3 major reasons to study complement:

1. Complement deficiencies are associated with infections and autoimmune diseases.
   Deficiencies of the classical pathway are often associated with SLE, glomerulonephritis and susceptibility to infections. Deficiencies of the alternative pathway often leads to Neisserial infections. An excellent way to screen for deficiencies is to study the function of the three pathways of the system.
   
2. Overactivation or dysregulation of the complement system contribute to the pathology in various immune, inflammatory, neurodegenerative, ischemic and age-related disorders.
   Complement activation occur in acute conditions like trauma, shock and sepsis. Complement activity plays a role in many chronic inflammatory disorders and autoimmune diseases such as SLE and vasculitis but is also of importance in transplantation and immune response to biomaterials.
   
   
3. New therapies are aiming at stopping or increasing complement activity.
   Functional assessment of complement activity is essential to evaluate potency and efficacy of complement blocking/manipulating drugs. As a result of the increased awareness of the importance of complement in many clinical situations a number of drug candidates are in the pipeline. The development of these drugs requires easy and accurate means of functional assessment of all three complement pathways, both for development and monitoring purposes.