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Liquid Gold
Allbrgy Test
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SrrnNG THE Rrcono SrnntGHT
You asked for a serum allergy test that you can trust
will help you successfully hyposensitize your allergic
dog and cat patients ... We heard!
Liquid Gold
The Liquid Gold technology is different from the ELISA in several
fundamental aspects. VARL Liquid Gold is a liquid-phase technology ...
engineered to eliminate false positive results without compromising
sensitivity.
The allergen in Microplate#1 is tagged with a
... the complex is isolated into
ligand and remains
Microplate #2.
in liquid matrix
Microplate #1
during the critical
reaction with patient
lgE
serum. After
Microplate #2
Specific lgE
Specific lgE
specific lgE in
patient serum has
coupled with the
liquid allergen ...
An anti-ligand introduced into the new microplate
ffi
anchors the
allergen-
specific lgE
complex to
Microplate #2.
(With Ligand)
The use of two microplates allows liquid allergen and patient serum
to react in the first microplate and the measurement of captured
specific lgE to be carried out in a new microplate thereby avoiding
quantifying non-specific lgE stuck inside Microplate #1.
Quantification of specific lgE is accomplished in Microplate #2 with
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a cocktail of three monoclonal crlgE antibodies. ln the VARL
liquid-phase test patient serum can be tested undiluted so that false
negative results are avoided.
ELISA
Unlike the liquid-phase technology of VARL, all ELISA tests utilize a
solid-phase methodology where the reaction of patient serum with
allergen must occur with allergen immobilized on a solid surface.
Sure, you detest
is reacted with allergen solidified on the wall of
. Quantification of lgE is carried out in the same well in
serum reacts with solid phase allergen. Non-specific
lgE sticking
on the solidphase will be
measured as
well as the
allergen-
specific lgE.
Nonspecific lgE antibodies stuck in the only microplate used for
ELISA cannot be differentiated from the allergen-specific lgE
complexed with solidified allergen.
After lgE antibodies have stuck in the only microplate used for ELISA
testing it would not matter whether Fc-e receptor molecule or
polyclonal crlgE or monoclonal olgE is used to quantify the lgE on the
solid surface. Both the specific and non-specific lgE will be quantified
and false positive results will be unavoidable.
false positives.
You don't have to
settle for false
negatives either!
ln order to minimize such false positive results, it is a common practice with ELISA testing to dilute
patient serum 20-50 folds. The higher the dilution, the greater the possibility exists for false negative
results. Any amount of dilution of patient serum can potentially result in false negative results and thus
presenting only a partial picture of the whole. ln VARL Liquid Gold patient serum can be tested undiluted
to maximize sensitivity and withdrawal of corticosteroid is not required.
EvnrunoN oF VARL LrqulD Golo
AND EIISN
Serum from a three-year old, female, Labrador Retriever clinically diagnosed with allergic dermatitis
was analyzed by VARL with VARL Liquid Gold for various categories of allergens. The same dog serum
was analyzed by other commercial laboratories with their respective ELISA methods. A selected number
of the allergens
reported were
simultaneously
analyzed by
VARL with
Western blot
technique.
ELISA
with Fc-e receptor with polyclonalolgE
with monoclonals
Class Score
Units
Units
0 (undetectable)
0 (negative)
213 (positive)
3 (high positive)
0 (negative)
165 (positive)
0 (undetectable)
41 (negative)
201 (positive)
a. Sage
b. Mulberry
c. Alternaria tenuis
d. Timothy Grass
e. D. farinae
3 (high positive)
0 (negative)
224 (positive)
2 (low positive)
1523 (positive)
248 (positive)
f.
0 (undetectable)
0 (negative)
109 (negative)
4 (high positive)
0 (negative)
256 (positive)
5 (very high positive)
0 (negative)
265 (positive)
1 (very low positive)
0 (negative)
101 (negative)
D. pteronyssinus
g. Short Ragweed
h. Aspergillus fumigatus
Table 1.
ELISA
VARL Liquid Gold
Allergens
i.
