A Rapid Test for Soy Aeroallergens Exposure Assessment

Abstract

BackgroundDetermining soy aeroallergens levels is extremely important in the assessment of health risks due to these airborne substances. Currently, soy aeroallergens exposure in the environment is monitored using enzyme immunoassays (EIA) which must be evaluated in a specialized laboratory by skilled personnel.ObjectiveTo describe the development and performance of a rapid immunochromatography assay for the detection of soy aeroallergens in environmental samples.MethodsA test strip using gold labeled anti-soy hull low molecular weight extract (SHLMWE) antibody for the rapid detection of soy aeroallergens in environmental samples was developed. One hundred nineteen airborne samples were analysed in parallel by the strip assay and the anti-SHLMWE sandwich EIA. The assay results were visually analysed by three independent observers who ranked samples as: -, + or ++. Strips were also scanned and analysed by densitometry.ResultsThe rapid test detected a range of concentrations from 6.25 to 25 ng/mL. Agreement in strip assay interpretations between evaluators was substantial (Kappa = 0.63; CI 0.544–0.715). Visual interpretation also gave a good concordance with EIA results, with sensitivity ranging from 77.3 to 100 and specificity from 65 to 83.5 depending on the observer. Furthermore, a strong correlation was observed between densitometry results of strip assay and EIA determinations.ConclusionsThe strip assay developed is rapid, simple, and sensitive and does not require expensive equipment or specific skills. It has considerable potential in the environmental monitoring field for screening soy aeroallergens levels in port cities where allergen measurements are not currently performed. Due to its simplicity, the test will improve the management of soy allergic patients by controlling environmental allergen exposure without the need for apparatus or skilled personnel.

A rapid test for the environmental detection of pigeon antigen

“…The visual interpretation of the ICT showed high levels of sensitivity and specificity, comparable to those recorded with other rapid assays measuring other aeroallergens ( Bogdanovic et al, 2006 ; Tsay et al, 2002 ; Álvarez-Simon et al, 2014 ; Koets et al, 2011 ). Furthermore, the line intensity (analysed by densitometry, an objective measurement) of samples categorized as negative was significantly lower than that of positive and double positive samples.…”

“…This observation has also been reported in other studies: for example, Tsay et al (2002) graded the line intensity of some samples analysed as medium or high even although the allergen levels analysed by ELISA were below the theoretical LOD of the rapid assay. Similarly, in the studies by Bogdanovic et al (2006) and Álvarez-Simon et al (2014) , some samples with allergen levels below the sensitivity of the rapid test were classified as positive. Moreover, visual interpretation of rapid assays is inherently subjective, and depends on factors such as the rater's color perception.…”

“…Second, we developed and validated a novel ICT using the same antibodies used in the ELISA method. Previous studies have proposed that ICT may be a valid alternative to the ELISA, as it speeds up the last step of the process ( Bogdanovic et al, 2006 ; Tsay et al, 2002 ; Álvarez-Simon et al, 2014 ).…”

“…In this test, a sample with labeled specific antibodies is mixed and incubated with a strip. Then, the immunocomplexes formed migrate by capillarity through the nitrocellulose membrane and bind to the line of immobilized specific capture antibodies if the sample contains the specific antigen ( Bogdanovic et al, 2006 ; Tsay et al, 2002 ; Álvarez-Simon et al, 2014 ).…”

A rapid test for environmental detection of pigeon antigen

“…This observation has also been reported in other studies: for example, Tsay et al (2002) graded the line intensity of some samples analysed as medium or high even although the allergen levels analysed by ELISA were below the theoretical LOD of the rapid assay. Similarly, in the studies by Bogdanovic et al (2006) andÁlvarez-Simon et al (2014), some samples with allergen levels below the sensitivity of the rapid test were classified as positive. Moreover, visual interpretation of rapid assays is inherently subjective, and depends on factors such as the rater's color perception.…”