Immuno - Immunodeficiencies Review

drraythe's version from 2015-06-14 22:18


Question Answer
What is a 1⁰ immunodeficiency?Result of inherited (genetic) defect
What is 2⁰ immunodeficiency?Deficiencies resulting from another cause
Examples of 2⁰ immunodeficiency’sViral infections, microbial infections, toxins, malnutrition
Describe Grey collie syndrome. Aka?Canine cyclical neutropenia- autosomal recessive. Cyclic bone marrow defect in stem cells. Neutrophils periodically decreased. Usually die w/in a week, have lighter coat & NOT BLACK NOSE
What is SCID? Explain.SEVERE COMBINED IMMUNE DEFICIENCY horses/dogs/mice. diff genetic defects which all result in defective T & B cells - cant make their own Abs. autosomal recessive. Healthy while getting maternal Ab.
What is hypotrichosis w/ thymic dysplasia (cats)Genetic defect. Dont know what gene is problem. Kittens born w/out hair or thymus. Thymus makes T-cells
How can viruses cause immunodeficiency?Destroy lymphoid tissues. Esp. retroviruses target CD4+ T cells & FDCs
Examples of viruses which cause immunodeficiency?Feline immunodeficiency virus, herpes virus, canine distemper, canine parvovirus, etc
Which immune system does grey collie syndrome affect?Innate (neutrophils)
Which immune system does SCID affect?Acquired (B & T)
Which immune system does Hypotrichosis w/ thymic aplasia in cats & nude mice affect?Acquired (T)

Tests to know ctd

Question Answer
Reagents/procedures for ELISA?Use enzymes, look for color change (1⁰)
Reagents/procedures for Direct FA?Use Ab-FITC (florescence), look for florescence under UV (1⁰)
Reagents/procedures for Indirect FA?Use Antiglobulin-FITC, look for florescence under UV (1⁰)
Reagents/procedures for IHC?Use Ab-enzyme, treat w/ enzyme substrate look for color change (1⁰)
Reagents/procedures for precipitation/immuno diffusion tests?Use soluble Ag, look for precipitation of Ab-Ag complexes (2⁰)
Reagents/procedures for hemagglu tests?Add pt serum w/ Ab, look for clumping of RBCs (2⁰)
Reagents/procedures for hemagglu INHIB tests?Add pt serum w/antibodies, look for NO clumping (2⁰) no clumps = positive test result
Reagents/procedures for latex agglu?Add pt serum, ab presence shows latex bead clotting (2⁰)
Reagents/procedures for serum neutralization?Add pts serum w/ Ab to virus solution, then add that to cells, lack of cell death is positive
Reagents/procedures for western blot?Add pt serum w/ Ab & then add labeled antiglobulin to detect Ab. If looking for Ag, add enzyme-labeled Ab. Either way, look for color change
Reagents/procedures for complement fixation?Add RBCs to serum, if hemolysis = neg for Ab; no hemolysis is a positive test result.
What is mouse-anti-feline IgG?An Ab from a mouse which would attach to a cat's IgG Ab.
Monoclonal vs polyclonal Ab?Polyclonal = Abs that all react to different epitopes of 1 antigen
Monoclonal = Abs which all react to the Ags 1 epitope only
Explain acute vs convalescent sampleAcute - Collect serum early after onset of illness
Convalescent - Collect 14-20 days after acute
Which would have a higher titer, acute or convalescent sample? When & why?Convalescent would have a higher titer (ex: acute= 1:2 & conv= 1:64) bc longer into infection would be when there was time to MAKE Ab against dz, so it's a higher conc of Ab, thus takes more dilutions to stop effect
How do you know if there was an infection, using acute & convalescent samples for titers?If there is a 4 FOLD INCREASE between acute & conv. it is compatible w/ a Dx of infection
What is a pro-zone?For precip/agglu-type tests, it's when there is TOO MUCH ANTIBODY so poor lattice formations occurs bc they just coat the Ag- cant visualize precipitate (Abs are the pros but theres too many of them)
What is a post-zone?For precip/agglu-type tests, it's when there is TOO MUCH ANTIGEN so there is poor lattice formation (cant visualize precipitate) (Abs too few to link together properly)
What does a test w/ high sensitivity do?Very sensitive so CORRECTLY ID THE POSITIVES, maybe extras, but you can TRUST the Negatives to be True Negatives. Used to SCREEN animals. (Correctly ID positives)
What does a test w/ high specificity do?Can correctly ID the NEGATIVES, used to RULE OUT Dz (often used after sensitivity test). You can TRUST the positives to be true positives
How do you calculate sensitivity?(# of true positive / # with the Dz (TP+FN) ) x 100
How do you calculate specificity?(# of true negative / # without the Dz (TN+FP) ) x 100
3 examples of when youd want a highly sensitive testWhen you REALLY dont wanna miss any positives. So, screening for HIV in blood donors, checking for a dz where early Dx is important in Tx, or when dz is rare but important to detect (BSE-bovine spongiform encephalopathy in cattle)
In equations for specificity & sensitivity, describe what the numerator & denominator meansPecificity numerator = True Negatives; denominator = Total w/out Dz (P → u can TRUST the Positives, so you are looking for False Negatives)
seNsitivity numerator = True Positives; denominator = Total Dzd (N → you can TRUST the Negatives, so you are looking for False Positives)