ABSTRACT METABOLIC DETOXIFICATION SYSTEM AND METHOD An extracorporeal filtration and detoxification system and method generally comprise separating ultrafiltrate from cellular components of blood, treating the ultrafiltrate independently of the cellular components in a recirculation circuit, recombining treated ultrafiltrate and the cellular components, and returning whole blood to the patient. A recirculation circuit generally comprises an active cartridge including active cells operative to effectuate a selected treatment in some embodiments, the active cells are the C3A cell line.