ABSTRACT
An intact host defence system is of fundamental importance in the defence against infection, tumour growth, and metastasis. The possibility that anaesthesia may alter the course of an infection by modifying the immune response, has been under consideration. The ultimate objective of the immune system is to protect the body against noxious agents, including those causing infections and development of neoplasms. Non-specific immunity is the first line of defence against "non-self" and it does not require prior exposure to the infectious agent, antigen or the foreign molecule. The cellular elements of non-specific immunity are the phagocytic leucocytes which include neutrophils, eosinophils, basophils and mononuclear phagocyte system comprised of circulating monocytes and tissue macrophages. Complement is the non-specific component of humoral immunity. The complement system is a group of about twenty serum proteins whose overall function is to control the inflammatory response.
