Immunology & Serology Part 2 Flashcards
HLA associated with Rheumatoid arthritis
HLA DR4
Autoantibodies associated with rheumatic fever
Anti-streptococcal Ab
Antibodies react with heart tissues
Rheumatic Fever
Patient commonly has a positive ASTO/ASO
Post Streptococcal Glomerulonephritis
Autoantibodies associated with Goodpasture’s syndrome
Anti-basement membrane (alveolar and glomerular)
Affects both lungs and kidney
Goodpasture’s syndrome
Autoantibodies associated with Idiopathic thrombocytopenic purpura
Antiplatelet antibodies
Destruction of own platelets
Idiopathic Thrombocytopenic Purpura
Autoantibody associated with Autoimmune hemolytic anemia
Anti-RBCs
Destruction of RBCs
Autoimmune hemolytic anemia
Autoantibody associated with primary biliary cirrhosis
Anti-mitochondrial antibodies
Immune reaction in the intrahepatic interlobular bile ducts
Primary biliary cirrhosis
Autoantibody associated with chronic active hepatitis
Anti-smooth muscle antibodies
Autoantibody associated with Croh’s disease
Perinuclear antineutrophil cytoplasmic (p-ANCA 10 – 30%)
Autoantibody associated with primary sclerosing cholangitis
Perinuclear antineutrophil cytoplasmic Ab (P-ANCA)
Autoantibody associated with Wegener’s granulomatosis
Antineutrophil cytoplasmic (c-ANCA)
Granulomatous inflammation. Necrotizing glomerulonephritis is common
Wegener’s granulomatosis
Autoantibodies associated with Multiple Sclerosis
Anti-myelin sheath antibodies
Chronic progressive inflammatory disease with demyelination of the nerves
Multiple sclerosis
Autoantibodies associated with myasthenia gravis
Anti-acetylcholinesterase
Neuromuscular transmission disorder
HLA B8
Myasthenia gravis
Autoantibodies associated with Insulin-dependent DM
Anti-glutamic acid decarboxylase
Anti-b-islet cells
Anti-insulin antibodies
Selective destruction of beta cells of the islets of Langerhans in the pancreas > leads to TYPE I DM
HLA DR3 and HLA DR4
Insulin-dependent DM
Autoantibody associated with anti-adrenal cells
Addison’s disease
Autoantibodies associated with pernicious anemia
Anti-parietal cells
Anti-intrinsic factor
Destruction of the parietal cells of the stomach mucosa
Pernicious anemia
Autoantibody associated with Grave’s disease
Anti-TSH receptor
autoAb reacts with the TSH receptor of the thyroid glands leading to overstimulation > hyperthyroidism
Grave’s disease
Autoantibodies associated with Hashimoto’s thyroiditis
Anti-thyroid peroxidase
Anti-microsomal
Anti-thyroglobulin
Destruction of the thyroid gland > leads to hypothyroidism
Hashimotos thyroiditis
Benign or malignant condition that results from a single clone of lymphoid-plasma cells producing elevated levels of a single class of immunoglobulin, referred to as M protein, paraprotein or monoclonal protein
Monoclonal gammopathy
AKA lytic bone disease. Plasma neoplasm that leads to overproduction of immunoglobulins particularly IgG (IgM and IgA may also be increased).
BJP is present in the urine.
IL-6 is the growth factor for plasma cell transformation
Multiple Myeloma
Infiltration of lymphoplasmacytic cells into the bone marrow.
Increase in IgM and cryoglobulins
Waldenstrom’s macroglobulinemia
Presence of monoclonal proteins but MM signs and symptoms are absent
Monoclonal gammopathy of undetermined significance
Only kappa and lambda chains are produced
BJP is also present
Light chain disease
AKA Franklin’s disease. Leads to overproduction of heavy chains, no production of light chains.
