Diagnostic Testing for Immunological Disorders

  1. What are the body's protective mechanisms?
    • non-specific or innate immune system
    • specific (acquired) immune system
  2. Which part of our body's protective mechanisms are we born with?
    non-specific or innate immune system
  3. Which part of our body's protective mechanisms do we develop as we grow?
    specific (acquired) immune system
  4. How does the body's protective mechanisms function?
    function by recognizing, destroying, or removing foreign substances
  5. Where do we find non-specific immune system?
    physical and biochemical parts of the skin, nasopharynx, GIT, lungs or urogenital tract
  6. What is normal flora?
    commensal bacteria
  7. What does the innate immune system do?
    responds specifically to foreign substances (antigens)
  8. What are the two parts of the innate immune system?
    • humoral immunity
    • cell mediated immunity
  9. What does the innate immune system consist of?
    a function of lymphocytes and some macrophages
  10. 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
  11. Do we always have our thymus?
    no, it goes away after the first year
  12. 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
  13. What are cytokines?
    messengers that stimmulate cells
  14. What kind of antibodies do plasma cells make?
  15. What are antibodies?
    plasma proteins
  16. How do antibodies work?
    • antibodies bind to antigen (Ag-Ab complex)
    • phagocytosis by macrophages
    • may see cell lysis
  17. What is cross reactivity?
    antibody binds to more than one antigen
  18. What are the different immunoglobulins?
    • IgG
    • IgM
    • IgA
    • IgE
    • IgD
  19. What are IgG?  Where is it found?
    • most numerous antibody
    • mostly in serum
  20. Which immunoglobulin is the first to appear and is the largest?
  21. Why don't we test for the IgM?
    because it decrease over time
  22. Where do we find IgA?  What does it do?
    • on mucosal surfaces
    • prevents antigen from attaching
  23. When do we see IgE?
    in allergic and parasitized animals
  24. Where do we find IgD?
    B lymph surface of antigen
  25. What is passive immunity a part of?
    humoral immunity
  26. How does passive immunity work?
    antibodies are being tranferred from animal to aimal thru the placenta or collostrum or plasma
  27. Does passive immunity provide immediate protection?  How long does it last?
    • yes
    • doesn't last long - gone within 2 weeks
  28. 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
  29. What is an anamnestic response?
    • second time patient is exposed to antigen
    • booster shot
    • shorter lag time
    • faster and higher levels of antibodies
  30. What is cell mediated immunity?
    respond to certain antigens and produce effector and memory cells
  31. What are the different types of effector cells?
    • helper T cells
    • cytotoxic T cells
  32. How do effector cells work?
    • T helper cells release cytokines
    • cytokines enable cytotoxic T cells to lyse infected tissue cells
  33. What are the different disorders of the immune system?
    • hypersensitivity reactions
    • immune deficiencies
    • suppression of the immune system
  34. Which animals are hypersensitivity reactions the most common in?
    small animals
  35. What causes hypersensitivity reactions?
    • allergies
    • immune mediated disorders
  36. Which animals are immune deficiencies the most common in?
    large animals
  37. What can suppress the immune system?
    • organisms
    • chronic stress
    • drug therapy (steroids)
  38. What do immunologic tests measure?
    Ag or Ab
  39. What is Type I hypersensitivity occur?
  40. What is another name for Type I hypersensitivty?
  41. Is Type I hypersensitivity seen in animals younger than 6 months?
    it rare
  42. What organ does Type I hypersensitivity target?
  43. 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
  44. What are the different signs of anaphylaxis?
    • hives
    • facial edema
    • pruritus
    • breathing difficulty
    • vomiting (cats)
