Initiated by recipients lymphocytes resulting in induction of recipient Th1 and

Initiated by recipients lymphocytes resulting in

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Initiated by recipient’s lymphocytes, resulting in induction of recipient Th1 and Tc cells against donor antigens - Th1 cells release cytokines that activate macrophages - Tc cells directly attack endothelial cells in transplanted tissue - Biopsy shows infiltration of lymphocytes and macrophages - Immunosuppressive drugs may delay or lessen the intensity of acute rejection - Acute antibody mediated rejection is another form of acute rejection, accounts for 10% of acute rejections - Mediated by antibody and complement, antibodies are against the HLA antigens but were not there at the time of transplant - Sensitization takes 2 weeks or longer, results in accumulation of antibody, complement, neutrophils, and thrombi in vasculature of graft - Chronic - Occurs after months or years, slow, progressive organ failure - May be caused by inflammatory damage to endothelial cells lining blood vessels as a result of a weak cell-mediated immunologic reaction against minor histocompatibility antigens on the grafted tissue - May also be caused through activation of complement or antibody dependent cellular cytotoxicity with NK cells f. Describe the role of the human leukocyte antigen (HLA) in solid organ rejection. Human Leukocyte Antigen (HLA) - The human MHC molecules are also referred to as HLA - Primary role of MHC is antigen presentation - Transplantation of organs commonly is complicated by an immune response against antigens (primarily HLA) on donated tissue - Not all HLA loci are equally important, matching HLA-DR most important, matching HLA-A and HLA-B lesser importance - Located in the short arm of chromosome 6 - See image from
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- Viral Infections 3. Evaluate the etiology, clinical manifestations and pathophysiology for influenza, measles, and HIV infection. a. Differentiate between the incubation, etiology, and modes of transmission for influenza, measles, and HIV infection and discuss the implications for clinical practice. Viral Infection Incubation Etiology Modes of Transmission Influenza The typical incubation period for influenza is 1— 4 days (average: 2 days). Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Some people, especially young children and people with weakened immune systems, might be able to infect others for an even longer time. Influenza viruses are encapsulated, negative-sense, single- stranded RNA viruses of the family Orthomyxoviridae. Large particle droplet transmission. Transmission via large-particle droplets requires close contact between source and recipient persons, because droplets do not remain suspended in the air and generally travel only a short distance (less than or equal to 1 meter) through the air. Contact with respiratory-droplet contaminated surfaces is another possible source of transmission. Airborne transmission (via small- particle residue [less than or equal to 5µm] of evaporated droplets that might remain suspended in the air for long periods of time) also is thought to be possible
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