INT-02 HAMA

Immunoassays are subject to interference from endogenous antibodies, especially human anti-mouse antibodies (HAMA) and rheumatoid factor (RF). The use of murine (mouse) monoclonal antibodies in both diagnostic and therapeutic procedures has resulted in a high prevalence of individuals with detectable human anti-mouse antibodies (HAMA) levels. Circulating HAMA can interfere with clinical assays resulting in false positive or false negative results.

A mouse monoclonal antibody is a foreign protein, and can trigger an immune response to produce HAMA, which can be an IgG, IgM, IgA, or even and IgE subclass. The magnitude and duration can be highly variable and may persist for many months. The true prevalence of people with positive HAMA is unknown, but the condition is significant enough to require vigilance on the part of manufacturers and clinic al laboratories to identify and prevent HAMA interference with clinical assays.

HAMA are heterogeneous, which means some samples with interfering endogenous antibodies will affect a specific assay and some will not. Using multiple HAMA positive samples will better assess interference with specific clinical assays.