Lab assessment of Immune Function Flashcards
Cells in natural immunity?
Interferon
Lysozome
Complement
What do infereons do?
activates macrophages for viruses
What do lysozomes do?
Its produced by macrophages and likes to target the cell walls of bacteria.
What is the complement system the primary mediator of?
humoral response
What is the complement system an important part of?
2
- inflammatory response
2. Host defenses against infection
What are complements (what kind of substance?)
glycoporteins
All pathways in the complement system end up at what complement component?
C3
What is the difference between the three types of complement pathways?
Classical pathway: Antigen:Antibody mediated (
MB-Lectin Pathway: Mannose binding lectin binds mannose on pathogen surface
Alternative pathway: Binds directly to pathogen surface
C3 is responsible for three things that help in pathogen destruction. What are they?
OIL
Opsonization- first attachment of pathogen
Inflammation- increase blood permeability and vasodilation
Lysis- destrucion of cell membrane by perforin
After C3 does its job with OIL what is attracted to the inflammaed area?
clotting factors
In the classical pathway what antibodies are involved and what do they bind to?
2
3
IgG and IgM
Virus
Bacteria
Autoantigen
What complement componenets are associated with the lectin pathway?
C4 and C2
What is the major goal of the complement system?
- deposit the C3 fragment on the target (pathogen)
What does the deposition of the C3b target do?
marks the target for immune adherence and phagocytic destruction
What does the complement pathway create?
membrane attack complex
When would you measure complements?
- Recurrant infection with normal WBC and no immunosuppresion
- Diagnose auto-antibody mediated immune syndromes
- Identify immune complex mediated syndromes
(lupus, Sjogrens, glomerulonnephritis)
What test do we order to check deficienceies in the classical pathway?
CH50
What test do we order to check deficiencies in the alternative pathway?
AH50
Decreased complement levels may be seen with?
7
- Recurrent microbial infections (usually bacterial)
- Autoimmune diseases, i
- Hereditary angioedema
Acquired angioedema - Various types of kidney disease, including: glomerulonephritis, lupus nephritis, membranous nephritis, IgA nephropathy
- Malnutrition
- Septicemia
- Serum sickness (immune complex disease)
To look for Humoral Immunodeficiency/Cellular Immunodeficiency what do we want to test?
4
- IgG, IgA, IgM,
- Full Blood Count and Diff,
- Lymphocyte subsets,
- HIV testing if indicated
If your neutrophils are elevated but your lymphocytes are low what does that indicate?
bacterial infection
What do eosinophils target?2
parasites and allergies
What does the CBC establish?
presence or absense of lymphopenia but you probably want a diff to figure out what kind of infection
Whats a left shift?
Getting more WBC. WBC bands may come out too.
Determining if patient has an inflammatory response. Neutrophils goes up
Bands have increased
What do neutrophils defend against?
4
Bacteria
Fungus
Physiological stress (even exercise mildly)
Steriod therapy
ANY INFLAMMATION
What percentage of the WBC are neutrophils?
50-60%
How fast do neutrophils show up?
90 min
What diseases can cause neutropenia?
5
Viral diseases: hep flu rubella mumps OVERWHELMING BACTERIAL INFECTION (has to be really bad)
What medications can cause neutropenia?
4
anitbiotics
lithium
phenothiazines
TCAs
Eosinophils are associated with what kind of reactions?
antibody-antigen
Whats the most common reason for increased eosinophils?
Allergic reactions
- hay fever
- asthma
Whats the most common cause of a decrease in eosinophils?
corticosteriods
Percentage of WBCs that are eosinophils?
1-3%
What three things do basophils contain?
3
heparin
histamines
serotonin
What are tissue basophils called?
mast cells
Why do we do basophil counts?
to analyze an allergic reaction
What is the body’s second line defense against iinfection?
phagocytes
What percent of WBC do monocytes make up?
3-8%
What are the monocytes in the tissue?
brain?
Liver?
histiocytes
microglia
Kupffer cells
What percent of WBC do lymphocytes make up?
20-30%
When you think lymphocytes what pathogens do you think?
virus
Lymphocytes can be stored for years. Why is this good and bad?
They are good because they make memory. and can make a better response to second exposure
They are bad because they kill and stay around still. The longer they are around the more risk they could become cancerous
Do you have more T or B lymphocytes?
T
In the WBC how are T lymphocytes reported?
together. you need to do a differential for
What can cause lymphocytosis?
TB and viral infections
When do lymphocytes go below 500?
chemotherapy
Whats the normal WBC count for adults?
4500-11,000 cells/cm2
