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Woman does analyze in a laboratory
March 31, 2016

False Immunoassay Results Due to Interfering Substances

What are Heterophilic Antibodies and Anti-animal Antibodies (HAAA)?

Heterophilic antibodies are “weak” antibodies and may be generated in patients who suffer from autoimmune diseases, and other inflammatory diseases, allergies, viral infections such as Epstein-Barr or influenza or after a vaccination. They are produced against diverse antigens and have multi-specific activities and include proteins such as rheumatoid factor.

In contrast, HAAA antibodies have strong avidity for well-defined antigens and may be present as a result of receiving therapeutic treatments containing animal derived monoclonal antibodies. One of the most documented HAAA is human anti-mouse antibodies (HAMA), which has seen increased prevalence following the introduction of in vivo treatments using mouse monoclonal antibodies. Interestingly, animal handlers may produce antibodies through coincidental immunization that exhibit the characteristics of either HAAA or heterophilic antibodies.

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