Which part of our body's protective mechanisms are we born with?
non-specific or innate immune system
Which part of our body's protective mechanisms do we develop as we grow?
specific (acquired) immune system
How does the body's protective mechanisms function?
function by recognizing, destroying, or removing foreign substances
Where do we find non-specific immune system?
physical and biochemical parts of the skin, nasopharynx, GIT, lungs or urogenital tract
What is normal flora?
What does the innate immune system do?
responds specifically to foreign substances (antigens)
What are the two parts of the innate immune system?
cell mediated immunity
What does the innate immune system consist of?
a function of lymphocytes and some macrophages
Where do we find the lymphocytes?
lymphoid stem cells start in yolk sac, then in fetal liver
develop later in the marrow
B cells mature in the marrow
T cells mature in the thymus
Do we always have our thymus?
no, it goes away after the first year
How does the humoral immunity work?
B cells respond to specific antigens
couples antigen with MHC II from its surface
T-helper lymph binds complex and releases cytokines
one cytokine enables B cell to produce plasma cells
plasma cells make antibodies
What are cytokines?
messengers that stimmulate cells
What kind of antibodies do plasma cells make?
What are antibodies?
How do antibodies work?
antibodies bind to antigen (Ag-Ab complex)
phagocytosis by macrophages
may see cell lysis
What is cross reactivity?
antibody binds to more than one antigen
What are the different immunoglobulins?
What are IgG? Where is it found?
most numerous antibody
mostly in serum
Which immunoglobulin is the first to appear and is the largest?
Why don't we test for the IgM?
because it decrease over time
Where do we find IgA? What does it do?
on mucosal surfaces
prevents antigen from attaching
When do we see IgE?
in allergic and parasitized animals
Where do we find IgD?
B lymph surface of antigen
What is passive immunity a part of?
How does passive immunity work?
antibodies are being tranferred from animal to aimal thru the placenta or collostrum or plasma
Does passive immunity provide immediate protection? How long does it last?
doesn't last long - gone within 2 weeks
How does active immunity work?
stimulation of B cells
a first there is a lag period of about 3 days
then there is a slow rise in antibodies (maxes by 2 weeks)
second time patient is exposed there is an anamnestic response
What is an anamnestic response?
second time patient is exposed to antigen
shorter lag time
faster and higher levels of antibodies
What is cell mediated immunity?
respond to certain antigens and produce effector and memory cells
What are the different types of effector cells?
helper T cells
cytotoxic T cells
How do effector cells work?
T helper cells release cytokines
cytokines enable cytotoxic T cells to lyse infected tissue cells
What are the different disorders of the immune system?
suppression of the immune system
Which animals are hypersensitivity reactions the most common in?
What causes hypersensitivity reactions?
immune mediated disorders
Which animals are immune deficiencies the most common in?
What can suppress the immune system?
drug therapy (steroids)
What do immunologic tests measure?
Ag or Ab
What is Type I hypersensitivity occur?
What is another name for Type I hypersensitivty?
Is Type I hypersensitivity seen in animals younger than 6 months?
What organ does Type I hypersensitivity target?
What happens with Type I hypersensitivity?
first exposure to antigen: IgE produced binds to mast cell surface
second exposure to antigen: interaction of IgE with antigen which causes degranulation of mast cells then histamine is released which causes an inflammatory response
this then leads to anaphylaxis
What are the different signs of anaphylaxis?
How long does Type II hypersensitivty take to occur?
days to weeks to show up
What is Type II hypersensitivity?
immunoglobulins attach to cell and cause cell lysis
What conditions are considered Type II hypersensitvity?
auto - immune hemolytic anemia or immune - mediated hemolytic anemia
How long does it take Type III hypersensitivity to occur?
days to weeks to show up
What is Type III hypersensitivity?
antibody-antigen complexes deposit in membranes
What conditions are considered Type III hypersensitivities?
What is Type IV hypersensitivity?
typically occurs more than 24 hours after exposure
What are the different types of Type IV hypersensitivities?
mosquito bite hypersensitivity
flea bite hypersensitivity
What is IMHA?
What will we see on a cytology of a patient with IMHA?
elevated reticulocyte count
hemolysis in extreme cases
Which test do we use to confirm IMHA?
What are some other immune mediated disorders?
also cause hypothyroidism, hypoadrenocorticism, glomerulonephritis
Which animals do we typically see IMHA?
middle aged female dogs
What is the Coomb's test?
direct antiglobulin test
_____ of patient's with IMHA will have a positive Coomb's test.
60 - 70%
Can false positive occur with Coomb's test? If so, what causes false positives?
if patient has had a transfusion with in 3 weeks
if the clotted blood has been refrigerated
Does a negative Coomb's test rule out IMHA?
Are false negatives common with Coomb's test?
