Extracorporeal immunoadsorption of circulating specific serum factors in cancer patients

Circulating serum factors have been said to abrogate the effects of immune response in cancer, i.e. "blocking" and "antigenic inhibition". The aim of this investigation was to isolate such specific factors in a purified and native state. F(ab)2 fragments isolated from hypernephroma were insolubilized on the surfaces of an extracorporeal perfusion chamber which was inserted into the circulation by means of an arterio-venous shunt. As a result, 3 proteins not present in normal serum were isolated and eluted for further study. In immunoelectrophoresis the 3 proteins were specifically precipitated by heterolgous (rabbit) antihypernephroma serum but not by anti-serum directed against normal serum components. Moreover C9 components, C3 activator and C3 were isolated in the chamber, the latter complement factor in large concentrations. This further sustained that specific antigen-antibody reactions had occurred in the chamber. One of the 2 patients studied were perfused for 60 h and 40 min. During this period 450 litres of blood were brought into intimate contact with the immunoadsorbent. Proteins in amounts sufficient for immunochemical analysis were isolated within 3 h.