71. A specific test for polymorphonuclear leukocyte-mediated fibrinogenolysis in plasma

Abstract

In response to inflammatory mediators, polymorphonuclear leukocytes (PMN) are activated and release potent serine proteases, i.e. elastase, cathepsin G and proteinase 3. The aim of this study was to develop an assay to determine PMNmediated fibrinogenolysis in plasma, as a biochemical marker for activated PMN in vivo. On the basis of a special monoclonal antibody, generated against a neo-antigenic site in elastase degraded fibrinogen (EOF), we developed a highly specific plasma test for PMN-generated fibrin(ogen) derivatives. Intact fibrin(ogen) did not cross react in the assay, nor did plasmin-generated fibrin(ogen) derivatives. With this assay we showed, amongst others, that smoking did not affect the values of EDF-like degradation products in plasma of normal healthy volunteers (overall 8.2±1.6 ng/ml; n= 18) and that EDF-values are increased in patients with an ccl-proteinase inhibitor deficiency (18.6±5.3 ng/ml; n=12) and with sepsis (365.7±198.4 ng/ml; n=16). The assay was also applied to assess PMN-mediated fibrinogenolysis in synovial tissue extracts of patients with rheumatoid arthritis; these contained very high levels of EDF (98.2±59.3 ng/ml; n=15), in contrast to synovial tissue extracts of patients with osteoarthritis (6.3±2.7 ng/ml; n=12). The assay may be useful to identify patients with activated PMN, and to monitor drug-efficacy during therapy. This study was partly supported by grants from the Dutch Asthma Foundation (NAF 91.39 and 93.73) and the Praeventiefonds (002819180). © Pearson Professional Ltd 1996.