Immunoglobulins:
Many of the viral tests in immunochemistry are based on the detection of the presence of viral antigens, antibodies present in the patient's blood or the matrix between cells, or the formation of antibody-antigen complexes when antibodies coating magnetic or paramagnetic particles in test/assay reagent combine with antibodies in the patient's serum or viral antigens present in the patient's serum combine with antigen particles in the test/assay reagent.
Immunoglobulins are antibodies. There are 5 major antibodies. They include:
Antigens are
The structure of an antibody looks like this:
Immunoglobulins are antibodies. There are 5 major antibodies. They include:
- IgG
- Four Forms
- Provides the majority of the immune response that is antibody-antigen based against pathogens within 24-48 hours of exposure
- The most common antibody circulating in the bloodstream
- Out of all the antibodies, this one represents about 75% of them
- This is the only immunoglobulin that is able to cross the placenta
- This antibody provides passive immunity to a developing fetus
- Protects the body's tissues from invasion of pathogens
- Has 2 antigen-binding sites
- IgG binds the antigens of pathogens and immobilizes them by binding them together, causing them to clump via agglutination
- IgG coats the surface of pathogens and flags them for destruction by phagocytes of the immune system in the process known as opsonization, resulting in the ingestion and elimination of the pathogen
- IgG activates the complement system via the classical pathway, resulting in a cascade of proteins that eliminate the pathogen
- IgG neutralizes toxins produced by microbes
- IgG aids in cell-mediated cytotoxicity to destroy viruses. It also participates in intracellular antibody-mediated proteolysis by binding a receptor that flags viral particles for destruction by causing them to bind to a proteosome
- IgG is part of the allergy response in that it is associated with both Type II and Type III Hypersensitivity reactions
- IgG is part of the secondary immune response and results in long-lasting immunity when memory cells are created, which is the basis of vaccinations/immunizations/boosters and checking titers for things like MMR, VZV, Hep B, etc...
- IgM
- Secreted on the surface of a plasma B lymphocyte
- Secreted outside of the plasma B lymphocyte and provides high affinity and avidity
- First antibody to appear during the humoral immune response until IgG is sufficient
- Destroys pathogens
- Able to form large antibody-antigen complexes
- Responsible for many of the auto-immune diseases
- IgE
- The antibody that responds to allergens, results in allergic response, and destroys parasites such as worms
- Releases histamine from mast cells and basophils
- IgA
- Produced in the gut
- The major antibody of the mucosa and secretions (gut, nasal passages, eyes, ears, respiratory tract, urogenital tract, etc...)
- Aids in the protection from and prevention of colonization of microbes
- Secreted in tears, sweat, breast milk, and saliva
- IgD
- This antibody is not secreted, rather it is expressed on the surface of plasma B lymphocytes
- Antigen receptor on surface of B cells
- Invokes the production of antimicrobial factors by mast cells and basophils
Antigens are
The structure of an antibody looks like this:
Antigens look like this:
This is what conjugate looks like attached to antibodies in reagent. They are typically fluorophores connected to paramagnetic or magnetic particles attached to the antibody. When they come into contact with antigen in the patient's serum, they form a complex that then lights up and fluoresces.
Antibody-Antigen Complexes look like this:
Viruses:
Hepatitis A:
TESTS:
- Anti-HAV IgM
- Anti-HAV IgG
Hepatitis B:
TESTS:
- Anti-HB core IgM
- Anti-HB surface
- HBSAG
- HBSAG Confirmatory Test
- Anti-Hb core IgG Total
Hepatitis C:
TESTS:
- Anti-HCV
HIV:
TESTS:
- HIV Ag/Ab Combo
Vitamins:
- Vitamin D
- Vitamin B12
- Folate
- Ferritin
Hormones:
- Estradiol
- BhCG
- DHEA
- FSH
- LH
- Progesterone
- Prolactin
- SHBG
- Testosterone
- Free PSA
- Total PSA
- TSH
- Free T4
- Total T4
- Free T3
- Total T3
- Anti-TG
- Anti-TPO
- Cortisol
- Insulin
- C-Peptide:
- Used in the diagnosis and treatment of individuals who have abnormal insulin secretion, as well as those who have diabetes mellitus type 1 (will be low)
- It is a single chain polypeptide consisting of 31 amino acids
- Connects the A and B chains of insulin in the molecule proinsulin
- Stored in the pancreatic B-cells of the pancreas
- Kicks of the biosynthesis of insulin by forming both secondary and tertiary protein folds in the structure of the insulin hormone
- Also secreted by the renal system, so it can be detected in 24-hour urine collections
- Elevated in conditions such as hyperinsulinism and insulinomas
- Used in the diagnosis and treatment of individuals who have abnormal insulin secretion, as well as those who have diabetes mellitus type 1 (will be low)
- iPTH STAT
Immunosuppressant Drugs:
- Cyclosporin
- Tacrolimus
- Phenytoin
- Valproic Acd
Tumor Markers:
- CA-125
- CA-15-3
- AFP
Cardiac Markers:
- BNP
- Troponin
- CKMB
Other:
- Homocysteine
- CEA