Figure 1.

Mechanism of the influence of heterophile antibodies on the concentration of cardiac troponins. Figure description: (A) Absence of interference. Classical immunoassay includes two stages. At the first stage, the analytes (molecules of cardiac troponins) being released in case of myocardial injury interact with the first (“capture”) antibodies, which results in the formation of an antigen–antibody complex. Then, the second (“labeled”) antibodies bind with this complex, which leads to the formation of a “sandwich-type” immune complex. The label on the second antibodies causes the generation of a signal, the level of which is directly proportional to the quantity of the antigen–antibody complexes formed at the first stage, i.e., the concentration of cardiac troponin molecules in the examined biological fluid sample. (B) Presence of interference. Heterophile antibodies can unspecifically bind with capture antibodies at the first stage in the absence of the analytes of interest (molecules of cardiac troponins) in biological fluid and lead, therefore, to false-positive results.