%0 Journal Article
%T Complement Diagnostics: Concepts, Indications, and Practical Guidelines
%A Bo Nilsson
%A Kristina Nilsson Ekdahl
%J Journal of Immunology Research
%D 2012
%R 10.1155/2012/962702
%X Aberrations in the complement system have been shown to be direct or indirect pathophysiological mechanisms in a number of diseases and pathological conditions such as autoimmune disease, infections, cancer, allogeneic and xenogeneic transplantation, and inflammation. Complement analyses have been performed on these conditions in both prospective and retrospective studies and significant differences have been found between groups of patients, but in many diseases, it has not been possible to make predictions for individual patients because of the lack of sensitivity and specificity of many of the assays used. The basic indications for serological diagnostic complement analysis today may be divided into three major categories: (a) acquired and inherited complement deficiencies; (b) disorders with complement activation; (c) inherited and acquired C1INH deficiencies. Here, we summarize indications, techniques, and interpretations for basic complement analyses and present an algorithm, which we follow in our routine laboratory. 1. Introduction The complement system is involved in numerous diseases and pathological conditions such as autoimmune disease, infections, cancer, allogeneic and xenogeneic transplantation, and inflammation [1]. The concentrations of various complement components and activation products have been measured in both prospective and retrospective studies of pathologic conditions, and significant differences have been found between groups of patients. However, in many diseases, it has not been possible to make predictions for individual patients because of the lack of sensitivity and specificity of many of the assays used. Basically, the indications for diagnostic complement analysis today can be divided into three major categories: (a) acquired and inherited complement deficiencies; (b) disorders with complement activation; (c) inherited and acquired C1INH deficiencies. Here, we give a personal view of how we perform basic complement investigations in our routine diagnostic laboratory. 2. The Complement System 2.1. Complement System Physiology The complement system has a primary function in host defense and clears the body of foreign cells, microorganisms, and cell debris, either by direct lysis or by recruitment of leukocytes that promote phagocytosis and cytotoxicity (recently reviewed in [2]). It consists of more than 40 plasma and cellular proteins (receptors and regulators). The central complement reaction is the cleavage of C3 into C3b and C3a, which is promoted by two multimolecular enzyme complexes, the C3 convertases, which are
%U http://www.hindawi.com/journals/jir/2012/962702/