure problems of the Third World is highlighted in the following because of the health emergency that exists in the Third World.

Sudden infant death syndrome Part 2: the response of the reticuloendothelial system to hypoxemia and infection

The incidence of ascites in chicks raised in a high-altitude chamber doubled from 6500 feet to 8000 feet. A similar condition developed in calves transported to pasture at high altitude. Chicks raised in a high-altitude chamber (compared to controls) produced more plasma cells in the germinal centres of the spleen about four days after an antigen challenge. Children usually suffering from a mild respiratory infection at sea level often developed pulmonary edema (HAPE) on transfer to high altitude. Sudden infant death syndrome (SIDS) victims produced more plasma cells in the germinal centers of the spleen. In one survey of SIDS, about half of the infants suffered an upper respiratory tract infection in the two weeks prior to death and the lungs were filled with fluid at autopsy. Elevated levels of hypoxanthine indicated hypoxemia before death, and a presumed response to hypoxemia in SIDS was the presence of extramedullary hematopoiesis in the liver. The effect of prolonged hypoxemia and infection are additive in increasing vascular permeability and the accumulation of edema fluid. The preferential uptake of zinc by edema fluid proteins at the expense of inflammatory cells increases the motility and metabolism of zinc-deprived activated macrophages. Activated macrophages release cytokines which in turn stimulate the release of pro-inflammatory peptides which increase vascular permeability and mortality. These inflammatory peptides are under proteolytic control. The neutral endopeptidase (NEP) is a cell-surface zinc metalloproteinase which modulates toxic shock.Zinc also modulates the inflammatory response of the activated macrophage. Interleukin-12 (IL-12), predominantly a product of macrophages, is involved in regulating both hematopoiesis and the adaptive immune response. IL-12 promotes interferon gamma (IFNgamma) production by T cells. IFNgamma acts on macrophages to release large amounts of nitric oxide (NO). An elevated immune response leads to NO overload, dilation of the cardiovascular system and toxic shock. A mechanism resulting in cardiovascular failure and a shock-like sequence is described in some cases of SIDS.Bradycardia, recorded on cardiorespiratory monitors in six SIDS infants, was considered a late event. Cytokines regulate all aspects of the immune response. Extramedullary hematopoiesis in the liver was one anatomical marker of hypoxemia in SIDS. This survey traces the function of the activated macrophage with the cytokines regulating extramedullary hematopoiesis and the precocious immune response in SIDS.