(P) Hemolytic Disease of the Newborn part 2 Flashcards
(54 cards)
the second most common cause of severe hemolytic
disease of the newborn (HDN) after Rh disease.
KELL HEMOLYTIC DISEASE OF THE NEWBORN
Hemolytic disease of the newborn (anti-Kell1) is caused by a
mismatch between the _____ antigens of the mother and
fetus.
Kell
T or F
There are more people that are Kell positive than negative
F (t 91% of the population are Kell1 negative and about
9% are Kell1 positive.)
T or F
Kell antigens can cross the placental barrier
T
What are the two effects of Kell hemolytic disease of the newborn
- anemia
- alloimmune hemolysis
when does the Kell hemolytic disease of the newborn take place?
20 weeks (occurs early)
What is the disease associated with Kell hemolytic disease of the newborn
hydrops fetalis
What is the laboratory test used to find Anti-Kell antibodies in antenatal screening blood test assessment
Indirect antiglobulin test (IAT)
T or F
The main cause of Kell hemolytic disease of the newborn is due to a previous pregnancy of a Kell negative mother with a kell positive baby
F (multiple blood transfusions)
a
condition where the passage of maternal antibodies
results in the hemolysis of fetal/ neonatal red cells.
hemolytic disease of the newborn
_____________ occurs when the maternal immune system is sensitized to RBC surface antigens
most common causes
* blood transfusion
* fetal-maternal hemorrhage
isoimmunization
What are the three results of the hemolytic process
- Hyperbilirubinemia
- Neonatal thrombocytopenia
- Neonatal neutropenia.
The following are true except:
a. Anti-Kell can cause severe anemia regardless of titer.
b. Anti-Kell suppresses the bone marrow, by inhibiting the lymphoid progenitor cells.
c. HDN can also be caused by anti-Kell2, anti-Kell3 and anti
Kell4 IgG antibodies
d. HDN by other kell antibodies are milder than anti-kell1
b. (Anti-Kell suppresses the bone marrow, by inhibiting the
erythroid progenitor cells. )
Testing for HDN
all of the following are true except one
a. testing for HDN involves blood tests from both the mother and the father
b. assessment uses amniocentesis
c. Middle cerebral artery scans are done and interpreted by radio technologists
c. (done by rad techs, interpreted by medical doctors)
Familiarize the HDN tests for mothers (3)
- Indirect Coombs test (ICT) or Indirect Agglutination test (IAT)
- Middle Cerebral Artery scans (MCA)
- Alloimmunization to the c, E, or C antigens.
(IMA)
determine the HDN test (mother’s)
- Purpose: to detect antibodies in the maternal plasma. If
positive, the antibody is identified and given a titer - Critical titers — Risk of fetal anemia and hydrops fetalis
o Critical for Kell: Titers of 1:8 or higher critical for Kell.
o Titers of 1:16 or higher critical for all other
antibodies
ICT / IAT
determine the HDN test (mother’s)
- needed if antibodies are low and have a sudden increase later in
pregnancy - This test is done noninvasively with ultrasound. By
measuring the peak velocity of blood flow in the middle
cerebral artery, a MoM (multiple of the median) score can
be calculated.
Middle Cerebral Artery (MCA) scans
In Middle Cerebral Artery (MCA) scans
a titer of 1.5 or greater indicates what?
What should be done if titer is greater than 1.5?
- severe anemia
- treat with INTRAUTERINE
TRANSFUSION (LUT).
T or F
If the titer undergoes a 4-fold increase, it should be
considered significant regardless of if the critical value has
been reached.
T
T or F
Maternal titers are not useful in predicting fetal anemia
after the first affected gestation and should not be used for
the basis of care.
T
Maternal titers should be tested every _______ until _______, after which they are done every ________.
- month
- 24 weeks
- 2 weeks
Alloimmunization to the c, E, or C antigens
- hemolysis may occur in patients with a titer lower than _____
1 : 16
If the initial titer is 1:4 and stable but increases at 26
weeks’ gestation to 1:8, assessment with MCA Doppler
velocity at that point is reasonable. However, if the patient presents in the first trimester with a
1:8 titer that remains stable at 1:8 throughout the second
trimester, the fetus is not viable for life.
a. only the first statement is true
b. only the second statement is true
c. both statements are true
d. both statements are false
a. (serial antibody titers are appropriate if 1:8 first trimester until second trimester)
Severe fetal hemolysis with anti-kell antibodies have occured in low titers. In the case of a positive ICT/IAT, the woman must carry a
medical alert card or arm band/wrist band for life
because of the risk of a transfusion reaction
a. only the first statement is true
b. only the second statement is true
c. both statements are true
d. both statements are false
c
