RH ANTIBODIES - ABO HDFN Flashcards
Part 2 (Quiz 2)
1
Q
IgG reacts at what temperature?
Rh antibodies
A
37C
2
Q
Rh antibodies are produced after exposure to foreign RBCs via?
A
transfusion or pregnancy
3
Q
Rh antibodies appears:
* primary ___
* secondary ____
A
appears within 120 days of primary exposure and within 2-7 days after secondary exposure
4
Q
which antibodies is formed first during exposure?
Rh antibodies
A
IgM then IgG
5
Q
t or f: Rh antibodies persist in the circulation years
A
true
6
Q
Which IgG subclass have the greatest clinical significance due to reticuloendothelial sysem rapidly clears RBCs coated with ___
Rh antibodies
A
IgG1 ang IgG3
7
Q
this antibody can appear but are extremely rare and not routinely tested
Rh antibodies
A
IgA
8
Q
A person with single Rh antibody
cannot produce additional Rh
antibodies if further stimulated
True or false
A
False, it can produce additional Rh antibodies
9
Q
why Rh antibodies does not bind complement?
A
because 2 IgG must attach to an RBC antigen in close proximity (30-40 nm) to each other.
10
Q
Rh antigens are not situated on the RBC surface this closely that’s why it does not bind complement
true or false
A
true
11
Q
RBC destruction is mostly __
Rh antibodies
A
extravascular
12
Q
Rh antibodies are enhanced when testing with __
A
enzyme-treated RBCs
13
Q
may show dosage, reacting preferentially with RBC processing ___
Rh antibodies
A
double-dose Rh antigen
14
Q
why D antigen is most potent?
A
exposure to <0.1 mL Rh + RBCs can stimulate antibody production (D > c > E > C > e)
15
Q
Rh antibody reaction includes?
4
A
- unexplained fever
- mild bilirubin elevation
- decrease hemoglobin and haptoglobin
- DAT (+)
16
Q
Low titer Rh-antibody may experience an ___ if exposed to some sensitizing antigen
A
anamnestic response
17
Q
first available typing reagent to test the D antigen
A
Saline reactive reagents
18
Q
Saline reactive reagents contains what antibodies?
A
Saline reactive reagents
19
Q
a low protein based typing reagent that can be used to test cells that are already coated with IgG antibody.
A
saline reactive reagents
20
Q
why saline cannot be used in weak-D typing?
Saline reactive reagents
A
due to its composition as IgM
21
Q
high-protein anti-D reagents was developed in what year?
A
1940s
22
Q
this reagent has IgG anti-D also with potentiators of bovine albumin and macromolecular additives (dextran or polyvinyl pyrrolidone)
A
High-protein anti-D reagents
with IgG anti-D from pooled hyman plasma with high-titer D-specific antibody
23
Q
enumerate the macromolecular additives of high-protein anti-D reagents
A
- dextran
- polyvinyl pyrrolidone
24
Q
RBCs are held in closer proximity to each other and allows IgG anti D to cross link and it can cause false positives
identify what Rh typing reagent
A
High-protein anti-D reagents
25
how will you manage false positives caused by the high-protein anti-D reagents?
**use a control** to counter the problem
26
enumerate the advantages of high-protein anti-D reagents
| 3
- reduced incubation time
- can perform weak-D testing
- polyspecific
27
Scientists **chemically modified** the ___ by breaking the disulfide bonds that maintain the antibody’s rigid shape
what year chemically modified was developed?
| Rh typing reagent
IgG anti-D molecule
year 1940s
28
this reagent is derived from single clones of antibody-producing cells
monoclonal antibody
29
Antibody producing cells are hybridized
with myeloma cells to increase
reproduction
| identify the reagent
Monoclonal antibody
## Footnote
monoclonaly antibody is usually a combination of monoclonal anti-D reagents from different clones due to D antigen with many epitopes to ensure
reactivity with broad spectrum of Rh-
positive RBCs
30
what reagent will you use for antigens other than D?
can be a *low-protein* (monoclonal or polyclonal or blends) or *high-protein beased*
31
monoclonal antibody reagent is a human derived therefore it cannot transmit infectious disease
| true or false
false, it is **not a human derived** that's why it cannot transmit infectious diseases
32
hemolytic disease of the fetus and newborn is caused by?
