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IMMUNE DISORDERS OVERVIEW/GENERAL CONCEPTS. HYPERSENSITIVITY TYPE 1 (ANAPHYLACTIC) TYPE 2 (CYTOTOXIC) TYPE 3 (IMMUNE COMPLEX) TYPE 4 (DELAYED TYPE) AUTOIMMUNITY IMMUNODEFICIENCY. TYPE 1 / ANAPHYLACTIC HYPERSENSITIVITY: GENERAL CONCEPTS.
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IMMUNE DISORDERSOVERVIEW/GENERAL CONCEPTS • HYPERSENSITIVITY • TYPE 1 (ANAPHYLACTIC) • TYPE 2 (CYTOTOXIC) • TYPE 3 (IMMUNE COMPLEX) • TYPE 4 (DELAYED TYPE) • AUTOIMMUNITY • IMMUNODEFICIENCY
TYPE 1 / ANAPHYLACTIC HYPERSENSITIVITY: GENERAL CONCEPTS • MECHANISMS: INVOLVE IgE AND THE RELEASE OF MEDIATORS SUCH AS HISTAMINE BY MAST CELLS AND BASOPHILS • TIME COURSE: RAPID - USUALLY WITHIN 30 MINUTES
ALLERGENS SENSITIZATION MAST CELLS & BASOPHILS TRIGGERING ANAPHYLACTIC HYPERSENSITIVITY:MECHANISMS Y
ALLERGENS SENSITIZATION MAST CELLS & BASOPHILS TRIGGERING ALLERGEN ANAPHYLACTIC HYPERSENSITIVITY:MECHANISMS Y HISTAMINE ...
ALLERGEN B Y Y Y Y Y Y IgG, IgA ... IgE ANAPHYLACTIC HYPERSENSITIVITY:SOME HAVE IT, SOME DON’T ... “NORMAL” PEOPLE ALLERGIC PEOPLE
USUALLY ASSOCIATED WITH INJECTED ANTIGENS SYSTEMIC VASCULAR PERMEABILITY & BRONCHOCONSTRICTION CAN BEFATALWITHIN A FEW MINUTES EPINEPHRINE CLINICAL MANIFESTATIONS:SYSTEMIC ANAPHYLAXIS(ANAPHYLACTIC SHOCK)
INSECTS HONEYBEE YELLOW JACKET HORNET WASP FIRE ANT SYSTEMIC ANAPHYLAXISCAUSES
SYSTEMIC ANAPHYLAXISCAUSES DRUGS & MEDICAL AGENTS • HORMONES INSULIN VASOPRESSIN • ANTIBIOTICS • PENICILLIN AMPHOTERICIN B • OTHER DIAZAPAM (VALIUM) BARBITURATES
This young woman presented with a rash. Her lips were swollen and her skin was covered with a red, raised, blanching rash. This started shortly after taking an Aleve tablet. She had a history of aspirin allergy. Her BP was 70/40 and her pulse was 140. SYSTEMIC ANAPHYLAXISA CASE
TRIGGERED BY INHALANT ALLERGANS ALLERGIC RHINITIS (HAY FEVER)
INHALANT ALLERGENS • PLANT POLLEN • FUNGAL SPORES • ANIMAL DANDER • HOUSE DUST MITES
ITCHY, TEARY EYES CONGESTED NASAL PASSAGES SNEEZING ALLERGIC RHINITISSYMPTOMS
ALLERGIC RHINITISTREATMENT • ANTIHISTAMINES • BLOCKERS …
ASTHMA • CAUSES: ALLERGENS, IRRITANTS, EXERTION, STRESS • MECHANISMS: TRIGGERS AIRWAY NARROWING AND MUCUS PRODUCTION
ASTHMASYMPTOMS • COUGH, WHEEZING, BREATHING DIFFICULTY • REVERSABLE AIRWAY OBSTRUCTION Pulmonary function test
SMOOTH MUSCLE RELAXANTS CORTICOSTEROIDS / BLOCKERS ASTHMATREATMENT
CAUSE: USUALLY FOOD OR DRUGS SYMPTOMS: SWOLLEN PLAQUES ON THE SKIN HIVES (URTICARIA)
PEANUTS EGGS MILK FISH WHEAT STRAWBERRIES TOMATOES CRUSTACEANS NUTS CHOCOLATE FOOD ALLERGIES10 MOST COMMON CAUSES
RICE FOOD ALLERGIESSAFEST FOOD?
