1 neonatal screening for prenatal alcohol exposure daphne chan motherisk laboratory for drug...

20
1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

Upload: lewis-williamson

Post on 30-Dec-2015

214 views

Category:

Documents


1 download

TRANSCRIPT

Page 1: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

1

NEONATAL SCREENING FOR

PRENATAL ALCOHOL EXPOSURE

Daphne ChanMotherisk Laboratory for Drug Exposure

Page 2: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

2

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

Page 3: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

3

Detection of Prenatal Alcohol Exposure• Biological mother sometimes unavailable

– Medical-legal issues

• Maternal self-reporting– Denial, under-reporting

• Maternal biomarkers– Variable sensitivity and specificity

TRUE FETAL

EXPOSURE

Neonatal Screening

Test

Page 4: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

4

Neonatal Screening Test

• Biological markers indicative of fetal exposure• Objective and independent of maternal history

• Ideal scenario: Hair + meconium analyses

Sample Advantages DisadvantagesCord blood Large sample size Narrow timing to collect

Non-invasive Recent exposure onlyUrine Concentrates metabolites Difficult to collect

Recent exposure onlyHair Indicates fetal exposure from TM 3 Small sample size

Timing of collection not critical Not favored by parentsMeconium Easy to obtain None

Non-invasiveUnique matrix of the fetusIndicates fetal exposure from TM 2-3

Page 5: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

5

ETHANOL METABOLISM

ETHANOL

ADH and MEOS (CYP 2E1)ACETALDEHYDE

Cytosolic FAEE Synthase

FAEEFAEE

Non-Oxidative

FATTY ACIDS

Oxidative

Microsomal FAEE Synthase

FATTY ACYL CoA

POTENTIALBIOMARKERS

Page 6: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

6

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

Page 7: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

7

Meconium Analysis ProtocolParental 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 Collect meconium sample (>1g) directly from newborn’s diaper into specimen containernewborn’s diaper into specimen container

Extract FAEE from meconium

Analyze by gas chromatography

Store frozen and ship to Motherisk Lab on dry ice

Page 8: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

8

FAEE Detected In MeconiumFATTY 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

E17

(IS

)

E12

E14

E16

E16

:1*

E18

E18

:1

E18

:2

E20

:4*

E18

:3*

E22

:6*

• New FAEE* included into screening profile

• Derived from endogenous FA or FA acquired from diet

Page 9: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

9

Development of FAEE asBiomarkers 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 ?

Page 10: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

10

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.

Page 11: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

11

RationaleRationale

• 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.

Page 12: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

12

ObjectiveObjective

• To determine basal FAEE levels in the meconium of neonates without prenatal alcohol exposure from 2 distinct populations

Study PopulationsStudy 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

Page 13: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

13

STUDY DESIGNSTUDY DESIGN

Jerusalem (n = 104 mothers)Jerusalem (n = 104 mothers)Toronto (n = 104 Toronto (n = 104 mothers)mothers)

Expecting mother recruited upon admission to delivery ward

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)Meconium Sample Collection for Analysis (n = 206)

Toronto (n = 102)Toronto (n = 102) Jerusalem (n = Jerusalem (n = 104)104)

3 excluded due to dirty matrix

15 social drinkers excluded

84 mother-child pair included into baseline analysis

3 excluded due to dirty matrix

2 social drinkers excluded

99 mother-child pair included into baseline analysis

Page 14: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

14

Results:FAEE DISTRIBUTION IN MECONIUM

0

20

40

60

80

100

Lauric(E12)

Myristic(E14)

Palmitic(E16:0)

Stearic(E18:0)

Oleic(E18:1)

Linoleic(E18:2)

FAEE DETECTED

PE

RC

EN

TA

GE

(%

) O

F

SU

BJE

CT

S

TORONTO (n=84) JERUSALEM (n=99) SOCIAL DRINKERS (n=17) HEAVY DRINKERS (n=6)

MEAN MEDIAN SD

1.37 0.89 1.432.08 1.25 2.390.42 0.41 0.4611.08 6.43 14.02

TOTAL FAEE (nmol/g meconium)

HEAVY DRINKERS (N=6)UD - 1.40

GROUPTORONTO (n=84)

JERUSALEM (N=99)SOCIAL DRINKERS (N=17)

RANGE

0.27 - 5.260.34 - 10.21

1.98 - 39.35

Page 15: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

15

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

Page 16: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

16

• 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

DETERMINATION OF POSITIVE CUT-OFF

Page 17: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

17

• 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

DETERMINATION OF POSITIVE CUT-OFF

Page 18: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

18

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

Page 19: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

19

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

Page 20: 1 NEONATAL SCREENING FOR PRENATAL ALCOHOL EXPOSURE Daphne Chan Motherisk Laboratory for Drug Exposure

20

An alternative Harm Reduction approach to treat the mother, her child, and her future pregnancies

Neonatal screening for prenatal alcohol exposure

Remember……

FASD are 100% preventable