What can cause false negative with Coomb's test?
if on steroid treatment for more than 1 week
incorrect species reagents
test done at improper temp
What is IMTCP?
When do we see IMTCP?
anemia or bleeding
How do we diagnose IMTCP?
check platelet count
What are the different tests of hemostasis?
thrombocyte count below 50,000/ul
ACT and OSPT (one step pro time)
Marrow tap (if megakaryocytes are present then there are platelets)
How do we confirm a presumptive diagnosis for IMTCP?
antimegakaryocyte antibody test
antiplatelet antibody test
How do we do the antimegakaryocyte antibody test?
need marrow smear
false negative if on steroids
high specificity - false positives rare
What can cause antiplatelet antibody test to have a false positive?
What is another name for the antiplatelet antibody test?
platelet factor 3 test
What is pemphigus complex?
rare autoimmune diseases
What are the clinical signs of pemphigus complexes?
non-itchy skin blisters all over (foot pads, nail beds, ears, eyelids, nose)
What are the different types of pemphigus complexes?
How do we diagnose pemphigus complex?
rule out other diseases
cytology, scrapying, culture
diagnose with regular biopsy
diect immunofluorescence using Michel's media
What is systemic lupus erythematosus?
chronic, multisystemic immune mediated disease
Which species is lupus common in?
dogs and people
What are some problems seen with lupus?
polyarthritis - shifting lameness
hypoalbuminemia - ascites, edema
bullous, or red skin lesions
IMHA - icterus
IMTCP - petechia
How do we diagnose lupus?
tests usually depend on system affected
must rule out other causes
What is the Antinuclear antibody (ANA) test?
detects circulating Abs against host's DNA
Is the ANA test sensitive and specific?
not very specific (lots of false positives)
What is the LE prep?
older time consuming test that can be done in house
detects nuclear material phagocytized by segs in blood or marrow
Is rheumatoid arthritis a common disease?
no, its rare
What is erosive polyarthritis?
progressive joint destruction
Which types of dogs is rheumatoid arthritis common in?
small breed dogs
What is the rheumatoid factor test?
detects IgM directed agains Ig's in sera
positive in rheumatoid arthritis - looking for elevated titer
neither sensitive or specific
What is the CRF test?
in house test for rheumatoid arthritis
latex agglutination tests
can see positive reaction
Can we do a cytology to diagnose rheumatoid arthritis?
What is the most common allergic disease seen in small animals?
flea allergic dermatitis
What causes a flea allergic dermaititis?
react to Ag in flea saliva
What does a flea allergy dermatitis look like?
What is a miliary dermatitis?
little bumps on the skin
Where do we typically see the flea allergy dermatitis on the patient?
along the rear end, base of the tail, down the hind legs
What is the second most pruritic disease? What's the first?
second most pruritic disease: flea allergic dermatitis
first most pruritic disease: sarcoptic mange
What type of hypersensitivity is flea allergic dermatitis?
Is a flea allergic dermatitis seasonal?
What does the sensitivity of a test mean?
the ability of a test to determine true positives
What does the specificity of a test mean?
the ability of a test to determine true negatives
What are acute moist dermatitis?
What is atopy?
allergic inhalant dermatitis
How is atopy different in humans than in animals?
in humans atopy typically results in itchy eyes, sneezing, etc where as in animals atopy results a dermatitis
Is atopy seasonal or nonseasonal?
What percent of dogs do we see atopy in?
10 - 30%
Is atopy inherited?
What do animals react to that causes atopy?
At what age do we typically see atopy?
1 - 3 years old
Is atopy prurtic?
Where on the body do we see atopy?
Can a dog have a flea allergic dermatitis, a food allergy, and atopy?
yes, a dog can have more than one...they can overlap
What are the different ways to diagnose atopy?
What is the gold standard test for atopy?
What do we use skin testing to diagnose?
atopy and FAD
How do we do skin testing?
prep and mark skin
inject 0.1cc intradermally of each antigen
inject 0.1cc of saline and 0.1cc of histamine as a control
see wheal reaction 15 - 20 minutes later
What is a wheal reaction?
raised flattened plateau (hives)
this means a positive result to the allergen
What is the RAST/ELISA test?
test using serum to determine allergies
once allergies are determined, lab will provide hypsensitizing agents (allergy shots) as treatment
Are RAST/ELISA tests accurate?
some doctors do not think they are very accurate and would rather do skin testing
What are hyposensitizing reagents? Are the helpful?
allergy shots to desensitize body to the allergy (immunotherapy)
60 - 80% see improvement but not many will have the allergy totally go away
Food allergies make up _____ of allergic skin diseases.
Are food allergies seasonal or nonseasonal?
If a skin allergy does not respond to steroid treatment, what should we suspect it is?
What are the signs we will see with food allergies?