Alpha chain disease is the most common disorder
Heavy chain disease
Consist of one or more heavy chain classes and both light chain types
Polyclonal gammopathy
Failure of the immune system to protect against diseases or malignancies
Immunodefiency
Caused by genetic or developmental defects of immune system
Primary immunodeficiency
Loss of immune function due to aging, exposure to infectious agents and immunosuppression
Secondary acquired immunodeficiency
x-linked recessive disorder
Defect in the production of NADPH oxidase resulting in decreased intracellular killing of ingested organisms
Chronic Granulomatous Disease (CGD)
Test used for diagnosis of CGD
Nitroblue tetrazolium test (NBT)
Deficiency in myeloperoxidase which is an important microbicidal agent in neutrophils
Myeloperoxidase deficiency
Impaired chemotaxis and phagosome degranulation
Presence of giant cytoplasmic granules
Chediak-Higash syndrome
Neutrophils demonstrate defective chemotaxis
Job’s syndrome
Defective chemotactic response and random movement
Lazy Leukocyte Syndrome
Deficiency of tuftsin, a phagocytosis-promoting serum tetrapeptide that is cleaved from an Ig like molecule, leukokinin, in the spleen
Tuftsin Deficiency
Lack of CD 18
Leukocyte Adhesion Deficiency
Genetic defect in the long arm of X chromosome
-Block in the maturation of pre B cells
-Recurrent infections and low serum levels of immunoglobulin and lack of B cells
Bruton’s C-Linked agammaglobulinemia
Arrest in the development of B cells is the cause
Selective Ig Deficiency (dysgammaglobulinemia)
Most common form of selective Ig deficiency. Recurrent sinopulmonary infections. IgA levels lower than 5 mg/dL
Selective IgA deficiency
Results when the onset of Ig synthesis is delayed. Hypogammaglobulinemia is common in infnats between the 5th – 6th month of life.
Transient hypogammaglobulinemia
Faulty development of 3rd and 4th pharyngeal pouches. Associated with defect if chromosome 22
Digeorge syndrome (Congenital Thymic Hypoplasia)
Thymic dysplasia resulting in decreased to absent T cell mediated immunity. Usually have marked lymphadenopathy and hepatosplenomegaly
Nezelof’s Syndrome
Impaired synthesis of MIF (Migration Inhibitory Factor) by T cells
Chronic Cutaneous Candidiasis
Deficiency in the expression of MHC II gene products on the T cell surface leading to a failure of antigen presentation
Bare Lymphocyte Syndrome
Combined defect of both humoral and cell mediated immunity. Autosomal recessive type is associated with adenosine deaminase deficiency. Rarely survive beyond age 1 if no treatment is done.
Severe Combined Immunodeficiency Disease (SCID)
Mutation in the WASP gene. Triad of eczema, thrombocytopenia, and immunodeficiency
Wiskott Aldrich Syndrome
Mutation in SH2DAI/SAP gene resulting in weakening of both cellular and humoral immunity
Vulnerability to EBV infection
X Linked Lymphoproliferative Disease (Duncan’s Syndrome)
Exaggerated response to a typically harmless antigen that results in injury of tissue, disease or even death.
Hypersensitivity
Anaphylactic or immediate hypersensitivity reaction
Type I
Examples of Hypersensitivity Reaction Type I
Hay fever
Asthma
Food allergies
Urticaria
Anaphylactic reaction
Cytotoxic or antibody-mediated hypersensitivity reaction
Type II
Examples of Type II hypersensitivity reaction
Transfusion reactions
HDN
Autoimmune HA
Grave’s disease
Myasthenia Gravis
Goodpasture Syndrome
HTR
Drug-induced HA
Warm-induced HA
Immune complex hypersensitivity reaction
Type III
Examples of Type III hypersensitivity reactions
SLE
RA
Post-strep GN
Arthus reaction
Farmer’s lung
Serum sickness
T cell mediated or delayed hypersensitivity reactions
Type IV
Examples of Type IV hypersensitivity reactions
Contact dermatitis
Tuberculin test
Poison ivy
Mantoux reaction
MS
Hashimoto’s thyroiditis
Needle or pricking device is used to introduce a small drop of allergen into the upper layer of skin of the forearm or back. Positive result is wheal and flare with a size of 3-4 mm
Percutaneous / Prick / Puncture Test
Greater amount of antigen is used and is more sensitive than percutaneous test but higher chance of anaphylactic reaction
Intradermal test
Used to measure the amount of specific IgE
Radioallergosorbent Test (RAST)
Patient serum is incubated with allergen coated cellulose sponge > washed > enzyme labeled anti-IgE is added > washed > add the chromogenic substrate > fluorescence if IgE specific to the allergen is present
Noncompetitive Fluoroimmunoassay
Patient IgE competes with radiolabeled IgE for a limited antibody binding site attached in a solid phase
Radioimmunosorbent Test (RIST)
Detects in vivo sensitization of RBCs and to check if a patient is suffering from HTR, HDN, AIHA,
Direct Antiglobulin Test
Contains antibodies directed to IgG, C3b, C3d
Polyclonal AHG
Determines whether IgG, C3b, C3d
Monoclonal AHG
