Heterophile Interference
Analytical interference in immunoassays caused by patient antibodies that react with assay antibodies, producing erroneous results.
Full Definition
Heterophile interference occurs when endogenous antibodies in patient samples cross-react with the animal antibodies used in immunoassays, leading to falsely elevated or suppressed hormone results. These interfering antibodies may include human anti-mouse antibodies (HAMA), rheumatoid factor, or other heterophile antibodies that can bridge capture and detection antibodies in sandwich assays or compete for binding sites in competitive assays. This interference is particularly problematic in hormone testing because it can produce clinically implausible results that may lead to inappropriate treatment decisions. Common manifestations include persistently elevated results that don't respond to expected physiological changes or therapeutic interventions. Detection strategies include dilution studies, blocking agents, and alternative analytical methods. Laboratory protocols should include procedures for investigating suspected heterophile interference when results don't correlate with clinical findings.
Usage
Usage note: Often abbreviated as HAMA when specifically referring to human anti-mouse antibodies.
In Context
- "The persistently elevated TSH despite adequate thyroid hormone replacement suggested possible heterophile interference." — Clinical case review
- "Implement heterophile interference detection protocols for samples with clinically discordant hormone results." — Quality control procedure