HIVES ITCHING SWOLLEN LIPS ... NAUSEA VOMITING CAN BE FATAL FOOD ALLERGIESSYMPTOMS
A Case An 11-year-old girl ate one bite of a beef hot dog. Within minutes her lips, face, and tongue became swollen, and generalized hives and swelling of her joints developed. She was treated with subcutaneous epinephrine and intramuscular hydroxyzine at an emergency room. Subsequent analysis of the hot dog revealed that it contained milk proteins (which had been added to improve texture). The child had been previously determined to be allergic to milk. FOOD ALLERGIESPROBLEMS – HIDDEN ALLERGENS
MECHANISMS: INVOLVE ANTIBODIES (IgG, IgM) AND CAUSING CELL DAMAGE TIME COURSE: VARIABLE - USUALLY 5 - 12 HOURS TYPE 2 / CYTOTOXIC HYPERSENSITIVITY:GENERAL CONCEPTS
ABO, Rh, … TARGET IS DONOR RBCs EXAMPLES OF CYTOTOXIC HYPERSENSITIVITY:TRANSFUSION REACTIONS
Rh (-) MOTHER Rh(+) FETUS (OR ABO INCOMPATIBLE) EXAMPLES OF CYTOTOXIC HYPERSENSITIVITY:HEMOLYTIC DISEASE OF THE NEWBORN (Rh DISEASE)
A 33-year-old multigravid woman (gravida 3; para 1) presented in week 11 of her fourth pregnancy. Her first pregnancy had been uneventful and this child was now 13 years old. Her second and third pregnancies had ended with dead fetuses at 36 and 23 weeks respectively. A rising level of antibody to the D antigen of the Rh blood group had been noted in each pregnancy, but no treatment had been available. Fetoscopy was performed at 19 weeks’ gestation and blood samples obtained. The fetus was found to be Rh-positive with a low hemoglobin. An intravascular intrauterine blood transfusion was performed the next week and repeated at 3-week intervals through the rest of the pregnancy. A live female infant was delivered by Cesarean section at 34 weeks. Her hemoglobin and serum bilirubin levels were normal at birth but she gradually became jaundiced over the next 72 h. An exchange transfusion was given to reduce the level of previously transferred maternal antibody. HEMOLYTIC DISEASE OF THE NEWBORNA CASE
GRAVES DISEASE MYASTHENIA GRAVIS EXAMPLES OF CYTOTOXIC HYPERSENSITIVITY:AUTOIMMUNE DISEASES
MECHANISMS: INVOLVE ANTIBODIES(IgG OR IgM) FORMING IMMUNE COMPLEXES (PRECIPITATES)AND TRIGGERING LOCAL TISSUE DAMAGE TIME COURSE: VARIABLE - USUALLY 3 - 8 HOURS TYPE 3 / IMMUNE COMPLEX HYPERSENSITIVITY:GENERAL CONCEPTS
LOCALIZED INFLAMMATION IN LUNG TRIGGERED BY EXPOSURE TO LARGEAMOUNTS OF INHALED MATERIAL E.G.: “FARMERS LUNG” FROM MOLDY HAY EXAMPLES OF IMMUNE COMPLEX HYPERSENSITIVITY:IMMUNE COMPLEX PNEUMONITIS
RHEUMATOID ARTHRITIS SYSTEMIC LUPUS ERYTHEMATOSUS EXAMPLES OF IMMUNE COMPLEX HYPERSENSITIVITY:AUTOIMMUNE DISEASES
MECHANISMS: INVOLVE T CELLS AND MACROPHAGES TRIGGERING INFLAMMATION TIME COURSE: SLOW - USUALLY 24 - 48 HOURS APC Th Macrophage TYPE 4 / DELAYED-TYPE HYPERSENSITIVITY:GENERAL CONCEPTS ALLERGEN INFLAMMATION
LOCALIZED TO THE SKIN MAXIMUM RESPONSE 24- 48 HOURS AFTER EXPOSURE SYMPTOMS ARE ERYTHEMA AND INDURATION - SOMETIMES BLISTERING TRIGGERED BY CERTAIN MATERIALS TYPE 4 CLINICAL MANIFESTATIONS:CONTACT DERMATITIS Poison Ivy
