1050 Finals Flashcards
1
Q
Describe acute phase reactants
A
- Proteins that increase due to infection, injury and trauma
- proteins usually are:
→ c reactive protein
→ alpha-1 anti-trypsin
→ haptoglobin
→ fibrinogen
→ others, such as complement
2
Q
What is an antigen?
A
→ foreign substance that stimulates antibody production
→ they are large complex molecules
→ molecular weight → usually more than 10,000
→ usually protein or polysacchandes in nature
3
Q
What is an antibody?
A
immunoglobulin produced by plasma cells in response to antigen
4
Q
What is avidity?
A
Strength of bond between antigen and antibody
5
Q
What are chemokines?
A
→ are cytokines that attract cells to a particular site
→ important in inflammatory response
6
Q
What is chemotaxis?
A
→ Migration of cells towards the chemokine
7
Q
What are cytokines?
A
→ are chemical produced by activated immune cells that affect function of other cells
→ includes:
-interferons
- chemokines
-tumor necrosis factor
- transforming growth factor
- colony-stimulating factors
-interleukins
8
Q
What is epitope?
A
- A determinant site on an antigen
9
Q
What are haptens?
A
-Low molecular weight
-substance that bind to antibody once its formed but is incapable of stimulating antibody’s production and less bound to large carrier molecule
10
Q
What is histamine?
A
Vasoactive amines released from mast cells and basophils during an allergic reaction
11
Q
What is hypersensitivity?
A
During allergic reaction hypersensitivity heightened state of immune responsiveness that causes tissue damage in the host
12
Q
What is immunity?
A
immunity is resistance to infection
13
Q
What is immunogen
A
Any substance capable of inducing an immune response
14
Q
What is immunoglobulin?
A
-(Ig)
An antibody
15
Q
What is immunology?
A
Study of reactions of hosts when exposed to foreign substance
16
Q
What is inflammation?
A
Cellular and humoral mechanisms involved in reaction to injury or infection
17
Q
What are interferons?
A
→ Cytokines with anti-viral properties
→ active against certain tumors and inflammatory processes
18
Q
What are interleukins?
A
Cytokines produced by leukocytes that affect inflammatory response through increase in soluble factors i cent
19
Q
What are ligands?
A
→ A molecule that binds to another molecule of complementary configuration
→ the substance being measured in immunoassays
20
Q
What is Lysozyme?
A
Enzyme found in tears and saliva that attacks cell walls of microorganisms
21
Q
What is major histocompatibility complex?
A
→ System of genes that controls expression of MHC molecules found on all nucleated cells originally
→also known as human leukocytes antigens
22
Q
What is monoclonal? antibody
A
Antibody derived from a single b-cell clone
23
Q
What is opsonin?
A
Serum proteins that attach to foreign substance to enhance phagocytosis
24
Q
What is phagocytosis?
A
Engulfment of cell or particular matter by neutrophils or macrophages
25
What are plasma cells?
- Transformed B cells that secrete antibody
-in peripheral lymphoid tissues is non-dividing and they die in a few days
26
What is polyclonal antibody?
Antibody produced by many B cell clones
27
What is postzone?
→ Reduced antigen- antibody complexes due to antigen excess
→ can cause false negatives in aerological testing
For antibody
→test can be repeated in 1-2 weeks
28
What is prozone
→ Is a reduced antibody. Antigen complex due to antibody excess
→ this can cause false negatives in serological tests for antibody
→ dilute the semi, and retest it
29
What is seroconversion?
A change of serological tests from negative to positive due to the development of detectable antibodies
30
What is serum sickness?
Type III hypersensitily reaction that results from a build up of antibodiesto animal serum used in some passive immunizations
31
What is the thymus?
→ Small flat bi-lobed organ found in the thorax
→ is site of T lymphocytes development
→ one of the primary organs of lymphoid system
32
What is titer?
→ Means of expressing antibody concentration
→is reciprocal of the highest dilution with a positive reaction
33
What is a vaccination?
→ Injection of immune genetic material to induce immunity
34
What is zone of equivalence?
→ When number of multivalent sites of antigen and antibody are approximately equal
→ results in optimal precipitation
35
What are the branches of the immune system?
-humoral
- cell-mediated
36
What is humoral immune response?
→ Antibody mediated
→ defends against bacteria and extracellular
→ cells involved are B cells and plasma cells
→ these cells produce antibody production
37
What is cell-mediated immune response?
→ cell-mediated
→. Defends against viruses-fungi, mycobacteria and other intracellular pathogens and tumor cells
→ cells involved are T lymphocytes and macrophages
→ examples: graft rejection, hypersensitivity reactions and elimination of tumor cells
38
What are the steps of the humoral immune response?
① first exposure to antigen
② antigens engined and displayed by dendritic cells
③intact antigen activates B cells which give rise to the plasma cells and memory B cells
④these cells eventually secrete antibodies that defend against the pathogens or toxins in the extracellular fluid
39
What are the steps of cell-mediated immune response?
① first exposure to antigen
② antigens engulfed and displayed by dendstic cells
③ antigens displayed by infected cells and activates the helper T cells secrete the cytokines
④this activates the cytotoxic T cells and give rise to active and memory helper T cells
⑤ cytotoxic t-cells give rise to memory cytotoxic T-cells and active cytotoxic T cells
⑥this defends against infected cells, cancer cells and and transplanted tissue
40
What are the types of immunity
-innate (natural) defense
-adaptive (acquired) defense
41
Describe the innate defense?
