Background: Quantitating levels of therapeutic proteins in serum or plasma is critical for determining exposure levels and establishing pharmacokinetic parameters. Traditionally, whole blood is not used, mostly due to its inability to be frozen and potential issues with assay interference. To investigate the ability to reproducibly quantitate therapeutic antibodies present in dried blood spots (DBS) compared with a typical serum sample-based method, we used ELISA and electrochemiluminescence immunoassays to measure therapeutic drug levels present in DBS samples.
Results: Measurements of antibody therapeutics in DBS were reproducible, yielding methods that are precise, accurate and met expected sensitivity requirements compared with plasma-based methods.
Conclusions: DBS are a viable alternative to the use of conventional serum or plasma samples for quantitative therapeutic antibody measures.