WAC 2011 Debates 4, 6 December 2011: 10:45 - 11:45 Skin test or in-vitro Test for Food Allergy? IgE...

WAC 2011 Debates 4, 6 December 2011: 10:45 - 11:45Skin test or in-vitro Test for Food Allergy?

IgE

“In vitro”

Motohiro Ebisawa, MD, PhD

Disclosures of Motohiro Ebisawa, MD, PhD

1) Employee of Sagamihara National Hospital

2) Academic activitiesWAO: Board member at large,AAAAI: International Assembly vice-chairJapanese Society of Allergology: Board memberJapanese Society of Pediatric Allergy: Board member

3) Grant support from Japanese government, Ministry of Labor, Health, and Welfare for 12 years as PI

4) No Conflicts of Interests

3

RAST: First Generation

RAST 1st on the market in 1974, considerable variability & questionable quantification-no longer in use and term is no longer appropriate

Allergen bound to paper discAllergen bound to paper disc

All antibody isotypes bind: Ig of A,M,G,E class

All antibody isotypes bind: Ig of A,M,G,E class

Bound IgE detected with polyclonal I125

Anti-IgE

Bound IgE detected with polyclonal I125

Anti-IgE

Results reported as log-related classes or arbitrary units by interpolation of heterologous IgE anti-birch pollen curve

Results reported as log-related classes or arbitrary units by interpolation of heterologous IgE anti-birch pollen curve

Hamilton R, Adkinson F. J Allergy Clin Immunol 2004;114:213-25.

Historical Manual Chemistries RAST = disc allergosorbent 1o (transitioned) 1968 Hycor Hy-Tec (paper disc based) FAST = Allergenics/Biowhittaker, fluorescent allergosorbent test MAST = Hitachi: thread pipette EAST = Sanofi Dignostics Pasteur Magic Lite = ALK/Corning/Bayer Matrix = Abbott

Historical Semi-automated Chemistries Alastat, Diagnostic Products Corp. (biotinylated-allergen) AutoCAP, Pharmacia (Allergen insolubilized on sponge)

“The Pearls and Pitfalls of Diagnostic Allergy Testing” developed by the ACAAI/AAAAI Specific IgE Test Task Force (SETTaF)

ImmunoCAP (250, 1000): Phadia (changed from Pharmacia, Jan 06)

HyTec-288: Hycor Biomedical-Agilent (June 07)

Immulite 2000/2500: Siemens Medical Solutions Diagnostics (Jan 07)

•The antibody binds to the allergen on the solid phase •Enzyme anti-IgE detects bound IgE•All assays report in similar units (kUa/L) with comparable

analytical sensitivities of 0.1 kUa/L•All assays primarily use allergens from extracts

ImmunoCAP perceived as gold standard for in vitro IgE testing

”The Pharmacia CAP system is in world wide use and is a de facto standard to which other methods are compared”

Dolen WK. Allergy 2003; 58: 717-723

”The predicitive values associated with clinical evidence for ImmunoCAP cannot be applied to Turbo-MP and Immulite”NIH/NIAID

Food allergy guideline. J Allergy Clin Immunol 2010; 126:S1-S58

In-vitro In-vivo IgE Antibody SPT

High sensitivity* Yes YesHigh specificity* Yes YesHigh reproducibility Yes YesQuantitative results in kIU/L^ Yes NoWHO Standard calibrated Yes NoQuality assurance test program Yes No

Can be used independently Yes Noof pharmaceutical treatment

Can be used independently Yes Noof patient skin status

Time factor 1-7 days 15-30 minutesCost factor more expensive inexpensiveUsefulness in motivating patients obscure dramatic

*Results may vary between specific bioassays^Although all are expressed with same units, cannot compare results between different bioassays

“The Pearls and Pitfalls of Diagnostic Allergy Testing” developed by the ACAAI/AAAAI Specific IgE Test Task Force (SETTaF)

IgE testing in vitro

Standardization of reagents! No common standardization exists for SPT extracts

Huge variability between extracts from different producers,and also from the same producer

Blood tests are standardized to WHO ref

World wide proficiency testing assure low CV% with ImmunoCAP IgE

Van Ree R. JACI 2007; 119: 270-277

Probability of Reacting to a Food at a Given IgE Value

Retrospective study

Prospective study

Logit model using log(kU A /L)

1.0

0.8

0.9

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.00.35 0.7 3.5 17.5 50 100

IgE antibody concentration (kUA/L)

