serology of pregnancy

Question 1

HCG is…

Answer 1

Human Chorionic Gonadotropin
glycoprotein hormone
secreted by trophoblastic cells

Question 2

When is HCG detected in pregnancy?

Answer 2

within a few days after conception
peaks during 2-3 months

Question 3

what are the HCG subnunits?

Answer 3

alpha (blue aa chain) [shared w/ TSH, FSH, LH]
beta (green aa chain) [specific to HCG]

Question 4

Which subunit of HCG is used for testing?

Answer 4

beta subunit

Question 5

clinical usefulness of abnormal HCG testing

Answer 5

high risk pregnancy
ectopic pregnancy
trophoblastic tumors
detection of ectopic pregnancy (hydatidiform mole, choriocarcinoma)
testicular tumors

Question 6

choriocarcinoma

Answer 6

epithelial malignancy of fetal orgin
develops from chorionic portion of the products of conception
dissemination, cause bleeding, contain components of ab. fetus, arise in men from testicular teratoma

Question 7

testicular tumors

Answer 7

embryonic germ cell tumor with cells from the 3 germ layers
produce HCG

Question 8

The first morning urine specimen is usually recommended in testing for urine HCG because

Answer 8

The specific gravity is highest in this sample and low specific gravity may cause a false negative test result and It contains the greatest concentration of HCG for a qualitative determination

Question 9

The hormone which elevates in pregnancy and is used as a detection marker is:

Answer 9

Human chorionic gonadotropin

Question 10

Indicate ALL the infectious agents listed below that are tested for in the TORCH test

Answer 10

Toxoplasma
gondii
Rubella virus
Cytomegalovirus
Herpes virus

Question 11

Which of the following individuals would be
least likely
to be severely affected by a cytomegalovirus infection?
a 10-year old child
a heart transplant patient
a three week premature infant
an AIDS patient

Answer 11

a 10-year old child

Question 12

A healthy 20 year old woman showed a
1
:32 titer of rubella IgG antibodies with no clinical symptoms. What is indicated by thisfinding?

Answer 12

Developed immunity at some time in the past

Question 13

Which populations are of most concern regarding transmission of CMV in transfused blood?

Answer 13

transplant patients
premie babies

Question 14

What will cause elevations in a pregnancy test?

Answer 14

pregnancy
testicular tumor
hydatiform mole
choriocarcinoma

Question 15

A pregnant woman is exposed to a child with a rubella infection. She had no clinical symptoms but had a rubella titer performed. The titer was less than 1:8. Three weeks later, she had a repeat test and the titer was1:128. She still had no clinical symptoms. Was the laboratory finding indicative of rubella infection?

Answer 15

Yes, a greater than fourfold rise in titer is indicative of early infection in this case.

Question 16

If antibody against the appropriate subunit is not used in the development of the test system for pregnancy testing, other hormoneswith a shared subunit may cross-react and cause a false positive result. Which hormones share a subunit with HCG?

Answer 16

TSH (thyroid stimulating hormone)
FSH (follicle stimulating hormone)
LH (leutinizing
hormone)

Question 17

To confer specificity (eliminate false negatives) in a pregnancy test, a manufacturer can BEST

Answer 17

Develop a monoclonal antibody to the beta subunit of the HCG molecule as the test antibody

Question 18

Older methods of pregnancy testing

Answer 18

agglutination
agglutination inhibition

Question 19

current method of pregnancy testing

Answer 19

monoclonal antibody tests:
EIA method (sandwich technique)
modular methods
home pregnancy tests

Question 20

modular methods of pregnancy testing test method

Answer 20

add sample, moves by wicking action, control line (dye imbedded in strip), test line anti HCG w/ dye + color w/ Antigen/antibody complex

Question 21

home pregnancy tests test method

Answer 21

lamminar flow immunoassay
similar to modular methods

Question 22

hCG hormone ranges during week:

Answer 22

week 1-3: 5-50
week 4: 10-425
week 5: 19-7,340
wk 6: 1,080- 56,500
wk 7-8: 7,670-229,000
wk 9-12: 25,700-288,000
wk 13-16: 13,300- 254,000
wk 17-24: 4,060- 165,400
wk 25-40: 3,640- 117,000

Question 23

why test pregnant women for toxoplasmosis?

Answer 23

can result in CNS malformations or prenatal mortality in neonates

Question 24

toxoplasmosis characteristics

Answer 24

coccidian parasite
worldwide
host: cat

Question 25

toxoplasmosis life cycle

Answer 25

oocyts ingested by human
animals & mice develop cyst phase in tissue
either phase ingested by human tachyzoites formed which invade neural tissue

Question 26

treatment for toxoplasmosis

Answer 26

pyrimethamine and sulfadiazine

Question 27

risks of rubella infection during pregnancy

Answer 27

if infected during 0-12 wks pregnant: 100% risk of fetus congenitally infected= congenital ab., 20% die
wks 13-16: 15% deafness
after 16 wks: normal develop. may have deafness/ retinopathy

Question 28

rubella complications

Answer 28

microcephaly
hepatosplenomegaly
thrombocytopenia purpura
low birth weight
cardiac defects
cataracts
hearing loss
encephalitis
bone defects
still birth
mental retardation

Question 29

recent rubella infection can be determined by what antibody?

Answer 29

IgM

Question 30

what populations are more at risk for CMV infection?

Answer 30

HIV+ people
transplant people
premature infants

Question 31

What does CMV infection look like in the tissue?

Answer 31

owl eye inclusions

Question 32

complications of CMV

Answer 32

pneumonitis
hepatitis
GI ulceration
interstitial pneumonitis (hiv+)
meningoencephalitis
retinitis

Question 33

in utero complications of CMV

Answer 33

mental retardation
deafness
vision defects
motor dysfunctions

Question 34

types of herpes simplex virus

Answer 34

type 1; upper body, oral cavity
type 2: genital lesions

Question 35

how does herpes infect?

Answer 35

integrates DNA into host cells, latent infection in lymphoid/ganglia cells of CNS

Question 36

herpes complications

Answer 36

neonates: fatal
encephalitis
bronchitis, pneumonia, esophagitis, eye infec., disseminated disease