Uams Immunology Exam #5 Updated Questions And Correct Answers

UAMS IMMUNOLOGY EXAM #5 UPDATED QUESTIONS
AND CORRECT ANSWERS
Question:
1. What is the ulcera-tive disease that fa-cilitates the trans-mission of HIV and what organism is it
caused by? What is the term for its shape?
Answer:
Syphilis, caused by Treponema pallidum. Spirochetes

Question:
2. What is the transmis-sion for Syphilis?
Answer:
Usually sexual and congenital via the placenta.

Question:
3. What is the physical indication of primary syphilis? What is the infectious stage?
Answer:
Appearance of chancre, which is a painless superficial ulcer at the inoculation site that heals
spontaneously. Serum reactive within 1-3 weeks after chancre appears. Spirochetes in chancre is
infectious.

Question:
4. What characterizes the secondary stage of syphilis and when does this usually ap-pear? What is the
in-fectious stage?
Answer:
Rash and fever with spontaneous healing after several weeks, serology is almost always positive.
Appears 6-8 weeks after appearance of chancre. Spirochetes in rash is infectious.

Question:
5. What characterizes the latent stage of syphilis?
Answer:
Usually no clinical manifestations and may last for up to 30 years, serology is positive. Mother can
pass to baby during this stage in vertical transmission.

Question:
6. What characterizes congenital syphilis?
Answer:
Intrauterine infection of the fetus, likelihood of infection increases as preg-nancy progresses, rhinitis
and rash present as clinical symptoms. The Hutchinson's triad appears - notches in teeth, eye damage
(keratitis), and deafness.

Question:
7. What characterizes the tertiary syphilis stage?
Answer:
Gumma lesions that can affect any site but are most common in cardiovas-cular and CNS sites.

,Question:
8. What is the fastest method of detection for syphilis? What is the slide examined for? What method
is not used?
Answer:
Darkfield microscopy is used to look for corkscrew shaped microbes with flexing motility. Isolation
methods are not used.

Question:
9. What is fluorescent testing most com-monly used for?
What does direct flu-orescent use? What does indirect fluores-cent use?
Answer:
Detection of AGNs. Direct - Monoclonal ABY and material from lesion. Indi-rect - patient specimen
and ABY/Ig and ABY/TP

Question:
10. What is syphilis serology used for?
Answer:
Diagnostic tool.

Question:
11. What indicates the frequency of positive test results in pa-tient WITH a partic-ular disease;
detects true positives
Answer:
Sensitivity

Question:
12. What indicates the frequency of nega-tive test results in patients WITHOUT a disease; detects
true negatives
Answer:
Specificity

Question:
13. What is the dif-ference between screening lab tests and confirmatory lab tests?
Answer:
Screening - non treponemal test use patient ABYs with reagin to cardiolipin, don't test organism
directly. Less expensive and easily performed. Usually only helpful with sensitivity - can get many
false positives. Confirmatory - treponemal test that tests organism directly; expensive and harder to
perform. Helpful with sensitivity and specificity - will help ID true positives.

Question:
14. How is non trepone-mal screening test performed?
Answer:
Patient ABY with reagin to cardiolipin as reagent. Flocculation is used which is a special
precipitation test that sediments out the AGN in very fine parti-cles.

Question:
15. How are the results determined in a non treponemal screen-ing test? When does the peak titer
occur?

, Answer:
Results are pos within 1-4 weeks after chancre appearance. Not all patients show pos in early primary
and late stages. Peak titer occurs during the secondary or early latent stages.

Question:
16. What are false neg-atives due to in secondary syphilis stages?
Answer:
The prozone

Question:
17. After adequate syphilis treatment, what are test results?
Answer:
Test results eventually become non reactive, which is used to monitor therapy

Question:
18. When can biological false syphilis posi-tives happen?
Answer:
Can happen is patient has another infectious disease such as TB, HIV, measles, or mono, can happen
if patient has other non infectious conditions such lymphoma, autoimmune diseases, or drug
addiction, and can also happen if patient is pregnant.

Question:
19. What was devel-oped in 1946 and was first suitable for mass screening?
What is this a pri-mary test for? What is the reagent AGN?
What is different with modified VDRL?
What is the reagent for modified VDRL?
Answer:
Venereal disease research laboratory or VDRL. Primary test for CSF. Reagent AGN is cardiolipin,
lecithin, and cholesterol. Modified VDRL can't test CSF. Modified VDRL reagent is cardiolipin,
lecithin, cholesterol, choline, and charcoal.

Question:
20. What are the confir-matory treponemal tests?
Answer:
Fluorescent Treponemal ABY - Absorption test or FTA-ABS = indirect assay for ABY from patient.
Nichol's strain of T. pallidum for reagent AGN. Hemagglutination - passive hemagglutination test
that has RBCs coated with nichol's strain. MHA-TP = treated with sheep RBC. HATTS & TPHA =
treated with turkey RBC. Gelatin particle agglutination - Serodia TP PA = sensitive in detecting
primary syphilis; similar to MHA-TP except gelatin particles are coated with AGN and not RBCs.

Question:
21. Which confirmato-ry test is sensitive for detecting prima-ry syphilis?
Answer:
Gelatin particle agglutination - Serodia TP PA

Question:
22. What new technolo-gies are emerging for IgM and IgG sensitivity? What is not currently
avail-able for syphilis test-ing but is used of-ten with other speci-mens?