Complement activation in shock associated with a surgically provoked bacteriaemia.

The activation of complement (C) factors in a patient exhibiting an anaphylactoid shock 10 min after the initiation of transurethral coagulation of vesical papillomas was studied. Streptococcus faecalis was cultured from he urine before and after the shock and from the blood on two occasions within 2 days after the shock. The shock was associated with a marked but transient complement activation as judged from serial determinations of C3d and C3c by doubledecker rocket immuno electrophoresis and native C3 and C3c by crossed immuno electrophoresis. Conventional total C3 quantitation by rocket immuno electrophoresis did not reveal the activation. A decrease of native C4 to 20% of normal values and the appearance of C4 split products indicated classical pathway activation. Factor B conversion showed the alternative pathway to be involved as well. Total haemolytic complement activity was temporarily reduced, increasing without reaching normal values within 20 hours. The results indicated that the classical pathway was transiently activated, pointing to an acute antigen-antibody reaction, probably caused by the entrance of bacteria and bacterial products into the circulation of an immunized host.