Hypersensitivity. Hypersensitivity reactions An immunological responses not controlled by normal...
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Transcript of Hypersensitivity. Hypersensitivity reactions An immunological responses not controlled by normal...
Hypersensitivity
Hypersensitivity reactions
• An immunological responses not controlled by normal regulatory mechanism.
• Classification- Gell and Coombs system
Gell and Coombs system• Type I – immediate (Ig E)
• Type II – antibody mediated (ADCC)
• Type III – immune complex mediated
• Type IV – T cell mediated (delay type hypersensitivity)
OUTLINE
• Hypersensitivity-mechanism (Sensitization phase/Effect phase)-clinical manifestation
-lab testing
Type I - immediate hypersensitivity IgE-mediated reactions
• Mechanism :
IgE
SolubleAntigen
FcεROn mast cells or basophils
degranulation
Cross linking of Fab
Type I - immediate hypersensitivity IgE-mediated reactions
• clinical manifestationAtopy:Genetically linkage-Allergies-Allergic rhinitis-Asthma-Atopic dermatitis
-Allergic gastoenteropathy
Lack genetic linkage and target organ :
-Urticaria -Anaphylaxis-Anaphylacic shock
全身性過敏反應
蕁麻疹
異位性皮膚炎「濕疹」
Allergic rhinitis
Allergic rhinitis
Type I - immediate hypersensitivity IgE-mediated reactions
• allergen
Host dust, arthropod, mold, weeds (ragweed), pollen, tree, animal, food, drug, latex
Inhalant allergenContact allergenFood allergen
Type I - immediate hypersensitivity IgE-mediated reactions
• Lab test
Skin test
In vitro tests
Lymphocyte stimulation
Intranasal provocative tests鼻內激發法
Skin test
• Cutaneous test (prick test)pucture small amount to dermis and read after 20 min
• Intradermal testsemiquantitative
皮下過敏注射
扎刺法
In vitro tests• Total IgE :
IMMULITE Total IgE (serum IgE only)• Allergen specific IgE
RAST : radioallergosorbent testMAST : multiple antigen simultaneous test CAP
Immunoblot (AlaBLOT test) --allergen: Ep strip• Eosinophilia : 114-142 300-500/mm3• ECP (eosinophil cationic protein)
體外敏感試驗
過敏原檢測
Total IgE Test
CAP( 混合過敏原群 IgE 抗體篩檢 )
Phadiatop, fx5
CAP(特定過敏原 IgE 抗體篩檢 , 自選 )
or
MAST allergy test
MAST(Multiple Antigen Simultaneous Test)• 同時測定 36 種抗原• 使用 Chemical Luminescent ImmunoAssay • 半定量
Allergen + tested IgE → Allergen-IgE-(Anti-IgE) → CLA-1
• 結果判讀 : 4 : >2423 : 143~2422 : 66~142 1 : 27~65±: 12~26- : 0~11
↑Anti-IgE*Enzyme
( 單位 : LUs)
* Total IgE>500 IU/mL MAST 中的某些 ± 可能為 non-specific binding
Principle
• Chemiluminescence Analysis ( 化學冷光酵素免疫分析法 )
MAST allergy test• Introduction ─ 同時測定血清中 36 種過敏原的特異性 IgE 抗體 ─ 半定量計量。結果值 (LUs 淨值 ) 以級數表示
• Result ─ 分四級: 0, 0/1, 1, 2, 3, 4 ─ 2 級以上表示有意義
• Clinical significance ─ Atopic allergy 屬第一型過敏反應。 ─常見的臨床症狀有花粉熱、氣喘、皮膚炎、蕁麻疹、過敏
性休克 ─ 得知患者對不同過敏原的 IgE 濃度,是診斷和治療過敏的 重要資訊。
• MAST 36種過敏原測試
CAP
cellulose carriersβ-Galactosidase 的抗 IgE 抗體反應後 , 清洗掉未反應物 ,
加入反應呈色劑於 CAP 機器判讀結果。
β-Galactosidase
CAP• 吸入性混合過敏篩檢 (23 種 ) 及食物性混合
過敏篩檢 (6 種 )
CAP• 吸入性混合過敏篩檢 (23 種 ) 及食物性混合
過敏篩檢 (6 種 )
UniCAP
UniCAP 原理 : FEIA
• Fluorescence Enzyme Immunoassay (FEIA)
• Enzyme : β-galactocidase• Substrate : 4-MUG → 4-MU• Stop Solution : 4% Sodium Carbonate
UniCAP• 以 FEIA 的方法,應用於 Autoantibody(Specific IgG) 和過敏免
疫系統 (Total IgE, Specific IgE) 的定量• Total IgE
檢測體內所含 IgE 濃度,作為過敏的指標 ─ 測定範圍 : 2~5000 kU/L• Specific IgE
檢測不同過敏原產生的特異性 IgE 抗體 ─ 吸入性混合過敏篩檢 (23種 ) 及食物性混合過
敏篩檢 (6種 )
Cyclic cirtullinared peptide(CCP) AbExtractable Nuclear Antigen Ab(ENA)
Eosinophil cationic protein(ECP)