-present at birth
- not antigen specific
- surface barriers ( skin, mucous membrane, mucus in respiratory tracts)
-internal defenses (inflammation phagocytes, NK cells fever)
42
What are the two types of adaptive defenses
- humoral immunity (B cells)
- cellular immunity (T cells)
43
What are two types of adaptive immunity?
-naturally acquired
-artificially acquired
44
What are the two types of naturally acquired adaptive immunity?
① active → antigen enters body naturally
→ body induces antibodies and specialized lymphocytes
② passive → antibodies pass from mother to fetus via placenta or to infant via breast milk
45
What are two types of artificially acquired adaptive immunity?
① active → antigens introduced via vaccine
→ body produces antibodies and specialized lymphocytes
② passive → preformed antibodies in immune serum are introduced by injection
46
What are the 5 leukocytes of natural immune system?
①basophil
②eosinophil
③neutrophil
④ monocyte/macrophage
⑤ lymphocytes
47
What the 3 granulocytes of the natural immune system?
①basophil
②neutrophil
⑤ eosinophil
48
Describe neutrophil
- Functions for phagocytosis and inflammatory response
-respond to chemotaxis
-granules contain bacterial enzymes
49
Describe eosinophils
- Neutralize basophil or mast cell products
-responsible for destruction of some helmets (parasites)
-they have some phagocytic ability
50
Describe basophils
-seen in hypersensitivity reactions
-they have granules that contain histamine, heparin, eosinophil chemotactic factor A
-in allergic response, they bind to IgE and granules release contents in the presence of the antigen
51
Describe monocytes
-responsible for phagocytosis
-they migrate to tissues and become macrophages
-respond to chemotaxins
52
Describe mast cell
-A tissue cell
-responsible for hypersensitivity reaction
-seen in connective tissue cells
-resemble basophils but are larger and they contain more granules and bind to IgG
53
Describe macrophages
-phagocytosis
-help eliminate bacteria, intracellular parasites, tumor cells
- secretion of cell mediators
- antigen presentation
-activated by contact with microorganisms or cytokines from T lymphocytes
54
Describe dendritic cells
-phagocytosis in nature
-responsible for presentation of antigen to helper T cells in the blood and lymph organs
-initiate acquired immune response.
- tissue cells with long membranous extensions
55
Describe Natural killer cells (NK)
- First line of defense against tumor cells and cells infected with viruses
-lymph's without T or B markers
-CD16 and CD56 positive on cell surface
- bridge between acquired and innate immunity
- lack specificity
- stimulated by cytolones
-respond early infection which allows time for the T and B cells to be activated
56
What are the cells of the acquired immune system
-T lymphocytes
- plasma cell
- killer cells
57
Describe T lymphocytes
- function of cell mediated immunity
-derived from cells in bone marrow
-they develop T cells specific surface antigen in the same thymus
-60 - 80 % lymphocytes are T lymphocytes
58
Describe helper inducer cells
- Orchestrate cell mediated immunity,
- activate B cells, cytoxic cells and NK cells
-CD4 positive
- 2/3 peripheral T cells
- normal CD4 is about 1,000 per milliliter, in AIDS → > 200 per milliliter
59
What is attenuation?
→ A process of producing nonpathological bacteria or rinses for use in vaccines
→ organisms have been weakened by treatment with chemicals, changed temperature or repeated passage in cell culture
60
What are chemotaxins?
- A protein or other substances that acts as a chemical messenger to produce chemotaxis
61
What is diapedesis
Process by which cells are capable of moving from the circulating blood to the tissues by squeezing through the wall of blood vessel
62
Describe germinal center
Interior of secondary follicle where blast transformation ot B cells take place.
63
Describe memory cells
- Progeny of an antigen activated B or T cells that is able to respond to antigen more quickly than the parent cell
64
Describe primary follicle
A cluster of B cells that have not yet been stimulated by antigen
65
Describe primary lymphoid organs
-the organs in which lymphocytes mature: these are bone marrow and the thymus
66
Describe secondary follicle
→ A cluster of cells that are proliferating in response to specific antigen.
→ has germinal center and stimulated B cells
67
Describe secondary lymphoid organs
- Where the main contact with forgein antigens takes place
- spleen, lymph nodes, appendix, tonsils and other mucosal-associated lymphoid tissue
68
Describe spleen
- Largest secondary lymphoid organ
- filters out aged cells and foreign
69
Describe thymocytes
-immature lymphocytes
-found in the thymus
-undergoes differentiation of T cells to become a mature cells
70
Describe complement
- Series of proteins (30 or more) that are normally present in serum
-overall functions are medication, osponization, chemotaxis, cell lysis or inflammation and destruction of foreign cells
-most are inactive enzyme precursor that ave converted to active enzymes in precise order
71
Describe defenses
- Small canonic proteins
- released by lysosomal granules
- can kill bacteria and many fungi by destroying their cell walls
72
Describe fibrinogen
-acute-phase reactant that changes to fibrin
-forms clot in the bloodsteam
73
Describe haptoglobin
- An acute-phase reactant
- binds irreversibly to free hemoglobin released by intravascular hemolysis.
