Stability of anti-drug antibodies in human serum samples

Stability of anti-drug antibodies (ADAs) is important as ADA-analysis should be reliable over time at different storage conditions. Stability of anti-insulin antibodies in serum samples was assessed after short-term storage at different temperatures and after long-term storage at -20 °C. Correlation between measurements was tested and acceptance criteria for incurred sample reanalysis were applied. ADAs were stable after 72 h at 22 °C, after 2 weeks at 4 °C, and after 6.3 years at -20 °C. The study confirms that ADAs in serum are stable for several years at -20 °C and suggests that investigation of short- and long-term stability of ADAs is not needed if samples are handled at standard laboratory-conditions.