New perspectives in coagulation testing.
The field of coagulation testing has undergone some major technological and conceptual developments, which are briefly reviewed here. The assessment of coagulation parameters is no longer restricted to the study of clot formation and its dissolution. The understanding of the biochemical nature of coagulation processes, coupled with the development of new therapeutic agents in the treatment of hemostatic disorders, has brought about the development of fast, reliable, and clearly defined laboratory test procedures to evaluate the components of this system. The introduction of methods involving synthetic substrates has been very significant because many of the coagulation parameters can now be measured with a spectrophotometer or fluorometer, by methods that lend themselves to the automation found in most large clinical chemistry laboratories. In our laboratory, we use automated synthetic-substrate methods for antithrombin-III, plasminogen, and prothrombin, and are developing the synthetic-substrate assay equivalent of clot-based prothrombin time and partial thromboplastin. Immunological methods such as laser/rate nephelometry, enzyme-linked immunoassays, electroimmunodiffusion, and radioimmunoassays have been utilized to evaluate coagulation proteins. The relation of functional and immunological properties of these proteins to their physiological function is being studied. In coming years the testing of coagulation function will undergo some major changes and will require input from clinical chemists and other laboratory scientists to facilitate the technology transfer and proper standardization of new methods.