What 2012 diagnosis atopy

WHAT YOU SHOULD HAVE READ BUT….2012

diagnosis of atopy
Attilio Boner
University of
Verona, Italy

• Local allergy
• Hidden allergy

Practical guide to skin prick tests in allergy to
Aeroallergens. Bousquet, Allergy 2012;67:18

Performance of skin prick tests.


Common errors in skin prick tests.


Inhibitory effect of various treatments on skin prick tests.


Global Allergy and Asthma European Network-suggested panel of allergens
to be tested in all patients in Europe.


Which results are regarded as positive?

• Only the wheal is needed. The largest size of the wheal
is considered to be sufficient.
• Wheal diameters ≥3 mm are considered positive in skin prick
tests. It is considered that small wheals ≤3 mm of diameter
are not significant in clinical studies whereas they
are considered to be positive in epidemiologic studies.
• Very large reactions are not necessarily associated with
more severe disease.


How do skin tests compare to serum-specific IgE?
• Serum-specific IgE, skin prick tests and allergen challenge
do not have the same biological and clinical relevance
and are not interchangeable.
• There may be age-dependent differences, and elderly people
may more commonly have negative skin tests
or tests of a smaller size.
• Low levels of serum-specific IgE are less often associated
with symptoms than higher levels, but they do not exclude
allergic symptoms, particularly in very young children.
• Some allergens exhibit poor allergenic activity and skin testing
may be useful to identify such allergens.


How to interpret skin test results?

• False-positive skin tests may result from dermographism
or may be caused by ‘irritant’ reactions
or a nonspecific enhancement from a nearby strong reaction.
• False-negative skin tests can be caused by the following:
1. Extracts of poor initial potency or subsequent loss of potency;
2. Drugs modulating the allergic reaction;
3. Diseases attenuating the skin response;
4. Improper technique (no or weak puncture);
5. Limited local production of allergen-specific IgE only in the
nose or in the eye.


What is the role of skin tests in primary care?

• Allergic rhinitis is a growing primary care challenge
because most patients consult primary care physicians.
• General practitioners play a major role in the management
of allergic rhinitis as they make the diagnosis,
start the treatment, give relevant information and monitor
most of the patients.
• A structured allergy history appears to be insufficient
when assessing patients with asthma and rhinitis
in general practice. However, performing and interpreting
skin prick tests requires adequate training.

Phadiatop Infant detects IgE-mediated diseases among
pre-school children: a prospective study
Nilsson, Pediatr Allergy Immunol 2012;23:159

Background
IgE-sensitization to food and inhalant
allergens may precede and accompany the
appearance of clinical symptoms of allergic
diseases. 2.26%
The aim was to study the diagnostic capacity 2.02
of Phadiatop Infant (Phinf) for detecting
IgE-sensitization at 5 yr of age and further
to evaluate the predictive capacity of Phinf
longitudinally with regard to sensitization and
allergic symptoms in pre-school children.


In positive Phinf test
at 2 yr OR for
 201 children with
complete data on sIgE 40 –
testing for 10 individual
allergens 30 –
2.26%
35.6
 Phinf analyses, and 20 –
clinical evaluations at 2
and 5 yr of age 10 – 14.7
0
IgE-sensitization any allergic
symptom
at 5 yrs of age


In positive Phinf test
Phinf at 2 yr OR for
 201 children with
complete data be sIgE
seems to on a 40 –
reliable tool for
testing for 10 individual
allergens
predicting future 30 –
2.26%
35.6
 sensitization as well
Phinf analyses, and
20 –
as allergic
clinical evaluations at 2
and 5 yr of age young
symptoms in 10 – 14.7
child
0
IgE-sensitization any allergic
symptom
at 5 yrs of age

Significance of ovomucoid- and ovalbumin-specific
IgE/IgG4 ratios in egg allergy Caubet, JACI 2012;129:739
IgE/IgG4 ratio to
O
V
A
L
B
U
 107 egg-allergic children M
I
(mean age 6.9 years) N