74
Describe opsonins
- Serum proteins that attach to a foreign substance and enhance phagocytosis
75
Describe oxidative burst
- Increase in oxygen consumption in phagocyticceas which generate oxygen radicals used to kill/engulf microorganism
76
Describe Pathogen-associated molecular patterns (pamps)
-.structural patterns of carbohydrates, nucleic acids, bacterial peptides or microorganism
- recognized by the pathogen recognition receptors on the cells of the innate immune system
77
Describe toll-like receptors
-receptors found on human leukocytes and other cell types
-recognize microorganisms and aid in their digestion
78
Describe adjuvant
Substance administered with a immunogen that enhances and potentates the immune system
79
Describe alloantigen
- Antigen that is found in another membrane of the hosts species
- capable of eliciting an immune component host
80
Describe autoantigen
Antigen that belongs to the host and is not capable of eliciting an immune response under normal control circumstances
81
Describe hapten
- A small molecule which, when combined with a larger carrier such as a protein, can elicit the production of antibodies which bind specifically to
82
Describe heteroantigens
An antigen of a species different from that of the host, such as other animals,, plants, or microorganism
83
Describe antigen dependent stage
-final phase of B cell development in bone marrow that results in mature B cells that have not been exposed to antigen.
84
Describe antigen- independent phase
-If a B call is stimulated by antigens it undergoes transformation to blast stage that eventually forms memory cells and antibody secreting plasma cells
85
Describe heterophil antigen
Antigen that exists in unrelated plants or animals but either identical or closely related so that antibody to one Will cross- react with antibody to the other.
86
Describe suppressor T cells
- Inhibit helper T cells and cytotoxic cells that kill other cells
- CD8 positive
- 1/3 of peripheral T cells
87
What is the normal ratio of CD4 and CD8? What is it in AIDS?
Normal → 2:1
AIDS → 0.5:1
88
Describe T regulatory cells
- Suppress immune response to self
-CD4 and CD25 positive
89
Describe B lymphocytes
- After antigenic challenge → transform into blast cells that give rise to plasma cells and memory cells
- develop in bone marrow
-when mature, they have surface IgM or IgD which act as receptors for antigens
- 10 - 20% of lymphocytes ave B cells
90
Describe memory B cells
- Respond to antigen when encountered again with an increased speed and intensity
-in peripheral lymphode organs they live months to years
91
Describe the antibody structure
-two heavy chains and light chains hold together by disulfide bonds
- bond determines class
-FAB fragment ( each have 2)
-FC fragment
92
What are 2 types of light chains in an antibody structure?
- Kappa
-lambda
- found in all classes but only one type per molecule
93
free L light chains is also called what?
- Bence jones proteins
94
Describe FAB fragment
- Fragment antigen binding it consists of one light and one heavy chain held together by the SS bonds
-a per antibody, each can bind the antigen
95
Describe FC fragment
-crystallizable terminal
- carbonyl (spelling?)terminal carboxy halves ot two heavy chains held held together by Disulfide bonds
-plays a role in ospinization and complement fixation
96
Describe constant region of an antibody structure
-carboxyl terminal ends of the heavy and light chains where nano acid sequence is the same for all chains of that type
97
Describe variable region of antibody structure
-amino terminal ends of the heavy and light chains where anime and sequence varies
- aka antigen recognition unit
-responsible for antibodies specificities
98
Describe hinge region of antibody structure
-Flexible portion of heavy chain between first and second constant region
-allows molecules to bend so that two antigen binding site can operate independently
99
Describe Joining chain of antibody structure
-glycoprotein that links the antibody monomers to IgM and secretory IgA
100
Describe IgG
- Monomer
-150,000 moleuker weight
-heavy chain → gamma
- light chain → kappa or lambda
-70-75% of immunoglobulins
-serum concentration is 800- 1600 mg/dl
- 2 antigen binding sites
-will fix complement
-will cross placenta
- role→ defense against bacteria/viruses,neutralizes toxins, opsionin antigens, and part of passive immunity in new born
-more effective at precipitation than agglutination
101
Describe IgM
-pentamer → largest
- 900,000 molecular weight
- heavy chain is mu
- light chain → lambda or kappa
- 10% of total antibody
-serum concentration → 120-150 mg/dl
- 10 binding sites
- fixes complement
-neutralize toxins and opsonin
-first produce in bodies immune response
- only one produced by newborn
-most efficient at initiating complement cascade
-move efficient in agglutination than IgG
- destroyed by sulfa-dial compounds
102
Describe IgA
- Serum structure → monomer
- Secretions → dimer
- Monomers → 160,000 molecular weight
-Dimer → 400,000 molecular arweight
- heavy chain → alpha
- light chain → lamba or kappa
- serum concentration→ 70-350 mg/dl
-10-15% total antibody count
-either 2 or 4 antigen binding sites
- does not fix complement
-first line of defense,patrols mucosal surfaces, prevents adherence of bacteria, and neutralizes toxins
- can be found in tears, sweat, saliva, breast milk, and respiratory and GI mucousa
103
Describe IgD
-monomer
-180,000 molecular weight
- heavy chain is delta
-light chain is lambda or kappa
-serum concentration → 1-3 mg/di
- >1% total antibody count
- 2 antigen binding sites
- does not fix complement
-B cell maturation
-found on surface of B lymphocytes
104
Describe IgE
-monomer
- 190,000 molecular weight
- heavy chain is epsilon
- light chain is kappa or lambda
- 0.002 % total antibody count
-serum concentration→ 0.005 mg/dl
-2 antigen binding sites
- does not fix complement
- role is in allergic reaction→ can bind to the basophil or mast cells
- when two adjacent molecules on mast cans bind the antigen → degranulation of the cell with release of histamine and heparin
-found in type I immediate hypersensitivity reactions
105
Describe classical pathway
-trigged by an antigen-antibody reaction
-IgM is most efficient activator
- single molecule attached to a adjacent antigens can initiate the cascade
- IgG1, IgG2, and IgG3 can activate complement but at least 2 molecules are required
- recognition unit →C1
- activation unit →C4, C2, C3
- membrane attack complex→ C5, C6, C7, C8, and C9 causes cell lysis
106
Describe alternative pathway
- Antibody independent
- activated by bacteria, fungi, viruses, tumor cells, and some parasites
107
Describe lectin pathway
- Antibody independent the
-initiated by mannose binding lectin (MBL)
- nonspecific recognition of sugars on microorganisms
-important defense mechanism during infancy
- C3 in highest concentration in our plasma
108
What is the key component of all 3 complement pathways?