Pecan/Hickory
*Verification of
fr
Allergen-Specific
lgE from Table
1
with Western Blot
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!
IFEII
Analysis
a
VARL Liquid Gold
ELISA Fc-e receptor
ELISA (polyclonal)
+
+
cdefghi
-++-+++
+
+++++-
b
+-
The allergens and the serum of the dog tested (summarized in Table 1)
were also analyzed with western blot. The western blot results confirm
ra
the presence of allergen-specific lgE towards (b) Mulberry, (d) Timothy
grass, (e) D. farinae, (g) Short Ragweed, (h) Aspergillus fumigatus and
(i) Pecan as determined in VARL Liquid Gold test. The Western blot is
also in agreement with VARL Liquid Gold result for (a) Sage, (c)
fui,-ffi
Alternaria tenuis and (f) D. pteronyssinus, confirming that the dog
serum contained no specific lgE antibodies to these three allergens.
Except for the dust mite allergen (e), D. farinae, the ELISA test using
the Fc-e receptor molecule did not detect allergen-specific lgE in the
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serum to all the other allergens, These are clear cases of false negative
results. The ELlSAtest using a polyclonal crlgE reported a negative
result for (i) Pecan and lgE specific to (c) Alternaria in the dog serum
but the Western blots show that lgE specific to Pecan was present and
B
Gl
none was present forAlternaria in the serum tested.
VARL LtqutD Golo
FoR Cnrs
VARL Liquid Gold test for cats is also consid
ered to be highly sensitive and specific. The
VARL Liquid Gold was used to test three cats:
Cat#1 (DSH), Cat#2 (Siamese) and Cat #3
(Persian) which were clinically diagnosed with
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0
Class
I
D.pteronyss
Class 3
Cat#1 DSH
Dandelion
Class 0
Cat
#2
P Rye
Class 4
Siamese
Mucor
Class
r.
0
Melaleuca
Class 5
Cat
#3
Persian
miliary dermatitis, generalized pruritus with
alopecia and chronic coughing with sneezing
respectively. The results obtained with VARL
Liquid Gold for each cat are verified by
Western blots and confirmed to be accurate.
No more pruritus!
No more asthma!
No more alopecia!
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LlqulD Golo ltrlrtruNorHERAPY
RrsuLTS
A study, executed in a double-blinded fashion, compared the
2.6
results of hyposensitization of dogs based on Liquid Gold
test and intradermal skin test results. Both groups of dogs
2.4
2.2
showed good response to hyposensitization, with the dogs
2
hyposensitized based on the results of Liquid Gold tests
performing slightly better.
ln two separate studies, the Liquid Gold test showed higher
VARL Liquid Gold Vs. Skin Test
% Correlation with Western Blot-
correlation with Western blot than the intradermal skin test.
VARL Liquid Gold will help you successfully
hyposensitize your allergic dogs and cats.
VARL LrqulD Golo .o.
ATLERGY TESr You CnN Tnusr
Dogs and cats can be rendered immune to various substances detected by the Liquid Gold allergy blood
test. Successful hyposensitization is highly dependent on an accurate diagnosis and an adherence to a
prescribed schedule of treatment. VARL can effectively provide allergy tests you can trust
Lrquro
Cor-o
ELISA
To Prevent False Positive Results:
Can each test allergen be used as its own
control using the patient serum?
negative
Yes
No
Can reacted specific lgE-allergen complex
isolated into a second microPlate?
be
Yes
No
Yes
No
To Prevent False Negative Results:
Can the patient serum be tested undiluted?
(Diluted 20-50 folds)
Are all relevant allergens guaranteed to be present in
Yes
No
Yes
No
Yes
No
Yes
No
every test?
Are allergens present during a test guaranteed to have
the same antigenic activity as liquid allergen?
Can the amount of allergen used in a test be increased
specific lgG?
To Ensure Overall Sensitivity and Consistency:
Can Western blot be utilized?
,&J
To lmprove Success with Hyposensitization:
Can the repertoire of allergens present during testing
be guaranteed to also be in the treatment formulation?
