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The different types of Immune
- I Immediate Hypersensitivity such as to food or animal allergies
- II Cytotoxic Hypersensitivity such as hemolytic diseases or ABO and blood transfusion
- III Immune Complex such as autoimmune disorders such as RA and Grave's Disease
- IV Cellular Hypersensitivity such as TB and contact dermatitis
- Immunodeficiency Disorders such as AIDS/HIV, SCIDs, and agammaglobulinemia
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Immediate Hypersensitivity
it is the harmful result of IgE antibodies made in response to allergens
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Allergen
- can enter the body inhalation, ingestion, and injection
- includes pollen, dust mites, mold, dander, antibiotic, drugs, food, vaccines or insect and snake bites
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Mechanism of allergens
- Sensitization - IgE antibodies are made in response to foreign substances (antigen) attach to mast cells and basophils
- on the second encounter to an antigen, the antigen attaches to sensitized mast cells and basophils
- Cells release histamine which dilates the capillaries, contracts the bronchial smooth muscles, and increase mucus secretions causing itching, redness, and swelling
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3 types of Immediate hypersensitivity
- Localized
- Anaphylactic
- Respiratory anaphylaxis
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Localized hypersensitivity
- it is an immediate hypersensitivity
- aka atopy
- if allergen enters the skin, there is redness, swelling, and itching
- if inhaled, mucous membranes or respiratory tract becomes inflamed, runny nose, water eyes -> hay fever
- if ingested, the digestive tract becomes inflamed causing abdominal pain, diarrhea, and skin rash
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Respiratory anaphylyaxis
- skin reddening, itching, and hives
- respiratory airways become constricted and filled with mucus such as asthma
- can lead to anaphylactic shock
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Anaphylactic Shock
- blood vessels dilate and there is a drop in blood pressure
- edema in the wrist, ankles, and face
- can lead to death
- insect bites and stings are the most common
- respiratory anaphylaxis and anaphylactic shock must be treated immediately
- epinephrine (epipen) acts by constricting blood vessels and relaxing smooth muscles of respiratory tract
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Tx of Allergies
- desensitization - gradually increasing does of allergens
- IgG blocking antibodies are produced against the allergen
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Cell mediated or Delayed hypersensitivity
- reactions take more than 12 hours to developMediated by T-Cells which release various lymphokines causing swelling, reddened area
- includes contact dermatitis such as poison ivy, soap or metal allergies
- includes TB skin testing - the skin test antigen causes a reaction of the dermis in sensitized person
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Cytotoxic Hypersensitvity
- antibodies react with cell-surface antigens interpreted as foreign by the immune system
- examples include mismatched blood transfusion, Rh incompatibility of mother and infant
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Transfusion reaction
- if a patient receives RBC with a different antigen, IgM antibodies agglutinate foreign RBCs by clumping, a complement is activated and hemolysis occurs
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Immune Complex
- are autoimmune disorders where the person becomes hypersensitive to antigen on cells of their own body
- autoantibodies are antibodies that attack one's own tissue
- genetic factors, diminished suppressor T cell function which accompanies aging, viruses, and stem cell defects
- Some examples: RA, Lupus, Grave's Disease, Hashimoto's Thyroiditis, Rheumatic fever, and Type 1 Diabetes
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Rheumatoid Arthritis
- aka RA
- inflammation and destruction of the joints
- it is the antigen and antibody complex in the joints
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Systemic Lupus Erythematosus
- antibody made to own DNA
- affects many organs
- kidney or wolf-like facial rash
- immune complexes form in the tissue
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Grave's Disease
- hyperthyroidsim
- auto antibody
- stimulates antibody to increase T4
- bulging eyes and goiter are some symptoms
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Hashimoto's Thyroiditis
- hypothyroidism
- destroys thyroid tissue
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Rheumatic fever
- auto antibody to Beta Strep Group A
- affects heart valves and kidneys
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Type 1 Diabetes
- antibody destroys beta cells in the kidneys
- beta cells cannot secrete insulin
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Immunodeficiency Disease
- arises from lack of lymhocytes, defective lymphocytes or destruction of lymphocytes
- includes agammaglobulinemia, HIV/AIDs, and SCIDs
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agammaglobulenima
- it is an immunodeficiency disease where there is a lack of B-cells
- found primarly in male infants
- tx: give gamma globulin (IgG) to replacing missing antibodies, bone marrow stem cell transplant
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Severe Combine Immunodeficiency Disease (SCIDs)
- "boy in bubble" disease where a germ-free environment is needed
- lack T-cell and B-cells
- bone marrow transplant needed
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AIDS
- autoimmune deficiency disorder syndrome
- HIV infects the helper T cells and eventually destroys the majority, lack of activation of specific immunity
- death from opportunistic secondary infections
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Transplant rejection
- all human cells have a set of antigens due tot he Histocompatability Antigen aka Human leukocytes antigens (HLA)
- same as the MHCI self antigens on all nucleated cells of the body
- if the donor and recipient antigens are different, then recipient T-cells destroys the donor tissue causing transplant rejection
- More successful if more MHCI antigens are a match then there is a less chance of attack
- tissue transplant patients must stay on immunocompromised therapies for life to suppress T-cells (Cyclosporin A, Immuran)
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autograft
- grafting from the same person on another part of the body to another
- never rejected
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150 graft
- graft between identical twins
- never rejected
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allograft
- grafting from one species to another same species
- variable successful
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xerograft
- graft from 2 different species
- rarely successful
- anti-rejection -> antimitotic -> decrease lymphocytes productions
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