C3
109
What ions are required for the cascade of complement?
Calcium and magnesium
110
What do deficiencies in complement pathway cause?
- Increased susceptibility to infection
- accumulation of immune complexes which can lead to glomenuar nephritis
111
What are the agglutination methods?
① direct agglutination
② hemagglutination
③ passive (indirect) agglutination
④ reverse agglutination
⑤agglutination inhibition
⑥ hemaggietination inhibition
⑦ coagulation
⑧antiglobusin - mediated agglutination
112
Describe direct agglutination
- Naturally occurring antigens on particles
-particles agglutinate in the presence of a corresponding antibody
-examples
→ widal test for typhoid fever, salmonella
→O and H antigens used to detect antibodies in patient scheme
113
Describe hemagglutination
-this is antigen and antibody reaction that results in clumping of RBCs
-examples
→ ABO slide typing
114
Describe passive (indirect) agglutination
- Soluble antigens bound particles
- example
→ latex and particles of gluten and in the presence of a corresponding antibody
→rheumatoid factor
→ anti-nuclear antibody
115
Describe reverse passive agglutination
- Antibodies attach to carrier particles
-particles agglutinate in presence of the Corresponding antigen
-rapid ID of bacteria is used with this type of testing
116
Describe Agglutination inhibition
- competition between particulate antigens such as a reagent and soluble antigen into specimen for sites on a reagent -antibody
-lack of agglutination is a positive result in this test
- can be used in detection ofinicitargs
117
Describe hemagglutination inhibition
- Detects antibodies to certain viruses that agglutinate RBCs
- in presences of antibody, virus is neutralized and hemagglutination does not occur
-examples
→ rubella and other viruses
118
Describe coaggulation
- Reagent antibody is attached to carrier bacteria
- staph aureus most frequently used carrier
-protein A binds the fc portion of the reagent antibody
-visible agglutination in presence of corresponding antigen
-example
→ rapid ID of bacteria
119
Antiglobulin-mediated agglutination
- Detection of non-agglutinating antibodies by coupling with second antibody anti-human globulin
- example
→ direct and indirect anti-globulin test
120
What are the precipitation methods'
①ouchterlony double diffusion
② radial immunodiffusion (RID)
③ Rocket immunoelectrophoresis
④ immunoelectrophoresis (IEP)
⑤ immunofixation electrophoresis (IFE)
⑥ nephlometry
121
What is precipitation?
- Soluble antigen that combines with soluble antibody to produce visible complex
- less sensitive than agglutination
122
Describe ouchterlony double diffusion
- Antigens and antibodies diffuse from wells in gel and form precipitation lines where they meet
-examples
→ fungal antigens
→ extractable nuclear antigens
123
Describe radial immunodiffusion
- Antigen diffuses out of the well in gel containing the antibody
-precipitation ring forms
- diameter is proportional to the concentration of the antigen
- examples
Flow volume testing for IgD and lgG
124
Describe rocket immunoelectrophoresis
-electrical charge applied to RID to facilitate migration of antigen into the auger
- height of the rocket shaped precipitation band is proportional to the concentration of the antigen
- examples
→ antigen IGs or antibodies complement
→ alpha-fetoprotein
125
Describe immunoelectrophoresis
- Proteins separated by electrophoresis than double diffusion with reagent antibodies in trough in the auger
- shape, intensity, and location of the precipitation arcs are compared with a normal control
- example
→ serum proteins including antibodies
126
Describe immunofixation electrophoresis
- Proteins separated by electrophoresis
- anti-serum is placed directly on the gel and antibody complexes precipitate out
- examples
→IDs of antibodies and monoclonal gamonopathies
→ pence jones proteins and western blot
127
Describe nephelometry
- Light is scattered by the antigen antibody complexes
- used to detect antibodies complement and o reactive protein
128
Describe isotopic immunoassay
-immunoassay that uses radioisotopes as the label
129
Describe non-isotopic immunoassay
-uses something other than radioisotope as a label
- could be enemies, florachrome, chemiliminescent molecules
130
Describe competitive immunoassay
-Patent antigen and a labeled reagent antigen compete for binding sites on reagent antibody
131
Describe non-competative immunoassay
- Does not involve competition for binding sites
- more sensitive than competitive assay
132
Describe heterogenous immunoassay
- has separation step to remove the free form bound analyte
- more sensitive than homogeneous
133
Describe homogenous immunoassay
- That doesn't require separation state
- easier to automate
134
What are the 3 types of enzyme immunoassays?
