antigen excess


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an·ti·gen ex·cess

1. in a precipitation test, the presence of uncombined antigen in excess of that required to combine with all of the antibody; precipitation may be inhibited because the presence of excess antigen gives rise to soluble antigen-antibody complexes;
2. in vivo, the resultant antigen-antibody interaction in such an antigen excess may give rise to immune complexes, which have a potential to induce cellular damage; could be tolerogenic.

an·ti·gen ex·cess

(an'ti-jen eks'es)
1. In a precipitation test, the presence of uncombined antigen above that required to combine with all of the antibody.
2. In vivo, the resultant antigen-antibody interaction in such an antigen excess may give rise to immune complexes, which have a potential to induce cellular damage.
References in periodicals archive ?
If the sum of the 4 IgG subclasses differs by >20% from the total IgG concentration, the assays are repeated at higher dilutions to rule out antigen excess. During our validation studies, serum from an 82-year-old male was submitted for subclass quantification.
In conclusion, both nephelometric methods for urinary FLCs were objective and reproducible and identified those samples containing high concentrations of monoclonal FLCs without antigen excess problems.
This procedure with the 0.200 cutoff value for the prozone check effectively detected all samples in which antigen excess caused falsely low microalbuminuric or normal values.
We were careful to characterize our procedure regarding antigen excess, a prozone artifact that can occur with IFE (19).
The imbalance of antigenic determinants between polyclonal and monoclonal light chains makes methods susceptible to the risk of antigen excess. Problems of antigen excess occur, with even robust immunoassays for total light chains yielding falsely low light-chain concentrations and thus missing the diagnosis of potentially serious conditions such as light chain myeloma or light chain amyloidosis.
The purpose of this study was to evaluate the analytical performance of these Abbott Aeroset specific-protein assays and, in particular, their ability to correctly handle antigen excess frequently found in immunoglobulin estimations.
To verify that an assay does not give falsely low results in the presence of the very high concentrations of PSA or FPSA that may be present in human samples (antigen excess or hook effect), aliquots of the zero calibrator containing PSA concentrations of 19-625 000 [micro]g/L and FPSA concentrations of 5-160 000 [micro]g/L were prepared by the manufacturer.
Furthermore, this simple prozone detection method can be adapted to other nephelometric assays with the potential for erroneous results from antigen excess.