18. Transplant Immunology PDF

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Summary

IMMUNOLOGY SEROLOGY TRANSPLANT IMMUNOLOGY IMMUNOMODULATION of Immune response Types of Immunomodulation: 1. IMMUNOENHANCEMENT IMMUNOPOTENTIATION accomplished through Adjuvants Examples: o COMPLETE ADJUVANTS acts on cells o INCOMPLETE Components of Adjuvants: MURAMYL DIPEPTIDE: activated reagent CELL...

Description

IMMUNOLOGY & SEROLOGY

TRANSPLANT IMMUNOLOGY IMMUNOMODULATION - modification/alteration of Immune response Types of Immunomodulation: 1. IMMUNOENHANCEMENT / IMMUNOPOTENTIATION (+) - accomplished through Adjuvants - Examples: o COMPLETE / FREUD’S ADJUVANTS - acts on Th-1 cells o INCOMPLETE - Components of Adjuvants:  MURAMYL DIPEPTIDE: activated reagent  CELL WALL CONSTITUENTS:  M. tuberculosis  C. parvum  B. pertussis  Brucella  OTHERS:  Mineral oil  Lanolin  Alum  Detergent  Polynucleotides  Acrylic Particles 2. IMMUNOSUPRESSION (-) - Types of Immunosupression: a. SPECIFIC b. NON-SPECIFIC  NATURALLY-INDUCED - Ex: Immunodeficiency disorders  ARTIFICIALLY-INDUCED  PHYSICAL MEANS - Examples: o Thymectomy (removal of Thymus) o Bursectomy (removal of BM) o Thoracic duct Drainage o Irradiation  CHEMICAL MEANS - Examples: o Antibiotic: Cyclosporine-A o Alleviating Agent: Cyclophosphamide o Anti-Metabolite: Folic Acid Analogues o Corticosteroids

JOYCE ANN S. MAGSAKAY

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 BIOLOGICAL MEANS - Examples: o Anti-Lymphocyte o Anti-Thymocyte o Antigen Desensitization MONOSPOT TEST - Reagent: Horse RBC - Sample: Patient’s Serum absorbed with: GUINEA PIG BEEF KIDNEY CELL ERYTHROCYTE IM (Ab) to (+) (-) Forsmann Ag Adsorbed not adsorbed Ab in IM (-) (+) Ab in Serum (+) (+) Sickness TRANSPLANTATION - transfer of cell, tissues, organs Types of Transplantation: 1. ORTHOTOPIC - transfer of tissue/organ from the site of the donor to the site of the recipient 2. HETEROTOPIC - transfer of tissue/organ from the site of the donor to different site of the recipient 3. HOMOSTATIC - no tissue growth after transplantation 4. HOMOVITAL - there is tissue growth after transplantation MOST COMMONLY TRANSFERRED ORGANS: 1. Bone Marrow 2. Skin 3. Islet of Langerhans 4. Heart 5. Kidney 6. Liver 7. Bone 8. Xenogenic value replacement 9. Cornea

BS MEDICAL LABORATORY SCIENCE

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OLFU VALENZUELA

IMMUNOLOGY & SEROLOGY

TRANSPLANT IMMUNOLOGY TYPES OF GRAFTS: 1. AUTOGRAFT - self-tissue transferred from one body site to another in the same individual 2. ISOGRAFT / SYNGRAFT - tissue transferred between genetically identical individuals 3. ALLOGRAFT / HOMOGRAFT - tissue transferred between genetically different members of the same species 4. XENOGRAFT / HETEROGRAFT - tissue transferred between different species GRAFT ACCEPTANCE - when vascularization & healing lead to a repaired site in about 2 weeks

Types of Graft Rejection: 1. FIRST-SET REJECTION - first time a graft is encountered & rejected - the immune system attacks & ultimately destroys the “non-self-tissue” which occurs 10-14 days after transplantation 2. SECOND-SET REJECTION - the second time the same set of “non-self-tissue” is encountered which is usually rejected within 6 days TYPES OF REJECTION REACTIONS TYPES

TIMES OF TISSUE DAMAGE

HYPERACUTE

within few minutes to first 2hrs after transplantation

ACUTE

within first few weeks after transplantation

PREDOMINANT MECHANISM - H1

- CM

CAUSE - oneformed ABO & HLA Antibodies - development of Allergic reaction - distruption of Graft vs. Host tolerance

GRAFT REJECTION - ADCC - caused by cell-mediated immune response to Alloantigens expressed on cells of the graft within months to - H1 CHRONIC years after - both Delayed-type Hypersensitivity & Cell-mediated - CM transplantation Cytotoxicity reactions have been implicated Stages of Graft Rejection: TESTS ON DONOR TESTING & TISSUE TYPING: 1. SENSITIZATION STAGE 1. ABO/Rh Typing - where CD-4 & CD-8 T-cells recognize Alloantigens 2. CMV,EBV, PV-B19 expressed on cells of the foreign graft & proliferate 3. Anti-HIV 1 & 2, HTLV-I & II in response 4. HBsAg, HBcAg, HCV - The host T-helper cell becomes activated when it 5. RPR, FTA interacts with an Antigen presenting cell 6. HLA matching - Depending upon the tissue, different population of cells within a graft may function as Antigen presenting cells. Migration of passenger Leukocytes from a donor graft to regional Lymph nodes of the recipient results in the activation of T-helper cells in response to different Class-II MHC antigens expressed by the passenger Leukocytes - these activated T-helper cells then induce generation Cytotoxic-T cells of which mediate graft rejection 2. EFFECTOR STAGE - most are Cell-mediated reactions involving Delayedtype Hypersensitivity & CTL-mediated cytotoxicity - less common mechanisms are Antibody-plusComplement lysis & destruction by Antibodydependent cell-mediated cytotoxicity (ADCC) JOYCE ANN S. MAGSAKAY | BS MEDICAL LABORATORY SCIENCE | OLFU VALENZUELA...