The total complement activity, the titers of C4 and the late-acting components (C3-C9) as well as C3 concentration were measured serially in sera of 20 artificially ventilated patients suffering from infections due to gram-negative bacteria and developing acute complications during the period of observation. Seven chronic bedridden patients living in peaceful commensalism with and constantly excreting gram-negative bacteria served as controls. In the control patients without infectious complications the complement titers remained constant. In the cases where acute complications developed, the complement values showed large fluctuations, and complement activation frequently occurred. Septic shock developed in 18 cases; in 17 this was accompanied by significant complement activation. In the four cases where samples were obtained 1-2 hr and in one case 6 hr before the septic shock developed, complement activation preceded the first clinical signs of shock. In the majority of cases and mainly in those with septic shock, the activation of the complement system took place via the alternative pathway.
ASJC Scopus subject areas
- Immunology and Allergy
- Pathology and Forensic Medicine