①direct EIA
②indirect EIA
③solid phase
135
Describe EIA
-Uses enzymes as the label
- substrate is added to measure enzyme activity
136
Describe direct EIA
- Competitive enemy labeled reagent is part of initial antigen-antibody reaction
-all reactants are added at the same time
-incubation and then Wash step
137
Describe the indirect EIA
- Non competitive
- enzyme labeled reagent isn't involved in the initial antigen- antibody reaction
-two incubations and two washes
-more sensible than ELISA
138
Describe solid phase
Reagent antigen or antibody that 1s bound to support medium, could be polystyrene testtubes, microtiter plates, cellulose membranes and glass beads
139
What are the formats of EIA?
- Heterogenous
-competitive
-direct
-enemy labeled ligand and unlabeled patient ligand compete for binding sites on antiboy attached to a solid phase
-free labeled ligand is removed by washing
- substrate is added, color is inversely proportional to the concentration of the ligand and its specimen
- used to measure small relatively pure antigens for
→ examples: insulin and estrogen
140
What are the formats of ELISA?
- Heterogenous
-non competitive
- indirect
- antigen is attached to solid phase
- antibody and specimen attaches
- unbound antibodies are removed by washing
-then enzyme labeled anti-globulin is added
-attaches to antibody through solid phase
-substrate is added, color is directly proportional to antibody concentration
-move sensitive than competitive EIA
- most common immunoassays
- used to detect antibodies to viruses such as HIV, hepatitis A, C, and epstein-barr virus
141
Describe sandwich ELISA/ capture assay
- Heterogenous
-noncompetitive
- indirect
- antibody attaches to solid phase
-antigen in specimen attaches
-enzyme labeled antibody is added which attaches to different determinant
-Enzymatic activity is directly proportional to the amount of antigen in sample
- antigens must have multiple determinants
- used to measure antibodies, hormones,proteins, tumor marker, viruses, parasites,
and fungi
-high concentration of antigen can cause that hook effect → undiluted samples have lower absorbence
142
Describe rapid ELISA
- Membrane-based '
- reagent antigen or antibody is bound to the membrane in single use cassette
-sample is added the presence of antigen- antibody complex is indicated by a colored reaction
-built in quality control
-usually qualitative
143
Describe EMIT format
- Homogenous
- antigen in specimen and enzyme labeled antigen compete for binding sites on a reagent antibody
- when enzyme labeled antigen binds → enzyme activity is inhibited
-enzyme activity is dircetly proportional to concentration of the antigen in specimen
.used for determinations of low molecular weight analytes not readily measured by other methods ( hormones, therapeutic drugs, abused drugs)
- also can be used in automated format
144
What are the 3 fluorescent immunoassays
① direct (DFA)
② indirect (IFA)
③ polarization (FPIA)
145
Describe direct fluorescent immunoassay
- Antibody staining
- specimen on glass slide overlaid with a fluorescent labeled tag or antibody.
-is corresponding antigen is present, the labels antibody will bird.
-then fluorescence is observed with a fluorescent microscope
- can detect antigens fluorescents labels can be fluorescein, isothiocyanate and rhodamine B isothiocyanate
- can also be used for bacterial and viral antigens
146
Describe indirect Fluorescent immunoassay
-antibody staining
- reagent antigen in the serum
on glass slide overlaid with patient serum
- if corresponding antibody is present in the serum
It attaches to the antigen
-when fluorescine labeled anti-human globulin is added, it will attach to the antibody
-fluorescence is observed again with your fluorescent microscope→ this is called a sandwich technique
-this technique and it will detect the antibodies to the particular virus
-examples
→used for fluorescent anti-nuclear antibody fana(sp?)
→fluorescent treponemal antibody (FTA)
147
Describe fluorescent polarization immunoassay
- Labeled antigen that will compete with an antigen in specimen for sites on reagent antibodies
-free labeled antigen rotates rapidly and admits little polarized light
-the bound labeled antigen rotates more slowly and will admit more polarized light
- amount of polarized right is directly proportional to the concentration of the antigen in the speciemen
- can be used as competitive homogenous and can be automated
- used to detect therapeutic drugs and hormones
148
What are the labeled immunoassay?