    • weakness
    • collapse
    • death
  45. How long does Type II hypersensitivty take to occur?
    days to weeks to show up
  46. What is Type II hypersensitivity?
    immunoglobulins attach to cell and cause cell lysis
  47. What conditions are considered Type II hypersensitvity?
    • auto - immune hemolytic anemia or immune - mediated hemolytic anemia
    • pemphigus
  48. How long does it take Type III hypersensitivity to occur?
    days to weeks to show up
  49. What is Type III hypersensitivity?
    antibody-antigen complexes deposit in membranes
  50. What conditions are considered Type III hypersensitivities?
    • immune-mediated thrombocytopenia
    • rheumatoid arthritis
    • immune-mediated nephritis
    • SLE (lupus)
  51. What is Type IV hypersensitivity?
    • delayed hypersensitivity
    • typically occurs more than 24 hours after exposure
  52. What are the different types of Type IV hypersensitivities?
    • mosquito bite hypersensitivity
    • flea bite hypersensitivity
    • contact hypersensitivity
  53. What is IMHA?
    responsive anemia
  54. What will we see on a cytology of a patient with IMHA?
    • elevated reticulocyte count
    • spherocytosis
    • RBC agglutination
    • hemolysis in extreme cases
  55. Which test do we use to confirm IMHA?
    Coomb's test
  56. What are some other immune mediated disorders?
    • rheumatoid arthritis
    • pemphigus diseases
    • also cause hypothyroidism, hypoadrenocorticism, glomerulonephritis
  57. Which animals do we typically see IMHA?
    middle aged female dogs
  58. What is the Coomb's test?
    direct antiglobulin test
  59. _____ of patient's with IMHA will have a positive Coomb's test.
    60 - 70%
  60. Can false positive occur with Coomb's test?  If so, what causes false positives?
    • yes
    • if patient has had a transfusion with in 3 weeks
    • if the clotted blood has been refrigerated
  61. Does a negative Coomb's test rule out IMHA?
  62. Are false negatives common with Coomb's test?
  63. 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
  64. What is IMTCP?
    immune-mediated thrombocytopenia
  65. When do we see IMTCP?
    anemia or bleeding
  66. How do we diagnose IMTCP?
    check platelet count
  67. 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)
    • presumptive diagnosis
  68. How do we confirm a presumptive diagnosis for IMTCP?
    • antimegakaryocyte antibody test
    • antiplatelet antibody test
    • ELISA test
  69. How do we do the antimegakaryocyte antibody test?
    • direct immunofluorescence
    • need marrow smear
    • false negative if on steroids
    • high specificity - false positives rare
  70. What can cause antiplatelet antibody test to have a false positive?
  71. What is another name for the antiplatelet antibody test?
    platelet factor 3 test
  72. What is pemphigus complex?
    rare autoimmune diseases
  73. What are the clinical signs of pemphigus complexes?
    non-itchy skin blisters all over (foot pads, nail beds, ears, eyelids, nose)
  74. What are the different types of pemphigus complexes?
    • P. erythematosus
    • P. foliaceous
    • P. vulgaris
  75. How do we diagnose pemphigus complex?
    • rule out other diseases
    • history
    • PE
    • tests
    • cytology, scrapying, culture
    • diagnose with regular biopsy
    • diect immunofluorescence using Michel's media
  76. What is systemic lupus erythematosus?
    chronic, multisystemic immune mediated disease
  77. Which species is lupus common in?
    dogs and people
  78. What are some problems seen with lupus?
    • polyarthritis - shifting lameness
    • hypoalbuminemia - ascites, edema
    • glomerulonephritis
    • bullous, or red skin lesions
    • IMHA - icterus
    • IMTCP - petechia
    • pyrexia
    • splenomegaly
    • lymphadenopathy
  79. How do we diagnose lupus?
    • tests usually depend on system affected
    • must rule out other causes
    • Coomb's test
    • ANA test
    • rheumatoid factor
    • LE prep
  80. What is the Antinuclear antibody (ANA) test?
    detects circulating Abs against host's DNA
  81. Is the ANA test sensitive and specific?
    • very sensitive
    • not very specific (lots of false positives)
