Alpha-2-plasmin-inhibitor inactivation by human granulocyte elastase

Role of granulocyte elastase in tissue injury in patients with septic shock complicated by multiple-organ failure

To better understand the role of granulocyte elastase (GE) in mediating tissue injury during sepsis, GE levels were measured in plasma and bronchoalveolar lavage fluid (BALF) in patients with septic shock (n = 16) and hemorrhagic shock (n = 30). Granulocyte elastase levels were compared to levels of alpha 1-protease inhibitor (alpha 1-PI). Results show that although plasma GE-alpha 1-PI complex was initially elevated in patients with hemorrhagic and septic shock, elevations in plasma GE-alpha 1-PI complex (831 +/- 241 micrograms/L) persisted in septic shock patients. alpha 1-Protease inhibitor levels in serum were increased, resulting in an inhibition of serum GE activity. Granulocyte elastase activity in BALF, however, was significantly higher in those patients with septic, as compared to hemorrhagic shock (31.4 +/- 25.8 versus 3.7 +/- 4.0 U/L, respectively). In addition GE levels were compared to other parameters, including respiratory index, blood neutrophil count, and plasma levels of endotoxin, fibronectin, and coagulation factor XIII. Significant correlations were observed between GE-alpha 1-PI and increased endotoxin concentration and decreased fibronectin and coagulation factor XIII levels. Significant correlation was found also between GE activity in BALF and respiratory index. These findings suggest that severe tissue damage occurred in patients with septic shock complicated by multiple-organ failure. Although GE activity appeared to be adequately inhibited by alpha 1-PI in blood, increased GE activity in local tissues, such as lung alveoli, may be responsible for significant local tissue injury during septic shock.

Acquired alpha-2-antiplasmin deficiency in acute promyelocytic leukaemia

We report a prospective study in nine consecutive adult patients with acute promyelocytic leukaemia (APL). The study objective was to assess the prevalence of activation of blood coagulation and/or activation of fibrinolysis in APL. Coagulation and fibrinolytic parameters relevant to the objective included antithrombin III, plasminogen, fibrin/fibrinogen degradation products and alpha-2 antiplasmin activity and antigen levels. The results of this study revealed consistently normal antithrombin III levels, both before and in the course of antileukaemic treatment. Plasminogen levels were slightly decreased or normal. However, a distinct alpha-2 antiplasmin activity deficiency in all patients was observed with levels even reaching zero in three patients, during chemotherapy. Alpha-2 antiplasmin activity levels were consistently lower than the alpha-2 antiplasmin antigen levels. The in vitro binding of alpha-2 antiplasmin activity to fibrin clots was severely reduced which appeared to be due to the reduced alpha-2 antiplasmin plasma levels. Upon crossed-immunoelectrophoresis against alpha-2 antiplasmin antiserum two alpha-2 antiplasmin antigen peaks were observed in the plasma of all nine patients. All abnormalities were reversible 4 d after completion of chemotherapy. In a second series of 12 consecutive APL patients we confirmed the consistency of the alpha-2 antiplasmin activity deficiency and normal antithrombin III plasma levels. In addition Protein C activity and antigen levels were normal or near normal in 10 and reduced in two patients. Thrombin-antithrombin III complexes were increased in 10 and normal in two patients. We conclude that some activation of blood coagulation is present in APL (increased thrombin-antithrombin III complex levels) but its contribution to the coagulopathy seems to be minor (normal antithrombin III and only slightly reduced protein C levels). The observed reduced alpha-2 antiplasmin content of the fibrin clot in vitro may result in vivo in a fibrin clot that is highly susceptible to fibrin degradation, thus aggravating the coagulopathy in APL.

Consumptive coagulopathy, fibrinolysis and protease-antiprotease interactions during acute human pancreatitis

Twenty-seven attacks of acute human pancreatitis of different severity were analysed concerning clinical outcome and activation of the coagulation and fibrinolytic systems. Consumptive coagulopathy was suggested by decreased platelet counts, decreased prothrombin values and consumption of fibrinogen during the first days in severe attacks. Factor X was slightly decreased the first 5 days in all attacks. Increased fibrinolysis was suggested by decreased plasminogen values in severe attacks. Fibrinogen degradation products were seen in 40% of the patients in blood and in 100% of the patients in the peritoneal fluid. The four main protease inhibitors of the two systems all showed protease-antiprotease complexation and lower functional than quantitative values. Plasma levels of antithrombin III and alpha 2-macroglobulin were low, while the levels of C1-inhibitor and alpha 2-antiplasmin were high. Functional levels of all the four protease inhibitors were almost zero in the peritoneal fluid in severe attacks. It is concluded that severe acute pancreatitis results in both consumptive coagulopathy and in increased fibrinolysis. A local antiprotease deficiency is seen in the peritoneal cavity and high levels of protease-antiprotease complexes are also seen in plasma. All these changes are closely correlated to the severity of the disease and may probably determine the clinical outcome of the acute attack.