Detects in vitro sensitization of RBCs and is used for antibody screening, identification, crossmatching and weak-D testing
Indirect antiglobulin test
Nonadsorbent adhesive patch containing allergens is applied in the back of the patient > check for redness over the next 48 hours
Patch testing
Skin testing for exposure for M. tuberculosis
Mantoux method
Particulate antigens such as cells aggregate to form larger complexes when a specific antibody is present
Agglutination
Antigen-antibody combination through single antigenic site
Sensitization phase
Sum of interaction between antibody and multiple antigenic determinant on a particle
Lattice formation
Insoluble particles react with an antibody which results in aggregation or clumping
Direct agglutination
Agglutination is caused when an antibody reacts with an antigen that is ___ in the cell
Naturally present
Examples of direct immune agglutination
ABO blood grouping (Hemagglutination)
Aggregation of indicator cells (sRBCs) but not caused by antigen-antibody interaction
Direct Non-immune
Examples of Direct non-immune agglutination
Viral hemagglutination test
Used to detect if an antibody is present. Reaction where antigen is attached to a carrier particle
Indirect or Passive Agglutination
Examples of Indirect/Passive Agglutination
Rapid Latex Agglutination for RA
Used to detect if antigen is present in a patient sample. Antibody attached to a carrier particle
Reversed Passive Agglutination
Examples of Reversed Passive Agglutination
CRP assays and haptoglobin detection
Based on competition between particulate and soluble antigen for limited antibody-binding sites
Agglutination inhibition
Indicator of positive reaction for agglutination inhibition
Lack of agglutination
Examples of agglutination inhibition
Pregnancy test / HCG
Used to detect patient antibodies while utilizing RBCs as indicator cells
Viral Hemagglutination inhibition
Positive result for viral hemagglutination inhibition
No agglutination
Uses antibodies directed against the Fc portion of a human antibody. Used to detect incomplete antibodies.
Antihuman Globulin Test
Used to detect in vivo sensitization
DAT
Examples of DAT
HDFN
HTR
AIHA
DIHA
Used to detect in vitro sensitization
IAT
Examples of IAT
Antibody screen
Antibody identification
Crossmatching
Weak D testing
Antibody is adsorbed in bacteria, most frequently used carrier bacterium is S. aureus due to presence of protein A
Coagglutination
Uses gold as carrier
Sol Particle Immunoassay
Uses dye as carrier
Disperse Dye Immunoassay
Most sensitive, uses latex as carrier
IMPACT/ Immunoassay by particle counting
Combination of soluble antigen with soluble antibody to produce insoluble complexes that are visible
Precipitation
Presence of excess antibody leading to false negative reaction
Prozone
Remedy of prozone
Dilute patient sample
Presence of excess antigen, poor crosslinking of immune complexes leading to false negative reaction
Post-zone
Remedy for post-zone
Wait for a week or two, then retest the patient
There are equal amounts of antigen and antibody, leading to maximum precipitation
Zone of equivalence
Overall strength and is the sum of affinities of antigen-antibody interaction. Strength with which a multivalent antibody binds with multivalent antigen
Avidity
Interaction of single Fab site and a single epitope
Affinity
Soluble antigen and/or antibody diffuses through the gel pore until optimum concentration is achieved and forms a stable immune complex
Precipitation in a Gel Medium
One reactant diffuses through the gel. Either antigen (more common) or antibody
Single Diffusion
Reactants move only in one direction (up or down). Tube is commonly used.
Single dimension
Reactants move radially
Double dimension
Single diffusion single dimension
Oudin
Single diffusion double dimension
Radial immunodiffusion
Double diffusion single dimension
Oakley and Fulthrope
Double diffusion double dimension
Ouchterlony and Elek
Principle: Ag diffuses through the gel containing immobilized Abs forming insoluble Ag-Ab complexes
Oudin
Circular wells cut into the gel (with antibody) and antigen is loaded. Antigen diffuses producing a ring of precipitate
Radial immunodiffusion
Measurement is taken while the disc is still expanding. Read at 18 hours after loading
Kinetic (Fahey/McKelvy)
Measurement is taken when the ring has stopped expanding, allowing maximal precipitation. Read at 24-72 hours
Endpoint (Mancini)
Principle: Both Ag and Ab both diffuse towards each other. Antibodies place first in the tube followed by neutral agar. Lastly, antigen is added on the top of the part of the mixture
Oakley and Fulthrope
Antigen and antibody diffuses radially through a semisolid medium
Ouchterlony
Fused band or precipitate, indicating identical antigens
Serological identity
Spur formation is seen, antigens are not identical but have the same determinant. Spur always points toward the simpler antigen.