 Challenged to baked egg
 Specific IgE and IgG4 to O
V
ovomucoid (OVM) and O
ovalbumin (OVA) M
U
C
O
I
D

Significance of ovomucoid- and ovalbumin-specific
IgE/IgG4 ratios in egg allergy Caubet, JACI 2012;129:739
IgE/IgG4 ratio to
O
V
A
The balance L
B
between IgE U
 107 egg-allergic children M
and IgG4 to
(mean age 6.9 years)
I
N
OVA and
 Challenged to baked egg
OVM has
 Specific IgE and IgG4 to
functional
O
V
ovomucoid (OVM) and O
consequences
ovalbumin (OVA) M
U
C
O
I
D

Patients suffering from non-IgE-mediated cow’s milk
protein intolerance cannot be diagnosed based on
IgG subclass or IgA responses to milk allergens
Hochwallner H, Allergy 2011;66:1201

Background: Cow’s milk is one of the most common causes of food
allergy. In two-thirds of patients, adverse symptoms following milk
ingestion are caused by IgE-mediated allergic reactions, whereas
for one-third, the mechanisms are unknown.
Aim of this study was to investigate whether patients suffering
from non-IgE-mediated cow’s milk protein intolerance can be
distinguished from persons without cow’s milk protein intolerance
based on serological measurement of IgG and IgA specific for
purified cow’s milk antigens.

Patients suffering from non-IgE-mediated cow’s milk
protein intolerance cannot be diagnosed based on
IgG subclass or IgA responses to milk allergens
Hochwallner H, Allergy 2011;66:1201

 IgG1–4 subclass and IgA antibody
to recombinant αS1-casein, Cow’s milk protein
αS2-casein, β-casein, κ-casein, intolerant patients
α-lactalbumin, and β-lactoglobulin. cannot be
distinguished from
 Patients with IgE-mediated cow’s
persons without
milk allergy (CMA, n = 25),
cow’s milk protein
patients with non-IgE-mediated
intolerance (CMPI, n = 19), intolerance on the
patients with gastrointestinal basis of
symptoms not associated with IgG subclass or
cow’s milk ingestion (GI, n = 15) IgA reactivity to
and control persons (C, n = 26) cow’s milk allergens.

Comparison of conventional and component-resolved
diagnostics by two different methods
(Advia-Centaur- Microarray-ISAC) in pollen allergy
Lizaso Ann Allergy Asthma Immunol 2011;107:35

Background
Component-resolved diagnostics (CRD) has recently been
introduced into clinical allergology.

Objective
The aim of this study was to assess the contribution that this
new diagnostic technique makes to conventional diagnosis in
patients with pollen allergy, comparing CRD with conventional
technologies, and to compare 2 CRD methods, Advia-Centaur
and Microarray-ISAC.


% cases in whom the diagnosis
was modified by component
resolved diagnostics

 Serum samples from 120 30 –
pollen-allergic patients.
20 –
30%
 IgE to total extracts
(CAP System) and individual
allergens using both Component- 10 –
resolved diagnostics methods
00


% cases in whom the diagnosis
was modified by component
resolved diagnostics
Either by detecting new
 Serum samples from 120
relevant sensitizations
30 –
pollen-allergic patients.
(mainly to Olea) or by 30%
 IgE to total out clinically
ruling extracts 20 –

(CAP System) sensitizations
irrelevant and individual
allergens usingpanallergens.
caused by both Component- 10 –
resolved diagnostics methods
00

Identification of a new major dog allergen highly
cross-reactive with Fel d 4 in a population of cat- and
dog-sensitized patients Hilger, JACI 2012;129:1149

 Allergy to cat and dog are frequently associated
 Reports have shown IgE cross-reactivity between cat and dog dander
in sensitized patients
 It is important to distinguish cosensitization from IgE
cross-reactivity to cat and dog allergens
 Three lipocalins have been isolated from dog dander
(Can f 1, Can f 2, and Can f 4)
 Two lipocalins have been characterized from cat (Fel d 4 and Fel d 7)

