(Allergy Lateral Flow Assay) - fooke-labs.de · ALFA (Allergy Lateral Flow Assay) Rapid test for...

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ALFA (Allergy Lateral Flow Assay) Rapid test for the qualitave determinaon of allergen specific IgE (sIgE) in whole blood, serum or plasma The worldwide frequency of allergies has increa- sed significantly over the past decades. The term al- lergy is used for type I hypersensivity reacons (immediate type reacons), whose symptoms ge- nerally occur within 30-60 minutes aſter contact with the allergen. The most frequent symptoms are: hay fever (rhinis), conjuncvis, hives (urca- ria), allergic asthma and as the most dangerous ma- nifestaon anaphylaxis (the anaphylacc shock). The allergens causing type I hypersensivityreacons are mostlyproteins derived from the natural environment e.g. plant pollen, animal hair, food, mites and insect venoms. A characterisc of type I allergies is the invol- vement of allergen specific immunoglobulins (an- bodies) of class E (sIgE). Hence, the detecon of sIgE is an important tool of modern allergy diagnoscs. ALFA (Allergy Lateral Flow Assay) is a rapid test for the qualitave determinaon of allergen specific Immuno- globulin E (sIgE). sIgE ALFA Specificaons Serum, plasma and whole blood applicable Large palee of single allergens and allergen mix- tures available (see current list of ALFA allergens) Recombinant and nave, highly purified allergen components are available (see current list of re- combinant and nave allergens) Test results in 20 min Quantave evaluaon and documentaon with the help of the LFA (Lateral Flow Assay) Reader in Units (U/mL) and Classes, analog to RAST Clas- ses, possible Excellent correlaon with skin prick test and other in-vitro test methods for sIgE (Figure 2 und 3) ALFA single-strip cassee REF 1800010 20 ALFA eight-strip cassee REF 184000 80 ALFA Test procedure ALFA consists of a uniform test device - the ALFA Basis Set - in combinaon with several arbitrary single- or allergen-mixture-soluons (screens). The sample (serum, plasma or whole blood) is transfer- red onto the sample applicaon point of the Basis Set. Immediately aſterwards the desired allergen soluon is added. Aſter 20 minutes the result can be evaluated based on the test line (T). The funconality of the test is evalua- ted based on the control line (C). Two different test formats are available, a sing- le-strip and an eight-strip cassee. a b c Figure 1 a) Test principle ALFA, b) Posive result (single-strip cassee), c) Different results (eight-strip cassee). Dr. Fooke-Achterrath Laboratorien GmbH - Habichtweg 16 - 41468 Neuss - Germany Phone: + 49 2131 2984-0 - Fax: + 49 2131 2984-184 - email: [email protected] + blood sIgE allergen control line conjugate sIgE and allergen complex of conjugate anti-conjugate antibody conjugate + test line complex of

Transcript of (Allergy Lateral Flow Assay) - fooke-labs.de · ALFA (Allergy Lateral Flow Assay) Rapid test for...

Page 1: (Allergy Lateral Flow Assay) - fooke-labs.de · ALFA (Allergy Lateral Flow Assay) Rapid test for the qualitative determination of allergen specific IgE (sIgE) in whole blood, serum

ALFA (Allergy Lateral Flow Assay)Rapid test for the qualitative determination of allergen specific IgE (sIgE) in whole blood, serum or plasmaThe worldwide frequency of allergies has increa-sed significantly over the past decades. The term al-lergy is used for type I hypersensitivity reactions (immediate type reactions), whose symptoms ge-nerally occur within 30-60 minutes after contact with the allergen. The most frequent symptoms are: hay fever (rhinitis), conjunctivitis, hives (urtica-ria), allergic asthma and as the most dangerous ma-nifestation anaphylaxis (the anaphylactic shock). The allergens causing type I hypersensitivity reactions are mostly proteins derived from the natural environment e.g. plant pollen, animal hair, food, mites and insect venoms. A characteristic of type I allergies is the invol-vement of allergen specific immunoglobulins (anti-bodies) of class E (sIgE). Hence, the detection of sIgE is an important tool of modern allergy diagnostics. ALFA (Allergy Lateral Flow Assay) is a rapid test for the qualitative determination of allergen specific Immuno-globulin E (sIgE).

sIgE ALFA Specifications Serum, plasma and whole blood applicableLarge palette of single allergens and allergen mix-tures available (see current list of ALFA allergens)Recombinant and native, highly purified allergen components are available (see current list of re-combinant and native allergens)Test results in 20 minQuantitative evaluation and documentation with the help of the LFA (Lateral Flow Assay) Reader in Units (U/mL) and Classes, analog to RAST Clas-ses, possibleExcellent correlation with skin prick test and other in-vitro test methods for sIgE (Figure 2 und 3)

ALFA single-strip cassette REF 1800010 20 ALFA eight-strip cassette REF 184000 80

ALFA Test procedureALFA consists of a uniform test device - the ALFA Basis Set - in combination with several arbitrary single- or allergen-mixture-solutions (screens).