How should we diagnose food allergies?
put a patient on a hypoallergenic only diet (no people food, treats, rawhides)
keep on diet for at least 10 weeks
signs should disappear
What are some canine hypoallergenic diets?
hills prescription diet d/d
CNM HA - formula
vet's choice neutral formula
nutritional care R151
waltham rice and catfish
What are some feline hypoallergenic diets?
vet's choice neutral formula
prescription diet feline d/d
waltham venison and rice
home made formulas can be used
What is feline eosinophilic granuloma complex?
skin reaction to an underlying cause
What causes feline eosinophilic granuloma complex?
usually due to an allergy
What will we see on a cytology of feline eosinophilic granuloma complex?
lots of eosinophils
What are some other allergic diseases?
flea collar dermatitis
plastic dish syndrome
urticaria "wheal" reactions
What are the different laboratories that do allergy testing?
What are gammapathies?
increased concentration of immunoglobulins
What are the two types of gammapathies?
What is polyclonal gammapathy? What is monoclonal gammapathy?
polyclonal gammapathy: overproduction of many types
monoclonal gammapathy: overproduction of single types
What are some examples of polyclonal gammapathy?
What is an example of monoclonal gammapathies?
What is multiple myeloma?
neoplasia of plasma cells
blood becomes sticky - rouleaux increases
radiographic bone lesions (black spots in the bone)
There will be an increase in _____ and _____ with gammapathies.
increase in total protein
increase in gamma globulins
When do large animals have problems with immunological disorders?
most are due to a decreased antibodies
How do large animals have a decrease in antibodies?
antibodies do not cross thru the placenta and the baby gets its antibodies through passive transfer from the colostrum within the first 24 hours after birth...if the baby does not get the colostrum then it does not get antibodies
How long does the antibodies from colostrum last?
about 2 weeks and then active immunity kicks in
Anything that interferes with antibody production, passage, or absorption for large animals result in...
failure of passive immunity
neonate at risk for infections
How can we avoid problems with antibodies in large animals?
make sure we have good management
the better the management on the farm, the fewer the problems
Which animals do we see FPI in?
When do we test for FPI?
some doctors test at 12 hours and some test at 24 hours
What are the benefits to tests for FPI 12 hours after birth? 24 hours after birth?
testing at 12 hours: still have time for the baby to get colostrum from the mother (oral replacement), but testing on a hunch because we are unsure if there is a problem yet or not
testing after 24 hours: at this point we definitely know if there is a problem and the test is more definitive, since the baby can't get colostrum after 24 hours if there is a problem then the baby must get the necessary antibodies IV.
What are the different tests available to test for FPI in horses?
foal IgG test kit (CITE - brand name)
single radial immunodiffusion
zinc sulfate turbidity
How can the refractometer test for FPI?
measures the total protein of blood
does not measure gamma globulins but a lot of the times the total protein will be low when the antibodies are low
increase in disease/deaths if <5.5 gm/dl
Which animals can we use the zinc sulfate turbidity test in?
foals and calves
Can we do the zinc sulfate turbidity test in house?
What is Foalcheck?
in house latex agglutination test
When should we treat foals for FPI?
treat foals with IgG <400 mg/dl
we prefer for the IgG to be >800 mg/dl
What are the in house tests for FPI in ruminants?
sodium sulfite precipitation
How do we do the sodium sulfite precipitation?
tubes with 14%, 16%, 18%
look for precipitation in each
best if precipitation in all three tubes
What do we look for in the glutaraldehyde coagulation test?
look for a clot to form
What is CID? Which animals do we see this condition in?
inherited in arabian foals and arabian crosses
How do arabian horses get CID?
autosomal recessive trait - if both parents are carriers then the foal will have CID
What precent of arabian horses are carriers of CID?
Are there DNA tests available to test for CID before breeding?
What does CID do?
causes neither B or T cells to function
passive immunity is still intact so foal will have antibodies from the colostrum and will seem normal for about 2 - 65 days
then the foal will become sick with chronic illness - most commonly pneumonia
When do foals typically die from CID?
die by 6 months
What test can be done to test for CID?
RID - foal will lack IgM
CBC - presistent lymphopenia below 1000/ul
Histopathological lesions - small thymus that lack germinal centers (usually done in necropsy)
What are some allergic diseases in horses?
chronic obstructive pulmonary disease (COPD)
urticaria from insect bites
bio-medical services has ELISA tests for horse allergies
Is equine neonatal isoerythrolysis an immune disorder?
no, but it does related to a problem with antibodies
Which horses and what percent of them do we see equine neonatal isoerythrolysis?
thoroughbred and standardbred pregnancies
1 - 2%
What is equine neonatal isoerythrolysis?
foal has a different blood type from the mare and the mare is making antibodies againse that blood type
when the foal nurses it gets the bad antibodies from the mare and the mare's antibodies destroy the foal's RBCs
What do we see in a foal with equine neonatal isoerythrolysis?