將 Anti-ECP 固定於 cellulose carriers( 固相 ) 中 , 加入待測血清反應後 , 清洗掉未反應物 , 再加入 β-Galactosidase 的抗 ECP 抗體反應後 , 清洗掉 未反應物 , 加入反應呈色劑於 CAP 機器判讀結果。
檢驗活化的 eosinophil 及其產物 ECP 可追蹤病程 , 並在發炎期 (ex. 急性氣喘 ) 給予抗發炎藥劑 , 降低發炎 , 故檢驗血清中的 ECP 值是治療成效的指標。
Anti-ECP
Type I - immediate hypersensitivity IgE-mediated reactions
Therapy• Environmental measures : avoid allergen• pharmacological therapies -antihistamine -corticosteroids -cromolyn sodium• Desensitization treatment -Allergen shots (blocking antibody, IgG) • Antibody against free and membrane IgE • Antibody to CD23 (low affinity IgE receptor)• Cytokine intervention
Type II – antibody mediated
• Mechanism :
1.Cell surface antigen Transplanted cell
Host cell (autoimmune)
Foreign antigen bind to host cells
2.IgM IgG production (dep. on cytokine)
Sensitization phase
1.Complement activation
chemoattractant C5a C3a Anaphylatoxin C5a Opsonin
MAC 2.ADCC by NK3.Opsonin mediated
phagocytosis
Effect phase
Ag dose not clear from system
Destory cells
IgG
IgM
IgG IgM
Type II – antibody mediated
• clinical manifestation (dep. on cell type)
-Hemolytic disease of newborn
-Transfusion reactions
-Autoimmune disorders
-Drug induced reactions
-Transplantation
Hemolytic disease of newborn
RBC-Rh antigen
Autoimmune disorder• Goodpasture’s syndrome Ab against kidney and lung basement membranes Antiglomerular basement membrane antibody (Anti-GBM)
renal biopsy
even layer on the glomerular basement membrane
• Myasthenia gravis Ab against acetylcholine receptor in neuromuscular junctions
down regulation of receptors by endocytosis muscle weakness
Drug induced reactions
ex : penicillin
Drug (hapten) Bind to cell surface
Type II hypersensitivity
Cell destruction
Type III-immune complex mediated
Sensitization phase
1.Chronic Ag (soluble) exposureautoimmue disorders or persistent infection
2.IgM IgG production
(dep. on cytokine)
Too many immune complexesfor phagocytesto remove
Immune complex formationand
deposition in the capillary walls
IgG
IgM
• Mechanism :
1.Complement Anaphylatoxin C5a Opsonin C3b CR1 chemoattractant C5a C3a
2.Neutrophil phagocytosis
damage capillary walls (proteolytic enzyme)
3.Coagulation Vascular permeability PLA aggregation blood clot formation *4.Immune complexes penetrate and lodged in capillary
walls 5.Vascular occlusion
Effect phase
Type III-immune complex mediatedIgG
IgM
Type III-immune complex mediated• clinical manifestation -SLE
autoantibody, immune complexes deposit in various tissues
-Post streptococccal glomerulonephritisS. pyogenes, kidney, “captured antigen”
-Serum sicknesspassive immunization of non human IgGhuman antibody – non human IgG
(ex:horse serum:anti-diphtheria antibodies, antiserum administered following a snakebite )
-Farmer’s lungAg = spore of Thermophilic actnomycetes
-Arthus Reaction
Non human
IgG
Serum sickness
Arthus Reaction• Ag inject into immunized body• Local inflammatory response due to deposition of immune
complexes in tissues. • vaccine boosting( 第 2 劑 )
Detection of Immune Complex
• C1q binding assay
• Raji cell assay
• Detection of Cryoglobulins
C1q binding assay
C1q binding assay
False (-)Small immune complex 、 IgE, IgA, IgG4 immune complex
False (+)Fibrinogen 、 fibronectin 、 DNA 、endotoxin 、 heparin
Raji cell assay• Lymphoblastoid cell line from Burkitt’s lymphoma• C1q C3b C3d and Fcreceptor
• Normal:<15.0 μgEq/mL • positive: 20.0μg Eq/mL
Raji cell assay
• False-positives occur when antilymphocyte antibodies are present.
