Term
| Define immunodeficiency disorders |
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Definition
| The congenital or acquired absence of one or more components of the immune system |
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Term
| Explain how cancer often/always involves an immunologic abnormality |
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Definition
1. Immune system is supposed to prevent neoplastic diease
2. Cancer, especially that of the immune system, may result in an immunocompromised host |
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Term
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Definition
An untoward immunological response to a foreign immunogen which is called an allergen.
Since the immune system is supposed to respond to foreign immunogens it may be argued in some cases that there is no immunological abnormality involved. |
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Term
| Define alloimmune disease |
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Definition
An untoward immunological response to a foreign immunogen derived from another member of the same species. It can be correctly argued that this is just a special case of allergy.
But alloimmune disease of newborn, blood transfusion, and tissue transplantation are specialized enough to merit separate consideration. |
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Term
| Describe an ideal immune response |
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Definition
1. Directed only against immunogens capable of harming the host.
2. Completely effective in totally eradicating the offending immunogen.
3. Completely protective, with no tissue damage from either the immunogen nor the response. |
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Term
| When does tolerance develop? |
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Definition
Tolerance develops most readily during fetal life and requires the continued presence of the immunogen to remain.
It is more difficult to establish tolerance in adult animals but it can be induced under certain experimental conditions. |
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Term
| What mechanisms allow central tolerance? |
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Definition
1. Immunogen-induced apoptosis of immature, double-positive T cells
2. Immunogen-induced apoptosis of immature, IgM-expressing B cells |
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Term
| What mechanisms allow peripheral tolerance? |
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Definition
1. Immunogen-induced anergy of T cells in absence of costimulation
2.Immunogen-induced anergy of B cells in absence of costimulation (T cell help) (possibly) |
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Term
| What mechanisms allow tolerance in mature, immunogen-reactive cells? |
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Definition
1. Oral tolerance to proteins (Suppressor T cells, anergy)
2. High dose tolerance to aqueous protein administered systemically
3. Low dose tolerance by repetitive doses of immunogens in low concentration |
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Term
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Definition
| Autoimmunity is an immune response to self antigens (autoantigens). Since tolerance to autoantigens is considered normal, autoimmunity is considered to be loss of tolerance. |
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Term
| Is autoimmunity the same as autoimmune disease? |
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Definition
| Autoimmunity is not synonymous with autoimmune disease; some autoimmunity is observed in normal individuals. |
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Term
| Define autoimmune disease |
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Definition
Autoimmune diseases involves tissue damage resulting from immune responses directed against self antigens but this autoimmunity is likely to be the result rather than the cause of the disease.
Essentially all autoimmune disease is idiopathic (spontaneous/from an unknown source) |
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Term
| List five general characteristics of autoimmune disease |
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Definition
1. Idiopathic
2. Multiple factors (genetics, sex, age, infection, etc)
3. Usually HLA-associated
4. Multiple immunological mechanisms
5. Inability to avoid antigen/unknown cause |
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Term
| List five possible explanations for autoimmunity |
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Definition
1. Escape of autoreactive T cells from the thymus
2. Breakdown of peripheral tolerance
3. Nonspecific leukocyte activation (ex. superantigens)
4. Molecular mimicry
5. Abnormalities in lymphocyte interactions |
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Term
| How does the TH1 and TH2 balance affect autoimmunity? |
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Definition
| Inflammatory responses are associated with TH1 cells and it has been speculated that an imbalance of TH1 and TH2 cells (which mutually inhibit one another) may contribute to autoimmunity |
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Term
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Definition
| They inhibit (or ocassionally stimulate) important biological receptors, leading to autoimmune disease |
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Term
| List some examples of diseases involving anti-receptor antibodies |
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Definition
Myasthenia Gravis
Grave's Disease
Insulin-resistant Diabetes
Rhinitis/Asthma
Pernicious Anemia |
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Term
| What are the two classifications an anti-receptor antibody autoimmune disease can fall under? |
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Definition
| Coombs and Gell Type II reactions |
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Term
What T-cell mediates autoimmunity?
How did scientists discover this? |
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Definition
Th17 may be the primary mediator cells of autoimmunity, not Th1 as previously thought
IFN-γ deficient mice still had autoimmune disease |
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Term
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Definition
| Alloimmunity is an immune response to antigens from individuals of the same species— alloantigens— and is a reflection of the genetic and resulting chemical differences between individuals. |
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Term
| Give two synonyms of alloimmunity |
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Definition
| isoimmunity and isoantigens |
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Term
| List the three main alloantigen systems |
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Definition
1. ABO blood groups
2. Rh blood types
3. HLA-complex antigens |
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Term
| Describe the minor alloantigen systems |
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Definition
| There are about 600 known erythrocyte antigens and 195 of these are included in the 23 minor blood group systems. |
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Term
| Which alloantigen system is most important for transfusion reactions? |
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Definition
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Term
| Which alloantigen system is most important for newborn disease? |
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Definition
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Term
| Which alloantigen system is most important for allograft rejection? |
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Definition
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Term
| What happens during a Rh- mother's first pregnancy with a Rh+ fetus? |
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Definition
| Minor destruction of fetal erythrocytes by anti-Rh IgG, but healthy newborn |
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Term
| What happens during a Rh- mother's second and subsequent pregnancy with a Rh+ fetus? |
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Definition
Major destruction of fetal erythrocytes by anti-Rh IgG, anemic newborn
Unless treated with RHO (D) IMMUNE GLOBULIN [HUMAN] |
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Term
| What happens during a Rh- mother's second and subsequent pregnancy with a Rh+ fetus if she is treated with RHO (D) IMMUNE GLOBULIN? |
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Definition
| B cells think they are seeing self and shut off (inducing tolerance), primary immune response inhibited, healthy baby |
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Term
What increases medical need for transfusion?
What decreases medical need for transfusion? |
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Definition
More need: cancer chemotherapy
Less need: biologics like epoetin and oprelvekin |
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Term
| In a medical emergency, if a patient has never received a transfusion before could you give him any blood type? |
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Definition
| Yes, because there is a lack of memory. Multiple transfused patients more likely to exhibit transfusion reactions. |
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Term
| What drugs can be given to manage a transplantation reaction? |
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Definition
| Cyclosporine and other immunosuppressive agents |
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Term
| Define Graft-Versus-Host Disease |
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Definition
| A potential problem whenever immunologically-competent tissue is grafted into an immunologically-deficient patient. The most common clinical situation is bone marrow transplantation. |
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Term
| What is the mechanism of action of Cyclosporine A? |
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Definition
| Cyclosporine A inhibits production of IL-2 |
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Term
| What is the difference between hyper acute and acute transplantation reaction? |
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Definition
Hyper acute is very fast due to pre-existing antibodies
Acute is T-cell mediated |
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