**IgG antibodies** actively transported across the placenta
33
Destruction of RBCs of the fetus or neonate by antibodies produced by the
mother
| include what year and who were the people involved
hemolytic disease of the fetus and newborn (HDFN)
reported by **Levine and Stetson** in *1939*
34
Rh HDFN is due to the?
fetus inherited the Rh of the father but the mother is Rh (-)
35
which child will be unaffected of HDFN if the mother has already 3 sons
| first born, middle, or the youngest
**first born** due to the mother hasn't been immunized.
## Footnote
During delivery, variable numbers of fetal RBCs enter the maternal circulation. Subsequent offspring that inherits the D antigen will be affected.
36
if the Rh (-) woman has a Rh (+), what could be the effect?
cells from the Rh+ will enter the woman's bloodstream and the woman becomes sensitized
## Footnote
antibodies form to fight Rh+ blood cells then in the next pregnancy, maternal antibodies will attack fetal RBCs
37
enumerate the factors of Rh HDFN
| 5
- antigenic exposure
- host factors
- immunoglobulin class
- antibody specificity
- influence of ABO group
38
this can cause significant increase in maternal antibody titers during pregnancy
| antigenic exposure factor
Fetomaternal hemorrhage
## Footnote
Volume of the hemorrhage is small but as
little as **1 ml of fetal RBCs** can immunize
the mother
39
The ability of an individual to produce
antibodies in response to antigenic
exposure varies, depending on complex
genetic factors
| identify the HDFN factor
Host factors
40
what immunoglobulin can only be transported across the placenta?
| Ig class HDFN factor
IgG
## Footnote
All subclasses of IgG are transported to the
placenta with **IgG1 and IgG3** the more
efficient.
41
transport of IgG begins at ___ and continues until ___
| Ig class factor
begins at **second trimester** and continues until **birth**
42
IgG is transported via the ___ of the antibodies
| HDFN factor
FC portion
43
what antibody is the most antigenic?
| antibody specificity
D
44
these antibodies have caused HDFN which requires intervention and treatment
| 2 anti- __
anti-E and anti-C
45
the incompatibility protects somewhat against __
Rh immunization
## Footnote
Investigators noted that many years ago,
that the incidence of D immunization is less
in mothers with major ABO incompatibility
with the fetus
46
In ABO incompatibility, the ___ in the mother’s circulation are lysed even before it can be recognized by the mother’s immune system.
D positive fetal RBCs
47
effects of maternal antibody
| enumerate the two
hemolysis and anemia
48
this effect of maternal antibody occurs when IgG attaches to specific antigens on the fetal RBCs
hemolysis
49
IgG coated RBCs are removed from the circulation by what cells?
| hemolysis
Littoral cells
| macrophages of the spleen
50
rate of destruction depends on ___
| enumerate the 3
## Footnote
hemolysis: effects of maternal antibody
- antibody titer
- specificity
- number of antigenic sites on the fetal RBCs
51
this develops due to hemolysis
anemia
52
Stimulates fetal bone marrow to produce RBCs at accelerated rate and includes immature RBCs (Erythroblastosis fetalis)
| effects of maternal antibody
anemia
53
these organs helps (Extramedullary
hematopoiesis), resulting to hepatosplenomegaly, resulting in portal
hypertension and hepatocellular damage
| effects of maternal antibody: anemia
spleen and liver
54
Severe ___ leads to development of high-output cardiac failure with generalized edema, effusions, and ascites
| effects of maternal antibody
severe anemia and hypoproteinemia
55
refers to high-output cardiac failure with generalized edema, effusions, and ascites
| this is due to severe anemia and hypoproteinemia
hydrops fetalis
56
due to severe anemia, increase production of indirect bilirubin will be observed from the fetus
| true or false
false, due to **heavy hemolysis**
57
this crosses the placenta and
the mother’s liver helps in clearing
(conjugating) this out
| ___ of the fetus crosses...