Identification of a new major dog allergen highly
cross-reactive with Fel d 4 in a population of cat- and
dog-sensitized patients Hilger, JACI 2012;129:1149

 44 patients
(mean age 33.5 years) In addition to cat and dog
with (+) SPTs to cat & dog serum albumins and the
 32 with rhinitis and/or lipocalins
asthma related to cat Fel d 4 and Can f 6 now
and/or dog exposure shown to be
 5 patients with atopic cross-reactive with a
eczema possibly related sequence identity between
to cat and/or dog Can f 6 and
exposure Fel d 4 of
67%.

Pollen-food syndrome is related to Bet v 1/PR-10 protein
sensitization, but not all patients have spring rhinitis
Rashid, Allergy 2011;66:1391

 The pollen-food syndrome (PFS) results from
sensitisation to panallergens that are
common to pollen and edible plant products,
typically manifesting as oral symptoms upon
exposure to Rosaceae fruits.

 The panallergen molecules comprise three
protein clusters: Bet v 1/PR-10; profilins;
non-specific lipid transfer proteins (nsLTP).

Rashid, Allergy 2011;66:1391

Foods reported to cause symptoms in 24 patients
with pollen-food syndrome

Rashid , Allergy 2011;66:1391
Component-resolved diagnosis demonstrated ubiquitous
Foods reported to cause symptoms in 24 patients
sensitisation to the Bet v 1/PR-10 protein cluster
with pollen-food syndrome

Rashid , Allergy 2011;66:1391
Component-resolved diagnosis demonstrated ubiquitous
sensitisation to the Bet v 1/PR-10 protein cluster

Despite this finding, 4 of 24 had no history
(past or present) of spring rhinitis: of these, 2 had symptoms
restricted to the summer months only, 1 had chronic rhinitis
with house dust mite allergy and 1 had no history of rhinitis

Tropomyosin IgE-positive results are a good predictor of
shrimp allergy Gàmez, Allergy 2011;66:1375

Background: Shrimp is a common cause of
food allergy. Our aims were to determine
the value of IgE antibodies in the
diagnosis of shrimp allergy and to study
red shrimp (Solenocera melantho)
tropomyosin both as a new allergen and as
a crossreactive IgE-binding protein.


1) Shrimp allergy was confirmed in
18 shrimp-allergic patients.

45 subjects; 2) Skin prick test and IgE
antibodies to shrimp were
positive in all shrimp-allergic
Skin prick test (SPT)
patients.
and specific IgE (sIgE) to
shrimp, recombinant and 3) sIgE to rPen a 1 was detected in
natural shrimp 98% of these patients.
tropomyosins rPen a 1 and
nPen m 1, recombinant 4) Of the 18 shrimp-tolerant
Der p 10, and patients, 61% had positive SPT to
Dermatophagoides shrimp, 55% were IgE-positive to
pteronyssinus shrimp, and 33% showed IgE
antibodies to rPen a 1.


1) Shrimp allergy was confirmed in
18 shrimp-allergic patients.

45 subjects; 2) Skin prick test and IgE
antibodies to shrimp were
IgE levels positive in all shrimp-allergic
Skin prick test (SPT)
patients.
and specific IgEa 1
to rPen (sIgE) to
provided
shrimp, recombinant and 3) sIgE to rPen a 1 was detected in
natural shrimp value
additional
98% of these patients.
tropomyosinsdiagnosis and
to the rPen a 1
of
nPen m 1, recombinant 4) Of the 18 shrimp-tolerant
Der p shrimp allergy.
10, and patients, 61% had positive SPT to
Dermatophagoides shrimp, 55% were IgE-positive to
pteronyssinus shrimp, and 33% showed IgE
antibodies to rPen a 1.