• Especially in SLE, positive results often reflect the presence of lymphocyte antibodies.
• Raji assay are commonly found in systemic necrotizing vasculitis and might be useful for monitoring sarcoidosis( 肉狀瘤病 ).
Detection of Cryoglobulins
• Cryoglobulins are abnormal immunoglobulins which form complexes and precipitate out of serum at low temperatures and resolubilise on warming.
• 4oC 沉澱,加溫溶解• responsible for specific symptoms,such as
Raynaud’s phenomenon, vascular purpura, bleeding tendencies, cold-induced urticaria
http://www.labcorp.com/datasets/labcorp/html/chapter/mono/sc029100.htm
Detection of Cryoglobulins
Type of Cryoglobulin Immunochemical
Composition
Type 1 : Single monoclonal immunoglobulins
• IgM • IgG • IgA • Monoclonal light-chains
Type II : Mixed monoclonal immunoglobulins
• IgM-IgG • IgG-IgG • IgA-IgG
Type III : Mixed polyclonal immunoglobulins
• IgM-IgG • IgM-IgG-IgA
Detection of CryoglobulinsType 1 : Single monoclonal
immunoglobulins • Myeloma • Waldenstrom’s • Chronic Lymphocytic
Type II : Mixed monoclonal immunoglobulins
• Myeloma • Waldenstrom’s • Macroglobulinaemia • Chronic Lymphatic Leukaemia
Type III : Mixed polyclonal immunoglobulins
• Autoimmune Disease: • Lupus (SLE) • Rheumatoid arthritis • Scleroderma • Sjogren’s Syndrome • Chronic active hepatitis • Active Hepatitis. • Post streptococcal nephritis. • Vasculitis • Infections:
Type IV – T cell mediateddelayed-type hypersensitivity, DTH
Sensitization phase Effect phase
Type IV – T cell mediated macrophage activation
• clinical manifestation
chronic DTH
-Mycobacterium tuberculosis
acute DTH (24-48 hr.)
-Mantoux skin test (PPD= purified protein derivative)
Contact dermatitis
Mycobacterium tuberculosisTB prevent fusion of lysosomes and phagosomes TB live in macrophage
macrophage destruction chemotatic factors release chemotasis 聚集形成肉芽( Tubercle ,結核)
乾酪樣壞死
Type IV – T cell mediated
• Lab
patch test (read after 48 hr.):
PPD or tuberculin skin test (Koch phenomena)
Candida albicans Streptokinase Mumps Trichophyton
The DTH skin test: Mantoux test
• Determine the infection of Mycobacterium tuberculosis
PPD24-48 hr.
(PPD= purified protein derivative)
Sensitization phase
Effect
phaseClinical
Type I Immediate
Soluble
AntigenIgE
IgE cross-linked with Ag
Mast cells and basophils degranulation
Allergies Rhinitis Asthma
Anaphylaxis Anaphylacic shock Urticaria
Type IIAb mediated
Cell surface
Antigen
IgM IgG
Ab bind to surface Ag
*Complement
*ADCC by NK
*phagocytosis
(Opsonin)
cell destruction
Hemolytic disease of newborn
Goodpasture’s syndrome Myasthenia gravis
Drug induced reaction
Transfusion reaction
Transplantation
Type IIIImmune complex mediated
Soluble
Antigen
(many)
IgM IgG
Ab bind to free Ag immune complex
Immune complex deposited in
capillary wall localized destruction
SLE Post streptococccal glomerulonephritis Serum sickness
Persistent infection
Farmer’s lung
Type IVCell
mediated
Naïve CD4 T cell activation
Macrophage
DTH
Contact sensitivity
Delay hypersensitivity
Immunity to viral and fungal antigens and intracellular organisms
Rejection of foreign tissue grafts
Elimination of tumor cells bearing neoantigens
Formation of chronic granulomas
summary
Comparison of Different Types of hypersensitivity
characteristicstype-I(anaphylactic)
type-II(cytotoxic)
type-III(immune complex)
type-IV(delayed type)
antibody IgE IgG, IgM IgG, IgM None
antigen exogenous cell surface soluble tissues & organs
response time 15-30 minutes minutes-hours 3-8 hours 48-72 hours
appearance weal & flare lysis and necrosis erythema and edema, necrosis
erythema and induration
histology basophils and eosinophil
antibody and complement
complement and neutrophils
monocytes and lymphocytes
transferred with antibody antibody antibody T-cells
examples allergic asthma, hay fever
erythroblastosisfetalis, Goodpasture's nephritis
SLE, farmer's lung disease
tuberculin test, poison ivy, granuloma