The clinical usefulness of the measurement of cytokines

The utilization of accurate and sensitive methods for the measurement of cy tokines in body fluids is prerequisite for the proper use of these mediator s in clinical practice. Many factors contribute to the complexity of cytoki ne quantitation. Bioassays historically preceded immunoassays, which are no w very popular, but there is a need for standardization. Nevertheless, due to the local effects of cytokines, the study of their blood levels is of li mited value for an understanding of the pathophysiology of these mediators. This explains the development of alternative approaches to assess the abil ity of cells to produce cytokines. These include the Enzyme-Linked Immune S pot Assay (ELISPOT), the measurement of cell-associated cytokines by flow c ytometry, and the study of cytokine secretion by isolated peripheral blood mononuclear cells or by whole blood test. All these techniques, associated with a local detection of cytokines by immunohistochemistry or in situ hybr idization and reverse transcriptase polymerase chain reaction, appear to be complementary tools for a better understanding of the biology of cytokines . Selected examples of possible clinical applications related to infectious diseases, cancer, autoimmune diseases, allergy, transplantation and precli nical evaluation of drugs and biotechnology products are given.