Component-resolved diagnosis of vespid venom-allergic
individuals: phospholipases and antigen 5s are necessary
to identify Vespula or Polistes sensitization. Polistes
Monsalve, Allergy 2012;67:528
Vespula

Background: Cross-reactivity between hymenoptera species varies
according to the different allergenic components of the venom.
The true source of sensitization must therefore be established
to ensure the efficacy of venom immunotherapy.
Objective: In the Mediterranean region, Polistes dominulus & Vespula
spp. are clinically relevant cohabitating wasps. A panel of major
vespid venom allergens was used to investigate whether
serum-specific IgE (sIgE) could be used to distinguish sensitization
to either vespid.

Vespula

1) sIgE was positive to either the
antigen 5s (Pol d 5/Ves v 5) or
 59 individuals with to the phospholipases
allergic reactions to vespid (Pol d 1/Ves v 1) of the 2
stings and positive ImmunoCAP vespids, or to both components
and/or intradermal tests at the same time.
to vespid venoms. 2) In 69% of cases, it was
 sIgE against recombinant possible to define the most
probable sensitizing insect, and
and natural venom components
in the rest, possible double
using the ADVIA Centaur® sensitization could not be
system. excluded.

Vespula

antigen 5s (Pol d 5/Ves v 5) or
Vespula
 59 individuals with to the phospholipases
hyaluronidase
allergic reactions to vespid (Pol d 1/Ves v 1) of the 2
was shown to have
stings and positive ImmunoCAP vespids, or to both components
and/or intradermal tests at the same time.
no additional value
toas regards the
vespid venoms. 2) In 69% of cases, it was
 sIgEspecificity
against recombinant possible to define the most
probable sensitizing insect, and
and natural assay.
of the venom components in the rest, possible double
using the ADVIA Centaur® sensitization could not be
system. excluded.

Vespula

The major allergens antigen 5s (Pol d 5/Ves v 5) or
 59of P.dominulus’ and
individuals with to the phospholipases
allergic reactions to vespid
Vespula vulgaris’ (Pol d 1/Ves v 1) of the 2
stings and positive ImmunoCAP
venom, namely vespids, or to both components
and/or intradermal tests
phospholipases and at the same time.
to vespid venoms.
antigen 5s, are required 2) In 69% of cases, it was
to discriminate the possible to define the most
 sIgE against recombinant
probable sensitizing probable sensitizing insect, and
andspecies in vespid-
natural venom components
in the rest, possible double
using the ADVIA Centaur®
allergic patients. sensitization could not be
system. excluded.

Ovomucoid (Gal d 1) specific IgE detected by microarray
system predict tolerability to boiled hen’s egg
and an increased risk to progress to multiple environmental
allergen sensitization. Alessandri, Clin Exp Allergy 2012;42:441

% subjects
 68 children
with a suspected 60 –
egg allergy. 50 –
51.4%
 Double-blind, 40 –
placebo-controlled
food challenge 30 –
with boiled & raw eggs. 28%
20 –
 sIgE to egg allergens 20.5%
10 –
available on the
immunosolid phase 00
allergen chip (ISAC) Reactive to both Reactive to Tolerated both
raw&boiled egg raw egg only raw&boiled egg
103 microarray.


% Gal d 1 negative subjects
 68 children
100 –
with a suspected
egg allergy.
94%
90 –
80 –
placebo-controlled
60 –
food challenge
50 –
with boiled & raw eggs.
40 –
 sIgE to egg allergens 30 –
available on the 20 –
immunosolid phase
10 –
allergen chip (ISAC)
0
103 microarray.
tolerated boiled egg


% Gal d 1 negative subjects
 68 children
100 –
with a suspected
egg allergy.
94%
90 –

 Double-blind, negative
Gal d 1 80 –
70 –
children have
placebo-controlled
60 –
food challenge
a high frequency 50 –
of tolerance 40 –
 sIgE to egg allergens
to boiled egg. 30 –
immunosolid phase
10 –
0
103 microarray.
tolerated boiled egg


% Gal d 1 positive subjects
 68 children
100 –
with a suspected
egg allergy.
95%
90 –
80 –
placebo-controlled
60 –
food challenge
50 –
40 –
 sIgE to egg allergens 30 –
immunosolid phase
10 –
0
103 microarray.
reacting to raw eggs


