Relationship between angiotensinogen, alpha 1-protease inhibitor elastase complex, antithrombin III and C-reactive protein in septic ARDS.

The time-course of plasma angiotensinogen (Ao), elastase-alpha 1-protease inhibitor complex (EL alpha 1PI), antithrombin III (AT III) and C-reactive protein (CRP) have been investigated of six patients suffering from adult respiratory distress syndrome (ARDS). The total plasma Ao level (active and inactive Ao) varied in individuals but was increased up to five-fold. An increasing amount of inactive Ao is found. From the beginning of their stay in the intensive care unit up to five days half of the patients displayed a positive correlation between the plasma CRP and Ao level. The CRP and Ao values were either not or were negatively correlated with the AT III values. In contrast plasma Ao and AT III levels in all patients were positively correlated during a particular period in the subsequent phase of the disease, where there was no or a negative correlation with CRP. The two acute phase reactants CRP and EL alpha 1PI were only correlated in two patients at the beginning of the disease. The markedly increased plasma level at the beginning of the inflammatory disease indicates that Ao is an acute phase reactant, and this is supported by the parallel changes in plasma CRP and Ao levels during the early days of ARDS. The relationship between the plasma levels of Ao and AT III for more than fourteen days suggests similar regulation of these members of the serpin family after termination of the acute-phase.