Partial identity
Precipitate cross react serologically distinct
Non-identity
Double spurring
Double partial identity
Molecules are separated based on their net charge when an electrical field is applied to the system
Electrophoresis
Single diffusion single dimension electrophoresis
Rocket IE/ Technique of Laurell
Single diffusion double dimension electrophoresis
Ressler’s Method/ Double crossed IE/ Crossed IE
Double diffusion single dimension electrophoresis
Counter IE/ countercurrent electrophoresis/ double electroimmunodiffusion
Double diffusion double dimension electrophoresis
Classic immunoelectrophoresis or IEP/ Grabar and Williams
Height of the rocket is proportional to antigen concentration
Rocket IE
Involves two electrophoretic separations. Antigen and antibody complexes form mountain peaks
Ressler’s Method
Reactants move linearly towards each other due to the electric current applied
Counter IE
Used for identifying multiple myeloma
Classic immunoelectrophoresis
All reactants are mixed simultaneously and labeled antigens compete with unlabeled patient antigen for limited antibody-binding site of the antibody
Competitive labeled assay
The relationship of the measured label is ___ to the amount of patient antigen
Inversely proportional
Captured antibody is adsorbed to a solid phase medium. Patient antigen is allowed to react with the antibody. Labeled antibodies are then added to the mixture.
Non competitive labeled assay
The relationship of the measured label is ___ to the amount of patient antigen
Directly proportional
Discovered by Rosalyn Yalow, uses radioactive substances as labels.
Radioimmunoassay (RIA)
Gamma emitters
(125I most common and 131) are measured by ___
Gamma counter
Beta emitters
(3H tritium) measured by ____
Liquid scintillation counter
Antigen in patient serum competes for antibody-binding sites with a known quality of antigen to which a radioactive label is attached
Competitive binding assay
Antibody is bound to a solid phase medium > analyte is added > solid phase is washed > second antibody that is labeled is added > preparation is washed and measured
Non- competitive assay (imunoradioteric assay)
Most commonly used enzyme in enzyme immunoassay
Horseradish peroxidase
Do not need a separation step, simpler to perform but less sensitive. Bound enzyme are catalytically inactive
Homogenous
Requires a separation step of bound and unbound labels. Bound enzymes are catalytically active
Heterogenous
Enzyme label antigen competes with unlabeled antigen form the patient for the limited number of antibody-binding sites. Enzyme activity is inversely proportional to the concentration of the test substance
Competitive ELISA
Patient antibody is incubated with a solid phase antigen. Signal detected is directly proportional to the patient antibody
Noncompetitive ELISA
Patient antigen is incubated with solid phase antibody. Directly proportional
Capture assay or sandwich immunoassay
antigen in the sample competes for limited antibody-binding sites with an enzyme labeled antigen
homogenous EIA
uses a fluor/ fluorochrome which has the ability to absorbed light at shorter wavelengths and emit light with lower energy with longer wavelength (visible spectrum)
immunofluorescence immunoassay
FITC emit ___
green color
Tetramethylrhodamine emits
red color
solid phase antigen fixed to a slide is incubated directly with a fluorescent labeled antibody. if specific antigen us present, fluorescence will be observed
Direct immunofluorescent assay
patient antibody is reacted with specific antigen fixed to a microscopic side
Indirect Immunofluorescent assay
solid phase antigen is exposed to a patient serum > labeled antibody is then added > washed > measured. If a patient has an antibody, the labeled antibody will not bind to the antigen
Inhibition immunofluorescence
based on the change of polarization of fluorescent light emitted from a labeled molecule when an antibody binds it
Fluorescence Polarization Immunoassay
invented by Kary/Kerry Mullis in 1993
- an in vitro method that amplifies low levels of specific DNA sequences to higher levels for further analysis
Polymerase Chain Reaction (PCR)
denaturation temperature
95 deg C
Annealing temperature
52 to 55 deg C
Extension temperature
72 deg C
PCR process is repeated approximately ___ times
30
If the nucleic acid of interest is RNA, it can be converted to cDNA in the initial step of PCR by using ____
reverse transcriptase
useful in identification of HIV and Hepatitis C
RT-PCR
Measures the amount of amplicons in each cycle with the use of ethidium bromide / SYBR green / TaqMan probes, which reduces the time it takes to run a PCR
qPCR
uses numerous primers within a single reaction to amplify nucleic acid fragments from different targets
Multiplex Polymerase Chain Reaction
analyzed using agarose gel electrophoresis after ethidium bromide staining.
