Transcript No Slide Title

NEONATAL SCREENING FOR
PRENATAL ALCOHOL EXPOSURE
Daphne Chan
Motherisk Laboratory for Drug Exposure
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Fetal Alcohol Spectrum Disorders
• Range of outcomes resulting from maternal
alcohol use --> 100% preventable
• Incidence & cost of treatment in Canada unknown
– About 1 to 3 live births per 1000 affected
– Estimated $1.4 million (U.S.) per person affected
• Early diagnosis and intervention leads to
significant improvements in development and
overall quality of life
– Only a small fraction of affected individuals are identified
and treated
• Difficult to diagnosis
• Maternal Hx required for Dx of CNS disorders
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Detection of Prenatal Alcohol Exposure
• Biological mother sometimes unavailable
– Medical-legal issues
• Maternal self-reporting
– Denial, under-reporting
• Maternal biomarkers
TRUE
FETAL
EXPOSURE
– Variable sensitivity and specificity
Neonatal
Screening
Test
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Neonatal Screening Test
• Biological markers indicative of fetal exposure
• Objective and independent of maternal history
Sample
Cord blood
Urine
Hair
Meconium
Advantages
Large sample size
Non-invasive
Concentrates metabolites
Indicates fetal exposure from TM 3
Timing of collection not critical
Easy to obtain
Non-invasive
Unique matrix of the fetus
Indicates fetal exposure from TM 2-3
Disadvantages
Narrow timing to collect
Recent exposure only
Difficult to collect
Recent exposure only
Small sample size
Not favored by parents
None
• Ideal scenario: Hair + meconium analyses
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ETHANOL METABOLISM
Oxidative
ADH and MEOS (CYP 2E1)
ETHANOL
ACETALDEHYDE
FATTY ACYL CoA
Microsomal FAEE Synthase
FAEE
FATTY ACIDS
Cytosolic FAEE Synthase
Non-Oxidative
POTENTIAL
BIOMARKERS
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FATTY ACID ETHYL ESTERS (FAEE)
• Significant FAEE accumulation in organs and tissues
commonly damaged by chronic alcoholism
– Brain, heart, liver, pancreas, adipose tissue
• FAEE synthase activity detected in human and
mouse placentae, and FAEE accumulation in mouse
fetal tissues
• Biomarker with short and long term clinical utility
– Positive blood test 24 hrs post alcohol consumption
– Postmortem markers for premortem ethanol intake
– Recent development of FAEE hair screening test
• Recently detected in the meconium of neonates
exposed heavily to alcohol in utero
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Meconium Analysis Protocol
Parental Consent / Physician’s or CAS referral
Collect clinical information (e.g. questionnaire,
including self-reported drug use history)
Review maternal and neonatal records
Collect meconium sample (>1g) directly from
newborn’s diaper into specimen container
Store frozen and ship to Motherisk Lab on dry ice
Extract FAEE from meconium
Analyze by gas chromatography
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FAEE Detected In Meconium
FATTY ACID
COMMON FOOD SOURCE
LAURIC (C12)
Coconut oil
MYRISTIC (C14)
Coconut oil, butterfat
PALMITIC (C16)
Animal and vegetable fat
PALMITOLEIC (C16:1)
Butter fat
STEARIC (C18)
Animal and some vegetable fat
OLEIC (C18:1)
Olive oil
LINOLEIC (C18:2)
Linseed oil
LINOLENIC (C18:3)
Linseed oil
ARACHIDONIC (C20:4)
Derivative of linoleic acid
DOCOSAHEXANOIC (C22:6)
Derivative of linolenic acid
• Derived from
endogenous FA
or FA acquired
from diet
• New FAEE*
included into
screening
profile
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Development of FAEE as
Biomarkers in Meconium
• Selective FAEE analysis - ethyl linoleate
(C18:2) [Bearer et al. 1999]
• FAEE spectrum analysis - profile of common
esters [Moore et al. 2001]
• Existence of basal FAEE levels ?
• Positive cut-off not clearly defined ?
• Clinical sensitivity and specificity ?
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Population Baseline Of Meconium Fatty Acid
Ethyl Esters Among Infants Of Non-Drinking
Women In Jerusalem And Toronto
D. Chan; B. Bar-oz*; B. Pellerin; C. Paciorek; J. Klein;
B. Kapur; D. Farine**; G. Koren.
Division of Clinical Pharmacology/Toxicology, The Hospital for
Sick Children, Toronto, Canada; *Department of Neonatology,
Hadassah University Hospital, Jerusalem, Israel; **Department of
Obstetrics, Mount Sinai Hospital, Toronto, Canada.
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Rationale
• Ethanol is a metabolite of normal
physiological metabolism. However, a well
defined baseline and positive cut-off that
accounts for the endogenous presence of
FAEE does not exist for the meconium
screening test in clinical practice to date.
