Interference of heterophilic antibodies with free prostate-specific antigen in the Beckman-Coulter (Unicel DxI) assay, inverting the free/total prostate-specific antigen ratio.

摘要

Heterophilic antibodies are polyspecific natural human antibodies that bind to animal immunoglobulins. These antibodies interfere in immunoassays by forming a bridge between the capture and detection antibodies, leading to false-positive results. Interference with false-negative results is rarely observed. The incidence of interference in immunoassays has been reported to range from 0.4% to 4%, although an estimate of only 0.05% has also been suggested. The magnitude of interference depends on the affinity of the heterophilic antibody (binding strength between the antigen and antibody) and its concentration in serum.