The sample (serum, plasma or whole blood) is transfer-red onto the sample application point of the Basis Set. Immediately afterwards the desired allergen solution is added.

After 20 minutes the result can be evaluated based on the test line (T). The functionality of the test is evalua-ted based on the control line (C).

Two different test formats are available, a sing-le-strip and an eight-strip cassette.

a

b

c

Figure 1a) Test principle ALFA, b) Positive result (single-strip cassette),c) Different results (eight-strip cassette).

Dr. Fooke-Achterrath Laboratorien GmbH - Habichtweg 16 - 41468 Neuss - GermanyPhone: + 49 2131 2984-0 - Fax: + 49 2131 2984-184 - email: [email protected]

+blood sIgE

allergen

control line

conjugatesIgE andallergen

complex ofconjugateanti-conjugate antibody

conjugate

+

test line

complex of

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2017-09

Literature1. Hamilton RG, Franklin Adkinson N Jr: In-vitro assays for the diagnosis of IgE-mediated disorders. J Allergy Clin Immunol 2004; 114: 213-

25.2. Lucassen R, Fooke M, Kleine-Tebbe J, Mahler M: Development and Evaluation of a Rapid Assay for the Diagnosis of IgE-mediated Type I

Allergies. J Investig Allergol Clin Immunol. 2008; 18 (3):223-30.3. Reicke B, Offermann N, Fooke M: Evaluation of a scanner based allergy lateral flow assay system for the determination of specific IgE

within 20 minutes. Oral Poster Presentation: EAACI 2017, Helsinki, Finland.

Performance against skin prick test and nasal Provocation

Performance against IVD methodes Sensitivity and specificity of ALFA was determined against different in-vitro diagnostic test methods (Im-munoCAP® und ALLERG-O-LIQ).

Dr. Fooke-Achterrath Laboratorien GmbH - Habichtweg 16 - 41468 Neuss - GermanyPhone: + 49 2131 2984-0 - Fax: + 49 2131 2984-184 - email: [email protected]

Figure 2ROC analysis for ALFA vs. in-vivo results (Skin Prick Test and nasal Provocation) for five different allergens (d1, d2, g6, t3 and t4) with n=211 results. Figure 3

A) ROC analysis for ALFA vs. ImmunoCAP® for five different aller-gens (d1, d2, g6, t3 and t4) with n=360 results. B) Spearman corre-lation between ALFA and ImmunoCAP® for five different allergens (d1, d2, g6, t3 and t4) with n=360 results.

A B

pos neg TotalIn-vivo 145 66 211

Test AUC 95% CIALFA 0.96 0.93 0.99

Area under the curve (AUC) value of ALFA compared to 211 in-vivo results were found > 0.95. Compared to in-vivo results ALFA shows a sensitivity of 0.96 (Confi-dence interval, CI 0.92-0.98) and specificity of 0.85 (CI 0.74-0.92).

Table 1Agreement between ImmunoCAP® and ALFA results for d1, d2, g6, t3 and t4 (n=72 patient samples).

Excellent agreements were observed between ALFA results and ImmunoCAP® results. AUC values were found at > 0.95 for each allergen (see table 1) and 0.97 for all allergens (see figure 3A) compared to Im-munoCAP® results.

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Agreements between ALFA and ImmunoCAP® ac-cording to Spearman were found at 0.92 for d1 (CI 0.87-0.95), 0.92 for d2 (CI 0.97-0.95), 0.96 for g6 (CI 0.94-0.98), 0.95 for t3 (CI 0.92-0.97) and 0.91 for t4 (CI 0.86-0.94). Spearman correlation between ALFA und ImmunoCAP® for all five allergens reveals a coef-ficient of 0.93 (CI 0.91-0.94, see figure 3B). AUC value of ALFA compared to 497 ALLERG-O-LIQ results were found at 0.95 with a sensitivity of 0.92 (CI 0.87-0.95) and specificity of 0.84 (CI 0.74-0.92) (see figure 4).

pos neg TotalALLERG-O-LIQ 274 223 497

Test AUC 95% CIALFA 0.95 0.93 0.97

Figure 4ROC analysis for ALFA vs. ALLERG-O-LIQ results for five different allergens (d1, d2, g6, t3 and t4) with n=497 results.

Number of negative / positive

results with ImmunoCAP®

ALFA vs ImmunoCAP®

Allergen neg pos AUC Sensitivity (%) Specificity (%)

d1 (Der. pteronyssinus) 25 47 0.95 91.5 92.0

d2 (Der. farinae) 26 49 0.97 91.3 96.2

g6 (Timothy Grass) 14 58 0.97 96.6 92.9

t3 ( Birch) 19 53 0.97 96.2 89.5

t4 (Hazel) 21 51 0.97 92.2 90.5

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