Transcript Haemolytic Disease of the Fetus and Newborn

Haemolytic Disease of the
Fetus and Newborn
Chapter 11
Mollison 11th Edition- notes and embellishments
Dr Debra Lane
Medical Director
Canadian Blood Services Winnipeg
First Case
• Levine and Stetson (1939) described a
woman who bore a macerated fetus and
then developed a transfusion reaction after
a transfusion from her husband
• POSTULATED IT WAS PRODUCTS
FROM THE FETUS
HDN-Definition
• Haemolytic Disease of Newborn is a
condition in which the lifespan of the
infants red cells is shortened by the action
of mother’s antibodies which have crossed
the placenta
• The disease starts in the fetus and should
be renamed Hemolytic Disease of the
Fetus
Sensitization
• RH (D) negative fetus may develop a
positive DAT by the 8th week
• Severe death and anemia can occur by
the 18th week
• The hemolytic process is maximal at birth
and decreases with the diminution of the
maternal antibody
• Jaundice increases after birth
+DAT≠ HDN
• Many infants with a positive DAT do not
have increased red cell destruction
• Serum bilirubins rise in most infants first
two to three days of life
• Hemoglobins fall for the first two months of
life
Transfer of Antibodies
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Only occurs via the placenta
IgG only bound to FC receptor
Specialized neonatal FC receptor (FcRn)
Function depends on dimerization with β2
microglobulin
• Only occurs between mother and fetus
• It is an active process- only small amounts
transferred early in pregnancy
IgG transfer
• This is slow initially
• At term infants IgG may be higher than
mothers
• Half life two to three weeks in the newborn
• DAT may remain positive for three months
in non-treated infants
Most common
• Anti-A and Anti-B are the most common
antibodies
• ABO hemolytic disease is common, but
not severe
• Anti-D used to be the most common
antibody causing HDN
• Still the most common causing Fatal HDN
• In England Wales fatal HDN:
– 1977 106
– 1990 11
• Fatal anti-c and Kell
– 1977 4
– 1990 4
Immunogenicity
• D>c>K
• Most antibodies can cause HDN
• Severe ones include RH, anti-K, -k, -Kpa,
-Ku, -Jsa, -Jsb, -Jka, -Fya, -M, -U, PP1Pk, -Dib, -LAN, LW, -FAR, -Good,
-WRA, -Zd
Quantification of Fetal Cells
• Number of fetal cells
• Number of Adult cells
Detection of Fetal Cells by Acid
Elution
• Described by Kleihauer and Betke
• Blood films are treated with acid buffer
• Counter-stained the fetal cells appear as
red cells on a sea of white ghosts
• Normally 1 to 2% red cells are fetal
• In 25% of females the fetal hemoglobin
rises during pregnancy and may reach 7%
Must remember
• Fetal cells are larger than adult cells
• Not all fetal cells stain darkly by
acid-elution
• Arbitrary figure for maternal cell volume
has to be assumed
Assumptions
• Fetal red cells 22% bigger
• 92% of the red cell stain darkly
• Average red cell volume of recently
delivered woman is 1800 mls
• The volume of fetal red cells in the
maternal circulation is 2400/ ratio of darkly
staining cells to regular cells
Estimating Transplacental
Hemmorhage-Slides
• Using slides is inaccurate
• Depends on the thickness of slides
• Skill of technologists
Rosetting Tests
• Used as a screen
• Anti-D is added to red cells from the D neg
mom which coats any D pos cells
• Red cells are washed
• D positive (enzyme treated) detector cells
are added which form rosettes around the
D positive cells in the original sample
Flow Cytometry
• Maternal sample treated with anti-D and
then fluorescein-labelled anti-IgG
• Can detect 1/1000
• Lack of consensus in studies comparing
flow to BK may be a reflection of technical
differences.
