HDN_Case_Study_power_point

Report
Hemolytic Disease of the Newborn
Case #3
Scenario
•Baby Girl Dae
two-day old
jaundiced newborn
girl
•sample of her
blood is submitted
to the Blood Bank
for an HDN workup
What we know about the Mother
• Doris Dae (mother)
• mother's first pregnancy
• pre-natal type and screen done at 2 months - ADT
negative
• Blood was tested again at 28 weeks gestation ADT negative
• Received prophylactic antenatal RhIg at 28 weeks
• a post-delivery specimen was submitted for an
RhIg retest
What we know about Baby
• Blood type - A pos
• Test for Circulating Antibody (reverse type)
– shows 1+ reaction with A1 cells, no reaction with B cells
– indicates presence of anti-A1 in baby's serum (must be
maternal IgG since baby is not producing antibodies yet)
• Antibody screen - negative
– indicates ABO antibody or rare antibody
• DAT - positive at immediate spin (indicates IgG
antibody)
– NOTE: positive result means that antibody is present on
baby's cells; does NOT indicate severity of reaction
Elution Results on Baby’s blood
• Elution results
– Positive for A1 cells (both Rh pos and neg)
– indicates that antibody coating the baby's RBCs is
ABO, not Rh
• At this stage we know that the baby has
maternal ABO antibody coating her cells
– Most likely culprit is anti-A,B
Further work up on Mom
• Doris Dae
• Post-delivery confirmation of blood type - O
negative
• Post-delivery antibody screen (ADT)
– positive reaction for both screening cells at AHG
(1+)
• Antibody Detection Panel
– most likely antibody: anti-D
– can't rule out anti-C, -E, -Cw, -K
Is there a serological problem in either
the mother or the baby?
• Yes - baby is reacting to any antibody from the
mother; mother has tested positive for an
antibody as well
Does the child have HDN? What type
of HDN?
• Yes - ABO HDN
The baby's back typing/test for circulating
immune antibody is positive; reacting at the AHG
level at a 1+, and the baby's DAT is positive at
both the initial spin and at 5 minute incubation.
This indicates there has been in vivo sensitization
of the baby's RBC's with IgG and/or complement
by the mother's cells. The baby's cells are coated
with (most likely) IgG antibodies to A from the
mother, and are thus being removed from her
body via the spleen and liver causing the jaundice
What led you to the conclusion of HDN
and what is/are the implicated
antibodies?
• DAT - shows that there is an IgG antibody coating
the baby's RBCs
• Back type and elution - shows that it is an ABO
reaction, not Rh or non-Rh. Weak D reaction is
negative
• Clinical presentation and patient history also
helps
–
–
–
–
jaundiced baby within 48 hours of delivery
mother's first pregnancy
Mother is type O- and baby is type A+
Antibody present: most likely anti-A,B
How would you explain the testing results to the
physician as they relate to the clinical picture of
the infant?
• Discuss clinical presentation of ABO HDN, both the
mother and the newborn’s test results and common
treatments
– transfusion is rarely needed for ABO HDN
– Increasing levels of bilirubin can be treated with
phototherapy using a blue light of a specific frequency that
breaks down the bilirubin to a water soluble form that is
easier for the body to get rid of
– the infant’s rising bilirubin levels are seen due to the liver’s
immaturity/inability to keep up with the excess free
hemoglobin from the lysis of the baby’s IgG coated RBC’s.
While inutero, the mother’s liver was clearing the antibody
coated infant’s RBC’s, therefore the excess bilirubin was
not building up
Transfusion indicated treatment in the
newborn for HDN ABO
• Rapidly increasing bilirubin levels not
controlled by the phototherapy
• Transfusion with group O Rh- RBC’s may be
required
What type of red cells, plasma, and
platelets should be given if the mother
requires blood?
•
•
•
RBC - O neg
Plasma - O preferred, any type will be acceptable
Platelets - O neg
Red Cells
Recipient type
1st Choice
2nd Choice
3rd Choice
4th Choice
AB
A
B
O
AB
A
B
O
A
O
O
B
O
Platelets, Plasma, and Cryoprecipitate
AB
A
B
O
AB
A
B
O
AB (universal plasma donors)
AB
Any – Depending on inventory because there is no antigen on the red
cells
Rh matching is not required with plasma and cryo
Platelets must be selected according to Rh D neg or positive type of recipient.
•
•
•
•
What type of red cells, plasma, and
platelets should be given if the baby
requires blood?
RBC - O neg
Plasma - AB
Platelets - O neg
Baby should be transfused using cells that
match the mother’s blood type and Rh. Also
O neg is the universal donor type since it has
no antibodies on the surface of the red cells
Were there any unnecessary tests
done?
• Back-typing the baby with B cells was not
necessary -- baby is not producing antibodies
yet, and if maternal ABO crossed the placenta
it is most likely anti-A,B (anti-A and anti-B are
IgM unless the mother was immunized in
some rare scenario)
Are there any additional tests that
would be useful in solving this
problem?
• Test baby's eluate or mother's serum for anti-A,B
to confirm that it is the antibody causing the
reaction
• To finish the work-up you should try to rule out
the additional antibodies from the mother's
antibody panel
• Titer in first trimester.
• Paternal Testing - phenotyping the father to see if
the he has the antigen corresponding to the
mother's antibody can help the diagnosis.
Should this mother receive RhIg? Why
or why not?
• yes - mother is Rh neg and the baby is Rh pos
and we want to prevent the mother from
becoming immunized
• the mother's pre-natal and 28 week ADT were
both negative
• post-natal ADT was positive but weak
• Baby RBC elution shows no anti-D
• positive post-natal ADT is due to residual RhIg?
from the prophylactic treatment at 28 weeks
Why is baby only reacting with A?
• cells have more A receptors than B receptors the A response was already pretty weak so the
B response may not have been detectable (not
high enough titer of antibody?)
• mom could have been previously immunized
and formed IgG anti-A (rare!)

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