①RIA
②EIA
③FIA
④CIA
149
Comparison of RIA labeled immunoassay
- Labels arc 125 and 131 iodine detection
- can defect radio isotopes that admit radioactivity
- the types are competitive and heterogenous
- advantages → its sensitive and specific
- disadvantages → radiation hazard, short shelf life of reagents, disposal problems and licensing and federal regulations
- not commonly used anymore
150
Companion of EIA labeled immunoassay
- Label can be alkaline phosphates, horseradish peroxides, diactylase glucose 6-phosphate dehydrogenease
- used to detect enzymes that react with substrate to produce color change
-mostly non competitive
- heterogenous and homogenous are available
Advantages→ sensitive, Specificity, no health hazard
Or disposal problems, reagents with long shelf life and it can be automated
Disadvantages → natural inhibitors in some specimens nonspecific protein binding
151
Comparison of FIA labeled immunoassay
-labels are fluorisim and rhodammine
-used to detect Floor chromes that absorb energy from light source and can convert to longer wavelengths or lower energy
- assays available are usually competitive
- can be both heterogeneous and homogenous
-advantages → automated, sensitivity, specificity, long reagent shelf life
-disadvantages → autofluorescence from organic substances in serum, nonspecific binding to substances in the self, expensive and have dedicated instrument
- commonly used
152
Comparison of CIA labeled immunoassay
-labels can be luminal, acronym, esters, and nitrophenyloxalate
-used to detect chemiluminescent molecules that produce light from chemical reactions
- competitive and non competitive available
-heterogenous and homogenous
- advantages→ sensitive, specificity, automated, long reagent shelf life
.disadvantages → quenching of lightemission by some biological materials
- commonly used
153
Describe hypersensitivity type I
-IgE- mediated
-"anaphylactic"
- release of mediators from most cells and basophils
- on set of symptoms is immediate
-examples
→ anaphylaxis
→ hay fever
→ asthma
→ food allergy
154
Describe hypersensitivity type II
-"cytotoxic"
- key reactants are IgG or IgM complement and cellular antigens
- cyto lysis due to antibody and complement
- immediate of onset symptoms
- examples
→transfusion reactions
→ hemolytic disease of a newborn
→ autoimmune hemolytic anemia
155
Describe hypersensitivity type III
-is immune complex
- it includes IgG, IgM, complement and soluble antigens
- it deposits antigen antibody complexes in the tissues
-immediate onset of symptoms
- examples
→ artherus reaction
→ serum sickness
→SLE
→ rheumatoid arthritis
156
Describe hypersensitivity type IV
-T cell dependent
-key reactants → T-cells
- release of cytokines
- onset of symptoms is delayed
- sensitization after first contact with antigen
And then symptoms upon re-exposure
- examples
→ contact dermatitis hypersensitivity
→ pneumonitis
→ tuberculous skin test
157
What are 2 nontreponemal tests for syphilis
①VDRL
②RPR
158
Describe VDRL (syphilis)
-flocculation→ it detects reagin which is the antibodies against cardiolipin that is in serum of patients with syphilis.
- antigen is cardiolipin
- positive reaction is microscopic clumps
-specimen is inactivated serum or spinal fluid
- reactivity during disease may be negative in primary stage
-titer usually peak during secondary and early late stages
-titer in late stages,even untreated, more rapid decline with treatment
-becomes non reactive one to two years following
Successful treatment now
-false positives→ can be biological with infectious mono, infectious hepatitis, malaria, leprosy, lupus, rheumatoid arthritis, advanced age and pregnancies
- screening test and should be confirmed treponema test
159
Describe RPR (syphilis)
- Flocculation → detects reagin
-antigen is cardio lipin combined with charcoal
-macroscopic agglutinate
- speciemen are serum
-inactivation not required
- same reactivity and false positives as VDRL
- used for screening and treatment monitoring
- for screening test → reactive should be confirmed by treponema test
160
What are the 3 treponomal test for syphilis?
①FTA-ABS
② TP-PA
③ELISA
161
Describe FTA-ABS for syphilis
- Antibody absorbent test
- defects antibody to T. Palladium
-reagents
→absorbent non-pathogenic treponema such as reiter stain
→ slides with Nichols' strain of t, palladium
→ fluorescences labeled anti-human globulin
-a positive reaction in this is the fluorescence
- specimens→ serum and spinal fluid
- reactivity of disease is usually positive before Reagan tests are.
-false negatives→ primary syphiliscusually positive for life)
162
Describe TP-PA (syphilis)
- Antibody is to t, palladium
-reagents → colored gelatin particles coated with treponemal antigen
-positive reaction is an agglutination of sensitized gel particles.there's a smooth over a surface of wells
-specimen is serum
- reactivity→ not as sensitive in primary syphilis as FTA, sensitivity y is close to 100% in secondary syphilis and positive in late stages
163
Describe ELISA (syphilis)
-Detects antibody to T palladium
- reagent is enzyme labeled treponemal antigen
-positive reaction is color development following addition of substrate
- speciemen is serum
- reactivity→ highly sensitive in primary syphilis but decreases in later stages
164
If RPR and FTA are reactive, what is the interpretation?
- positive for syphilis
165
If RPR is reactive and FTA is non-reactive, what is the interpretation
- Negative for syphilis
166
Describe serological testing for anti-streptolysin O (ASO)
-group A strep infection, rheumatic fever, and post streptococcal glomerular nephritis
- common test is nephlometry
- uses recombinant streptomycin antigen
- if antibody is present, antigen-antibody complex that forms and an increase in light scatter
-replaces classic neutralization method
167
Describe serological test for Anti-DNase B
- Diagnoses sequel of group a strep, rheumatic fever, glomerular nephritis following skin infection
- common methods→ EIA and nephlometry
- High specific
-may be positive when ASO is negative
168
Describe serological test of streptozyme
- Diagnosis sequel of group a strep infections
- slide agglutination test it
-uses RBCs coated with several streptococcal antigens
-moRe false positives and false negatives Are seen with this test
- should be used with ASO and antii-dnase B
-serial titers should be performed with this
169
Describe serological testing for helicobacter pylori antibodies
- Diagnose gastric and duodenal ulcers caused by H. Pylori
- method of testing → ELISA, rapid test, and PCR
- most tests detect IgG
-25% decrease in titer→ successful treatment
- antibodies will remain for a year
-positive rapid test should be confirmed by ELISA
170
Describe serological tests for mycoplasma pneumonia
- Diagnosis primary atypical pneumonia
- most common test methods → EIA, agglutination, IFA, and molecular methodsthat are available
- contest for IgM and IgG antibodies
- replaces cold agglutinin ( was non specific)
171
Describe serological test for rickettsial antibodies
- Diagnose typhus, Rocky Mountain spotted fever and others
-gold standard is IFA and micro-IF
-PCR is available
172
What are the 2 tests for infectious mono
① heterophil antibodies
②EBV - specific antibodies
173
Describe serological testing for heterophile antibodies (IM
- Nonspecific antibodies that agglutinate horse, sheep and bovine RBCs
- heterophile antibodies→ antibodies that react with similar antigens from different species
- occurrence → 90% of patients develop first n the first month of illness
- can persist for one year
-negative and 10% ot adults and up to 50 percent of children with IM
-if they are symptomatic and heterophile negative→ test for EBV- specific antibodies
-testing method→ rapid latex agglutination, solid phase immunoassays
- antigen is a puntied bovine RBC extract and typically screening tests
174
Describe EBV- specific antibodies
-this has specific antibodies against epstein-barr virus
-these antigens present in different phases of infection
-early → early antigen
- late → is viral capsule capsid antigen which is VCA
-Latent→EBV nuclear antigen (EB-NA)- occurance - the anti -VCA IgM appears at onset of symptoms and disappears in about 3 months
- anti-VCA IgG appears at onset of symptoms and will persist for life
-EB-NA present during convalensenCE
- acute infection would include the anti-VCA IgM and IgG and anti-EA.
