Proteomics as a tool for assessment of therapeutics in transfusion medicine:: evaluation of prothrombin complex concentrates

BACKGROUND: Proteomic technologies are evolving tools to analyze complex protein patterns that to date have been rarely applied to transfusion medicine. The analysis of prothrombin complex concentrates (PCCs) was used as a model to evaluate to what extent these technologies can detect differences in blood-derived therapeutics beyond that of standard quality control. STUDY DESIGN AND METHODS: Three PCCs (two batches each) were individually analyzed for differences in protein content by functional assays, two-dimensional gel electrophoresis, and mass spectrometry. The results were compared to a pool of 72 normal plasma samples. RESULTS: A highly complex protein pattern was found that varied considerably among the three PCCs: 192 spots comprising 40 different proteins were identified. Factor (F) IX activities of the three PCCs were comparable, but their F IX protein contents differed considerably. Many proteins were present in multiple spots (e.g. FII, FX, protein C, vitronectin), indicating a high degree of posttranslational modifications. In comparison with untreated pooled plasma, PCCs displayed several low-molecular-weight variants of proteins that likely constitute potential degradation products. CONCLUSION: Proteomic technologies allow the identification of potentially modified proteins in clotting factor concentrates, indicating that they could become a useful tool for transfusion medicine to assess the impact of processing on the integrity of blood-derived therapeutics.