D-DIMER TESTS DETECT BOTH PLASMIN AND NEUTROPHIL ELASTASE DERIVED SPLIT PRODUCTS

Both plasmin and elastase, a protease released from neutrophil granulo cytes, are known to degrade fibrin(ogen). This raises the possibility that elevated plasma levels of split products such as D-dimer may in p art result from elastase action. After incubation in vitro of fibrinog en and fibrin clots with elastase, a clearcut increase of D-dimer immu noreactivity was demonstrated by two commercial ELISA kits. In the pla sma of 79 patients with inflammatory bowel disease, D-dimer values mea sured by one of the ELISA kits were correlated significantly not only with markers of thrombin and plasmin activation, but also with elastas e-alpha(1)-antitrypsin complexes (r = 0.3555; P = 0.014). Thus, the fi ndings of this study suggest that indeed the D-dimer levels in patient s with inflammatory disorders are influenced by neutrophil elastase. N ew tests discriminating effects of activated haemostasis from proteoly sis by neutrophil enzymes might be helpful in differential diagnosis a nd monitoring of therapy.