Host cellular protein quantification

摘要: Host-cell proteins (HCPs) are bioprocess-related impurities that may be present in intermediate or final biopharmaceutical products such as recombinant monoclonal antibodies (MAbs). Although the potential clinical and genetic effects of HCPs are largely unknown, studies have shown that HCPs may cause immune responses and adverse reactions in patients when present at sufficient high levels (1–3). Consequently, US Food and Drug Administration (FDA) and European Commission regulations require that the level of HCP in a bioproduct be quantitatively measured during manufacturing and before approval for therapeutic use (1–2). The safe level of residual HCP is suggested as< 100 parts per million (ppm) or below detectable levels using a highly sensitive analytical method (1–4). For such reasons, detection and evaluation of HCPs are critical parameters for the development of robust and consistent bioprocesses for protein-based biologics.Detection and quantification of HCPs pose a great challenge to biopharmaceutical quality assurance/quality control. The vast molecular divergence and complexity of HCPs make it very difficult to establish accurate and specific detection methods. Extremely low levels of HCP may be present, especially at later bioprocess steps and in final bioproducts. So detecting nanograms of HCP in milligrams of drug substances requires use of highly sensitive methods. Currently, the most common techniques for HCP detection and quantification are immunoassays, such as enzyme-linked immunosorbent assay (ELISA), Western blotting, and mass spectrometry. Proximity ligation assay (PLA) is an immunoassay …