Conventional method
does not require enzyme digestion or electrophoretic separation of DNA fragments
Dot blot
DNA from the patient is added and immobilized in the membrane. labeled probe is then added
Reverse Dot Blot
DNA is denatured with restriction enzymes to create DNA fragments
Southern Blot
mRNA is separated by electrophoresis and blotted
Northern blot
proteins are separatd electrophoretically and identified through the use of labeld antibodies specific for the protein of interest
Western Blot
AKA great pox, evil pox
Syphilis
Causative agent of Syphilis
Treponema palladium subspecies palladium
Presence of hard chancre painless, firm, raised with well-defined lesion. Seen 10 – 90 days after infection. Stage lasts for 1-6 weeks. Highly contagious
Primary Syphilis Infection
Most contagious stage, characterized with lymph-adenopathy, malaise, fever, pharyngitis, and rash (indicating disseminated organism).
Observed 1-2 month.
Condyloma lata
Secondary syphilis infection
Asymptomatic syphilis infection. diagnosis can only be made by serological methods.
Latent syphilis infection
Neurosyphilis, the most common complication. Gummas (granulomas). Can affect cardioivascular system. Tabes dorsalis: general paralysis
Tertiary syphilis infection
AKA cardiolipin, a diphosphatidyl glycerol (phospholipid) derived from the host
Wassermann antigen
Non virulent Treponemal antigen
Reiter strain
Virulent Treponemal antigen
Nichol strain
AKA regain antibodies. It is anticardiolipin/ anti-lipoidal antibodies. Produced by infected individuals against components of their own bodies
Non-treponemal antibodies
Produced against the antigen of the organism themselves. Specific for outer membrane protein, endoflaggelar protein
Treponemal antibodies
Treponemes are identified eon the basis of ____ and ____
Corkscrew morphology and flexing motility
Specimen of choice for Syphilis Dark field microscopy
Serous fluid
Non-Treponemal test
Principle: rapid slide microflocculation or precipitation
Sample: serum/CSF
Venereal Disease Research Laboratory (VDRL)
In VDRL, serum should be heat inactivated by heating at ___
56 deg C for 30 minutes
If the serum sample is not used for 4 hours after heat inactivation, it should be reheated at ____
56 deg C for 10 minutes
Equipment used for VDRL when sample is serum
14 mm diameter
Equipment used for VDRL when sample is CSF
16 mm diameter
Qualitative serum VDRL
Gauge:
Drops:
Bevel:
RPM:
Qualitative serum VDRL
Gauge: 18
Drops: 60/mL
Bevel: none
RPM: 180 RPM for 4 mins
Quantitative serum VDRL
Gauge:
Drops:
Bevel:
RPM:
Quantitative serum VDRL
Gauge: 19 or 23
Drops: 75/mL or 100/mL
Bevel:none
RPM: 180 RPM for 4 mins
CSF VDRL
Gauge:
Drops:
Bevel:
RPM:
CSF VDRL
Gauge: 21 or 22
Drops: 100 / mL
Bevel: none
RPM: 180 for 8 mins
Non-Treponemal Test
Principle: flocculation or charcoal agglutination
Recommended for screening test
Sample: serum
Slide: 18 mm ring diameter
Delivery needle: 20 gauge, 60 drops/mL, no bevel
Rotation: 8 mins for 100 RPM
Rapid Plasma Reagin (RPR)
3 other nontreponemal test
Toluidine Red Unheated Serum Test (TRUST)
Unheated Serum Reagin (USR)
Reagin Screen Test (RST)
Biological False (+) of Syphilis
Tuberculosis
Rheumatoid arthritis
Infectious mononucleosis
Pregnancy
Leprosy
Systemic lupus erythematosus
Measles
Malaria
Old age
Treponemal Test
Old reference method for confirmatory test.
