Interference in Immunoassay

Abstract

Additional key phrases: heterophilic antibodies; hook effects; matrix effects; specificity 'reagent excess' (type I) and 'reagent limited' (type II) assays. IMMUNOASSAY REACTIONS 'd~':rain ",stionFabfrar ;;Anti body binding site N pepsii~n / digest/-F("')'f'F IGURE I. Stylized diagram of the immunoglobulin molecule showing derivation of the various fragments used for preparation of antibodies in immunoassay.The editor regretfully notes that Mr Colin Selby has died since submitting this review. This article was prepared under the auspices of the Analytical Investigations Standing Committee of the Association of Clinical Biochemists.

Heterophilic antibodies may be a cause of falsely low total IGF1 levels

“…Assays using either polyclonal or monoclonal antibodies may be affected and assays previously reported to be affected by heterophilic antibody interference include those for TSH, tri-iodothyronine, T 4 , prostate specific antigen (PSA), testosterone, and LH (13)(14)(15)(16). Interference from circulating antibodies is specific for an individual patient, and these proteins have the potential to interfere in an unpredictable way with some (but not necessarily all) immunoassay tests used (17).…”

“…These antibodies can arise as a result of occupational exposure of farm workers, from activities such as keeping pets, ingesting animal antigens in food (like cow's milk), vaccination, infection, or even blood transfusion (19,24,25) and may persist for several years (26). The published estimates of the presence of heterophilic antibodies in the normal population vary between 1 and 80% (13,19).…”

“…There are several methods to reduce the effects of heterophilic antibodies. Addition of serum of nonimmune animal species will reduce the effect of heterophilic antibodies in many cases (13). This method works best when the species of the human anti-animal antibody is matched with nonimmune animal serum (13).…”

“…Addition of serum of nonimmune animal species will reduce the effect of heterophilic antibodies in many cases (13). This method works best when the species of the human anti-animal antibody is matched with nonimmune animal serum (13). Therefore, it is routine practice for assay manufacturers to incorporate the serum of nonimmune animal species in the reagents of most methods.…”

Co-detection: Ultra-reliable nanoparticle-based electrical detection of biomolecules in the presence of large background interference

“…1a where analyte 1 serves as the target to be detected and analyte 2 serves as the background interference. Ideally, the detection errorrate (DER) or the sum of false-positive or false-negative errors decreases with the increase in analyte 1 concentration (ignoring the Hook effect 7 ) and the DER is largely unaffected or increases when the concentration of analyte 2 (acting as background interference) increases. However in "co-detection", addition of analyte 2 reduces the DER for analyte 1, as illustrated in Fig.…”