– Need standardization of flow
– Gating of red cells
– Not universally accessible
Fetal Cell detection in Third
Trimester
Authors
28-30 weeks
30-39 weeks
Bowman and
Pollock
0.40%
1.84%
Huchet et al
5.8%
7.0%
Trans Placental Hemorrhage (TPH)
with Amniocentesis
• 1981 to 1984 of 1000 women with
amniocentesis for genetic disorders,
– 2.6% had TPH >0.1 ml
– 1.6% > 1.0 ml
TPH with Amniocentesis
• Bowman and Pollock
• 1200 having amniocentesis for HDN
– 2.3% TPH >0.1 ml
– 1.8% TPH > 1.0 ml
Chorionic Villus Biopsy
• Done at 7 to 10 weeks
• No fetal cells were detected
• But αfetoprotein increases- so Rh Immune
globulin is recommended
Normal Delivery
• 1.0% have 3.0 ml or more
• 0.3% have 10 mls or more
• When there is ABO incompatibility
between the fetus and mom, less fetal
cells are found in circulation
• Caesarean section and manual removal of
placenta give a considerable increase in
fetal cells
Clinical manifestations of HDN
• Rapid jaundice
• If not treated may develop kernicterus
with:
– Lethargy
– Spasticity
– Opisthotonos
Kernicterus
• Rare under 306μmol/L
• Non-immunologic hydrops 1/3500 births
– Cardiac
– Genetic
– Twin to twin transfusion
Anti-D
• Develops late in first pregnancies28 weeks
• First child rarely affected
• Stillbirth rate
– 6% with second pregnancy
– 29% with third
Prenatal testing
• All D negative women should be tested at
the first antenatal visit and at 28 weeks
• Anti-D at first trimester due to previous
transfusion or undiagnosed or undisclosed
abortion
New anti-D in Second Pregnancy
• Due to missed anti-D
• Anti-D given too late or insufficient dose
PCR for Prenatal Determination of
“D” Status
• PCR amplification of fetal DNA for RHD
• Uses fetal DNA present in the maternal
sample
• No risk of TPH
• No possibility of sensitizing the mother
• RHD is absent in D negatives- in whites
• Pseudo RHD in blacks
Real time PCR
• Read Mollison
Antenatal Assessment
• Used to include fetal blood sampling
Amniocentesis
• Estimating the amount of bile pigment in
amniotic fluid is performed by measuring
the optical density at 450 nm between the
observed density and an extrapolated
baseline
• Amount falls with pregnancy so the age of
the fetus must be considered
Liley (1961)
• Developed charts to determine the
severity from 27 weeks onward
• They cannot be used prior to 27 weeks
• Liley had three zones indicating the
approximate severity of HDN
Comparison of Liley {Delta}A450 values with bilirubin concentrations measured with the standard (A)
and modified (B) iterative methods, and log-linear chart (C), extrapolated to 17 weeks of gestation,
showing the three risk zones described by Liley
Egberts, J. et al. Clin Chem 2002;48:2045-2047
Copyright ©2002 American Association for Clinical Chemistry
Examination of the Fetus by
Ultrasongraphy and fetal Doppler
blood flow
• Can be used to diagnose hydrops fetalis
– Ascites
– Pleural effusions
– Pericardial effusions
– Skin edema (Bowman 1983)
Ultrasonography
• Can detect small pericardial effusions
• Dilated cardiac chambers
Fetal Doppler
• Reported 2006 NEJM Oepkes et all 355(2)
156
• Prospective International Trial of woman
with anti-D, anti-c, anti-E,and anti-FYa
• With a titre of 1/64
• 165 fetus
• 74 with anemia
Comparison Fetal Doppler versus
Amniotic Fluid
Doppler
Amniotic Fluid
Sensitivity
88 %
76%
Specificity
82%
77%
Accuracy
85%
76%
Fetal Blood Sampling
• Ultrasound guidance with a needle into the
fetal umbilical or hepatic vein
• 394 woman with 606 samplings the fetal
loss was 0.8%
• Fetal MCV 118 to 135
• Betke- Kleihauer Fetal hemoglobin
determined prior to fetal transfusion
Assessment of Severity of HDN in
Newborn
• Cord blood gives the most reliable
hemoglobin
• 13.6 to 19.6
• Range is wider for first day of life
Methods of Treatment
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Plasma exchange in the mother
IVIG to mom
IVIG to fetus
Transfusion of the fetus in-utero
Post –natal exchange transfusion
Phototherapy to reduce serum bilirubin
IVIG to mom/baby
• IVIG 2g/kg over 5 days
• Weekly injections of 1g/kg +/- plasma
exchange
• Might act by saturating the fetal FcRn and
inhibiting placental transfer
• A small series was done transfusing
fetuses with IVIG mean dose
85.7mg/kg/body weight
• No benefit- Dooren et al 1994
Transfusion of the Fetus in Utero
• 1963 Liley used intra-peritoneal transfusion
• Taken into the bloodstream via the subdiaphragmatic lacunae and right lymphatic duct
• Uptake depends on diagphragmatic movements
• Easy to perform