Serum should mix with live treponemes or Nichols strain from testicular chancre of a rabbit and complement
Treponemal Pallidium Immobilization Test
Reporting for Treponemal Pallidium Immobilization Test
Positive:
Doubtful:
Negative:
Positive: >/= 50% of the treponemes are immobilized
Doubtful: 20 – 50%
Negative: < 20%
Treponemal Test
Serum is heat inactivated, then added with sorbent consisting of (Reiter strain) > Nichols strain of T. palladium is fixed in the slide > fluorescence microscopy
Fluorescent Treponemal Antibody Absorption Test (FTA Abs)
Reporting for FTA Abs:
Negative: No fluorescence
Minimal reactive: 1+
Reactive: >/= 2+
Employs blood cells coated with T. palladium antigens
-uses turkey RBC
Hemagglutination Tests
Reporting of Hemagglutination test
Reactive: smooth matte at the bottom of the reaction well
Non-reactive: compact button of cells
Patient serum is diluted in a microtiter plate and incubated with gel particules sensitized with T. palladium
Particle Agglutination (Serodia TP-PA Test)
Reporting of Particle Agglutionation
Positive: agglutination resulting to smooth mat
Negative: compact button
Deafness, keratitis and Hutchson’s teeth (Hutchinsonian Triad)
Congenital syphilis
Recommended test to confirm congenital syphilis
Western Blot
Most sensitive method for detection of congenital syphilis and primary syphilis (maybe used as an alternative for dark field microscopy)
PCR
Yaw
MOT: direct contact with skin lesion
T. palladium subspp pertenue
Bejel
MOT: direct contact (mouth to mouth or through utensils)
T. palladium subspp endemicum
Pinta (skin ulcers)
MOT: direct contact with skin lesion
T. carateum
Causative agent of typhoid fever
Salmonella typhi
Most common cause of Salmonellosis in N. America
Salmonella enteritidis
Causes typhoid fever, the most severe form
Salmonella typhi
Thermostable somatic antigen, made of polysaccharide
O antigen
Flagellar antigen, made of protein
H antigen
Capsular antigen, associated with virulent strain and indicative of carrier state
Vi antigen / K antigen
Gold standard for the diagnosis of Typhoid fever
Bacterial culture
Principle: direct agglutination
Widal test / Febrile Agglutination test
Dot enzyme immunoassay, which detects serum antibody to antigen dotted on a nitrocellulose membrane
Typhidot test
Ig for definite typhoid fever, acute typhoid fever
IgM (+) and IgM/IgG (+/-)
Ig for previously successfully treated case of typhoid fever. Reinfection with typhoid fever, typhoid carrier
IgG (+)
Ig for not typhoid fever
IgM and IgG (-)
Is a dot enzyme immunoassay for detection of specific IgM to Salmonella typhi
Typhidot-M
Gold standard for serological diagnosis of RMSF
Indirect Immunofluorescence Assay (IFA)
Principle: Direct agglutination
-A febrile agglutinin test that is based on the cross reaction of heterophile antibodies produced in response to rickettsial infection, with antigens in the three strains of Proteus
Weil Felix Reaction
Antigens in Proteus vulgaris
OX – 2 and OX-19
Antigens in Proteus mirabilis
OX-K
Causative agent: S. pyogenes / Group A strep
Disease: URTI, Scarlet fever, skin infection (impetigo, necrotizing faciitis), rheumatic fever, glomerulonephritis
Group A Streptococcus infection
Based on neutralization of hemolytic activity of streptolysin O
Antistreptolysin O (ASTO/ ASO) – Classical / Traditional Antistreptolysin O titer
Slide agglutination screening test in which sheep RBCs are coated with streptolysin, streptokinase, hyaluronidase, DNase, and NADase so that antibodies to any of the streptococcal antigens can be detected.
Multienzyme Test / Streptozyme
Most reliable measurement of recent S. pyogenes skin infection (used if ASTO is negative)
Sensitivity is increased for the detection of glomerulonephritis and rheumatic fever preceded by streptococcal skin infections
Streptococcal Anti-DNase B Determination
DNA is complex with methyl green, if anti-DNAse B antibodies are present, it will neutralize the reagent DNAse B preventing it from cleaving the complex
Classical Neutralization Method
Used for rapid quantitation of Anti-DNAse by measuring light scattering produced by immune complexes
Nephelometry
Causative agent Lyme disease
B. burgdorferi a vector-borne spread by ticks in the genus Ixodes
Second test in CDC-recommended two tier scheme. Recommended are supplemental test for positive for borderline, result from ELISA. Positive IgG blot is serological evidence of Lyme disease
Western Blot / immunoblotting
Most reliable test for Brucella infection if the culture is negative
Agglutination methods
Brucella antigen is printed as black dot
Surface Fixation or the Castaneda Strip Test
Most specific test to detect H. pylori
Culture
Method of choice for H. pylori antibody detection
ELISA
The primary antibody present and detected by serological methods since most infections have become chronic before diagnosis
IgG
Low sensitivity antibody for ELISA
IgA
Lack clinical value of ELISA
IgM
Detects urease activity in gastric mucosal biopsies, ideal for rapid diagnosis
CLOTEST
Positive result for CLOTEST
Bright magenta,
Negative: yellow
Patient ingest radioactive carbon > urea is the metabolized breaking down into ammonia and bicarbonate (excreted in the breath) and radiolabeled carbon is measured by its radioactivity.
