Immunology Exam 1 Flashcards
GAS Extracellular Virulence Factors
- SLO and SLS
- Hyaluronidase
- DNAses A, B, C, D
- Streptokinase
- Erythrogenic Toxins
Streptokinase
Helps to dissolve clots
Hyaluronidase
Breaks down extracellular matrix (ECM)
Erythrogenic toxins
Associated with scarlet fever strains
- 2nd day rash on trunk and face
- “Strawberry” tongue
- Sloughing of skin in second week
Impetigo
- Common symptom of GAS (children)
- Extremely contagious
- Honey-colored crusts
Necrotizing fasciitis
- Rare complication of GAS
- Secondary to wound infection, organism rapidly progresses through muscle
Treatment:
1. Debridement
2. Intramuscular Antibiotics
3. Amputation
GAS Sequelae Causes
Rheumatic Fever - ASO
Acute Glomerulonephritis - Anti-DNAse B
ASO Reference Method
- Neutralization Reaction
- Todd Units (1 / titer of last tube w/o hemolysis)
Significant titers: >200 TU (adult), >300 TU (child), up 50 TU in 2 weeks
Infectious Mononucleosis
- EBV (herpes virus)
- Infects B lymphocytes
- Lymphoproliferative disorder (60-90% of WBC are lymphs, 5-30% are reactive)
Forssman (Heterophile Antibody)
Guinea Pig Kidney - Reacts
Bovine RBCs - NR
Sheep RBCs - Reacts
Mono (Heterophile Antibody)
Guinea Pig Kidney - NR
Bovine RBCs - Reacts
Sheep RBCs - Reacts
Serum Sickness (Heterophile Antibody)
Guinea Pig Kidney - Reacts
Bovine RBCs - Reacts
Sheep RBCs - Reacts
Anti-VCA (IgM)
“Viral Capsid Antigen”, first antibody to appear
Anti-VCA (IgG)
Appears early and a higher levels, may be present life long
Anti-EA-D
Associated with acute infection of EBV
Anti-EA-R
Associated with acute infection of EBV. Found in young adults but not children.
Anti-EBNA
“Epstein Barr Nuclear Antigen”. Appears after acute infection and increases in convalescence.
Febrile Agglutinins
Antibodies to microorganisms associated with persistent fever
- Cause RBCs to agglutinate (cold agglutinins)
Widal Test
Agglutination test to detect antigens of various Salmonella species.
- Can differentiate between species
- O = Somatic Antigen (< 6 months) (1:160+ indicative)
- H = Flagellar Antigen (1 year +) (1:80)
- Vi = Capsular Antigen, highly virulent S. typhi and S. paratyphi (Never leaves Carriers), Can cause false negative O, boil to correct
Tularemia
- Francisella tularensis
- Small mammals and birds
- Acquired through contact with animals
- Cross react with Brucella antibodies
- High titers in primary disease (1:160+)
Brucellosis
- Brucella abortus
- Normal flora in genital and urinary tract of cows, pigs, and buffalo
- Acquired through eating meat or occupational exposure
- (1:80 significant, 1:160 indicative)
Rickettsial Disease
- Recurrent Fever
- Acquired through tick, mite, and lice bites
- GNC
Weil Felix Reactions
Detect Reckettsia Disease by cross reactivity with Proteus Antigens
RMSF (Rocky Mountain Spotted Fever)
Epidemic Typhus
Murine Typhus
OX19 ++++ (1:160-1:320)
OX2 +
OXK neg
Scrub Typhus
OX19 neg
OX2 neg
OXK ++++
Other tickborne SFG (Spotted Fever Group) Infections
OX19 +
OX2 ++++
OXK neg
Hydatidiform Mole
- Chorionic villi enlarge into grapelike clusters
- Can be complete moles (no fetal tissue) or partial moles
- More common in older women
Choriocarcinoma
- Malignancy of fetal origin
- May disseminate, usually to lungs
Testicular Teratoma
- Embryonic germ cell tumor
- Composed of different kinds of tissues (skin, hair, muscle)
- Produce HCG in men
BHCG
Lateral Flow Sandwich Immunoassay
- Highest near end of 1st Trimester
- Fall to 10-15% of peak in 2nd and 3rd Trimester
TORCH Test
TOxoplasmosis
Rubella
Cytomegalovirus
Herpes
Oocysts
Toxoplasmosis. Spore-like stage that is ingested by humans
Tachyzoites
Toxoplasmosis. Mobile form that invades neural tissue
Bradyzoites
Toxoplasmosis. Tissue cyst forming units that can lay dormant indefinitely
Toxoplasmosis Treatment
- Pyrimethamine and sulfadiazine
- Treat baby for first two weeks after birth
Rubella Characteristics
- ssRNA virus of the togavirus family
- Benign, self-limiting with mild upper respiratory tract infection, erythema (rash)
Rubella Immune Titer (IgG)
1:8 or 1:10
CMV (Cytomegalovirus)
- Belongs to herpes family
- Associated with WBCs
- Greatest risk: HIV+, Transplant patients, Premees
- “Owl Eye” inclusions in infection
Herpes
- Herpes simplex virus
- Type 1: upper body, oral cavity (most infections)
- Type 2: genital lesions
- Latent infection in lymphoid and CNS ganglia cells
Herpes Treatment
- Acyclovir or vidarabine
Direct Agglutination
Antigen is a natural particle (often an RBC)
Indirect (Passive) Agglutination
AntiGEN is adsorbed onto surface of an artificial particle (latex beads, etc)
Reverse Indirect Agglutination
AntiBODY is adsorbed onto surface of an artificial particle (latex beads, etc)
Agglutination Inhibition
Competitive between particle and the and its antigen for limited antibody
- If agglutination, neg
- If no agglutination, pos
Capture (sandwich) immunoassays
Antibody-antigen-antibody
Double Antibody immunoassays
Antigen-antibody-antibody
Direct Immunofluorescence
Patient antigen adsorbed to slide, tagged antibody bound
Indirect Immunofluorescence
Antigen adsorbed to slide, patient antibody bound, tagged antibody bound (like double-antibody immunoassay)
