Experimental cryosurgery has been found to result in the formation of circulating antibodies, directed against antigenic material of the tissue frozen. These antibodies were detected by passive haemagglutination and immunodiffusion. The tissue that was subjected to destructive freezing by means of this surgical procedure was the coagulating gland and seminal vesicle of rabbit. A probe carrying liquid nitrogen and a thermocouple assembly for measuring temperature changes was utilized. Control rabbits were manipulated in the same way but with no freezing.
A large number of rabbits subjected to tissue freezing exhibited the development of a rapid antibody response, achieving a maximum titre in 7–10 days, followed by a decline. This antibody response has been compared to that seen following isoimmunization by injection. As an additional comparison, several rabbits were autoimmunized by injection of homogenate from their own accessory tissue; these rabbits also produced antibodies. It was found that the time sequence in the antibody production was quite similar for auto- and isoimmunization, but was quite distinctive for cryo-stimulation.
By several means of evaluation, it was shown that the antibody response to the freezing of tissue was an autoantibody. It was not, however, an antibody against serum γ-globulin.
The consequences of the freezing of tissue are thus seen to simulate the effects of incorporating adjuvant. This method of producing autoantibodies and investigating the nature of the response has been termed cryo-immunology.