Hyperimmune F(ab′)2 antibody: Role in canine hyperacute renal allograft rejection

An attempt to obtain protection of the renal allograft in a sensitized recipient by ex vivo perfusion with F(ab′)2-modified antibody was unsuccessful. The major contributing factor to this failure appeared to be related to the species differences in IgG and their mode of degradation. The canine IgG molecule proved to be very hard to degrade to F (ab′)2 as tested by the loss of the lymphocytotoxic titer at the end of 20 hr of pepsin digestion.