B1
58
at the time of delivery, the mother is in danger since it cannot process the remaining bilirubin due to damaged liver, leading to ___ and ___
| true or false
false, the **newborn** is in danger
## Footnote
But at time of delivery, the newborn is in
danger since it cannot process the remaining bilirubin due to damaged liver, leading to **Jaundice or Hyperbilirubinemia**
59
Around or more than ___ can cause “Kernicterus” or brain tissue damage
18-20mg/dL bilirubin
60
Effects may persist if the infant was delivered alive. It may continue until the remaining antibodies will be eliminated.
| true or false
true
## Footnote
The rate of effects decreases as long as no additional maternal antibodies are entering the newborn’s circulation
61
IgGs are distributed __
intravascularly or extravascularly?
distributed **both intravascularly and extravascularly**
62
enumerate the serologic tests of the mother needed for diagnosis
| 4
- antibody screen
- antibody identification
- paternal phenotype and genotype
- fetal DNA testing
63
antibody screen should be done preferably during?
first trimester
## Footnote
Previous pregnancy outcomes can be asked and evaluated. Prior transfusions can be evaluated.
64
this test must be able to detect significant IgG antibodies reactive at 37 and in AHG
antibody screen
65
prenatal specimen must be typed for ABO and Rh for atibody screen
| true or false
true
66
If the antibody screen is reactive, the ___ must be __
| antibody identification
If the *antibody screen is reactive*, the **antibody identity must be determined**
67
father's blood is tested for?
| paternal phenotype and genotype
presence and zygosity of the antigen
68
If mother has anti-D and the father is D-positive, a complete Rh phenotype can help determine his chance of being
homozygous or heterozygous for the D antigen
| true or false
true
## Footnote
sensitive and precise genotype can be determined by **DNA methods**
69
this can be performed as early as *10-12 weeks* gestation to determine whether the **fetus has the gene for D antigen**
| fetal DNA testing
Amniocentesis or Chorionic villus
70
In second trimester, __ can be tested for fetal DNA to determine genotype
| fetal DNA testing
maternal plasma
71
Relative concentration of all antibodies
capable of crossing the placenta and
causing HDFN is determined by antibody titration
antibody titers
## Footnote
**Patient serum** is serially diluted and tested against appropriate RBCs to determine the highest dilution at which a reaction occurs.
72
used to confirm HDFN and test for possible transfusion
| newborn testing
serologic testing of the **cord blood**
73
enumerate the tests needed to perform for newborns
| 5
* serologic testing of the cord blood
* ABO forward typping
* Rh typing
* direct antiglobulin test
* elution
74
Rh typing is performed with caution due to “blocked Rh”
| true or false
true
75
Rh typing is the most important test for diagnosis HDFN
| true or false
false, **direct antiglobulin test**
76
this test is not needed unless the cause of HDFN is in question
| newborn testing
elution
77
this is used to prevent immunization to D antigen
**RhIG**
Rh Immune globulin
anti-D immunoglobulin
78
Administered RhIG attaches to the ___ in the maternal
circulation
fetal Rh-positive RBCs
79
the antibody-coated RBCs are then removed by the?
maternal spleen
80
RhIG should be given ___
| administered Rh immunoglobulin
early in the 3rd trimester (28 weeks gestation)
81
this should be given early in the 3rd trimester (28 weeks gestation)
| RhIG indications
antenatal
| **DAT** may be positive in the newborn.
82
Non-immunized mother should be given
RhIG soon after delivery of an Rh (+) infant
| true or false
true
83
recommended interval for administering RhIG to mothers
72 hours after deliver
## Footnote
It should still be given even after more than 72 hours have passed.