  82. 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
  83. Is rheumatoid arthritis a common disease?
    no, its rare
  84. What is erosive polyarthritis?
    progressive joint destruction
  85. Which types of dogs is rheumatoid arthritis common in?
    small breed dogs
  86. 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
  87. What is the CRF test?
    • in house test for rheumatoid arthritis
    • latex agglutination tests
    • can see positive reaction
  88. Can we do a cytology to diagnose rheumatoid arthritis?
  89. What is the most common allergic disease seen in small animals?
    flea allergic dermatitis
  90. What causes a flea allergic dermaititis?
    react to Ag in flea saliva
  91. What does a flea allergy dermatitis look like?
    • miliary dermatitis
    • hot spots
  92. What is a miliary dermatitis?
    little bumps on the skin
  93. Where do we typically see the flea allergy dermatitis on the patient?
    along the rear end, base of the tail, down the hind legs
  94. What is the second most pruritic disease?  What's the first?
    • second most pruritic disease:  flea allergic dermatitis
    • first most pruritic disease:  sarcoptic mange
  95. What type of hypersensitivity is flea allergic dermatitis?
  96. Is a flea allergic dermatitis seasonal?
  97. What does the sensitivity of a test mean?
    the ability of a test to determine true positives
  98. What does the specificity of a test mean?
    the ability of a test to determine true negatives
  99. What are acute moist dermatitis?
    hot spots
  100. What is atopy?
    allergic inhalant dermatitis
  101. 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
  102. Is atopy seasonal or nonseasonal?
  103. What percent of dogs do we see atopy in?
    10 - 30%
  104. Is atopy inherited?
  105. What do animals react to that causes atopy?
    • pollen
    • molds
    • hair
    • dust
    • cotton
    • wool
  106. At what age do we typically see atopy?
    1 - 3 years old
  107. Is atopy prurtic?
  108. Where on the body do we see atopy?
    • face
    • feet
    • axilla
    • otitis
  109. Can a dog have a flea allergic dermatitis, a food allergy, and atopy?
    yes, a dog can have more than one...they can overlap
  110. What are the different ways to diagnose atopy?
    • skin testing
    • RAST/ELISA testing
  111. What is the gold standard test for atopy?
    skin testing
  112. What do we use skin testing to diagnose?
    atopy and FAD
  113. 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
  114. What is a wheal reaction?
    • raised flattened plateau (hives)
    • this means a positive result to the allergen
  115. 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
  116. Are RAST/ELISA tests accurate?
    some doctors do not think they are very accurate and would rather do skin testing