ATLERGTc
DrRMATlls
Allergy in dogs and cats is usually an itch that rashes
Rather than a rash that itches!
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I
lgE antibody-mediated disease of genetic origin
\
May begin as a seasonal pruritic dermatitis
Paw licking, axillary scratching, face rubbing and eventually whole
body scratching
Age of onset is as early as 3 months and up
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Often becomes year-round problem
Caused by allergens, mostly absorbed cutaneously, ingested or inhaled
Usually responds favorably to antihistamine and corticosteroid
therapy at the outset
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Response to corticosteroid often declines with long term use
Flea allergy is a factor in most atopic dogs and cats and can interfere with a hyposensitization program
Classical allergic dermatitis may be overlapped by food allergy and insect hypersensitivity
These added factors will influence threshold for onset of symptoms
Allergy patients are more likely predisposed to secondary pyoderma and yeast infections
Krvs ro SuccESS wlrH
lrnunruNorHERApy
Select the right patients by ruling out other causes of pruritus such as:
A. Scabies
B. Bacterial pyoderma (Allergy
may be the underlying cause of recurrent bacterial pyoderma)
C. Yeast dermatitis
D. Demodicosis
E. Primary
2
seborrhea
Select appropriate allergens for testing and immunotherapy.
Allergens wrongly identified or not detected will decrease success with hyposensitization.
3
Give clients realistic expectations and follow each individual
case carefully to control complications.
Allergen immunotherapy is considered to be an effective treatment
for allergies. Does not work every time! 65-75% of patients will
show favorable response to allergen immunotherapy or have their
requirement for corticosteroid reduced significantly. Response is
slow; expect to see improvement in six to nine months. Do not give
up hope for one year. Most patients will require treatment for life.
Stopping allergen therapy on patients that have responded will
result in reoccurrence of symptoms of allergy in 90% of patients.
I
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INJECTION
Fooo
ATLERGY
The main reason a food allergy test or diet elimination trial is performed is to find a food or foods that
will help relieve allergy symptoms of the patient. Food allergy testing is far more complex than environmental allergy. This is due mostly to the antigenic modifications that foods undergo during different
preparations, and further in the gastrointestinal tract. Our analyses with Western blots indicate that
some patients are reacting to epitopes in partially digested materials that are not revealed in the intact
proteins in some foods. VARL incorporates these findings in the Liquid Gold test for foods.
I
I
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I
Onset can be at any age
Symptoms are not apt to be seasonal if the same food is fed year-round
Small-percentage of cases responds favorably to corticosteroid
Otitis is a common early finding in over 70% of cases
Usually present in conjunction with other environmental allergies and contributes to
the pruritic threshold - level of allergen load above which clinical signs are observed
Successful immunotherapy may appear to be a failure if the patient also has
a food allergy that has not been a part of the patient work-up
Diet elimination trial is useful but frustrating for clients and practitioners '100% compliance is mandated
VARL
Liquid Gold
test results will help
you confidently get
your patients well.
You will not be treating false positives ...
GUARANTEED!
SrnrE-oF-THE-Anr LngoRAToRy Fnct ury
Veterinary Allergy Reference Laboratory (VARL) is a USDA licensed laboratory serving veterinarians
worldwide. VARL focuses on the specialized area of serum allergy testing and preparation of
individualized prescription allergen vaccines for allergic dogs and cats. The laboratory is dedicated
solely to helping veterinarians precisely identify the allergens responsible for their patients' allergies
and formulate treatment allergy vaccines to desensitize them to the identified culprit allergens.
Accurately identify allergens with no false positives
Superior liquid phase technology
Customized allergen prescription services to desensitize pets
* Allergies in Dogs and Cats: Allergen-specific lgE Determination byVARL Liquid Gold Compared with ELISA/RAST. JVACI 5:93-101 ,1977
rt
PO Box 41059, Pasadena, CA 91104 . Fax: (626) 357-5097 . Email: info@varlallergy.com
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www.varlallergy.com