Urea Breath Test
Detects the presence of the organism in a fecal sample but cannot distinguish living and dead H. pylori. Used to assess a patient’s bacterial load
Molecular method
Extracellular bacteria, without cell wall but with triple layered cell membrane
Mycoplasma pneumoniae
Diseases caused by Mycoplasma pneumoniae
Primary Atypical Pneumonia (PAP)/ Walking Pneumonia
IgM antibodies, develop in individuals with M. pneumonia
Cold agglutinin
Gold standard for diagnosis. Characterized with fried egg growth
Culture
Most widely used method of detection of M. pneumonia, can test for IgM and IgG. Requires small volume and can test large numbers in automation
ELISA
Detects IgM and IgG, observed under fluorescence microscope
IFA
No longer recommended for diagnosing M. pneumonia infection because some viral infections and collagen vascular disease may also produce cold agglutinins
>/= 64 titer is suggestive of atypical pneumonia
Cold agglutinins
Infectious hepatitis
Short incubation hepatitis
HAV
Viral family of HAV
Picornaviridae
MOT of HAV
Fecal-oral
Incubation period of HAV
15 – 45 days
Serum hepatitis
Long incubation hepatitis
HBV
Viral family of HBV
Hepadnaviridae
MOT of HBV
Sex
Incubation period of HBV
45 – 160 days
Most infectious agent hepatitis.
HBV
Non A, Non B hepatitis (NANB)
HCV
Viral family of HCV
Flaviviridae
MOT of HCV
Blood transfusion
Incubation of HCV
15 – 150 days
Most frequently caused by chronic hepatitis, liver cirrhosis and hepatocellular carcinoma
HCV
Delta agent
Hepatitis Delta virus
HDV
Viral family of HDV
RNA
Hepatitis same as HBV
HDV
Incubation of HDV
30 – 60 days
Coinfection – same time with HBV
Super infection – HBV infection first
HDV
Viral family of HEV
Calcivirade/ Hepeviridae
MOT of HEV
Fecal-oral
Incubation period of HEV
15 – 60 days
Hepatitis associated with high mortality among pregnant women.
HEV
Shed in the feces of infected individuals during incubation and acute stage. Not a useful indicator of disease
HAV Ag
Markers of acute hepatitis, peak during the first month but become undetectable after 6- 12 months. May indicate recent infection
Anti-HAV IgM
Indicate immunity to HAV. Produce either through vaccination of infection
Anti-HAV/ Total Anti-HAV
Can be used to detect RBA in clinical , food and water sampes
HAV RNA
Represents the outer lipoprotein coat (envelope) of hepatitis B virus. Indicates acute infection and infectivity
First serologic marker to appear. Used for screening blood donors. Also known as Australia antigen
HBsAg
Indicates past infection with immunity of immune response to HBV vaccine. It is a marker of immunity and recovery. Protective tier is 10 mIU/mL of higher.
Anti-HBs
Not detectable in the serum, only seen in the liver biopsy
HbcAg
Antibody produced against the core of HBV. Marker used during window period.
Total anti-HBc
Indicates previous or pat infection. persist for life of an infected individual
IgG anti-HBc
Indicates acute infection. used in addition to HBsAg for screening blood
IgM anti-HBc
Hepatitis B related antigen. Associated to the core of HBV (circulating form of the core)
A marker for acute viral replication and high infectivity of serum
HBeAg
Suggest low titer of HBV. First serologic evidence of convalescene phase
Anti-HBe
First marker of HBV infection
HBV-DNA
3rd generation serological test for HBV
RIA
ELIA
Reversed passive hemeagglutination
2nd generation serological test for HBV
Counterelectrophoresis, complement fication, rheophoresis
1st generation serological test for HBV
Ouchterlony double diffusion
Used to diagnose Hepatitis C infection. may indicate current or past infection.