  117. 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
  118. Food allergies make up _____ of allergic skin diseases.
  119. Are food allergies seasonal or nonseasonal?
  120. If a skin allergy does not respond to steroid treatment, what should we suspect it is?
    food allergy
  121. What are the signs we will see with food allergies?
    • pruritus
    • urticaria
    • otitis
    • papules
    • vomiting
    • diarrhea
    • colic
  122. 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
  123. What are some canine hypoallergenic diets?
    • hills prescription diet d/d
    • IVD
    • CNM HA - formula
    • vet's choice neutral formula
    • iams FP/canine
    • nutritional care R151
    • waltham rice and catfish
  124. What are some feline hypoallergenic diets?
    • iams LB/feline
    • vet's choice neutral formula
    • prescription diet feline d/d
    • waltham venison and rice
    • home made formulas can be used
  125. What is feline eosinophilic granuloma complex?
    skin reaction to an underlying cause
  126. What causes feline eosinophilic granuloma complex?
    • usually due to an allergy
    • fleabite hypersensitivity
    • mosquito
    • food
  127. What will we see on a cytology of feline eosinophilic granuloma complex?
    lots of eosinophils
  128. What are some other allergic diseases?
    • contact dermatitis
    • flea collar dermatitis
    • plastic dish syndrome
    • bacterial hypersensitivity
    • urticaria "wheal" reactions
    • angioedema
  129. What are the different laboratories that do allergy testing?
    • heska
    • spectrum labs
    • greer laboratories
  130. What are gammapathies?
    increased concentration of immunoglobulins
  131. What are the two types of gammapathies?
    • polyclonal
    • monoclonal
  132. What is polyclonal gammapathy?  What is monoclonal gammapathy?
    • polyclonal gammapathy:  overproduction of many types
    • monoclonal gammapathy:  overproduction of single types
  133. What are some examples of polyclonal gammapathy?
    • heartworm
    • ehrlichiosis
  134. What is an example of monoclonal gammapathies?
    multiple myeloma
  135. What is multiple myeloma?
    • neoplasia of plasma cells
    • blood becomes sticky - rouleaux increases
    • radiographic bone lesions (black spots in the bone)
  136. There will be an increase in _____ and _____ with gammapathies.
    • increase in total protein
    • increase in gamma globulins
  137. When do large animals have problems with immunological disorders?
    most are due to a decreased antibodies
  138. 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
  139. How long does the antibodies from colostrum last?
    about 2 weeks and then active immunity kicks in 
  140. Anything that interferes with antibody production, passage, or absorption for large animals result in...
    • failure of passive immunity
    • neonate at risk for infections
  141. 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
  142. Which animals do we see FPI in?
    hoof stock
  143. When do we test for FPI?
    some doctors test at 12 hours and some test at 24 hours
  144. 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.
  145. What are the different tests available to test for FPI in horses?
    • refractometer
    • proten electrophoresis
    • foal IgG test kit (CITE - brand name)
    • Foal check
    • single radial immunodiffusion
    • zinc sulfate turbidity
  146. 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
  147. Which animals can we use the zinc sulfate turbidity test in?
    foals and calves
  148. Can we do the zinc sulfate turbidity test in house?
  149. What is Foalcheck?
    in house latex agglutination test
  150. When should we treat foals for FPI?
    • treat foals with IgG <400 mg/dl
    • we prefer for the IgG to be >800 mg/dl
  151. What are the in house tests for FPI in ruminants?
    • sodium sulfite precipitation
    • glutaraldehyde coagulation
  152. 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
  153. What do we look for in the glutaraldehyde coagulation test?
    look for a clot to form
  154. What is CID?  Which animals do we see this condition in?
    • combined immunodificiency
    • inherited in arabian foals and arabian crosses
  155. How do arabian horses get CID?
    autosomal recessive trait - if both parents are carriers then the foal will have CID
  156. What precent of arabian horses are carriers of CID?
  157. Are there DNA tests available to test for CID before breeding?
  158. 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
  159. When do foals typically die from CID?
    die by 6 months
  160. What test can be done to test for CID?
    • DNA tests
    • RID - foal will lack IgM
    • CBC - presistent lymphopenia below 1000/ul
    • Histopathological lesions - small thymus that lack germinal centers (usually done in necropsy)
  161. 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
  162. Is equine neonatal isoerythrolysis an immune disorder?
    no, but it does related to a problem with antibodies
  163. Which horses and what percent of them do we see equine neonatal isoerythrolysis?
    • thoroughbred and standardbred pregnancies
    • 1 - 2%
  164. 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
  165. What do we see in a foal with equine neonatal isoerythrolysis?
    • hemolysis occurs
    • foal becomes anemic/icteric
  166. How do we avoid equine neonatal isoerythrolysis?
    test before giving colostrum
  167. Image Upload 1
    What is this?
    acute contact dermatitis
  168. Image Upload 2
    What is this?
    acute moist dermatitis (hot spot)
  169. Image Upload 3
    What causes this?
  170. Image Upload 4
    What is this?
    chronic contact dermatitis
  171. Image Upload 5
    What causes this?
    flea allergic dermatitis
  172. Image Upload 6
    What caused this?
    flea collar dermatitis
  173. Image Upload 7
    What test is this for ruminants?
    Glutaraldehyde coagulation for testing for FPI
  174. Image Upload 8
    What is this?
    LE cell
  175. Image Upload 9
    What is this?
    rodent ulcer
  176. Image Upload 10
    What is this?
    skin testing
  177. Image Upload 11
    What test is this for ruminants?
    sodium sulfite precipitation for testing for FPI
  178. Image Upload 12
    What test is this for foals and calves?
    zinc sulfate turbidity for testing for FPI
Card Set
Diagnostic Testing for Immunological Disorders
Lab Tech ll