Generalized mathematical model for immunoassay interference.

As part of a landmark review of the antigen excess, Jacobs et al. (Autoimmunity Reviews 2015;14:160-167) contrast how immunoassay "interference" by non-target biomolecules can cause spurious readings for clinical diagnostic tests. The purpose of the present Letter is to complement and analytically extend this description by Jacobs et al. by briefly presenting a generalized mathematical model of immunoassay interference that is derived from a simple mechanistic system of differential equations. Derivation includes expressions for the location of the peak concentration of bound reporter as well as that maximum concentration of target biomolecule at which immunoassay interference drives concentration of bound reporter to zero. This parsimonious, mechanistic, and generalized model may prove foundational to analytic study of immunoassay interference. More comprehensive models for specific classes of immunoassays have and can be developed.