Complement C1q

The complement system - a group of about 40 proteins involved in the the body's immune response, mainly through opsonization i.e. facilitating phagocytosis, chemotaxis of feeding cells to the site of inflammation, direct lysis of bacteria and viruses, and initiating the inflammatory response. Activation of the complement system takes place by the classical, alternative or lectin pathway. The classical pathway activation plays an important role in the elimination of infections caused by pus-forming envelope bacteria, such as Haemophilus influenzae and Streptococcus pneumoniae. It is initiated by the C1q factor, which attaches to antibodies that are bound on the surface of microorganisms or which are components of immune complexes immune antigen-antibody complexes. C1q contributes to elimination of bacteria due to its ability to stimulate granulocytes Neutrophils, stimulating the production of pro-inflammatory cytokines, i.e. interleukin 6 and 8 (IL-6, IL-8) and chemotactic protein monocytes. C1q component determination is also performed in the diagnosis of autoimmune diseases such as lupus systemic lupus erythematosus.