84
US regular-dose vial
| RhIG dose
protect against 15 mL of packed RBCs or 30 ml WB
## Footnote
30ml WB (equal to 300 ug of WHO referencem aterial)
85
IV preparations for RhIg dose contains 300 ug per vial administered ___ or ___
administered intramuscular or intravenous
86
Regular-dose vial contains about 100ug
United kingdom
87
refers to the a large blood loss which is rare
true fetomaternal hemorrhage
88
other causes of FMH that rigens alloimmunization
| enumerate the 9
- ectopic pregnancy
- spontaneous absorption
- featl death
- cheonic villus sampling
- amniocentesis
- fetal blood sampling
- delivery
- abdominal trauma
- plancental abruption
89
enumerate the tests to determine severity
| Fetomaternal hemorrhage
* Fetal screen Rosette method
* Kleihauer-Betke test
90
a maternal sample should be collected within ___ of delivery and screened.
1 hour
91
this test is used for massive Fetomaternal hemorrhage in which the Mother’s blood is tested with anti-D reagent (incubate to promote binding)
Fetal screen Rosette method
## Footnote
The mixture is washed to remove excess
antibodies.
92
positive result of fetal screen rosette method
indicator cells surround the fetal cells
93
these are Rh positive cells added in the fetal screen rosette method
indicator cells
94
Maternal blood is smeared and treated with acid and then stained with counter stain
| identify what test
Kleihauer-Betke test
| Acid-Elution stain
95
fetal cells remains __
maternal cells appear as ___
| Kleihauer-Betke test (Acid Elution stain)
fetal cells = **pink**
maternal cells appear as **ghost cells**
96
how many cells are counted in the Kleihauer-Betke test?
| also know as Acid Elution stain
2000 cells
97
in fetal screen rosette method, calculated Fetomaternal hemorrhage volume is then divided by 30 to determine the number of RhIG vials
| true or false
false, Kleihauer-Betke test
| not the FSR method
98
how to calculate the volume of fetomaternal hemorrhage?
| Kleihauer-Betke test
Number of Fetal Cells x Maternal blood Volume/# of maternal cells
| Kleihauer-Betke test
99
this medication has no benefit if the person has already been immunized
RhIG
## Footnote
distinguish women who have been passively immunized via antenatal administration of RhIG from those who were really immunized
100
In RhIG, make sure to not interpret fetal Rh(+) RBCs as maternal (use tests available to distinguish)
| true or false
true
101
RhIG is not for mother with a D-negative infant
| true or false
true
| RhIG is not given to a new born infant
102
this refers to the small amounts of maternal blood enters the fetal
circulation
the Grandmother Effect
103
this test has been used to identify D-
positive DNA in the peripheral blood from preterm and full term D-negative newborns
| Grandmother effect
PCR testing
104
in grandmother effect, if the female reaches adulthood, she may produce anti-D before or early in her first pregnancy
| true or false
TRUE
The fetus then in the current pregnancy is at risk by maternal antibodies that was provoked by his or her grandmother’s RBCs
105
ABO incompatibility of the newborn and mother can cause?
Hemolytic Disease of Fetus and Newborn (HDFN)
106
Maternal antibodies that are IgG can cross the placenta and attach to incompatible RBCs of the fetus, this causes?
ABO HDFN
107
Antibodies occur more frequently as
high-titer IgG antibodies in what blood ABO group?
group O individuals
108
ABO HDFN is always limited
to A or B infants with O mother
| true or false
true
| A = whites B = blacks
109
Destruction leading to severe anemia is very common in ABO HDFN
| true or false
false, **less common**
110
ABO HDFN is observia via ____ within 12-48 hours of birth
hyperbilirubinemia and jaundice
111
History of past transfusions or pregnancies is unrelated to the occurrence and severity of the disease
| true or false
true
## Footnote
ABO HDFN can occur in first pregnancy
and in any pregnancy (not necessarily all)
112
this have been linked to production
of high tittered IgG ABO antibodies and severe HDFN during pregnancy
- tetanus toxoid administrations
- helminth parasite infection
113
sample recommended for ABO HDN test
**cord blood** samples on delivered infants
114
if the infant develops jaundice, which test/s should be performed?
| ABO HDFN
- ABO typing
- Rh typing
- Direct Antiglobulin Test (DAT)
## Footnote
If the *DAT result is negative* but the newborn is jaundiced, other causes of jaundice can be considered.
115
ABO HDFN indication (microscopic)
- microspherocytes
- increased RBC fragility