Pro

babi

lity

Egg white1.0

0.8

0.9

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.00.35 0.7 3.5 17.5 50 100

Pro

babi

lity

Cow's milk

IgE antibody concentration (kUA/L)1.0

0.8

0.9

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.00.35 0.7 3.5 17.5 50 100

Pro

babi

lity

Fish


1.0

0.8

0.9

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.00.35 0.7 3.5 17.5 50 100

Pro

babi

lity

Peanut


Reference: Calculated from Sampson and Ho, J Allergy Clin Immunol 1997; 100: 444-51

0.3 1 3 10 30 1000

0.2

0.4

0.6

0.8

1

IgE antibody concentration (kU A /L)

Pro

ba

bili

ty

< 1 year

1 year

2 year

0.3 1 3 10 30 1000

0.2

0.4

0.6

0.8

1

IgE antibody concentration (kU A/L)

Pro

ba

bili

ty

< 1 year

1 year

2 year

Probability of failed challenge in relation to the specific IgE antibody levels for egg and milk respectively divided into three age groups

Egg (n=764) Milk (n=861)

T. Komata, L. Soderstorm, M.P. Borres, H. Tachimoto ,and M.EbisawaJ Allergy Clin Immunol, 119(5); 1272-1274

Predicted threshold values for 90% and 95% probabilities for failing oral 359 challenge, for children below 1 years of age, 1 year of age and 2 years or older

T. Komata, L. Soderstorm, M.P. Borres, H. Tachimoto ,and M.EbisawaJ Allergy Clin Immunol, 119(5); 1272-1274

(UA/ml ）

nPPV

90% 95%

< 1 yearEgg 215 6.4 13.0

Milk 223 3.6 5.8

1 yearEgg 187 10.9 23.0

Milk 177 20.8 38.6

2 years or older

Egg 362 17.0 30.0

Milk 275 33.8 57.3

Positive and negative decision points using specific IgE antibody measurements obtained from challenge with raw or heated egg white

H. Ando, A Urisu et alJ Allergy Clin Immunol, 122 ;583-588

(UA/ml ）

Raw egg white Heated egg white

Specific IgE

Egg white Ovomucoid Egg white Ovomucoid

Positive decision

point7.38 5.21 30.7 10.8

Probability curves for wheat and soybean

0.1 0.3 1 3 10 30 1000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Specific IgE antibody concentration (kUA/L)

Pro

babi

lity

for

faile

d ch

alle

nge

Wheat (n= 277)

0.1 0.3 1 3 10 30 1000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1


Pro

babi

lity

for

faile

d ch

alle

nge

Soybean (n= 272)

T. Komata, L. Soderstorm, M.P. Borres, H. Tachimoto ,and M.EbisawaAllergol Int. 2009

Probability curves of Wheat and its age effect

0.1 0.3 1 3 10 30 1000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1


Pro

ba

bili

ty f

or

faile

d c

ha

llen

ge

Wheat (n=277)

T. Komata, L. Soderstorm, M.P. Borres, H. Tachimoto ,and M.EbisawaAllergol Int. 2009

<1 y

>=1 y

Plant Food AllergensPollen cross-

reactive components*

LTP Pollen non-cross-reactive components**

Peanut Ara h 8 Ara h 9 Ara h 1; Ara h 2; Ara h 3Arah 4; Ara h 6; Ara h 7Ara h 5

Hazelnut Cor a 1 Cor a 8 Cor a 9Cor a 11Cor a 2

Soybean Gly m 4 Gly m 1 Gly m 5Gly m 6Gly m 3

Wheat Tri a 12 Tri a 14 Tri a 19 (ω-5 gliadin)Tri a 21 - alfa gliadinTri a 26 - HMW gluteninTri a 28 - AAI dimer 0.19

Ana riskAna riskPRP-10

Profilin16

Allergen components in wheat

glutenalbumins and globulins

gliadins glutenins

Tri a 15 - AAI monomerTri a 28 - AAI dimerTri a 29, 30 - AAI tetramerTri a 12 - profilinTri a 14 - LTPTri a 18 - hevein-likeTri a 25 - thioredoxinTri a 33 - serpinHomologs to components in timothy

Tri a 19 - omega-5 gliadinTri a 21 - alfa/beta gliadinTri a gamma gliadinTri a omega-2 gliadin

Tri a 26 - HMW gluteninTri a 36 - LMW glutenin

17

Subjects and Methods

• 343 patients with suspected wheat allergy from 3 different hospitals in Japan.

