Heterophilic antibody interference in immunometric assays

Abstract

Immunometric assays are inherently vulnerable to interference from heterophilic antibodies, endogenous antibodies that bind assay antibodies. The consequences of such interference can be devastating. In this review, we discuss strategies that reduce the damage caused by heterophilic antibodies. Clinicians should only order blood tests that are indicated for the patient and clinical setting at hand, and have the confidence to question laboratory results discordant with the clinical picture. Laboratorians should familiarize themselves with the vulnerability of the assays they offer, and be able to perform and interpret adequate confirmatory measures correctly. When designing immunoassays, the immunoassay industry should invest the necessary resources in specific protective measures against heterophilic antibody interference. Examples include using antibody fragments and the addition of effective blockers to assay reagents. The increasing use of modified monoclonal mouse antibodies both in therapy and diagnostics could present a particular challenge in the future.

The clinical utility of mass spectrometry based protein assays

“…In some cases, immunoassay assay interferences including heterophilic antibodies have been reported to result in implausible assay readouts that could adversely affect patient care [9,46,47]. Typically during immunoassay assay validation, the presence of poor dilution linearity suggests the presence of matrix interferences, but the absence of poor dilution linearity does not guarantee the absence of matrix interferences [48]. There are several examples of clinical tests that have been improved with the development of a LC-MS based reference assay.…”

Interference in thyroid hormones with Roche immunoassays: an unfinished story

“…These results are in line with the normal scan which led us to hypothesize that the new Roche thyroid hormones reagent formulations were the cause of the false-positive results. In order to characterize this interference, different procedures have been implemented starting with the search for heterophilic antibodies [3]. Samples were processed using blocking tubes (Heterophilic Blocking Tube, Scantibodies Laboratory, Inc., Santee, CA, USA), and the results before and after treatment were: fT4 52.1 vs. 52.6 pmol/L and fT3 14.2 vs. 14.2 pmol/L ruling-out the likelihood heterophilic antibodies presence.…”

Falsely elevated serum follicle-stimulating hormone levels in the context of heterophilic interference and response of these patients to IVF/ICSI: case reports

“…The consequences of such interference can be devastating. 1 Heterophilic antibodies are common, naturally occurring antibodies with low affinities. These antibodies initiate weak interactions between antigens and antibodies, and may function to regulate the immune system.…”