% Gal d 1 positive subjects
 68 children
100 –
with a suspected
egg allergy.
95%
90 –
80 –
 Double-blind,1 positive
Gal d 70 –
placebo-controlled
children have
food challenge
60 –

witha high frequency
boiled & raw eggs. 50 –

of hen’s egg allergy.
 sIgE to egg allergens
40 –
30 –
immunosolid phase
10 –
0
103 microarray.
reacting to raw eggs

Is epitope recognition of shrimp allergens useful to
predict clinical reactivity? Ayuso, Clin Exp Allergy 2012;42:293

Background Shrimp is a frequent cause of severe
allergic reactions world-wide. Due to issues such as
cross reactivity, diagnosis of shrimp allergy is still
inaccurate, requiring the need for double-blind,
placebo-controlled food challenges (DBPCFC).
A better understanding of the relationship between
laboratory findings and clinical reactivity is needed.
Objective To determine whether sensitization to certain
shrimp allergens or recognition of particular IgE epitopes
of those allergens are good biomarkers of clinical reactivity
to shrimp.


% of patients with a positive
challenge to shrimps
100 –
 37 patients with 90 –
shrimp allergy. 80 –
70 –
 Skin prick
60 –
test, sIgE, DBPCF
50 –
C.
46%
40 –
 IgE binding to synthetic 30 –
peptides 20 –
(Lit v1, Lit v2, Lit v3, Lit v4). 10 –
17/37
0



 37 patientsmicroarray,
By with 100 –
90 –
patients
with positive 70 –
 Skin prick test,
challenges showed
specific IgE determinations, 60 –

DBPCFC. intense binding
more 50 –

to shrimp peptides.
46%
40 –
 IgE binding to synthetic
Particularly
peptides (Lit v1, Lit v2,
30 –
20 –
Lit v3, LitLit v1 & Lit v2
for v4). 10 –
17/37
epitopes. 0


100 –
 37 patients with 90 –
IgE antibodies

 Skin prick these shrimp
to test, 70 –

epitopes could be used
specific IgE determinations, 60 –

DBPCFC. biomarkers for
as 50 –

46%
40 –
 IgE prediction of clinical
binding to synthetic 30 –
reactivity.
peptides (Lit v1, Lit v2, 20 –
Lit v3, Lit v4). 10 –
17/37
0

Identification of a Dau c PRPlike protein (Dau c 1.03)
as a new allergenic isoform in carrots (cultivar Rodelika).
Wangorsch, Clin Exp Allergy 2012;42:156

1) Carrot (Daucus carota) allergy is one of the most common
types of birch pollen-related food allergy in central Europe.
2) Approximately 24% of food allergic subjects suffer
from allergic symptoms after ingestion of carrots.
3) Adverse reactions to carrots are elicited due to
cross-reactive IgE-epitopes between the major
birch pollen allergen, Bet v 1 and homologous food proteins.
4) Bet v 1 and the major carrot allergen Dau c 1 belong
to the family of pathogenesis related proteins 10 (PR-10).


•The Dau c PRPlike protein
Objective To investigate was identified as a new
potential allergenic properties allergenic isoform, Dau c
of a Dau c PRPlike protein, 1.03, in carrot roots.
a novel isoform of the
pathogenesis related proteins •68% of carrot allergic
10 (PR-10) protein family in patients were sensitized to
carrot. rDau c 1.03.


Dau c 1.03 appears •The Dau c PRPlike protein
to contribute to the was identified as a new
Objective To investigate
allergenicity allergenic isoform, Dau c
potential carrots and should
of allergenic properties 1.03, in carrot roots.
of a Dau cbe considered
PRPlike protein,
a novel isoform ofsilencing
for gene the PR-10 •68% of carrot allergic
protein family in carrot.
of carrot allergens. patients were sensitized to
rDau c 1.03.

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