• Age range: 6 months - 20.4 years. Median age: 2.3 years old.

Oral wheat challenge were performed for 339 children. Four children were included with a recent convincing case history of anaphylaxis in relation to wheat.

Ebisawa M, Söderström L, Ito K, Shibata R, Sato S, Tanaka A, Borres M and Morita E , EAACI ’09

Skin 113 (82%)

Cough 50 (36%)

Wheeze 28 (20%)

Gastrointestinal 9 (7%)

Anaphylaxis 3 (2%)

Nausea 9 (7%)

OAS 10 (7%)

Summary of positive reactions by challenge

138 children had positive reactions

Results

Ebisawa M et al,Int Arch Allergy Immunol, 2011(in press)

IgE to wheat and ω-5 gliadin in wheat allergics and non-wheat allergics

WA= wheat allergics137 challenge positives36 convincing history

NoWA= no wheat allergics78 challenge negative60 convincing history

Probability curves for the outcome of wheat allergy

at a given IgE value for ω-5 gliadin

for all children and for children ≤ 1 year

and >1 years of age

0.1 1 10 1000.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1 year; n=20

>1 year; n=291

All patients, n=311

-5 gliadin: sIgE antibody concentration (kUA/L)

Pro

ba

bil

ity

(%

)

Ebisawa M et al,Int Arch Allergy Immunol, 2011(in press)









Profilin22

Allergen components in soy bean

Allergen

Cupin superfamily Prolamin superfamily

PR-10 Profilin7S globulin /Vicillin

11S globulin/Legumin

2S albumin LTP

Soy Gly m 5 Gly m 6Gly m 2S Albumin

Gly m 1 Gly m 4 Gly m 3

Corresponding peanut allergen Ara h 1 Ara h 3 Ara h 2 Ara h 9 Ara h 8 Ara h 5

23

IgE to Gly m 5 and Gly m 6 (soy) predict severe reactions

Holzhauser et al, JACI 2009

IgE to Gly m 5 and/or Gly m 6 were found in 86% of the cases with anaphylaxis against soy

24

Ito, Ebisawa et al, JACI 2011

Gly m 5 & Gly m 6 Are Associated with Systemic Reactions in Soybean-allergic Japanese Children

25

Diagnostic value of measuring IgE to soybean 2S albumin in clinical assessment of soybean allergic Japanese children

Symptomatic Non-Symptomatic0.01

0.1

1

10

100

1000p<0.01

Sp

ecif

ic I

gE

(kU

A/l

)

• Quantitative measurement of IgE to 2S albumin from soybean in sera from 19 Japanese children allergic to soybean and 36 non-symptomatic controls

• Comparison of IgE level between symptomatic and non-symptomatic groups, the median levels are indicated.

Sigrid Sjölander et al, EAACI 2009









Profilin27

*Birch tree pollen, Timothy grass pollen for wheat** Storage seed proteins, albumins and globulins

Peanut

Ara h 2 Conglutin

Ara h 1 Vicilin

Ara h 3 Glycin

Ara h 4 Glycin

Ara h 5 ProfilinAra h 6

Conglutin

Ara h 7 Conglutin

Ara h 8 PR-10

Ara h 9 nsLTP

Ara h 10 Oleosin

Ara h 11 Oleosin

Annica Önell Nov 2010

Peanut components

29 Nicolaou et al. JACI. March 2011..

With components you correctly identify

97.5% of the peanut allergics

Allergy testing in the 21st century

For primary care

by eye or instrument

For specialists

Quantitative sIgE reduces the risk and needfor oral food challenge

Sampson et al reduced the need with 40%

Österballe et al reduced the need with 60%Sampson and Ho. J Allergy Clin Immunol 1997; 100: 444-51Österballe M. J Allergy Clin Immunol 2003;112:196-201

“Shifted to Immuno CAP from SPT, more and more” by Dr. Hugh Sampson

APAPARI 2011, in Fukuoka (Japan)

WAC 2011 Debates 4, 6 December 2011: 10:45 - 11:45 Skin test or in-vitro Test for Food Allergy? IgE...

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Transcript of WAC 2011 Debates 4, 6 December 2011: 10:45 - 11:45 Skin test or in-vitro Test for Food Allergy? IgE...