Complement component C1 and the collectins – first-line defense molecules in innate and acquired immunity

Abstract The 5th International Workshop on C1 and the Collectins was held in Lufthansa-Bildungszentrum, Seeheim, Germany from 26–28 October 2001.

Complement activation and innate immunity

Involvement of complement pathways in patients with bacterial septicemia.

The complement system is a major humoral portion of the innate immune system, playing a significant role in host defence against microorganisms. The biological importance of this system is underlined by the fact that at least three different pathways for its activation exist, the classical, the MBL and the alternative pathway. To elucidate the involvement of the classical and/or the MBL pathway during bacterial septicemia, 32 patients with gram-positive and 30 patients with gram-negative bacterial infections were investigated. In patients with gram-positive bacteria, a significant consumption of C1q (p=0.005) but not of mannose-binding lectin (MBL) (p=0.2) was found during the acute phase o…