Anti-HCV
AKA viral load. Used in monitoring response to antiviral therapy, indicating current infection
HCV-RNA
Current hepatitis E infection
IgM anti-HEV
Current or past hepatitis E infection
IgG anti-HEV
Current hepatitis E infection
HEV RNA
Codes for gp160, gp120, and gp41
Env gene
Codes for p55, p6, p9, p17, p24
Gag gene
Codes for enzymes necessary for HIV replication
Pol gene
CD4+ T cell counts for primary HIV infection
> 500/uL
CD4+ T cell counts for intermediate HIV infection
200 – 499/ uL
CD4+ T cell counts for final HIV infection
<200/uL
Standard screening test for HIV
ELISA
Based on indirect binding assay, using viral lysate as a source of antigen to detect HIV 1 and 2 antibodies
First generation
Based on indirect binding assay, utilizing purified recombinant or synthetic antigens to detect HIV 1 and 2 antibodies
Second generation
Based on sandwich ELISA, which detects and differentiate HIV 1 and 2 antibodies
Third generation
Based on sandwich ELIS that can simultaneously detect HIV 1 and 2 antibodies and p24 antigen
Fourth generation
Bead-based immunoassay that can detect HIV antibodies and p24 antigen, same as fourth generation assay but can differentiate HIV 1 and 2
Fifth generation
Most sensitive and specific test for HIV 1
-Detects IgG antibodies specific to HIV antigens
Western Blot
Separated HIV 1 proteins in Western Blot are transferred to a ___
Nitrocellulose membrane
2 out of 3 possible bands should be present in Western blot for a positive result
P24, gp41, gp120/gp160
AKA Kissing disease/mono/ glandular fever. It is an acute infectious disease of the mononuclear phagocyte system
Infectious mononucleosis
Produced by infected B cells (cytoplasm) found in the acute phase
VCA
Produced within 4-7 days of infection and persists lifelong
Anti-VCA IgG
Seen in the early course of infection. disappears in 2-4 months after infection
Anti-VCA IgM
Present in the early course of HCV infection
Anti-EA-D IgM
Highly indicative of acute HCV infection
Anti-EA-D IgG
Appears transitently in the convalescent phase of HCV infection
Anti EA-R IgG
Appears in the convalescent period of HCV infection. almost always present if IgG antibodies to VCA is present
Anti-EBNA IgG
Most common cause of congenital infection and most important infectious agent in association with organ transplantation
Cytomegalovirus
Causative agent of Dengue virus
Dengue
Family of DNA virus
Flavivirus
Gold standard for the diagnosis of dengue virus
Virus isolation
Highly conserved glycoprotein which appears essential for virus visibility (Dengue virus)
NS1
Causative agent of toxoplasmosis
Toxoplasma gondii
Method of choice to detect T. gondii DNA in CSF
PCR
Gold standard in the diagnosis of T. gondii
Sabin-Feldman Dye test
Causative agent of malaria
Plasmodium spp
Most common vector of malaria in the Philippines
Anopheles flavirostris
Immunochromatographic assay that uses monoclonal antibodies to detect parasitic lactate dehydrogenase present in finger prick sample.
Optimal assay
Detects HRP-2 antigen in P. falciparum
Malaquick standby malarial test
3 virulence factors of E. histolytica
Adhesion
SREHP (Serine Rich entamoeba histolytica protein )
2 kD cysteine rich protein
Cross react with histoplasmosis
Coccidioidomycosis
Used to demonstrate capsule antigen in serum or CSF creating a halo around the yeast cell
India ink
Chronic inflammatory disease with symptoms such as swelling of the joints, erythematous rash/butterfly rash and deposition of immune complexes in the kidneys
SLE
Neutrophil with ingested antibody-coated nucleus
LE cell
Chronic, symmetric, erosive, non-infectious and systemic autoimmune disease that affects the synovial membrane of multiple joints ; most common autoimmune disease
Rheumatoid arthritis
Antibody to the Fc portion of an IgG
Rheumatoid factor
Significant titer for the lab diagnosis of RA
> 80
More specific antibody for RA. Its presence preceded the onset of RA
Anti-cyclic citrullinated peptide antibody (anti-CCP)
homogenous staining pattern in ANA
SLE
RA
MCTD
Sjogren syndrome
Peripheral / Thread staining patterns of ANA
Active stage SLE and Sjogren syndrome
Speckled patterns in ANA
Scleroderma
MCTD
Nucleolar staining pattern in ANA
Sjogren syndrome
Seen in CREST
Centromere