• Can be done in conjunction with intravascular
transfusion
• Cannot be done in infants without diaphragm
movement
Intravascular Transfusion
• Needle into the umbilical vein with ultra
sonic guidance
• Excellent results by Bowman 1990
– 16/22 hydropic fetuses survived
– 3/6 deaths were between 19-22 weeks in
fetuses of iv drug abusers
• Rodeck 1984 infants 18-24 weeks
– 25/29 with RH D HDN survived ( 10 hydropic)
Requirements for Exchange
Transfusion blood
• UK uses blood less than 72 hours
• In Manitoba less than 5 days or we wash the units
• The supranatant is removed and replaced with AB
plasma
• St Justines uses albumin- reduces donor exposures
• O negtive, K negative and compatible with mothers
antibody ( c negative if required)
• PCV 0.70 to 0.85
• Irradiated
• CMV negative
Transfusion volume
• 50/ml /kg estimated non-hydropic weight
• 30-40ml/kg estimated non-hydropic weight
for hydropic fetuses (Bowman 1994)
• Red cells suspended in non-protein
solutions such as SAG-M or Adsol should
not be used for transfusion to the fetus inutero. ( In Mollison no reference)
Alloimummization of the Mother
• May occur with fetal transfusion
• Fetal cells may be shed into the
peritoneum
• May enter maternal vessels on placenta
• I had one mother develop three new
antibodies
• Donor red cells are less frequently the
source of immunization than fetal cells
Exchange Transfusion- Postnatal
• Diamond 1947 introduced the method
• Blood is withdrawn and injected,
intermittently through a catheter
• Passed up umbilical vein
• Primary objective- remove D pos rbcs
• Secondary- remove bilirubin
• Clinicians like to exchange relatively large
amounts of blood( 200 ml/kg)
Blood requirements
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Plasma reduced
Less than 7 days
Rh and Kell neg/ compatible with mom
PCV 0.60
Screened for anti-HBS
CMV neg
Mollison does not say irradiated- we
irradiate.
Indications for Exchange
Transfusion
• When fetus is exchange prenatally they
usually do not need exchanges just
booster transfusions
• 80% okay with phototherapy
• Exchange if bilirubin threatens to exceed
340umol/L
• Hg should be checked every 10 days
• if Hg, 70g/L 20ml/kg given- Bowman
Exchange continued
• Not transfused prenatally- cord Hg, 110g/L
is an indication for exchange
Phototherapy
• Light at 420-480nm bilirubin converts to
biliverdin
• First reported Cremer et al 1958
• Tabb 1972 (controlled trial)
• Some have combined phototherapy with
IVIG and have avoided exchange
• 11/16 only phototherapy needed exchange
• 2/16 needed exchange with both (Rubo
and Wahn 1991)
Kell HDN
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Very sever at any titre
1/1000 pregnancies
History of transfusion in 88%
1/40,000 Bowman 1994
Fetal anemia is due to the suppression of
erythropoiesis
• Kell antigens are present on early
erythroblasts
Kell HDN
• Poor correlation with severity of the
disease and the mother’s titre
• Women with anti-K should be sent to
Fetal assessment immediately and not
wait for a rise in titre
• Bowman (1989) saw a hydrops at 23 with
a anti-Kell of 8
Anti-k HDN
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Very rare
May also be sever despite low titre
Anti-k (cellano) anti-k 16
The hemoglobin was 60g/L at 31 weeks
Bowman 1989
Anti-c HDN
• Titre of 1:32 or greater identified all
affected fetuses
• 32/49 deaths from HDN 1977 to 1990 in
Wales
• 0.7/1000 pregnancies
• 40 to 50% immunized by transfusion
• Fetus relatively often c negative
• Antibody is of low titre
Anti-c
• Only 20% of c positive infants required
exchange transfusion
• (Astrup and Kornstad 1977)
• C typing of fetal DNS
• Polymorphism at nucleotide 307 of RHCE
• Quantitative real time PCR can be used
for c typing of cell-free DNS from maternal
blood in pregnancies at risk (Finning 2004)
Anti-E
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Most common after anti-D
Often naturally occurring
Seldom causes HDN
See more with Galileo
Review 1959 to 2004 one perinatal death
due to anti-E alone (Joy)
Anti-e
• Very rare
• Disease usually mild
Anti-Fya
• Mild hemolytic disease
• At titres of .1/64 they should be closely
monitored
Anti-Jkb
• Rarely causes sever HDN
• Single case of hydrops
Anti-M
• May fail to affect the fetus
• Rare cases of hydrops-two cases
ABO hemolyti disease
• Only two cases of hydrops due to ABO
• Main need for exchange is to treat
hyperbilirubinemia
• Moderate bilirubinemia controlled by
phototherapy
I could go on forever- but this
is it for today.
Questions?