Complement activation during extracorporeal therapy: biochemistry, cell biology and clinical relevance.

Abstract

Complement is a principal mediator of the acute inflammatory response and contributes to the non-specific recognition and elimination of foreign substances from the body. The system evolved to protect the host from invasion by various pathogens. However, due to the non-selective nature of the alternative pathway, biomaterial surfaces in any medical device used in contact with blood will also activate the system. This review summarizes our current understanding of the biochemistry and cell biology of complement. The relationship of this basic information to clinical observations is discussed in order to affirm the relevance of complement as a critical parameter of biocompatibility.