TRIGGERED BY CERTAIN MATERIALS METALS (e.g.: NICKEL IN JEWELRY, WATCHES) CLOTHING RUBBER (e.g.: ELASTIC, GLOVES, CONDOMS) LEATHER COSMETICS PLANTS (e.g.: POISON IVY) EXAMPLES OF TYPE 4 HYPERSENSITIVITY:CONTACT DERMATITIS Rubber in Brassiere Nickel in Watch Strap Patch Testing
A 47-year-old housewife presented with a 3-week history of an acute rash which started beneath her watch. Two weeks later, a further patch appeared at the umbilicus. She had previously noted that she could not wear cheap earrings without triggering a rash on her earlobes. On examination, the appearance was suggestive of contact dermatitis corresponding to nickel in the watch and on a jeans stud. She was patch-tested to a battery of commonly implicated agents: strongly positive results were induced by nickel sulphate and cobalt chloride only. CONTACT DERMATITIS A CASE
TYPE 4 HYPERSENSITIVITY:TB SKIN TEST • INTENTIONALLY TRIGGERING A TYPE 4 REACTION FOR DIAGNOSIS
AUTOANTIBODIES HEREDITARY PREDISPOSITION - ASSOCIATED WITH HLA ANTIGENS MORE COMMON IN WOMEN THAN IN MEN AUTOIMMUNITYGENERAL CONCEPTS
MECHANISMS:ANTINUCLEAR ANTIBODIES AND OTHERS - IMMUNE COMPLEX DISEASE SYMPTOMS: SKIN RASH, ARTHRALGIAS, KIDNEY DAMAGE, PERICARDITIS, OTHER … SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)
OCCURRENCE:MOST COMMON AUTOIMMUNE DISEASE (1:100) MECHANISMS: AUTOANTIBODIES AGAINST IgG - RHEUMATOID FACTOR - IMMUNE COMPLEX DISEASE - DAMAGES JOINT STRUCTURE SYMPTOMS:JOINT PROBLEMS RHEUMATOID ARTHRITIS (RA)
A 34-year-old female assembly line worker in a machinery factory had noted gradually increasing pain and swelling in several interphalangeal joints over 10 months. She had stiffness in these joints and elsewhere that seemed worse for the first 2 hours in the morning. She denied fevers, rash, or any clues to generalized disease. She had tried aspirin, over the counter ibuprofen, and a prescription for naproxen from her family physician without any help. Laboratory tests showed a normal complete blood cell count, rheumatoid factor positive in a titer of 1:640, and a negative antinuclear antibody assay. An x-ray of the hand showed metacarpophalangeal marginal erosions on the radial side along with some subluxation (joint space narrowing). RHEUMATOID ARTHRITISA CASE
MECHANISMS: AUTOANTIBODIES AGAINST ACETYLCHOLINE RECEPTOR SYMPTOMS: MUSCLE WEAKNESS MYASTHENIA GRAVIS
MECHANISMS: AUTOANTIBODIES AGAINST INTRINSIC FACTOR AND PARIETAL CELLS SYMPTOMS: ANEMIA, GASTRITIS PERNICIOUS ANEMIA
LACK OF SOME PART OF THE IMMUNE SYSTEM RECURRENT INFECTIONS (INCREASED INCIDENCE AND SEVERITY OF INFECTIONS) PRIMARY IMMUNODEFICIENCIES HEREDITARY OR CONGENITAL UNCOMMON SECONDARY IMMUNODEFICIENCIES CAUSED BY AN OUTSIDE FACTOR MORE COMMON IMMUNODEFICIENCYGENERAL CONCEPTS
BRUTON’S (X-LINKED) AGGAMMAGLOBULINEMIA FAILURE OF B CELLS TO DEVELOP DIGEORGE SYNDROME FAILURE OF THYMUS TO DEVELOP SEVERE COMBINED IMMUNODEFICIENCY (SCID) LACK OF B AND T CELLS SELECTIVE IgA DEFICIENCY PRIMARY IMMUNODEFICIENCIES
DRUGS ALCOHOLIC CHIRRHOSIS MALNUTRITION STRESS INFECTIOUS DISEASES INFLUENZA, MEASLES, .... LEAD TO SECONDARY INFECTIONS SECONDARY IMMUNODEFICIENCIES