Clinical applications of the immunohistochemistry of filamentous proteins.

The past few years have seen great progress in our knowledge of the biology and the chemistry of intermediate filaments and other filamentous proteins. This has translated into the development of antibodies that, together with new, highly sensitive immunohistochemical methods, have resulted in much improved diagnostic accuracy. New, more specific antibodies to these and other useful markers will no doubt be developed in the future. More efficient techniques for screening of these antibodies will contribute to their rapid evaluation. Libraries of antibodies that identify subclasses of filamentous proteins will very likely become routine tools in the histopathology laboratory in the near future. Moreover, as the chemical structure of the proteins that form the complex family of intermediate filaments becomes better understood, and the DNA sequences coding them are determined, it may become feasible to use molecular genetic approaches such as in situ hybridization to gain further insight into neoplastic processes of unclear histogenesis and to develop more precise diagnostic and taxonomic instruments. Nevertheless, it is worth repeating that application of these molecular tools cannot be successful unless it is backed by a thorough understanding of the principles of histopathologic diagnosis that have been painstakingly established by generations of anatomic pathologists.