- past infection →anti-EB-NA, anti -VCA IgG
-testing method → indirect immunoflurence assay, ELISA chemo luminouscent assay
-IFA is gold standard but time consuming and harder to interpret
- molecular testing use for immunocompromised patients
175
Describe hepatitis A and test
- Test for the total anti-hepatitis A virus
- indicates past infection and immunity
- can test for IgM anti-HAV→ acute infection
176
Describe hepatitis B tests
- Can test hepatitis B surface antigen → signify acute or chronic infection or infectivity
-first serological marker to appear
- used to screen donor blood
- positives should be confirmed with repeat testing and another assay such as hepatitis B surface antigen neutralization or hep B virus DNA
- hepatitis BE antigen→ signifies acute or chronic infection and indicates high degree of infectivity
- total anti-HBC → signifies current or past infections or corner.
- predominantly IgG and will persist for life
- IgM anti- hb core → current or recent infection, first antibody to appear
- detect hbv infection when the hepatitis B surface antigen is no longer detected (window period)
- anti-hbe→ signifies recovery and reduced infectivity
-anti-HBS→ signifies recovery and immunity
-hep B test → DNA→ signifies current infection, detected 21 days before the HBS antigen and use to monitor viral load
177
Describe hepatitis C test
- Anti -HCV → signifies acute, chronic, and previous ' infection
- positive should be confirmed by recombinant immunoblot assay
-HCV RNA → indicates current infection
-Used for new 1009 testing, blood organ donor screening,
-HCV genotypingto determine optimal treatment
178
Describe hepatitis D tests
-IgM anti-HDV → acute or chronic infection
-HDV is a defective viRUS that can only outer in presence of hep B
-IgG anti-HDV → indicates recovery or chronic infection
-HDV RNA → current infection
- marker of active vi therapy ral replication
- used to monitor
179
Describe hepatitis E tests
- Currently not approved by FDA for use in the United States
180
Hepatitis A profile
Acute → IgM anti-HAV+
Recovery→ total anti-HAV+
181
Describe profile for acute hepatitis B
-HBS antigen +
-total- anti-HBC +
-IgM anti HBC +
-anti-HBS -
182
Describe profile for recovery from hep B
-HBS-antigen+
-total anti-HBc+
-anti-HBs+
183
Describe profile chronic hepatitis B/ carrier
-HBs- antigen+
-total anti-HBc+
-IgM anti-HBc-
-Anti-HBs-
184
Describe profile of Hep B immunization
- HBs- antigen-
-anti-HBc-
-anti-HBs+
185
What are HIV markers?
- Viral RNA → is detectable within days of infection
-PG-24 antigen→ cove code for nucleic acids, detectable in 2 to 3 weeks and becomes undetectable as antibodies are developed and detectable again in late stages
- IgM antibody → usually detected in 2-8 needs and its transient, peaks at 1-2 weeks and undetectable 1-2 weeks later
-lg antibody → detectable shorty after the IgM antibody, gradually increases n titer for several months and its also long lasting
186
What are HIV screening test?
①EIA/ELISA
②rapid tests
③ nucleiC acid amplification testing (NAAT)
187
Describe EIA screening for HIV
-first generation →IgG antibodies to HIV one only last 6-12 weeks)
-second generation → lgG antibody to 1 and 2 types of HIV
- third generation → IgG and IgM antibodies to HIV 1 and 2. Detected in 3-4 weeks
-fourth generation →(current) IgG and IgM antibodies to HIV 1 and 2 plus testing for p24 antigen (detect in 2 weeks)
188
EIA/CIA p 24 antigen without HIV antibody indicates what?
An acute infection
189
EIA/CIA p 24 antigen with HIV antibody indicates what?
Established infection
190
Describe rapid tests for HIV screening
- Includes IgG and IgM antibody to HIV which can pick up w/ an infection 4-12 weeks
-testing → immunochromatic graphic assays
- Specimen → blood, serum, and oral fluids
191
Describe NAAT HIV screening
-HIV RNA→ window period is 5 days
-not cost effective
- used for screening blood donors and infants
192
What are false positives in ELISA testing for HIV?
- Heat inactivation of serum
- repeated freezing /thawing of serum
-autoantibodies
-multiple pregnancies
- liver disease
-administration of immunoglobulin
- administration of certain vaccines
- some malignancies
193
What are false negatives in screening for HIV?
