Module 12 Flashcards
(23 cards)
What is serology?
Study of Ags and Abs in vitro
What are the principles behind serology?
Reagent Ag detects Abs
Regent Ab detects Ags
What types of reactions can be used for serology?
Agglutination
Precipitate
Complement fixation
Fluorescent Ab
EIA
RIA
How is titre determined?
Reciprocal of the highest serum dilution that shows a positive serological reaction
What is the RA/RF test used for?
Diagnosis of rheumatoid arthritis
Rheumatoid factor in 80% of patients with RA
Why is RF produced?
IgM autoAb formed when an aberrant IgG Ab is not recognized (altered)
Form Ag-Ab complex that migrates to connective tissue
What is the reagent for RF testing?
Latex particles coated with specially treated IgG
What else gives a positive RF test?
Syphilis
Hepatitis
SLE
Hypergammaglobulinemia
What causes infectious mononucleosis?
Epstein Barr virus
What is seen hematologically with mono?
Lymphocytosis
What does the monogen test detect?
Presence of heterophile Abs produced in response to EBV
Reacts with Ags on the surface of erythrocytes of several species
Latex agglutination
How do pregnancy tests work?
Detect hCG in the first trimester
Also hydatidiform moles, ectopic pregnancy, cancer
What is the method of testing used in pregnancy tests?
Modified EIA
Reagent is Ab to beta subunit of hormone
What can a semiquantitative pregnancy test tell you?
High hCG- hydatidiform mole
Low hCG- ectopic pregnancy
What antibodies are produced with Treponema pallidum? Which is detected by the RPR test?
Ab against bacteria
Ab against reagin (released on tissue breakdown)
Detects reagin Ab
Why are pregnant women tested for syphilis?
Can cross the placenta and cause congenital syphilis which cants be treated
Treatment of mother can prevent fetal infection
What is the reagent for the RPR test?
Reagent Ag attached to charcoal particles
How are Syphilis results reported?
Reactive, weakly reactive or negative
Reactive and weakly reactive are further tested with treponemal test (specific)
What is rubella testing done for?
German measles
Mild infection but treat to fetus of infected nonimmune woman
Can be born with congenital rubella syndrome
How does rubella testing work?
Detects rubella Abs
What can rubella testing be used for?
Determine immune status
Diagnose acute infection
Diagnose congenital rubella
What do EIAs do in rubella testing?
Detect and quantitate IgM (recent infection) and/or IgG (determine immune status)
What indicates a recent rubella infection?
4x or greater titre increase
