immunosero

What are acute phase reactants?

Proteins that ↑ due to infection, injury, trauma. | *Examples of APRs are CRP, alpha-1 antitrypsin, haptoglobin, fibrinogen, ceruloplasmin, alpha-1 acid glycoprotein, complement

Vasoactive amine released from mast cells & basophils during allergic rxn.

Histamine

Low molecular weight substance that can bind to ab once it’s formed, but is incapable of stimulating ab | production unless bound to larger carrier molecule.

Hapten

Cytokines produced by leukocytes that affect inflammatory response through ↑in soluble factors or cells.

Interleukins

Cytokines with antiviral properties. Also active against certain tumors & inflammatory processes. Interfere with viral replication

Interferons

What is lysozyme?

Enzyme in tears & saliva

Serum proteins that attach to foreign substance & enhance phagocytosis.

Opsonin

Transformed B cells that secrete ab.

Plasma cells

Engulfment of cells or particulate matter by neutrophils & macrophages.

Phagocytosis

System of genes that control expression of MHC molecules found on all nucleated cells; originally | referred to as human leukocyte antigens (HLA).

Major histocompatibility | complex (MHC)

Reduced ag/ab complexes due to ag excess . Can cause false neg in serological test for ab. Repeat test in | 1–2 wk.

Postzone. | *Prozone - Reduced ag/ab complexes due to ab excess . Can cause false neg in serological test for ab. Dilute serum | & retest.

What type does serum sickness belong?

Type III hypersensitivity. | *Results from buildup of abs to animal serum used in some passive immunizations

What is naturally acquired active immunity?

Individual infected produces Ab

1st line of defense against tumor cells & cells | infected with viruses

Natural killer cells

Bridge between innate & acquired immunity

Natural killer | (NK) cells

What are the primary lymphoid organs?

Bone marrow, Thymus

What method is used for isolation of lymphocytes?

Density gradient centrifugation with Ficoll-Hypaque

Ig that is monomer and dimer

IgA

Ig that has J chain

IgA and IgM

Does IgG cross the placenta?

Yes

First Ig produced in immune response. Only Ig | produced by newborn. Most efficient Ig at initiating complement | cascade. Destroyed by sulfhydryl compounds.

IgM

Group of >30 proteins in phagocytosis & clearance of foreign antigen

Complement

What does inactivation of complement lead to?

↑ susceptibility to infection. Accumulation of immune complexes, which can lead to glomerulonephritis. | *Inactivation temp: 56°C for 30 min.

What is the key reactant for Type IV hypersensitivity?

T cells

PRINCIPLE: Ag-ab rxn that results in clumping of RBCs. APPLICATION: ABO slide typing serum.

Hemagglutination

PRINCIPLE: Naturally occurring ags on particles (e.g., bacterial ags). Particles | agglutinate in presence of corresponding ab. APPLICATION: Widal test for typhoid fever. SalmonellaO & H ags used to detect abs in patient | serum.

Direct agglutination. | *Refer to page 388 for additional examples of these.

What is the principle of precipitation?

Ag combines with Ab

What is EIA?

Immunoassay using enzyme

What does the Original EIA measure?

Used to measure small relatively pure ags, e.g., insulin, estrogen

What is the main principle of EMIT?

Ag in specimen & enzyme-labeled ag compete for binding sites on reagent ab

What is the principle of Direct Fluorescent Antibody (DFA) staining?

Labeled ab binds to ag.

What are the labels used in Chemiluminescent Immunoassay (CIA)?

Luminol, acridium esters, ruthenium derivatives, nitrophenyl oxalates. | *Refer to page 395 for additional examples of these.

What is a disadvantage of chemiluminescent immunoassay (CIA)?

Quenching of light emission.

Specimen/s of choice for FTA-ABS

Serum, CSF. | *Refer to page 398 for additional examples of these.

Sequelae of group A strep (GAS) infection: rheumatic fever, post-streptococcal glomerulonephritis

Anti-streptolysin O

Sequelae of GAS infection: rheumatic fever, glomerulonephritis following skin infection, i.e., impetigo

Anti-DNase B. | *Refer to page 401 for additional examples of these

Test for Infectious Mononucleosis (IM). When do 90% of patients develop heterophile antibodies?

In the 1st month of illness

Hepatitis A Total anti-HAV significance?

Past infection & immunity. | *Refer to page 403 for additional examples of these

What does HCV RNA test for?

Viral load testing

Acute Hepatitis A Marker

IgM anti-HAV +

When is Viral RNA detectable after HIV infection?

Within days

What does P24 ag without HIV ab indicate?

Acute infection. *Refer to page 407 for additional examples of these

What defines AIDS according to CDC?

What is the gold standard test for SLE?

Fluorescent antinuclear antibody (FANA)

Most specific antibody for SLE?

Anti-dsDNA. | *Refer to page 412 for additional examples of these

What is Rheumatoid Factor (RF)?

Autoantibody against IgG

What titer increase is diagnostic?

≥ 4-fold increase

What is an antigen?

Foreign substance that stimulates antibody production

Strength of bond between Ag and Ab.

Avidity

Determinant site on ag.

Epitope

Chemicals produced by activated immune cells that affect function of other cells. Includes interferons, | chemokines, tumor necrosis factors, transforming growth factors, colony stimulating factors, interleukins

Cytokines

Antibody formed in response to antigens from individuals of same species.

Alloantibody

What is immunity?

Resistance to infection

Immunoglobulin produced by plasma cells in response to ag

Antibody (ab)

Injection of immunogenic material to Induce immunity

Vaccination

Means of expressing ab concentration; reciprocal of highest dilution with pos rxn.

Titer

Small, flat bilobed organ found in thorax; site of T-lymph development. One of the primary lymphoid | organs

Thymus

What is artificially acquired active immunity?

Exposure to Ag through vaccine

What is the primary function of Helper T cells?

Orchestrate immunity

CD 8+

Cytotoxic/suppressor T cell | Mnemonics: | 8x1 = 8 | 4x2 = 8

CD 4+

Helper/inducer T cells | Mnemonics: | 8x1 = 8 | 4x2 = 8

What percentage of lymphocytes are T Cells?

60-80%

What are the secondary lymphoid organs?

Spleen, Lymph nodes, Tonsils, Appendix, Cutaneous-associated lymphoid tissue, (MALT), including Peyer’s patches in lower ileum

What connects the heavy and light chains in immunoglobulins?

Disulfide bonds

Specimen/s of choice for VDRL

Serum or CSF