- Blood drawn before seroconversion
- hypogammaglobulinemia
- immunosuppressive therapy
- strain of HIV not detected by assay
- technical errors
194
What are the HIV confirmatory/supplemental test?
① western blot
②IFA
③NAAT
195
Describe western blot HIV test
- detects antibodies to HIV
-traditional confirmatory test but not as sensitive as EIA anD NAAT
-interpretation is controversial because most labs report positive it atleast 2 of the following 3 bands ave present →P24, gp41, gp120 or gp160
-NAAT required folloWING negative or indeterminant results
- time consuming and difficult to interpret
196
Describe IFA for HIV screening
- detects antibody to HIV
- sensitive and specific compared to western blot
-expensive and subjective in testing results
197
Describe NAAT testing for HIV
- Detects HIV RNA specifically
-qualitative test used for conformation
198
What are the tests used to stage and monitor HIV?
① CD4 T cell count
②HIV-1 viral load assays
199
Explain CD4 T cell count for monitoring HIV
-HIV infects CD4 cells, number declines as disease ' progresses
- >200 per microliter defines AIDS
-used to monitor therapy to see iF cells were declining or staying steady or improving
-performed every 3-6 months
-flow cytometry is gold standard
200
Describe HIV-1 viral load assays
- Qualitativ eNAAT to determine pkesma HIV RNA
- used to predict progression, determine when to start retro-viral therapy and monitor response to therapy
-test 2-8 weeks after start of therapyand then every 3-4 months
201
What are the screen in test for SLE?
① fluorescent anti-nuclear antibody (FANA)
②EIA anti-nuclear antibody (EIA -ANA)
202
Describe fluorescent antinuclear antibody (FANA) screening for SLE
-high sensitivity → 95-100%
- low specificity
- antibodies present in other autoimmune diseases can interfere or cause false positive
-2% of healthy individuals and 75% of the elderly will also test positive
-dilution tested to eliminate lower titer reactions in normal population
-cut off for dilution is greater than or equal to 180
-end titer should be reported and are usually higher in SLE patents.
203
Describe indirect immune fluorescence of SLE screening
- Substrate of human epithelial tumor on line hep-2
- detects antibody to greater than 100 autoantigens
-Staining patterns do not need to be reported anymore
-very labor intensive and subjective
-still considered the gold standard
204
Describe EIA antinuclear antibody testing for SLE
- Not as sensitive
- specificity is low
-Easier to perform and less expensive
- can be automated
-interpretation is not subjective but notas many antigens we can test for
205
What are tests for specific antinuclear antibodies?
①anti-dsDNA
②anti-sm
③antihistone, anti-DNP, anti-ss-ARo, anti-ss-B/la and anti-nRNP
④extractable nuclear antigen antibiotics (ENA)
206
Describe anti-dsDNA testing for specific anti-nuclear antibodies
- Low sensitivity but high specificity for SLE because its uncommon in other diseases or normal individuals
- most specific antibody for SLE
-titers correlate with disease activity
- peripheral of fluorescent pattern is seen in IFA
- other methods → EIA, immunoblotting, and immune diffusion
207
Describe anti-sm test for specific anti-nuclear antibodies
-has low sensitivity, but high specificity for SLE
- uncommon in other diseases and normal individuals
- coarsely speckled pattern with the IIF
- other methods →EIA, immunoblotting and immune diffusion
208
Describe antihistone, anti-DNP, anti-ss-ARo, anti-ss-B/la and anti-nRNP tests for specific antinuclear antibodies
-low in sensitivity and specificity for SLE
- not used for diagnosing SLE but other tissue diseases
- Other methods →IIF,EIA, immunoblotting, and immunodiffusion
209
Describe extractable nuclear antigen (ena) antibodies tests for specific anti-nuclear antibodies
- Low sensitivity for SLE
-methods that can use→ immunOdiffusion, ouchterlony double diffusion
- typically test for the antibodies to SM
- can be SSA, SSB and RNP
- precipitation of lines of identity and non identity are reviewed
-new method→ multiplex bead assay
→use specific antigen coated beads and flow cytometry to detect multiple ANAs simultaneously
210
What are serological tests for rheumatoid arthritis?
① rheumatoid factor
② anti-cyclic citrulinated peptide antibody (anti-ccp)
211
Describe rheumatoid factor serological test For RA
- Common methods → agglutination, ELISA, and nephlometry
- autoantibody→ IgM Against the IgG
- positive in 70-80 % of patients with RA
- not specific for RA
- its present with other autoimmune diseases and infections and in some normal individuals
-agglutination only detects IgM RF but ELISA and nephlometry can also detect IgA and IgG classes of RF
-can be automated
212
Describe anti-cyclic citrulinated peptide antibody (Anti-CCP)
-most common method → ELISA
- more specific for RA than the RF test
- associated with move severe form of rheumatoid arthritis
213
What are 4 interpretations of serological tests?
① greater than or equal to 4 fold increase in titer
②IgM antibody
③IgG antibody
④IgG antibody in newborn
214
Describe it you see greater than or equal to 4-fold increase in titer
- From acute to convalescent speciemen drawn 10-14 days later is diagnostic of disease
- diagnostic of a disease process happening
215
Describe if you see IgM antibodies in serological testing
- Sign of recent infection
216
Describe if you see IgG antibodies in serological testing
- Sign of immunity
217
Describe if you see IgG antibodies in a newborn: in serological testing
- Material antibody
