Chicken antibodies are highly suitable for particle enhanced turbidimetric assays

Abstract

Antibody-based assays are commonly used in clinical laboratories for analyzing plasma, serum and other samples for particular protein markers. Although such assays have been traditionally based on antibodies raised in mammals (e.g., mice, rabbits, goats), there are several advantages of using avian antibodies (IgY) raised in chickens, including production volumes, costs, and ethical/animal welfare considerations. A further disadvantage of using mammalian IgG in such assays is the potential for agglutination when exposed to rheumatoid factor (RF) in serum. However, when used in the free form the immune complexes formed with avian antibodies have been reported to have less ability than those formed with mammalian antibodies to cause the light scatter which are used for instrument measurement. In addition, when the amount of antigen exceeds the maximum precipitating point in relation to the amount of antibody, there is a rapid decline in the absorbance values of the immune complexes (antigen excess) when IgY is used. However, when avian antibodies are conjugated to a substrate and used in particle enhanced turbidimetric assays (PETIA), these problems are avoided. Here we investigated three clinical assays using chicken antibodies, one using free (unbound) IgY and two with IgY-based PETIA. The IgY PETIA demonstrated a strong scatter response, even at high antigen concentrations in contrast to the steep decline seen with free IgY antibodies. IgY PETIA reagents can provide test results with low coefficient of variation (<1% for duplicate samples). We also investigated the effect of RF on agglutination of mammalian antibodies (IgG from mouse, rabbit, sheep, and human) and chicken antibodies. Whereas agglutination was observed with all the mammalian antibodies in the presence of RF, this was not observed at all with chicken IgY. Our results support the growing body of evidence that chicken egg yolks can thus be a valuable source of antibodies for use in PETIA in clinical laboratories.

Cistatina C como marcador de daño renal en pacientes con diabetes mellitus tipo II

“…El método de inmunoensayo turbidímetrico potenciado por partículas (PETIA), basados en el principio de turbidimetría, también es muy empleado dentro de la clínica. Consiste en la detección de cambios en la turbidez, dado que, se emplean partículas coloidales (látex) que están recubiertas con anticuerpos anticistatina C, las mismas que al unirse con la cistatina C de la muestra provocan una reacción de aglutinación, y por ende un cambio en la absorbancia, la misma que es proporcional a la concentración de cistatina C, se puede medir por espectrofotometría (Harvey, 2022;Larsson et al, 2022).…”

IgY Antibodies from Birds: A Review on Affinity and Avidity

“…IgY antibodies have been used in the development of ELISA, Western blotting, immunohistochemistry, immunochromatography, immunofluorescence, radioimmunoassay, and biosensors for the diagnosis of infectious and chronic diseases in humans and animals [46][47][48]. The use of IgY antibodies presents some advantages over mammalian antibodies, the most important of which are the non-interaction with the rheumatoid factor or mouse anti-IgG antibodies, with consequent interference in the test results [49,50]; the non-activation of the complement system and the generation of its fragments, which may result in the covering of epitopes important for diagnosis [49]; and a higher molecular stability than mammalian antibodies [51].…”