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Objective
• To determine basal FAEE levels in the
meconium of neonates without prenatal
alcohol exposure from 2 distinct populations
Study Populations
• Mount Sinai Hospital (Toronto)
• A large urban teaching hospital that serves a
culturally and ethnically diverse population
• Hadassah University Hospital (Jerusalem)
• Chosen as a negative control group as it
represents a true alcohol-abstaining population
because of cultural and religious reasons
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STUDY DESIGN
Expecting mother recruited upon admission to delivery ward
Toronto (n = 104 mothers)
Jerusalem (n = 104 mothers)
Obtain Informed Consent (Verbal or Written)
Questionnaire (Demographics, Diet, Drug & Alcohol Hx)
Transcription of Maternal and Neonatal Health Records
Meconium Sample Collection for Analysis (n = 206)
Toronto (n = 102)
3 excluded
due to dirty
matrix
15 social
drinkers
excluded
84 mother-child
pair included into
baseline analysis
Jerusalem (n = 104)
3 excluded
due to dirty
matrix
2 social
drinkers
excluded
99 mother-child
pair included into
baseline analysis
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Results:
PERCENTAGE (%) OF
SUBJECTS
FAEE DISTRIBUTION IN MECONIUM
100
80
60
40
20
0
Lauric
(E12)
Myristic
(E14)
Palmitic
(E16:0)
Stearic
(E18:0)
Oleic
(E18:1)
Linoleic
(E18:2)
FAEE DETECTED
TORONTO (n=84)
JERUSALEM (n=99)
GROUP
TORONTO (n=84)
JERUSALEM (N=99)
SOCIAL DRINKERS (N=17)
HEAVY DRINKERS (N=6)
SOCIAL DRINKERS (n=17)
HEAVY DRINKERS (n=6)
TOTAL FAEE (nmol/g meconium)
MEAN
MEDIAN
SD
RANGE
1.37
2.08
0.42
11.08
0.89
1.25
0.41
6.43
1.43 0.27 - 5.26
2.39 0.34 - 10.21
UD - 1.40
0.46
14.02 1.98 - 39.35
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SUMMARY OF RESULTS
• FAEE species distribution was similar in
Jerusalem and Toronto
• Social drinkers (< 1 drink per month during
pregnancy) led to the accumulation of FAEE
within normal baseline levels
• Additional presence of longer chain FAEE
(E16 +) in neonates exposed to alcohol
• Lauric (E12), myristic (E14), and palmitic
(E16:0) acid ethyl esters predominate
baseline meconium
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DETERMINATION OF POSITIVE CUT-OFF
• Important in clinical practice to distinguish
between true fetal exposure and natural
endogenous production
• Calculations of clinical sensitivity, specificity,
and predictive values
• SENS = TP/TP + FN
• SPEC = TN/TN + FP
• + PV = TP/TP + FP
• - PV = TN/TN+FN
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DETERMINATION OF POSITIVE CUT-OFF
• Positive cut-off was varied from the LOD (I.e. the
“presence” of FAEE constituted a positive test) at
intervals to 2 nmol/g (I.e. the lowest level
detected from a TP case)
• SENS = 100%; - PV = 100%
• SPEC increased from 12 to 91% (+PV from 4 to 25%)
• Repeat calculations excluding ethyl laurate and
myristate from the total FAEE sum
• SPEC increased from 45 to 98% (+PV from 6 to 63%)
• [ ]s of E12 and E14 ethyl esters in baseline and
cases were insignificantly different
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CONCLUSIONS
• FAEE exists at low levels in the meconium of
neonates without prenatal alcohol exposure
• There is a characteristic pattern of FAEE distribution
in baseline meconium (predominantly short chain
FAEE), which was similarly observed in two
culturally and genetically distinct populations
• Neonates born to minimally/ socially drinking
mothers were indistinguishable from baseline
• Significant improvement in specificity after exclusion
of ethyl laurate and myristate suggested the role of
these esters in constituting the background noise
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Future Directions
• Prospective study with a larger cohort of “true positives”
– To verify sensitivity and specificity
• Development of FAEE screening test in hair
• Provincial/ national epidemiological study
– Incidence of FASD in Canada
– Prevalence of heavy drinking during pregnancy
• Basis for more effective public health initiatives
• Predictive potential of screening test?
– Immediate: Correlation between laboratory result and
pregnancy/ fetal outcomes
– Longitudinal: Follow-up of neurobehavioral development
and other social parameters
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Remember……
FASD are 100% preventable
Neonatal screening for
prenatal alcohol exposure
An alternative Harm Reduction
approach to treat the mother, her
child, and her future pregnancies
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